Recombinant cytokine receptors and methods of use

Abstract

A recombinant cytokine receptor is provided that includes an intracellular domain of IL-2 and an extracellular domain that binds to cytokines other than IL-2. Treg cells and methods of use that include the recombinant cytokine receptor are also provided herein. The success of adoptive cell therapy requires robust expansion and persistence of the administered cells, and the surrounding signals received by the cells strongly contribute to these behaviors. In some embodiments, systems are provided herein in which the proliferation and in vivo persistence of immune cells (e.g., T cells), the production of cytokines that activate the immune system, and immune function can be promoted by the introduction of a recombinant cytokine receptor.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit of priority to U.S. Provisional Application No. 63 / 368,085, filed Jul. 11, 2022; U.S. Provisional Application No. 63 / 498,802, filed Apr. 27, 2023; and U.S. Provisional Application No. 63 / 499,929, filed May 3, 2023, the contents of each of which are hereby incorporated by reference in their entirety herein. Incorporation by Reference of Sequence Listing

[0002] The contents of the electronic sequence listing (237752000241SEQLIST.xml; size: 36,642 bytes; and generated on Jul. 7, 2023) are hereby incorporated by reference in their entirety herein.

Background Art

[0003] The immune system plays an important role in maintaining the homeostasis of an organism by maintaining a balance between the elimination of foreign antigens and self - tolerance to self - antigens. In particular, overactivated immune dysregulation can lead to various autoimmune disorders (such as irritable bowel syndrome, systemic lupus erythematosus, alopecia areata, multiple sclerosis), which is often the result of overactivated effector T lymphocytes or underactivated regulatory T lymphocytes (i.e., Tregs). Current treatment methods for autoimmune diseases include the administration of steroids, which cause severe side effects in patients and often provide little relief. Regulatory T cells are important players in maintaining the biological homeostasis of an organism to prevent the destruction of otherwise healthy tissues. Tregs are a unique subset of T cells that inhibit the cytotoxic or pro-inflammatory activities of effector CD4+ T cells or effector CD8+ T cells. Tregs differentiate from the parental T lymphocyte lineage upon upregulation of key Treg genes, particularly CD25 and FOXP3 (see, e.g., Chen, ML et al. (2005), Proc Natl Acad Sci USA 102(2):419-424; and Liu, VC et al. (2007), J Immunol 178(5):2883-2892, which are hereby incorporated by reference in their entirety). Upon T cell receptor (TCR) activation, these Tregs are responsible for directly suppressing effector T cell activity through cytokine production (e.g., TGF-β and IL-10) (see, e.g., Chen, J et al. (2019), Trends Mol Med 25(11):1010-1023, which is hereby incorporated by reference in its entirety) and engagement of immune checkpoint receptors (e.g., engagement of TIGIT or CTLA-4) (see, e.g., Knochelmann, HM et al. (2018), Cell Mol Immunol;15(5):458-469, which is hereby incorporated by reference in its entirety). Effector T cells can produce the cytokine IL-2 to support their own amplification upon TCR activation, but Tregs cannot produce their own IL-2, so Treg cells rely on exogenous IL-2 to enhance Treg survival and maintenance. However, like all lineages of T lymphocytes, Treg cells require IL-2 signaling for survival and proliferation.This biological mechanism ensures the maintenance of Tregs in a tissue niche enriched with activated effector T cells, thus generating a negative feedback mechanism of the cells, by which the increased IL-2 production by target effector T cells enhances the amplification of Tregs, which in turn acts to inhibit effector T cell activity and thus downstream inhibits its own amplification and survival (see, for example, Shevyrev, D & Tereshchenko, V (2020), Front Immunol; 10:3100, 1-13). Therefore, targeting the IL-2 receptor signaling pathway in Tregs is one of the recently interesting areas in the efforts to identify new therapies for autoimmune disorders.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Non-Patent Document 5

Summary of the Invention

[0005] In one aspect, the present application relates to a recombinant cytokine receptor comprising the intracellular domain of IL-2Rβ and the extracellular domain from a cytokine other than IL-2. Cells expressing the recombinant cytokine receptor and methods of use are also provided herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0006]

Figure 1A

Figure 1B

Figure 1C

Figure 1D

Figure 1E

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 2E

Figure 2F

Figure 3A-1

Figure 3A-2

Figure 3B-1

Figure 3B-2

Figure 3C-1

Figure 3C-2

Figure 3D-1

Figure 3D-2

Figure 3E-1

Figure 3E-2

Figure 3F-1

Figure 3F-2

Figure 3G-1

Figure 3G-2

Figure 3H-1

Figure 3H-2

Figure 3I-1

Figure 3I-2

Figure 4

Figure 5-1

Figure 5-2

Figure 5-3

Figure 6-1

Figure 6-2

Figure 6-3

Figure 6-4

Figure 7-1

Figure 7-2

Figure 7-3

Figure 7-4

Figure 7-5

Figure 7-6

Figure 7-7

Figure 7-8

Figure 7-9

Figure 7-10

Figure 7-11

Figure 7-12

Figure 7-13

Figure 7-14

Figure 7-15

Figure 7-16

Figure 7-17

Figure 7-18

Figure 7-19

Figure 7-20

Figure 7-21

Figure 7-22

Figure 7-23

Figure 7-24

Figure 8A

Figure 8B

Figure 8C

Figure 8D

Figure 8E

Figure 8F

Figure 8G

Figure 8H

Figure 8I

Figure 8J

Figure 8K

Figure 8L

Figure 8M

Figure 9-1

Figure 9-2

Figure 10

Figure 11-1

Figure 11-2

Figure 11-3

Figure 12-1

Figure 12-2

Figure 13-1

Figure 13-2

Figure 13-3

Figure 14A

Figure 14B

Figure 14C

Figure 15A

Figure 15B

Figure 15C

Figure 16A

Figure 16B

Figure 16C

Figure 16D

Figure 16E

Figure 17

Figure 18

Figure 19A

Figure 19B

Figure 19C

Figure 19D

Figure 20A

Figure 20B

Figure 21A

Figure 21B

Figure 21C

Figure 22

Figure 23-1

Figure 23-2

Figure 23-3

Figure 23-4

Figure 23-5

Figure 23-6

BRIEF DESCRIPTION OF THE INVENTION

[0007] The success of adoptive cell therapy requires the steady amplification and persistence of the administered cells, and the surrounding signals received by the cells strongly contribute to these behaviors. In some embodiments, provided herein are systems in which the proliferation, in vivo persistence, production of immunostimulatory cytokines, and immune function of immune cells (e.g., T cells) can be promoted by the introduction of recombinant cytokine receptors. These recombinant cells can be used, for example, as cell therapies for autoimmune disorders. The present invention generally relates to the field of immunology and relates in part to compositions and methods for growing, modifying, and amplifying cells, including recombinant cytokine receptors that allow immune cells, such as Treg cells, to proliferate in the absence of IL-2. Recombinant cytokine receptors that use alternative cytokines (e.g., other than IL-2) to activate IL-2Rβ signaling are provided herein. Also provided herein are recombinant cytokine receptors that are not dependent on exogenous cytokines for activation. Thus, cells transduced with the recombinant cytokine receptors described herein have certain advantages (including IL-2 independence) compared to non-transduced cells. In some embodiments of the methods and compositions provided herein, the cells are engineered to contain the recombinant cytokine receptors described herein. The recombinant cytokine receptors described herein provide stimulatory cytokine signals to the cells and improve the effectiveness of cell therapy. In some embodiments, the cells are T cells (e.g., Tregs).

[0008] Cells (e.g., Tregs) containing these recombinant cytokine receptors can still be activated, for example, by canonical TCR activation in the presence of a target antigen, to suppress conventional T cells. Thus, Tregs may not be able to suppress off-target T cells or produce inhibitory cytokines in the absence of their target T cells. Such off-target activity can lead to an increased risk of chronic infection or cancer progression due to the constant suppression of conventional T cells. Thus, in some embodiments, engineered Treg cells have fewer off-target effects and side effects compared to alternatives.

[0009] Each recombinant cytokine receptor provided herein demonstrates a similar trend, albeit to varying degrees. For example, exemplary recombinant cytokine receptors tested herein include the untethered IL-4Rα / IL-2Rβ, IL-7Rα / IL-2Rβ, IL-9Rα / IL-2Rβ, and IL-21Rα / IL-2Rβ recombinant cytokine receptors (each of their respective recombinant cytokine receptors turns on intracellular IL-2 signaling (e.g., when transduced into Tregs) upon receptor binding to their cognate ligand, i.e., IL-4, IL-7, IL-9, or IL-21, respectively); and the cytokine-tethered IL-4Rα / IL-2Rβ, IL-7Rα / IL-2Rβ, IL-9Rα / IL-2Rβ, and IL-21Rα / IL-2Rβ recombinant cytokine receptors, where intracellular IL-2 signaling is constitutively activated). In vitro analysis demonstrated varying degrees of Treg survival, proliferation, or function (e.g., both the tethered and untethered IL-21Rα / IL-2Rβ recombinant cytokine receptors showed the lowest proliferation rate and the earliest decrease in Treg survival in vitro among the eight receptors tested). Further in vivo experiments demonstrated that the tethered IL-9Rα / IL-2Rβ recombinant cytokine receptor conferred the highest degree of Treg engraftment, survival, and proliferation, while both the tethered IL-4Rα / IL-2Rβ and IL-7Rα / IL-2Rβ recombinant cytokine receptors demonstrated varying degrees of in vivo engraftment, survival, and proliferation across the receptors tested and across the tissues tested (see FIG. 16A). Thus, the in vitro and in vivo functional characteristics of the recombinant cytokine receptors are surprising and these differences can be exploited to meet the biological constraints of different diseases where targeting Tregs may be beneficial for therapeutic purposes.

[0010] Furthermore, various proposed methods for activating the IL-2 signaling pathway within Tregs have not shown functional success. See Example 9. There, three separate approaches each failed to support Treg function. That is, the constitutively activated STAT-5 Treg model, the IL-2 secreting Treg model, and the tagged protein Treg model with tethered IL-2 each failed to enhance Treg activity relative to conventional T cells, thereby demonstrating that not all approaches that promote IL-2 independence when applied to Treg cells are successful. Further, Treg cells are known to be quite different with respect to function, molecular profile, and genetic profile compared to conventional T cells (see, e.g., Grinberg-Bleyer et al. Cell 170(6):1096-1108, 2017; Grinberg-Bleyer et al. J Immunol 200(7):2362-71, 2018, both of which are incorporated herein by reference in their entirety), and for this reason, a Treg-specific, tailor-made approach as described herein is required.

[0011] All publications (including patent documents, scientific papers, and databases) referenced in this application are hereby incorporated by reference in their entirety for all purposes to the same extent as if each individual publication were incorporated by reference individually. If the definitions described herein conflict with or are otherwise inconsistent with the definitions set forth in patents, applications, published applications, and other publications incorporated herein by reference, the definitions described herein shall control over a definition incorporated herein by reference.

[0012] The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0013] I. Recombinant Cytokine Receptors The present invention provides a recombinant cytokine receptor that transmits intracellular interleukin 2 (IL-2) signaling in the absence of exogenous IL-2. In some embodiments, the recombinant cytokine receptor is an engineered molecule comprising an extracellular cytokine binding domain (ED; also referred to as the "extracellular cytokine receptor domain"), a transmembrane domain (TD), and an intracellular cytokine signaling domain (ID; also referred to as the "intracellular domain"). In some embodiments, provided herein are receptors that include an ED tethered to its cognate cytokine and thus can be activated in the absence of any exogenous cytokine. The recombinant cytokine receptors described herein are derived from interleukin cytokine receptors, and the ID includes the ID of the interleukin 2 receptor β (IL-2Rβ) chain of IL-2R. Canonical IL-2 signaling causes STAT5 phosphorylation, thereby activating nuclear translocation of STAT5 and initiating target gene transcription. In some cells (e.g., T cells including Treg cells), IL-2 signaling is required for cell survival and cell proliferation. Thus, a recombinant cytokine receptor that binds to a cytokine other than IL-2 and includes the L-2Rβ intracellular domain can activate cell survival and proliferation in the absence of IL-2 by binding to another cytokine.

[0014] In some embodiments, the recombinant cytokine receptors described herein are described with respect to their extracellular and intracellular domains. Thus, for example, an "IL-4Rα / IL-2Rβ" receptor includes the IL-4 receptor extracellular domain linked to the IL-2Rβ intracellular domain. In some embodiments, the receptor includes a transmembrane domain from the same cytokine receptor as the extracellular domain. In some embodiments, the receptor includes a transmembrane domain from a cytokine different from the extracellular domain.

[0015] In some embodiments, the recombinant cytokine receptor is more effective for maintaining immune cell survival. In some embodiments, the immune cell is a T cell. In some embodiments, the immune cell is a Treg.

[0016] In some embodiments, the recombinant cytokine receptor is more effective for maintaining Treg survival as compared to other strategies for the production of IL-2-independent Tregs (such as Tregs engineered to secrete IL-2, etc.). In some embodiments, cells transduced with the recombinant cytokine receptors provided herein are capable of maintaining a Treg phenotype and / or having increased survival as compared to Treg cells that secrete IL-2.

[0017] In some embodiments, the recombinant cytokine receptors provided herein have significant advantages, including but not limited to: (1) expression in regulatory T cells (Tregs); (2) increased survival and proliferation of Tregs in the absence of IL-2; (3) increased IL-2 receptor signaling via STAT5 phosphorylation; and (4) the ability to suppress effector T cells in the absence of IL-2 to approximately or nearly the same extent as wild-type Tregs expanded in the presence of IL-2. [Table 1] [Table 2]

[0018] Provided herein are recombinant cytokine receptors that include the extracellular domain (ED) and transmembrane domain (TD) of a cytokine receptor and the intracellular domain (ID) of interleukin-2 receptor β (IL-2Rβ), wherein the ED does not bind to exogenous IL-2. In some embodiments, the recombinant cytokine receptor is capable of signaling in the absence of exogenous IL-2. In some embodiments, the recombinant cytokine receptor includes the ED, TD, and one ID of an interleukin. In some embodiments, the ED binds to a cytokine other than IL-2. Thus, in some embodiments, provided are recombinant cytokine receptors that include (I) the ED of IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (II) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor includes the amino acid sequences set forth in SEQ ID NOs: 1-5. In some embodiments, the recombinant cytokine receptor includes an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequences set forth in SEQ ID NOs: 1-5. In some embodiments, the recombinant cytokine receptor includes an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequences set forth in SEQ ID NOs: 11-14.

[0019] In some embodiments, the recombinant cytokine receptor comprises (I) the ED of IL-4Rα; (II) the TD of IL-4Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 1. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 1 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the recombinant cytokine receptor comprises (I) an ED having an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11; (II) a TD having an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 16; and (III) an ID having an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor comprises (I) an ED comprising the amino acid sequence of SEQ ID NO: 11; (II) a TD comprising the amino acid sequence of SEQ ID NO: 16; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20.

[0020] In some embodiments, the recombinant cytokine receptor comprises (I) the ED of IL-4Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the recombinant cytokine receptor comprises (I) an ED comprising an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 11; (II) a TD comprising an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 21; and (III) an ID comprising an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor comprises (I) an ED comprising the amino acid sequence of SEQ ID NO: 11; (II) a TD comprising the amino acid sequence of SEQ ID NO: 21; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20.

[0021] In some embodiments, the recombinant cytokine receptor comprises: (I) the ED of IL-7Rα; (II) the TD of IL-7Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 2. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 2 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 12. In some embodiments, the recombinant cytokine receptor comprises: (I) an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 12; (II) a TD having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 17; and (III) an ID having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising the amino acid sequence of SEQ ID NO: 12; (II) a TD comprising the amino acid sequence of SEQ ID NO: 17; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20.

[0022] In some embodiments, the recombinant cytokine receptor comprises (I) the ED of IL-7Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence that has at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence set forth in SEQ ID NO: 12. In some embodiments, the recombinant cytokine receptor comprises (I) an ED comprising an amino acid sequence that has at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence of SEQ ID NO: 12; (II) a TD comprising an amino acid sequence that has at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence of SEQ ID NO: 21; and (III) an ID comprising an amino acid sequence that has at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor comprises (I) an ED comprising the amino acid sequence of SEQ ID NO: 12; (II) a TD comprising the amino acid sequence of SEQ ID NO: 21; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20.

[0023] In some embodiments, the recombinant cytokine receptor comprises (I) the ED of IL-9Rα; (II) the TD of IL-9Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 3. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 3 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence set forth in SEQ ID NO: 13. In some embodiments, the recombinant cytokine receptor comprises (I) an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence set forth in SEQ ID NO: 13; (II) a TD having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence set forth in SEQ ID NO: 18; and (III) an ID having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence set forth in SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor comprises (I) an ED comprising the amino acid sequence of SEQ ID NO: 13; (II) a TD comprising the amino acid sequence of SEQ ID NO: 18; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20.

[0024] In some embodiments, the recombinant cytokine receptor comprises (I) the ED of IL-9Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence shown in SEQ ID NO: 13. In some embodiments, the recombinant cytokine receptor comprises (I) an ED comprising an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 13; (II) a TD comprising an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 21; and (III) an ID comprising an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor comprises (I) an ED comprising the amino acid sequence of SEQ ID NO: 13; (II) a TD comprising the amino acid sequence of SEQ ID NO: 21; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20.

[0025] In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence shown in SEQ ID NO: 5 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence shown in SEQ ID NO: 5. In some embodiments, the recombinant cytokine receptor comprises (I) the ED of IL-21Rα; (II) the TD of IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence shown in SEQ ID NO: 4. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence shown in SEQ ID NO: 4 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 14 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto.In some embodiments, the recombinant cytokine receptor comprises (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 14; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 19; and (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor comprises (I) an ED comprising the amino acid sequence of SEQ ID NO: 14; (II) a TD comprising the amino acid sequence of SEQ ID NO: 19; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20.

[0026] In some embodiments, the recombinant cytokine receptor comprises (I) the ED of IL-21Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 14. In some embodiments, the recombinant cytokine receptor comprises (I) an ED comprising an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 14; (II) a TD comprising an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 21; and (III) an ID comprising an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor comprises (I) an ED comprising the amino acid sequence of SEQ ID NO: 14; (II) a TD comprising the amino acid sequence of SEQ ID NO: 21; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20.

[0027] In some embodiments, the recombinant cytokine receptor comprises: (I) the ED of IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (II) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (III) the ID of IL-2Rβ; and (IV) a cognate cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the ED is from the same cytokine receptor as the TD (e.g., the ED from IL-4Rα and the TD from IL-4Rα). In some embodiments, the cognate cytokine is IL-4, IL-7, IL-9, or IL-21. In some embodiments, the cognate cytokine is IL-4. In some embodiments, the cognate cytokine is IL-7. In some embodiments, the cognate cytokine is IL-9. In some embodiments, the cognate cytokine is IL-21. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequences shown in SEQ ID NOs: 6-9 and 15.

[0028] In some embodiments, the recombinant cytokine receptor comprises: (I) the ED of IL-4Rα; (II) the TD of IL-4Rα; (III) the ID of IL-2Rβ; and (IV) the cognate cytokine IL-4 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 6. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 6 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11.In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 11; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 16; (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker, the cytokine comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 22. In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising the amino acid sequence of SEQ ID NO: 11; (II) a TD comprising the amino acid sequence of SEQ ID NO: 16; (III) an ID comprising the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine comprising an amino acid sequence tethered to the ED of the recombinant cytokine receptor by a polypeptide linker, the amino acid sequence of SEQ ID NO: 22.

[0029] In some embodiments, the recombinant cytokine receptor comprises: (I) the ED of IL-4Rα; (II) the TD of IL-2Rβ; (III) the ID of IL-2Rβ; and (IV) the cognate cytokine IL-4 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 11 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising an amino acid sequence shown in SEQ ID NO: 11 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity; (II) a TD comprising an amino acid sequence shown in SEQ ID NO: 21 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity; (III) an ID comprising an amino acid sequence shown in SEQ ID NO: 20 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity; and (IV) a cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker, the cytokine comprising an amino acid sequence shown in SEQ ID NO: 22 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0030] In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising the amino acid sequence of SEQ ID NO: 11; (II) a TD comprising the amino acid sequence of SEQ ID NO: 21; (III) an ID comprising the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine comprising the amino acid sequence of SEQ ID NO: 22 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises: (I) the ED of IL-7Rα; (II) the TD of IL-7Rα; (III) the ID of ILR-2β; and (IV) the cognate cytokine IL-7 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 7. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 7 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 12.In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 12; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 17; (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker, the cytokine comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 23.

[0031] In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising the amino acid sequence of SEQ ID NO: 12; (II) a TD comprising the amino acid sequence of SEQ ID NO: 17; (III) an ID comprising the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine comprising the amino acid sequence of SEQ ID NO: 23 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises: (I) the ED of IL-7Rα; (II) the TD of IL-2Rβ; (III) the ID of IL-2Rβ; and (IV) the cognate cytokine IL-7 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence that has at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence set forth in SEQ ID NO: 12.In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 12; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 21; (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker, the cytokine comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 23.

[0032] In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising the amino acid sequence of SEQ ID NO: 12; (II) a TD comprising the amino acid sequence of SEQ ID NO: 21; (III) an ID comprising the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine comprising the amino acid sequence of SEQ ID NO: 23 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises: (I) the ED of IL-9Rα; (II) the TD of IL-9Rα; (III) the ID of IL-2Rβ; and (IV) the cognate cytokine IL-9 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 8. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 8 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 13.In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 13; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 18; (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker, the cytokine comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 24.

[0033] In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising the amino acid sequence of SEQ ID NO: 13; (II) a TD comprising the amino acid sequence of SEQ ID NO: 18; (III) an ID comprising the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine comprising an amino acid sequence tethered to the ED of the recombinant cytokine receptor by a polypeptide linker and having the amino acid sequence of SEQ ID NO: 24. In some embodiments, the recombinant cytokine receptor comprises: (I) the ED of IL-9Rα; (II) the TD of IL-2Rβ; (III) the ID of IL-2Rβ; and (IV) the cognate cytokine IL-9 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 13 and having an amino acid sequence with at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 13; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 21; (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker, the cytokine comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 24. In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising the amino acid sequence of SEQ ID NO: 13; (II) a TD comprising the amino acid sequence of SEQ ID NO: 21; (III) an ID comprising the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine comprising an amino acid sequence of SEQ ID NO: 24 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence shown in SEQ ID NO: 15. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence shown in SEQ ID NO: 15.

[0034] In some embodiments, the recombinant cytokine receptor comprises: (I) the ED of IL-21Rα; (II) the TD of IL-21Rα; (III) the ID of IL-2Rβ; and (IV) the cognate cytokine IL-21 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 9. In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 9 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 14.In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 14; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 19; (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker and comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 25. In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising the amino acid sequence of SEQ ID NO: 14; (II) a TD comprising the amino acid sequence of SEQ ID NO: 19; (III) an ID comprising the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine comprising the amino acid sequence of SEQ ID NO: 25 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker.

[0035] In some embodiments, the recombinant cytokine receptor comprises: (I) the ED of IL-21Rα; (II) the TD of IL-2Rβ; (III) the ID of IL-2Rβ; and (IV) the cognate cytokine IL-21 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 14 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 14; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 21; (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker, the cytokine comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 25.

[0036] In some embodiments, the recombinant cytokine receptor comprises: (I) an ED comprising the amino acid sequence of SEQ ID NO: 14; (II) a TD comprising the amino acid sequence of SEQ ID NO: 21; (III) an ID comprising the amino acid sequence of SEQ ID NO: 20; and (IV) a cytokine comprising the amino acid sequence of SEQ ID NO: 25 tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, cells expressing the recombinant cytokine receptor can survive and proliferate in the absence of IL-2. In some embodiments, at least about 60% (any of at least about 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, etc.) of the cells transduced with the recombinant cytokine receptor remain viable in the absence of IL-2. In some embodiments, the cells are T cells. In some embodiments, the cells are Treg cells.

[0037] In some embodiments, Tregs expressing a recombinant cytokine receptor can survive and proliferate in vitro in the absence of IL-2 in a suitable medium capable of maintaining the Tregs. In some embodiments, at least about 60% (any of at least about 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%, etc.) of the Tregs transduced with the recombinant cytokine receptor remain viable in vitro for about 2 days to about 30 days (about 10 to about 30 days, about 20 to about 30 days, or about 23 to about 30 days, etc. after transduction). In some embodiments, at least about 60% - 99% of the Tregs transduced with the recombinant cytokine receptor remain viable in vitro for about 7 to about 20 days after transduction. In some embodiments, at least about 60% - 90% of the Tregs transduced with the recombinant cytokine receptor remain viable in vitro for about 7 to about 20 days after transduction. In some embodiments, at least about 60% - 80% of the Tregs transduced with the recombinant cytokine receptor remain viable in vitro for about 7 to about 20 days after transduction. In some embodiments, at least about 60% - 99% of the Tregs transduced with the recombinant cytokine receptor remain viable in vitro for about 7 weeks after transduction. In some embodiments, at least about 60% - 90% of the Tregs transduced with the recombinant cytokine receptor remain viable in vitro for about 7 days after transduction. In some embodiments, at least about 60% - 80% of the Tregs transduced with the recombinant cytokine receptor remain viable in vitro for about 7 days after transduction. In some embodiments, at least about 60% - 99% of the Tregs transduced with the recombinant cytokine receptor remain viable in vitro for about 12 weeks after transduction.In some embodiments, at least about 60% to 90% of the Tregs transduced with a recombinant cytokine receptor remain viable in vitro for about 12 days after transduction. In some embodiments, at least about 60% to 80% of the Tregs transduced with a recombinant cytokine receptor remain viable in vitro for about 12 days after transduction. In some embodiments, at least about 60% to 99% of the Tregs transduced with a recombinant cytokine receptor remain viable in vitro for about 14 days after transduction. In some embodiments, at least about 60% to 90% of the Tregs transduced with a recombinant cytokine receptor remain viable in vitro for about 14 days after transduction. In some embodiments, at least about 60% to 80% of the Tregs transduced with a recombinant cytokine receptor remain viable in vitro for about 14 days after transduction. In some embodiments, the survival rate of Tregs transduced with a recombinant cytokine receptor is increased compared to Treg cells not transduced with a recombinant cytokine receptor. In some embodiments, the survival rate of Tregs transduced with a recombinant cytokine receptor is increased compared to Treg cells not transduced with a recombinant cytokine receptor when cultured without cognate receptor cytokines. In some embodiments, the survival rate of Tregs is increased by at least about 1.1-fold, at least about 1.5-fold, at least about 2-fold, at least about 3-fold, at least about 3.2-fold, at least about 4-fold, at least about 10-fold, about 20-fold, at least about 25-fold, at least about 30-fold, at least about 35-fold, at least about 45-fold, at least about 50-fold, or more compared to non-transduced T cells.

[0038] In some embodiments, Tregs expressing a recombinant cytokine receptor can survive and proliferate in vivo in the absence of IL-2 in the host organism. In some embodiments, at least about 60% (any of at least about 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% etc.) of the Tregs transduced with the recombinant cytokine receptor can survive in vivo for at least 3 days or more. In some embodiments, at least about 60% - 99% of the Tregs transduced with the recombinant cytokine receptor can survive in vivo for at least about 3 days or more. In some embodiments, at least about 60% - 90% of the Tregs transduced with the recombinant cytokine receptor can survive in vivo for at least about 3 days or more. In some embodiments, at least about 60% - 80% of the Tregs transduced with the recombinant cytokine receptor can survive in vivo for at least about 3 days or more.

[0039] In some embodiments, cells transduced with a recombinant cytokine receptor have increased or sustained proliferation after transduction and in vivo. In some embodiments, cells transduced with a recombinant cytokine receptor have more cells in an in vitro culture that has been amplified compared to the number of cells before transduction. In some embodiments, the cells are T cells. In some embodiments, the cells are Treg cells.

[0040] In some embodiments, Tregs transduced with a recombinant cytokine receptor have increased or sustained proliferation after transduction. In some embodiments, Tregs transduced with a recombinant cytokine receptor have more cells after amplification compared to the number of cells prior to transduction. In some embodiments, Tregs transduced with a recombinant cytokine receptor have a higher rate of proliferation compared to non-transduced Treg cells. In some embodiments, the number of cells after transduction is increased by at least about 1.1-fold, at least about 1.5-fold, at least about 2-fold, at least about 5-fold, at least about 10-fold, at least about 20-fold, at least about 50-fold, at least about 75-fold, or more compared to non-transduced cells. In some embodiments, the cells are cultured in the presence of cytokines after transduction. In some embodiments, the cells are cultured without cytokines after transduction.

[0041] In some embodiments, cell viability, transduction of intracellular signaling, activation of intracellular signaling, or the ability to proliferate is increased upon cell transduction with a recombinant cytokine receptor.

[0042] In some embodiments, cell viability, transduction of intracellular signaling, activation of intracellular signaling, or the ability to proliferate by division increases upon transduction of cells with a recombinant cytokine receptor. In some embodiments, the recombinant cytokine receptor expressed in the cell transmits intracellular IL-2 signaling intracellularly. In some embodiments, the recombinant cytokine receptor activates intracellular IL-2 signaling in the cell. In some embodiments, the recombinant cytokine receptor enhances intracellular IL-2 signaling in the cell. In some embodiments, the recombinant cytokine receptor increases intracellular IL-2 signaling in the cell as compared to cells without the recombinant cytokine receptor. In some embodiments, the intracellular domain of the recombinant cytokine receptor provided herein comprises an activated IL-2Rβ intracellular domain. In some embodiments, the recombinant cytokine receptor comprises an activated IL-2Rβ intracellular domain. In some embodiments, the intracellular domain of the recombinant cytokine receptor provided herein is capable of participating in downstream signal transduction. In some embodiments, the recombinant cytokine receptor comprises an IL-2Rβ intracellular domain that phosphorylates STAT5 via activation of the JAK1 kinase upon activation of the recombinant cytokine receptor. In some embodiments, the IL-2Rβ intracellular domain phosphorylates STAT5 via activation of the JAK1 kinase upon activation of the recombinant cytokine receptor. In some embodiments, the recombinant cytokine receptor phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream PI3K-AKT pathway. In some embodiments, the recombinant cytokine receptor phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream Ras / MAPK pathway. In some embodiments, the recombinant cytokine receptor comprises an extracellular / intracellular receptor domain of IL-4Rα / IL-2Rβ, IL-7Rα / IL-2Rβ, IL-9Rα / IL-2Rβ, or IL-21Rα / IL-2Rβ.In some embodiments, the cell is a T cell. In some embodiments, the cell is a Treg cell.

[0043] In some embodiments, the recombinant cytokine receptor phosphorylates STAT5 via activation of the JAK1 kinase upon activation of the recombinant cytokine receptor. In some embodiments, the recombinant cytokine receptor phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream PI3K-AKT pathway. In some embodiments, the recombinant cytokine receptor phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream Ras / MAPK pathway. In some embodiments, the recombinant cytokine receptor comprises an IL-4Rα / IL-2Rβ extracellular / intracellular receptor domain. In some embodiments, the recombinant cytokine receptor is IL-4Rα / IL-2Rβ.

[0044] In some embodiments, the recombinant cytokine receptor has the ability to stimulate STAT5 phosphorylation in cells (e.g., Tregs). STAT5 signaling can be measured, for example, by phosphorylation of STAT5, using any suitable method known in the art. For example, STAT5 phosphorylation can be measured using antibodies specific for the phosphorylated versions of these molecules, in combination with the flow cytometry analysis described herein.

[0045] 1. Extracellular domain IL-2 is a class I cytokine. Class I cytokine receptors generally have a large extracellular domain (ED) that contains multiple all-β Ig-like domains and Fn3 domains (see, for example, Metcalfe, RD et al. (2020), Front Immunol; 11:1424). These domains maintain a β-sandwich structure with two antiparallel β-sheets. Two Fn3 domains form a cytokine-binding homology region at the domain junction. The class I cytokine receptor ED acts to stabilize the receptor and contains a conserved WSXWS (Trp-Ser-X-Trp-Ser, where X is any amino acid) motif that can be extensively glycosylated upon cytokine binding and undergoes a structural change. Class I cytokine receptor chains, including IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, and IL-21Rα, are most often found as heterodimers or heterotrimers. For example, IL-2Rβ can be found as a heterodimer with IL-2Rγ c or as a heterotrimer with IL-2Rα and IL-2Rγ c where the IL-2 binding affinity to IL-2Rβ alone is K d ~100 nM, in the heterodimeric form is K d ~1 nM, and in the heterotrimeric form is K d ~10 pM (see, for example, Wang, X et al. (2009), Annu Rev Immunol; 27:29-60, which is hereby incorporated by reference in its entirety). The cognate cytokine binding affinities to IL-4Rα, IL-7Rα, IL-9Rα, and IL-21Rα identified from reconstitution studies are, respectively, the following: K d ~266 pM, K d ~250 pM, K d ~100 pM (see, for example, Lin, JX & Leonard, WJ (2018), Cold Spring Harb Perspect Biol; 10(9):a028449, which is hereby incorporated by reference in its entirety), and K dis about 70 pM (see, e.g., Kang, L et al. (2010), J Biol Chem; 285(16):12223 - 12231, which is incorporated herein by reference in its entirety). These binding affinities can become higher when each cytokine receptor complexes with the γ c chain. The EDs of IL-4Rα, IL-7Rα, IL-9Rα, and IL-21Rα are 232 residues, 239 residues, 270 residues, and 232 residues in length, respectively. The IL-2, IL-4, IL-7, IL-9, and IL-21 signaling pathways each have unique and distinct effects on T cell biology, and they are, respectively, T cell survival and proliferation; T helper 2 (T H 2) differentiation from naive T cells, and anti-inflammatory effects through suppression of T helper 1 (T H 1) and induction of Treg differentiation; survival of naive T cells and memory T cells; promotion of Treg suppressive activity and differentiation of T H 17 cells; and clonal expansion and enhanced cytolytic activity of CD8+ T cells.

[0046] In some embodiments, the recombinant cytokine receptor is capable of signaling in the absence of exogenous IL-2. In some embodiments, the recombinant cytokine receptor comprises the ED, TD, and 1ID of an interleukin. Thus, in some embodiments, there is provided a recombinant cytokine receptor comprising: (I) the ED of IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (II) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (III) the ID of IL-2Rβ; and (IV) optionally, a cognate cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the ED comprises the amino acid sequence set forth in SEQ ID NOs: 11 - 14. In some embodiments, the ED is from the same cytokine receptor as the TD (e.g., the ED from IL-4Rα and the TD from IL-4Rα). In some embodiments, the ED is from a different cytokine receptor than the TD.

[0047] In some embodiments, the recombinant cytokine receptor comprises the ED of IL-4Rα. In some embodiments, the ED comprises the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the ED comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the recombinant cytokine receptor, in the N-terminal to C-terminal direction, comprises (I) the ED of IL-4Rα; (II) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the N-terminal to C-terminal direction, comprises (I) the ED of IL-4Rα; (II) the TD of IL-4Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the N-terminal to C-terminal direction, comprises (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 11; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 16; and (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor, in the N-terminal to C-terminal direction, comprises (I) an ED comprising the amino acid sequence of SEQ ID NO: 11; (II) a TD comprising the amino acid sequence of SEQ ID NO: 16; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20.In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 1 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0048] In some embodiments, the recombinant cytokine receptor comprises the ED of IL-4Rα. In some embodiments, the ED comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the ED comprises the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the recombinant cytokine receptor, in the N-terminal to C-terminal direction, comprises (I) the ED of IL-4Rα; (II) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the N-terminal to C-terminal direction, comprises (I) the ED of IL-4Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the N-terminal to C-terminal direction, comprises (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 21; and (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 20.

[0049] In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) an ED comprising the amino acid sequence of SEQ ID NO: 11; (II) a TD comprising the amino acid sequence of SEQ ID NO: 21; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor comprises the ED of IL-7Rα. In some embodiments, the IL-7Rα ED comprises the amino acid sequence set forth in SEQ ID NO: 12. In some embodiments, the ED comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to SEQ ID NO: 12. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) the ED of IL-7Rα; (II) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) the ED of IL-7Rα; (II) the TD of IL-7Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 12; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 17; and (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20.In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an ED comprising the amino acid sequence of SEQ ID NO: 12; (II) a TD comprising the amino acid sequence of SEQ ID NO: 17; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 2.

[0050] In some embodiments, the recombinant cytokine receptor comprises the ED of IL-7Rα. In some embodiments, the ED comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 12. In some embodiments, the ED comprises the amino acid sequence set forth in SEQ ID NO: 12. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) the ED of IL-7Rα; (II) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) the ED of IL-7Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 12; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 21; and (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) an ED comprising the amino acid sequence set forth in SEQ ID NO: 12; (II) a TD comprising the amino acid sequence set forth in SEQ ID NO: 21; and (III) an ID comprising the amino acid sequence set forth in SEQ ID NO: 20.

[0051] In some embodiments, the recombinant cytokine receptor comprises the ED of IL-9Rα. In some embodiments, the ED comprises the amino acid sequence set forth in SEQ ID NO: 13. In some embodiments, the ED comprises an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to SEQ ID NO: 13. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) the ED of IL-9Rα; (II) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) the ED of IL-9Rα; (II) the TD of IL-9Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) an ED comprising an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence of SEQ ID NO: 13; (II) a TD comprising an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence of SEQ ID NO: 18; and (III) an ID comprising an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) an ED comprising the amino acid sequence of SEQ ID NO: 13; (II) a TD comprising the amino acid sequence of SEQ ID NO: 18; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20.In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence shown in SEQ ID NO: 3 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0052] In some embodiments, the recombinant cytokine receptor comprises the ED of IL-9Rα. In some embodiments, the ED comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 13. In some embodiments, the ED comprises the amino acid sequence set forth in SEQ ID NO: 13. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) the ED of IL-9Rα; (II) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) the ED of IL-9Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 13; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 21; and (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) an ED comprising the amino acid sequence of SEQ ID NO: 13; (II) a TD comprising the amino acid sequence of SEQ ID NO: 21; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20.In some embodiments, the recombinant cytokine receptor comprises the amino acid sequence set forth in SEQ ID NO: 5 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0053] In some embodiments, the IL-21Rα ED comprises the amino acid sequence set forth in SEQ ID NO: 14. In some embodiments, the ED comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 14. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) the ED of IL-21Rα; (II) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) the ED of IL-21Rα; (II) the TD of IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 14; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 19; and (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an ED comprising the amino acid sequence of SEQ ID NO: 14; (II) a TD comprising the amino acid sequence of SEQ ID NO: 19; and (III) an ID comprising the amino acid sequence of SEQ ID NO: 20.In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence shown in SEQ ID NO: 4 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0054] In some embodiments, the recombinant cytokine receptor comprises the ED of IL-21Rα. In some embodiments, the ED comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 14. In some embodiments, the ED comprises the amino acid sequence set forth in SEQ ID NO: 14. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) the ED of IL-21Rα; (II) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) the ED of IL-21Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 14; (II) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 21; and (III) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) an ED comprising the amino acid sequence set forth in SEQ ID NO: 14; (II) a TD comprising the amino acid sequence set forth in SEQ ID NO: 21; and (III) an ID comprising the amino acid sequence set forth in SEQ ID NO: 20.

[0055] In some embodiments, the recombinant cytokine receptor comprises the ED of IL-4Rα. In some embodiments, the ED comprises the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the ED comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-4 cytokine; (II) the ED of IL-4Rα; (III) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (IV) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-4 cytokine; (II) the ED of IL-4Rα; (III) the TD of IL-4Rα or IL-2Rβ; and (IV) the ID of IL-2Rβ.In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) a cytokine comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 22; (II) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 11; (III) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 16 or SEQ ID NO: 21; and (IV) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) a cytokine comprising the amino acid sequence of SEQ ID NO: 22; (II) an ED comprising the amino acid sequence of SEQ ID NO: 11; (III) a TD comprising the amino acid sequence of SEQ ID NO: 16 or SEQ ID NO: 21; and (IV) an ID comprising the amino acid sequence of SEQ ID NO: 20. In some embodiments, the cytokine is tethered to the ED via a linker. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence shown in SEQ ID NO: 6.In some embodiments, the recombinant cytokine receptor comprises a cytokine having an amino acid sequence shown in SEQ ID NO: 22 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0056] In some embodiments, the recombinant cytokine receptor comprises the ED of IL-7Rα. In some embodiments, the IL-7Rα ED comprises the amino acid sequence set forth in SEQ ID NO: 12. In some embodiments, the ED comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 12. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-7 cytokine; (II) the ED of IL-7Rα; (III) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (IV) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-7 cytokine; (II) the ED of IL-7Rα or IL-2Rβ; (III) the TD of IL-7Rα; and (IV) the ID of IL-2Rβ.In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) a cytokine comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 23; (II) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 12; (III) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 17 or SEQ ID NO: 21; and (IV) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) a cytokine comprising the amino acid sequence of SEQ ID NO: 23; (II) an ED comprising the amino acid sequence of SEQ ID NO: 12; (III) a TD comprising the amino acid sequence of SEQ ID NO: 17 or SEQ ID NO: 21; and (IV) an ID comprising the amino acid sequence of SEQ ID NO: 20. In some embodiments, the cytokine is tethered to the ED via a linker. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence shown in SEQ ID NO: 7.In some embodiments, the recombinant cytokine receptor comprises a cytokine having an amino acid sequence shown in SEQ ID NO: 23 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0057] In some embodiments, the IL-9Rα ED comprises the amino acid sequence set forth in SEQ ID NO: 13. In some embodiments, the ED comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 13. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-9 cytokine; (II) the ED of IL-9Rα; (III) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (IV) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-9 cytokine; (II) the ED of IL-9Rα; (III) the TD of IL-9Rα; and (IV) the ID of IL-2Rβ.In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, (I) a cytokine comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 24; (II) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 13; (III) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 18; and (IV) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, (I) a cytokine comprising the amino acid sequence of SEQ ID NO: 24; (II) an ED comprising the amino acid sequence of SEQ ID NO: 13; (III) one comprising the amino acid sequence of SEQ ID NO: 18; and (IV) an ID comprising the amino acid sequence of SEQ ID NO: 20. In some embodiments, the cytokine is tethered to the ED via a linker. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence shown in SEQ ID NO: 8 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto.In some embodiments, the recombinant cytokine receptor comprises a cytokine having an amino acid sequence shown in SEQ ID NO: 24 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0058] In some embodiments, the recombinant cytokine receptor comprises the ED of IL-9Rα. In some embodiments, the ED comprises the amino acid sequence set forth in SEQ ID NO: 13. In some embodiments, the ED comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 13. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-9 cytokine; (II) the ED of IL-9Rα; (III) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (IV) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-9 cytokine; (II) the ED of IL-9Rα; (III) the TD of IL-2Rβ; and (IV) the ID of IL-2Rβ.In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) a cytokine comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 24; (II) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 13; (III) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 21; and (IV) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) a cytokine comprising the amino acid sequence of SEQ ID NO: 24; (II) an ED comprising the amino acid sequence of SEQ ID NO: 13; (III) a TD comprising the amino acid sequence of SEQ ID NO: 21; and (IV) an ID comprising the amino acid sequence of SEQ ID NO: 20. In some embodiments, the cytokine is tethered to the ED via a linker. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence shown in SEQ ID NO: 15.In some embodiments, the recombinant cytokine receptor comprises a cytokine having an amino acid sequence shown in SEQ ID NO: 24 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0059] In some embodiments, the IL-21Rα ED comprises the amino acid sequence set forth in SEQ ID NO: 14. In some embodiments, the ED comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 14. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-21 cytokine; (II) the ED of IL-21Rα; (III) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (IV) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-21 cytokine; (II) the ED of IL-21Rα; (III) the TD of IL-21Rα or IL-2Rβ; and (IV) the ID of IL-2Rβ.In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) a cytokine comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 25; (II) an ED comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 14; (III) a TD comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 19 or SEQ ID NO: 21; and (IV) an ID comprising an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence of SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) a cytokine comprising the amino acid sequence of SEQ ID NO: 25; (II) an ED comprising the amino acid sequence of SEQ ID NO: 14; (III) a TD comprising the amino acid sequence of SEQ ID NO: 19 or SEQ ID NO: 21; and (IV) an ID comprising the amino acid sequence of SEQ ID NO: 20. In some embodiments, the cytokine is tethered to the ED via a linker. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence shown in SEQ ID NO: 9 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto.In some embodiments, the recombinant cytokine receptor comprises a cytokine having an amino acid sequence shown in SEQ ID NO: 25 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0060] In some embodiments, the recombinant cytokine receptor comprising the foregoing ED is expressed in a cell. In some embodiments, the recombinant cytokine receptor comprising the foregoing ED is expressed in an immune cell. In some embodiments, the immune cell is a T cell. In some embodiments, the immune cell is a Treg cell.

[0061] In some embodiments, the recombinant cytokine receptor comprising the foregoing ED is expressed in Tregs. In some embodiments, the Treg cells are CD4+, CD25+, and CD127lo. In some embodiments, the Tregs expressing the recombinant cytokine receptor comprising the foregoing ED also express FOXP3 and HELIOS. In some embodiments, the Tregs expressing the recombinant cytokine receptor comprising the foregoing ED also express high levels of FOXP3 and HELIOS. In some embodiments, the Tregs expressing the recombinant cytokine receptor comprising the foregoing ED can survive and proliferate in the absence of IL-2. In some embodiments, at least about 60% (any of at least about 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% etc.) of the Tregs transduced with the recombinant cytokine receptor comprising the foregoing ED remain viable in vitro for 2 to 20 days after transduction. In some embodiments, at least about 60% (any of at least about 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% etc.) of the Tregs transduced with the recombinant cytokine receptor comprising the foregoing ED can persist in vivo for at least 3 days or more. In some embodiments, the recombinant cytokine receptor comprising the foregoing ED expressed in Tregs transmits intracellular IL-2 signaling within Tregs. In some embodiments, the signaling via the recombinant cytokine receptor comprising the foregoing ED expressed in Tregs induces phosphorylation of STAT5. In some embodiments, the Tregs expressing the recombinant cytokine receptor comprising the foregoing ED can suppress the activity of effector T cells in the absence of IL-2 to at least the same extent or more than wild-type Tregs cultured with exogenous IL-2.In some embodiments, the suppressed effector T cells are CD4+ effector T cells. In some embodiments, the suppressed effector T cells are CD8+ effector T cells. In some embodiments, the Tregs expressing the recombinant cytokine receptor comprising the foregoing ED also express a chimeric antigen receptor (CAR).

[0062] 2. Intracellular domain IL-2Rβ is mainly expressed in hematopoietic cells, and its involvement in immune cell-mediated immune responses has been well documented. The IL-2Rβ polypeptide interacts with JAK1 via its C-terminal cytoplasmic domain containing amino acids 240-525. The intracellular domain (ID) of IL-2Rβ lacks intrinsic catalytic ability and thus depends on constitutive interaction with JAK1 at box 1 and box 3 motifs in the region near the membrane to enhance IL-2 signaling (see, for example, Wang, X et al. (2009), Annu Rev Immunol; 27:29-60). In activated T cells, IL-2 signaling via IL-2Rβ leads to activation of three pathways: (1) phosphorylation of STAT5 by JAK1 kinase, (2) activation of the PI3K-AKT pathway by Shc phosphorylation, and (3) activation of the Ras / MAPK pathway by Shc phosphorylation (see, for example, Ye, C et al. (2018), Signal Transduct Target Ther; 3:2, which is hereby incorporated by reference in its entirety). Among these three pathways, JAK1 / STAT5 signaling is dominant. Activation of the IL-2 pathway across all T cell lineages has been shown to induce T cell proliferation and survival. However, IL-2Rβ signaling participates only in the AK1 / STAT5 pathway within JCD4+CD25+ Treg cells (see, for example, Bensinger, SJ et al. (2010), J Immunol; 172(9):5287-5296, which is hereby incorporated by reference in its entirety), which is required for Treg inhibitory activity (see, for example, Ye, C et al. (2018), Signal Transduct Target Ther; 3:2). CD4+ effector T cells, and to a lesser extent CD8+ effector T cells, are capable of producing IL-2 to signal their own proliferation and survival after activation, but Treg are not capable of producing IL-2. Thus, Treg survival depends on IL-2 produced by effector T cells.

[0063] In some embodiments, the intracellular domain of the recombinant cytokine receptor provided herein comprises an activated IL-2Rβ intracellular domain. In some embodiments, the intracellular domain of the recombinant cytokine receptor is an activated IL-2Rβ intracellular domain. In some embodiments, the intracellular domain of the recombinant cytokine receptor provided herein is capable of participating in downstream signal transduction. In some embodiments, the IL-2Rβ intracellular domain phosphorylates STAT5 via its activation of the JAK1 kinase upon activation of IL-2Rβ ID. In some embodiments, the IL-2 intracellular domain phosphorylates Shc upon activation of the IL-2Rβ receptor, thereby activating the downstream PI3K-AKT pathway. In some embodiments, the IL-2 intracellular domain phosphorylates Shc upon activation of the IL-2Rβ ID, thereby activating the downstream Ras / MAPK pathway. In some embodiments, the IL-2Rβ intracellular domain phosphorylates STAT5 via the activation of the JAK1 kinase upon activation of the recombinant cytokine receptor. In some embodiments, the IL-2 intracellular domain phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream PI3K-AKT pathway. In some embodiments, the IL-2 intracellular domain phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream Ras / MAPK pathway. In some embodiments, the recombinant cytokine receptor comprises an extracellular / intracellular receptor domain of IL-4Rα / IL-2Rβ, IL-7Rα / IL-2Rβ, IL-9Rα / IL-2Rβ, or IL-21Rα / IL-2Rβ. In some embodiments, the recombinant cytokine receptor is IL-4Rα / IL-2Rβ, IL-7Rα / IL-2Rβ, IL-9Rα / IL-2Rβ, or IL-21Rα / IL-2Rβ.

[0064] In some embodiments, the IL-2Rβ intracellular domain phosphorylates STAT5 via activation of the JAK1 kinase upon activation of the recombinant cytokine receptor. In some embodiments, the IL-2Rβ intracellular domain phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream PI3K-AKT pathway. In some embodiments, the IL-2Rβ intracellular domain phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream Ras / MAPK pathway. In some embodiments, the recombinant cytokine receptor comprises an IL-4Rα / IL-2Rβ extracellular / intracellular receptor domain. In some embodiments, the recombinant cytokine receptor is IL-4Rα / IL-2Rβ.

[0065] In some embodiments, the IL-2Rβ intracellular domain phosphorylates STAT5 via activation of the JAK1 kinase upon activation of the recombinant cytokine receptor. In some embodiments, the IL-2Rβ intracellular domain phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream PI3K-AKT pathway. In some embodiments, the IL-2Rβ intracellular domain phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream Ras / MAPK pathway. In some embodiments, the recombinant cytokine receptor comprises an IL-7Rα / IL-2Rβ extracellular / intracellular receptor domain. In some embodiments, the recombinant cytokine receptor is IL-7Rα / IL-2Rβ.

[0066] In some embodiments, the IL-2Rβ intracellular domain phosphorylates STAT5 via the activation of JAK1 kinase upon activation of the recombinant cytokine receptor. In some embodiments, the IL-2Rβ intracellular domain phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream PI3K-AKT pathway. In some embodiments, the IL-2Rβ intracellular domain phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream Ras / MAPK pathway. In some embodiments, the recombinant cytokine receptor comprises an IL-9Rα / IL-2Rβ extracellular / intracellular receptor domain. In some embodiments, the recombinant cytokine receptor is IL-9Rα / IL-2Rβ.

[0067] In some embodiments, the IL-2Rβ intracellular domain phosphorylates STAT5 via the activation of JAK1 kinase upon activation of the recombinant cytokine receptor. In some embodiments, the IL-2Rβ intracellular domain phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream PI3K-AKT pathway. In some embodiments, the IL-2Rβ intracellular domain phosphorylates Shc upon activation of the recombinant cytokine receptor, thereby activating the downstream Ras / MAPK pathway. In some embodiments, the recombinant cytokine receptor comprises an IL-21Rα / IL-2Rβ extracellular / intracellular receptor domain. In some embodiments, the recombinant cytokine receptor is IL-21Rα / IL-2Rβ.

[0068] In some embodiments, the recombinant cytokine receptor is capable of signaling in the absence of exogenous IL-2. In some embodiments, the recombinant cytokine receptor is capable of signaling in the presence of cytokines other than IL-2. In some embodiments, the IL-2Rβ ID comprises the amino acid sequence set forth in SEQ ID NO: 20. In some embodiments, the ID comprises an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to SEQ ID NO: 20. In some embodiments, the recombinant cytokine receptor comprises (I) the extracellular domain (ED) of IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (II) the transmembrane domain (TD) of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (III) the ID of IL-2Rβ; and (IV) optionally, a cognate cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) the ED of IL-4Rα; (II) the TD of IL-4Rα; (III) the ID of IL-2Rβ; and (IV) optionally, the IL-4 cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) the ED of IL-7Rα; (II) the TD of IL-7Rα; (III) the ID of IL-2Rβ; and (IV) optionally, the IL-7 cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) the ED of IL-9Rα; (II) the TD of IL-9Rα; (III) the ID of IL-2Rβ; and (IV) optionally, the IL-9 cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker.In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) the ED of IL-21Rα; (II) the TD of IL-21Rα; (III) the ID of IL-2Rβ; and (IV) optionally, an IL-21 cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises: (I) optionally, a cognate cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker; (II) the ED of IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (III) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (IV) the ID of IL-2Rβ. In some embodiments, the ED is from the same cytokine receptor as the TD (e.g., the ED from IL-4Rα and the TD from IL-4Rα). In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) optionally, an IL-4 cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker; (II) the ED of IL-4Rα; (III) the TD of IL-4Rα; and (IV) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) optionally, an IL-4 cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker; (II) the ED of IL-4Rα; (III) the TD of IL-2Rβ; and (IV) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises: (I) optionally, an IL-7 cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker; (II) the ED of IL-7Rα; (III) the TD of IL-7Rα; and (IV) the ID of IL-2Rβ.In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) optionally, an IL-7 cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker; (II) the ED of IL-7Rα; (III) the TD of IL-2Rβ; and (IV) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) optionally, an IL-9 cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker; (II) the ED of IL-9Rα; (III) the TD of IL-9Rα; and (IV) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) optionally, an IL-9 cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker; (II) the ED of IL-9Rα; (III) the TD of IL-2Rβ; and (IV) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) optionally, an IL-21 cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker; (II) the ED of IL-21Rα; (III) the TD of IL-21Rα; and (IV) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) optionally, an IL-21 cytokine tethered to the ED of the recombinant cytokine receptor by a polypeptide linker; (II) the ED of IL-21Rα; (III) the TD of IL-2Rβ; and (IV) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises (I) the ED of IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (II) the TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the direction from the N-terminus to the C-terminus, comprises (I) the ED of IL-4Rα; (II) the TD of IL-4Rα; and (III) the ID of IL-2Rβ.In some embodiments, the recombinant cytokine receptor comprises, in the direction from the N-terminus to the C-terminus, (I) the ED of IL-4Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the direction from the N-terminus to the C-terminus, (I) the ED of IL-7Rα; (II) the TD of IL-7Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the direction from the N-terminus to the C-terminus, (I) the ED of IL-7Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the direction from the N-terminus to the C-terminus, (I) the ED of IL-9Rα; (II) the TD of IL-9Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the direction from the N-terminus to the C-terminus, (I) the ED of IL-9Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the direction from the N-terminus to the C-terminus, (I) the ED of IL-21Rα; (II) the TD of IL-21Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the direction from the N-terminus to the C-terminus, (I) the ED of IL-21Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ.

[0069] 3. Transmembrane Domain The TDs of the IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, and IL-21Rα receptors as members of class I cytokine receptors comprise a modular single-pass TD. The TDs of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, and IL-21Rα are 25 residues, 25 residues, 24 residues, 25 residues, 21 residues, and 21 residues in length.

[0070] In some embodiments, the recombinant cytokine receptor comprises a transmembrane domain. In some embodiments, the transmembrane domain is located between the extracellular domain and the intracellular domain of the recombinant cytokine. In some embodiments, the transmembrane domain is from a cytokine receptor. In some embodiments, the transmembrane domain is from a class I cytokine receptor. In some embodiments, the transmembrane domain is from a class II cytokine receptor. In some embodiments, the transmembrane domain is a transmembrane domain selected from the group consisting of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, and IL-21Rα. In some embodiments, the transmembrane domain is the transmembrane domain from IL-2Rβ. In some embodiments, the transmembrane domain is the transmembrane domain from IL-4Rα. In some embodiments, the transmembrane domain is the transmembrane domain from IL-7Rα. In some embodiments, the transmembrane domain is the transmembrane domain from IL-9Rα. In some embodiments, the transmembrane domain is the transmembrane domain from IL-21Rα. In some embodiments, TD is selected from the same cytokine receptor as ED. In some embodiments, TD is selected from a cytokine receptor different from ED. In some embodiments, TD comprises any one of the amino acid sequences shown in SEQ ID NOs: 16-19 and 21.

[0071] In some embodiments, IL-2Rβ TD comprises the amino acid sequence shown in SEQ ID NO: 21. In some embodiments, TD comprises the amino acid sequence shown in SEQ ID NO: 21 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor comprises a TD that is about 20-30 amino acids in length. In some embodiments, the recombinant cytokine receptor comprises a TD that is 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 amino acids in length. In some embodiments, the recombinant cytokine receptor comprises (I) the ED of IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) the ED of IL-4Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-4 cytokine; (II) the ED of IL-4Rα; (III) the TD of IL-2Rβ; and (IV) the ID of IL-2Rβ. In some embodiments, the IL-4 cytokine is tethered to the ED of IL-4Rα by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) the ED of IL-7Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-7 cytokine; (II) the ED of IL-7Rα; (III) the TD of IL-2Rβ; and (IV) the ID of IL-2Rβ. In some embodiments, the IL-7 cytokine is tethered to the ED of IL-7Rα by a polypeptide linker.In some embodiments, the recombinant cytokine receptor comprises, in the direction from the N-terminus to the C-terminus, (I) the ED of IL-9Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the direction from the N-terminus to the C-terminus, (I) an IL-9 cytokine; (II) the ED of IL-9Rα; (III) the TD of IL-2Rβ; and (IV) the ID of IL-2Rβ. In some embodiments, the IL-9 cytokine is tethered to the ED of IL-9Rα by a polypeptide linker. In some embodiments, the recombinant cytokine receptor comprises, in the direction from the N-terminus to the C-terminus, (I) the ED of IL-21Rα; (II) the TD of IL-2Rβ; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the direction from the N-terminus to the C-terminus, (I) an IL-21 cytokine; (II) the ED of IL-21Rα; (III) the TD of IL-2Rβ; and (IV) the ID of IL-2Rβ. In some embodiments, the IL-21 cytokine is tethered to the ED of IL-21Rα by a polypeptide linker.

[0072] In some embodiments, the IL-4Rα TD comprises the amino acid sequence set forth in SEQ ID NO: 16. In some embodiments, the TD comprises the amino acid sequence set forth in SEQ ID NO: 16 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor comprises a TD that is about 20 to 30 amino acids in length. In some embodiments, the recombinant cytokine receptor comprises a TD that is 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 amino acids in length. In some embodiments, the recombinant cytokine receptor comprises (I) the ED of IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (II) the TD of IL-4Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) the ED of IL-4Rα; (II) the TD of IL-4Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-4 cytokine; (II) the ED of IL-4Rα; (III) the TD of IL-4Rα; and (IV) the ID of IL-2Rβ. In some embodiments, the IL-4 cytokine is tethered to the ED of IL-4Rα by a polypeptide linker. [[ID=~1]] [[ID=~2]]

[0073] [[ID=~3]] In some embodiments, the IL-7Rα TD comprises the amino acid sequence set forth in SEQ ID NO: 17. In some embodiments, the TD comprises the amino acid sequence set forth in SEQ ID NO: 17 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto. In some embodiments, the recombinant cytokine receptor comprises a TD that is about 20 to 30 amino acids in length. In some embodiments, the recombinant cytokine receptor comprises a TD that is 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 amino acids in length. In some embodiments, the recombinant cytokine receptor comprises (I) an ED of IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (II) a TD of IL-7Rα; and (III) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an ED of IL-7Rα; (II) a TD of IL-7Rα; and (III) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-7 cytokine; (II) an ED of IL-7Rα; (III) a TD of IL-7Rα; and (IV) an ID of IL-2Rβ. In some embodiments, the IL-7 cytokine is tethered to the ED of IL-7Rα by a polypeptide linker.

[0074] In some embodiments, IL-9Rα TD comprises the amino acid sequence set forth in SEQ ID NO: 18. In some embodiments, the TD comprises the amino acid sequence set forth in SEQ ID NO: 18 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor comprises a TD that is about 20 to 30 amino acids in length. In some embodiments, the recombinant cytokine receptor comprises a TD that is 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 amino acids in length. In some embodiments, the recombinant cytokine receptor comprises (I) the ED of IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (II) the TD of IL-9Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) the ED of IL-9Rα; (II) the TD of IL-9Rα; and (III) the ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-9 cytokine; (II) the ED of IL-9Rα; (III) the TD of IL-9Rα; and (IV) the ID of IL-2Rβ. In some embodiments, the IL-9 cytokine is tethered to the ED of IL-9Rα by a polypeptide linker.

[0075] In some embodiments, IL-21RαTD comprises the amino acid sequence set forth in SEQ ID NO: 19. In some embodiments, TD comprises the amino acid sequence set forth in SEQ ID NO: 19 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor comprises a TD that is about 20-30 amino acids in length. In some embodiments, the recombinant cytokine receptor comprises a TD that is 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 amino acids in length. In some embodiments, the recombinant cytokine receptor comprises (I) an ED of IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (II) a TD of IL-21Rα; and (III) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an ED of IL-21Rα; (II) a TD of IL-21Rα; and (III) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-21 cytokine; (II) an ED of IL-21Rα; (III) a TD of IL-21Rα; and (IV) an ID of IL-2Rβ. In some embodiments, the IL-21 cytokine is tethered to the ED of IL-21Rα by a polypeptide linker.

[0076] In some embodiments, TD comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with any one of the amino acid sequences set forth in SEQ ID NOS: 16-19 and 21. In some embodiments, TD comprises an amino acid sequence selected from the group consisting of SEQ ID NOS: 16-19 and 21.

[0077] In some embodiments, the recombinant cytokine receptor comprising the aforementioned TD is expressed in immune cells. In some embodiments, the recombinant cytokine receptor comprising the aforementioned TD is expressed in T cells. In some embodiments, the recombinant cytokine receptor comprising the aforementioned TD is expressed in regulatory T cells (Tregs). In some embodiments, Treg cells are CD4+, CD25+, and CD127lo (i.e., low CD127). In some embodiments, Tregs expressing the recombinant cytokine receptor comprising the aforementioned TD express FOXP3 and / or HELIOS. In some embodiments, Tregs expressing the recombinant cytokine receptor comprising the aforementioned TD also express high levels of FOXP3 and / or HELIOS. In some embodiments, Tregs expressing the recombinant cytokine receptor comprising the aforementioned TD can survive and proliferate in the absence of IL-2. In some embodiments, at least about 60% (any of at least about 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% etc.) of the Tregs transduced with the recombinant cytokine receptor comprising the aforementioned TD remain viable in vitro for 12 to 20 days after transduction. In some embodiments, at least about 60% (any of at least about 60%, 65%, 70%, 75%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% etc.) of the Tregs transduced with the recombinant cytokine receptor comprising the aforementioned TD can persist in vivo for at least 3 days or more. In some embodiments, the recombinant cytokine receptor comprising the aforementioned TD expressed in Tregs transmits intracellular IL-2 signaling within Tregs. In some embodiments, signaling via the recombinant cytokine receptor comprising the aforementioned TD expressed in Tregs induces phosphorylation of STAT5.In some embodiments, Tregs expressing the recombinant cytokine receptor comprising the aforementioned TD can suppress the activity of effector T cells in the absence of IL-2 to at least the same extent as or even more than wild-type Tregs cultured with exogenous IL-2. In some embodiments, the suppressed effector T cells are CD4+ effector T cells. In some embodiments, the suppressed effector T cells are CD8+ effector T cells. In some embodiments, Tregs expressing the recombinant cytokine receptor comprising the aforementioned TD also express a chimeric antigen receptor (CAR).

[0078] 4. Tethered Cytokines and Linkers The foregoing recombinant cytokine receptors can optionally be tethered to their cognate cytokines by a polypeptide linker. In some embodiments, IL-4 can be tethered to the recombinant cytokine receptor IL-4RαED. In some embodiments, the recombinant cytokine receptor to which IL-4 is tethered comprises the amino acid sequence shown in SEQ ID NO: 6. In some embodiments, the recombinant cytokine receptor to which IL-4 is tethered comprises the amino acid sequence shown in SEQ ID NO: 6 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto. In some embodiments, IL-7 can be tethered to the recombinant cytokine receptor IL-7RαED. In some embodiments, the recombinant cytokine receptor to which IL-7 is tethered comprises the amino acid sequence shown in SEQ ID NO: 7. In some embodiments, the recombinant cytokine receptor to which IL-7 is tethered comprises the amino acid sequence shown in SEQ ID NO: 7 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto. In some embodiments, IL-9 can be tethered to the recombinant cytokine receptor IL-9RαED. In some embodiments, the recombinant cytokine receptor to which IL-9 is tethered comprises the amino acid sequence shown in SEQ ID NO: 8. In some embodiments, the recombinant cytokine receptor to which IL-9 is tethered comprises the amino acid sequence shown in SEQ ID NO: 8 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto. In some embodiments, the recombinant cytokine receptor to which IL-9 is tethered comprises the amino acid sequence shown in SEQ ID NO: 15.In some embodiments, the recombinant cytokine receptor with IL-9 tethered thereto comprises an amino acid sequence shown in SEQ ID NO: 15 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, IL-21 can be tethered to the recombinant cytokine receptor IL-21RαED. In some embodiments, the recombinant cytokine receptor with IL-21 tethered thereto comprises the amino acid sequence shown in SEQ ID NO: 9. In some embodiments, the recombinant cytokine receptor with IL-21 tethered thereto comprises the amino acid sequence shown in SEQ ID NO: 9 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor is capable of signaling in the absence of exogenous IL-2. In some embodiments, the recombinant cytokine receptor is capable of signaling in the absence of exogenous interleukin cytokine.

[0079] In some embodiments, the cognate cytokine tethered to the recombinant cytokine receptor by a polypeptide linker comprises any of SEQ ID NOs: 22-25. In some embodiments, the cognate cytokine comprises the amino acid sequences shown in SEQ ID NOs: 22-25 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0080] In some embodiments, the recombinant cytokine receptor comprises an IL-4 cytokine tethered to the extracellular domain of IL-4Rα. In some embodiments, IL-4 comprises the amino acid sequence shown in SEQ ID NO: 22. In some embodiments, IL-4 comprises the amino acid sequence shown in SEQ ID NO: 22 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor to which IL-4 is tethered comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 6, the recombinant cytokine receptor comprises an IL-4 cytokine having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 22, and the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 11.In some embodiments, the recombinant cytokine receptor to which IL-4 is tethered comprises an amino acid sequence shown in SEQ ID NO: 6 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, the recombinant cytokine receptor comprises an IL-4 cytokine having an amino acid sequence shown in SEQ ID NO: 22 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, and the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 11 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0081] In some embodiments, the recombinant cytokine receptor comprises an IL-7 cytokine tethered to the extracellular domain of IL-7Rα. In some embodiments, IL-7 comprises the amino acid sequence shown in SEQ ID NO: 23. In some embodiments, IL-7 comprises the amino acid sequence shown in SEQ ID NO: 23 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor to which IL-7 is tethered comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence shown in SEQ ID NO: 7, the recombinant cytokine receptor comprises an IL-7 cytokine having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence shown in SEQ ID NO: 23, and the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence shown in SEQ ID NO: 12.In some embodiments, the recombinant cytokine receptor to which IL-7 is tethered comprises an amino acid sequence shown in SEQ ID NO: 7 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, the recombinant cytokine receptor comprises an IL-7 cytokine having an amino acid sequence shown in SEQ ID NO: 23 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, and the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 12 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0082] In some embodiments, the recombinant cytokine receptor comprises an IL-9 cytokine tethered to the extracellular domain of IL-9Rα. In some embodiments, IL-9 comprises the amino acid sequence set forth in SEQ ID NO: 24. In some embodiments, IL-9 comprises the amino acid sequence set forth in SEQ ID NO: 24 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor to which IL-9 is tethered comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 8, the recombinant cytokine receptor comprises an IL-9 cytokine having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 24, and the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 13.In some embodiments, the recombinant cytokine receptor with IL-9 tethered comprises an amino acid sequence shown in SEQ ID NO: 8 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, the recombinant cytokine receptor comprises an IL-9 cytokine having an amino acid sequence shown in SEQ ID NO: 24 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, and the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 13 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor with IL-9 tethered comprises an amino acid sequence shown in SEQ ID NO: 15 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, the recombinant cytokine receptor comprises an IL-9 cytokine having an amino acid sequence shown in SEQ ID NO: 24 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, and the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 13 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.In some embodiments, the recombinant cytokine receptor to which IL-9 is tethered comprises an amino acid sequence shown in SEQ ID NO: 15 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, the recombinant cytokine receptor comprises an IL-9 cytokine having an amino acid sequence shown in SEQ ID NO: 24 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, and the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 13 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0083] In some embodiments, the recombinant cytokine receptor comprises an IL-21 cytokine tethered to the extracellular domain of IL-21Rα. In some embodiments, IL-21 comprises the amino acid sequence set forth in SEQ ID NO: 25. In some embodiments, IL-21 comprises the amino acid sequence set forth in SEQ ID NO: 25 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the recombinant cytokine receptor tethered with IL-21 comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 9, the recombinant cytokine receptor comprises an IL-21 cytokine having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 25, and the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 14.In some embodiments, the recombinant cytokine receptor to which IL-21 is tethered comprises an amino acid sequence shown in SEQ ID NO: 9 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, the recombinant cytokine receptor comprises an IL-21 cytokine having an amino acid sequence shown in SEQ ID NO: 25 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, and the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 14 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity.

[0084] The linker can be a polypeptide linker of any length. In some embodiments, the polypeptide linker is from about 1 amino acid to about 10 amino acids in length, from about 2 amino acids to about 15 amino acids in length, from about 3 amino acids to about 12 amino acids in length, from about 4 amino acids to about 10 amino acids in length, from about 5 amino acids to about 9 amino acids in length, from about 6 amino acids to about 8 amino acids in length, from about 1 amino acid to about 20 amino acids in length, from about 21 amino acids to about 30 amino acids in length, from about 1 amino acid to about 30 amino acids in length, from about 2 amino acids to about 20 amino acids in length, from about 10 amino acids to about 30 amino acids in length, from about 2 amino acids to about 19 amino acids in length, from about 2 amino acids to about 18 amino acids in length, from about 2 amino acids to about 17 amino acids in length, from about 2 amino acids to about 16 amino acids in length, from about 2 amino acids to about 10 amino acids in length, from about 2 amino acids to about 14 amino acids in length, from about 2 amino acids to about 13 amino acids in length, from about 2 amino acids to about 12 amino acids in length, from about 2 amino acids to about 11 amino acids in length, from about 2 amino acids to about 9 amino acids in length, from about 2 amino acids to about 8 amino acids in length, from about 2 amino acids to about 7 amino acids in length, from about 2 amino acids to about 6 amino acids in length, from about 2 amino acids to about 5 amino acids in length, from about 2 amino acids to about 4 amino acids in length, or from about 2 amino acids to about 3 amino acids in length. In some embodiments, the polypeptide linker is any one of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 amino acids in length. In some embodiments, the polypeptide linker is any one of 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 amino acids in length. For example, in some embodiments, the polypeptide linker is about 5 amino acids in length. In some embodiments, the N-terminus of the polypeptide linker is covalently linked to the C-terminus of the interleukin cytokine, and the C-terminus of the polypeptide linker is covalently linked to the N-terminus of ED.

[0085] The polypeptide linker can have a naturally occurring sequence or a non-naturally occurring sequence. For example, a sequence derived from the hinge region of an antibody of only the heavy chain can be used as a linker. See, for example, WO1996 / 34103. In some embodiments, the linker is a flexible linker. In some embodiments, an exemplary flexible linker is (GGGGS)n wherein, in the sequence, n is an integer of at least 1 (SEQ ID NO: 29; when n = 2, SEQ ID NO: 27). Glycine polymers and glycine-serine polymers are relatively unstructured and can thus potentially act as neutral tethers between components. Glycine has significantly more access to φψ space than alanine and is far less constrained than residues with longer side chains (see Scheraga, Rev. Computational Chem. 11 173 - 142 (1992)). Thus, exemplary flexible linkers include, but are not limited to, Gly-Gly-Gly-Gly-Ser-Gly-Gly-Gly-Gly-Ser (SEQ ID NO: 27), Gly-Gly-Gly-Gly-Ser (SEQ ID NO: 30), Gly-Gly-Gly-Gly-Ser-Gly-Gly-Gly-Gly-Ser-Gly-Gly-Gly-Gly-Ser (SEQ ID NO: 31), and Ser-Gly-Gly-Gly-Ser-Gly-Gly-Gly-Gly-Ser-Gly-Gly-Gly-Gly-Ser-Gly-Gly-Gly-Gly-Ser-Gly-Gly-Gly-Ser-Leu-Gln (SEQ ID NO: 32). One of ordinary skill in the art will recognize that the design of recombinant cytokine receptors tethered to their cognate cytokines can include all or in part a flexible linker, such that the linker includes a flexible linker portion and one or more portions that impart a less flexible structure, providing the desired recombinant cytokine receptor structure.

[0086] In some embodiments, the linker between the cytokine and the recombinant cytokine receptor is a stable linker. In some embodiments, the linker between the cytokine and the recombinant cytokine receptor is not cleavable by proteases.

[0087] II. Cells The present disclosure provides an adoptive cell immunotherapy composition comprising a genetically modified cell preparation (e.g., a genetically modified immune cell preparation, e.g., lymphocytes) described herein. These cells are, for example, pluripotent cells (such as hematopoietic stem cells), various progenitor or precursor cells of the hematopoietic lineage, and various immune cells (e.g., human autologous cells, allogeneic T cells, natural killer (NK) cells, dendritic cells, or B cells). These cells can also be pluripotent stem cells (PSCs) (such as human embryonic stem cells and induced PSCs) and can be used for the generation of a therapeutic cell population. In some embodiments, pluripotent and multipotent cells are differentiated into the desired cell type in vitro before being implanted, injected, or infused into a patient.

[0088] In some alternatives, the cell preparation is a T lymphocyte cell preparation. In some embodiments, the T lymphocyte cell preparation comprises (i) a chimeric receptor comprising an extracellular antibody domain, a spacer region, a transmembrane domain, and an intracellular signaling domain of a T cell receptor specific for a ligand associated with a disease or disorder, and (ii) CD4+ T cells having a recombinant cytokine receptor described herein. In other alternatives, the adoptive cell immunotherapy composition comprises a CD8+ cytotoxic T lymphocyte cell preparation modified by a chimeric receptor that provides a cellular immune response, and the cytotoxic T lymphocyte cell preparation comprises (i) a chimeric receptor comprising an extracellular antibody domain, a spacer region, a transmembrane domain, and an intracellular signaling domain of a T cell receptor specific for a ligand associated with a disease or disorder, and (ii) CD8+ T cells having a recombinant cytokine receptor described herein. In some alternatives, the T cell population modified by the chimeric receptor of the present disclosure can persist in vivo for at least about 3 days or more. In some alternatives, each of these populations can be combined with each other or with one or more other cell types to provide a composition. In some alternatives, the genetically modified cell is a Treg cell.

[0089] Regulatory T (Treg) cells are involved in maintaining immunological self-tolerance and reducing harmful immune responses to both self-antigens and non-self (allo) antigens. Tregs include natural or inducible subtypes. Natural Tregs (nTregs) are cells that arise as a distinct cell lineage during development. Peripheral or inducible Tregs (iTregs) differentiate from conventional T cells. In some embodiments, CD4+ T cells that are not nTregs and not iTregs can be engineered into Tregs using the methods and compositions of the present disclosure. In some embodiments, CD4+ T cells are used and, using the methods and compositions of the present disclosure, Treg cells that express a recombinant cytokine receptor are produced.

[0090] In some embodiments, the cells that express the recombinant cytokine receptor of the present disclosure do not occur naturally. In some embodiments, the cells are immune cells. In some embodiments, the cells are lymphocytes. In some embodiments, the cells are T cells. In some embodiments, the cells are regulatory T cells (Tregs).

[0091] In some embodiments, the Tregs that express the recombinant cytokine receptor of the present disclosure do not occur naturally (not nTregs and / or not iTregs). In some embodiments, the cells express one or more markers characteristic of Tregs. Treg markers include high levels of CD25 (CD25+), low levels of CD127 (CD127lo), or both high CD25 and low CD127. The levels of CD25 and CD127 are compared, for example, to CD4+ T cells that are not Tregs. In some embodiments, the Treg cells that express the recombinant cytokine receptor have a high CD25, high CD4, and low CD127 phenotype.

[0092] In some embodiments, Tregs expressing a tethered IL9Rα / IL-2Rβ recombinant cytokine receptor are not naturally occurring (not nTregs and / or not iTregs). In some embodiments, the cells express one or more markers characteristic of Tregs. Treg markers include high levels of CD25 (CD25+), low levels of CD127 (CD127lo or CD127 low), or both high CD25 and low CD127. In some embodiments, Treg cells expressing a recombinant cytokine receptor have a high CD25, high CD4, and low CD127 phenotype.

[0093] In some embodiments, Tregs expressing a tethered IL9Rα / IL2Rβ recombinant cytokine receptor survive in the absence of exogenous cytokines (e.g., IL-2). In some embodiments, Tregs expressing a tethered IL9Rα / IL2Rβ recombinant cytokine receptor proliferate in the absence of exogenous cytokines (e.g., IL-2). In some embodiments, Tregs expressing a tethered IL9Rα / IL2Rβ recombinant cytokine receptor proliferate in the absence of exogenous cytokines. In some embodiments, Tregs expressing a tethered IL9Rα / IL2Rβ recombinant cytokine receptor are transplanted into an individual (e.g., a rodent (such as a mouse) or a human). In some embodiments, the individual expresses IL-2. In some embodiments, Tregs expressing a tethered IL9Rα / IL2Rβ recombinant cytokine receptor survive and proliferate upon adoptive transfer into an individual (e.g., a rodent (such as a mouse) or a human, such as an individual expressing IL-2). In some embodiments, adoptively transferred Tregs expressing a tethered IL9Rα / IL2Rβ recombinant cytokine receptor prevent, treat, alleviate, or otherwise reduce the severity of a disease such as an autoimmune disease (e.g., graft-versus-host disease).

[0094] Cells expressing recombinant cytokine receptors are also provided herein. In some embodiments, the recombinant cytokine receptor comprises an intracellular IL-2 receptor β-chain domain, a transmembrane domain, and an extracellular domain that binds to a cytokine other than IL-2. In some embodiments, the recombinant cytokine receptor comprises an extracellular domain selected from the group consisting of an IL-4 extracellular domain, an IL-7 extracellular domain, an IL-9 extracellular domain, and an IL-21 extracellular domain. In some embodiments, the cytokine is tethered to the recombinant cytokine receptor. In some embodiments, the cytokine is not IL-2.

[0095] In some embodiments, the cells express one or more proteins associated with a Treg phenotype. In some embodiments, the cells express FOXP3. FOXP3 plays an important role in the development and function of Treg cells (see Yagi et al. 2004, Int Immunol. 16(11):1643-56; Sadlon et al. 2018, Clin Transl Immunology 7(2):e1011). FOXP3 is first expressed during T cell expansion, but subsequently there is a loss of FOXP3 expression after polyclonal stimulation. This is in contrast to Tregs, in which FOXP3 expression increases and is maintained for a long time. The expression level of FOXP can be assayed by conventional methods (such as Western blot, flow cytometry, or ELISA). The expression level can also be assayed by analysis of techniques using mRNA (such as RT-qPCR). In some embodiments, the expression of FOXP3 is increased compared to non-transduced cells. In some embodiments, the expression of FOXP3 is increased compared to cells without the recombinant cytokine receptor.

[0096] In some embodiments, FOXP3 expression is increased by at least about 2-fold, at least about 3-fold, at least about 4-fold, at least about 5-fold, or more as compared to cells without the recombinant cytokine receptor. In some embodiments, FOXP3 expression is increased by at least about 1.1-fold, at least about 1.5-fold, at least about 2-fold, at least about 3-fold, at least about 4-fold, at least about 5-fold, or more as compared to cells not transduced by the recombinant receptor. In some embodiments, the expression of FOXP3 is increased in Tregs transduced with the recombinant cytokine receptor as compared to non-transduced cells cultured without one or more cytokines. In some embodiments, the expression of FOXP3 is increased in Tregs transduced with the recombinant cytokine receptor as compared to non-transduced cells cultured with cytokines other than IL-2. In some embodiments, FOXP3 expression is maintained at approximately the same level as the day of the highest FOXP3 expression after transduction with the recombinant cytokine receptor.

[0097] In some embodiments, the Treg cells are CD4 positive (CD4+). In some embodiments, the cells are CD4+ / CD25+. In some embodiments, the cells are CD4+ / CD127 low (i.e., CD4+ / CD127lo). In some embodiments, the cells are CD4+ / CD25+ / CD127 low (i.e., CD4+ / CD25+ / CD127lo).

[0098] Tregs can be characterized by the expression of CD25+. In some embodiments, the cells are Treg cells that are CD25+. In some embodiments, the cells are CD4+ / CD25+. In some embodiments, the cells are CD25+ / CD127 low (i.e., CD25+ / CD127lo). In some embodiments, the cells are CD4+ / CD25+ / CD127 low (i.e., CD4+ / CD25+ / CD127lo).

[0099] In some embodiments, the cells express low levels of CD127 (CD127lo). In some embodiments, the cells are CD4+ / CD127 low (i.e., CD4+ / CD127lo). In some embodiments, the cells are CD25+ / CD127 low (i.e., CD25+ / CD127lo). In some embodiments, the cells are CD4+ / CD25+ / CD127 low (i.e., CD4+ / CD25+ / CD127lo). In some embodiments, the cells transduced with the recombinant cytokine receptor provided herein maintain a CD127 low (CD127lo) state upon transduction.

[0100] HELIOS is a transcription factor expressed in Tregs. In some embodiments, the Treg cells of the disclosure express HELIOS. In some embodiments, the expression of HELIOS is increased compared to conventional T cells. In some embodiments, the expression of HELIOS is detectable compared to conventional T cells. The expression level of HELIOS can be assayed by conventional methods (such as Western blot, flow cytometry, or ELISA). The expression level can also be assayed by analysis of techniques using mRNA (such as RT-qPCR). In some embodiments, the HELIOS expression is increased by at least 2-fold, at least 3-fold, at least 4-fold, at least 5-fold, at least 6-fold, at least 7-fold, at least 8-fold, at least 9-fold, at least 10-fold, at least 20-fold, or more compared to conventional T cells. In some embodiments, the expression of HELIOS is increased in Tregs transduced with the recombinant cytokine receptor compared to untransduced cells cultured without cytokines. In some embodiments, Tregs transduced with the recombinant cytokine receptor maintain HELIOS expression after transduction.

[0101] In some embodiments, the cells express or secrete low levels of IL-2. In some embodiments, the expression or secretion of IL-2 in the transduced Treg cells is decreased compared to conventional T cells. In some embodiments, the expression or secretion of IL-2 is decreased in the transduced Treg cells by recombinant cytokine receptors compared to untransduced cells cultured without cytokines. In some embodiments, the expression or secretion of IL-2 is decreased in the transduced Treg cells by recombinant cytokine receptors compared to untransduced cells.

[0102] In some embodiments, the cells have an immunosuppressive phenotype. In one embodiment, the cells produce an immunosuppressive effect in an individual having an immune-related disorder. In some embodiments, the individual is human. In some embodiments, the individual expresses IL-2. In some embodiments, the cells are autologous to the individual.

[0103] In some embodiments, the cells suppress, block, or inhibit graft-versus-host disease in an individual. In one embodiment, the cells suppress, block, or inhibit an immune-related disorder in an individual. In some embodiments, the cells are administered before the onset of the immune-related disorder. In some embodiments, the individual is human. In some embodiments, the individual expresses IL-2. In some embodiments, the cells are autologous to the individual. In some embodiments, the cells are allogeneic to the individual.

[0104] Methods for measuring markers used to characterize Treg cells will readily be apparent to those skilled in the art. For example, a population of Tregs, or T cells including Tregs, can be cultured using the methods described herein. Following culture, the Tregs can be collected and stained using antibodies against Treg markers such as FOXP3 (labeled, e.g., by PE), CD25 (labeled, e.g., by APC), and CD127 (labeled, e.g., by BV421), and expression can be analyzed using fluorescence-activated flow cytometry (FACS) or fluorescence microscopy. Gene expression can be measured by methods such as RT-qPCR.

[0105] III. Preparation Methods The recombinant cytokine receptors described herein can be prepared by any of the protein expression methods known in the art and introduced into host cells (e.g., Treg cells). See, for example, Examples 1-3. The DNA sequences encoding the recombinant cytokine receptors can be synthesized. After obtaining such sequences, they are cloned into a suitable expression vector and then introduced into a suitable host cell. The transfected host cells are recovered and cultured to obtain viable host cells that stably express the recombinant cytokine receptors of the invention.

[0106] In some embodiments, the present application provides an isolated nucleic acid encoding one or more of any one polypeptide of a recombinant cytokine receptor. The isolated nucleic acid can be DNA. In some embodiments, the isolated nucleic acid is inserted into a vector (such as an expression vector, a viral vector, or a cloning vector). For the expression of the nucleic acid, the vector can be introduced into a host cell to enable the expression of the nucleic acid within the host cell. The expression vector contains various elements for the control of expression, including but not limited to a promoter sequence, a transcription initiation sequence, an enhancer sequence, a selectable marker, and a signal sequence. These elements can be appropriately selected by those skilled in the art. For example, the promoter sequence can be selected to enhance the transcription of the polynucleotide in the vector. Suitable promoter sequences include but are not limited to the T7 promoter, the T3 promoter, the SP6 promoter, the β-actin promoter, the EF1a promoter, the CMV promoter, and the SV40 promoter. The enhancer sequence can be selected to promote the transcription of the nucleic acid. The selectable marker is selected to enable the selection of host cells into which the vector has been inserted from those that have not, and for example, the selectable marker can be a transmembrane gene such as EGFR that can be identified by flow cytometry and FACS analysis.

[0107] In some embodiments, a nucleic acid (e.g., a vector such as an expression vector, a viral vector, or a cloning vector) expresses an antigen receptor and / or another additional polypeptide. In some embodiments, a nucleic acid (e.g., a vector such as an expression vector, a viral vector, or a cloning vector) encodes an antigen receptor and / or another additional polypeptide. The antigen receptor can be, for example, an antibody, an engineered antibody (such as scFv), a CAR, an engineered TCR, a TCR mimetic or chimeric antibody T cell receptor, or a chimeric signaling receptor. The antigen receptor can target an antigen of interest (e.g., a tumor antigen, a pathogen antigen, or a target at an inflammatory site). The antigen can be AFP (alpha-fetoprotein), αvβ6 or another integrin, BCMA, B7-H3, B7-H6, CA9 (carbonic anhydrase 9), CCL-1 (C-C motif chemokine ligand 1), CD5, CD19, CD20, CD21, CD22, CD23, CD24, CD30, CD33, CD38, CD40, CD44, CD44v6, CD44v7 / 8, CD45, CD47, CD56, CD66e, CD70, CD74, CD79a, CD79b, CD98, CD123, CD138, CD171, CD352, CEA (carcinoembryonic antigen), claudin, c-MET, DLL3 (delta-like protein 3), DLL4, ENPP3 (ectonucleotide pyrophosphatase / phosphodiesterase family member 3), EpCAM, EPG-2 (epithelial glycoprotein 2), EPG-40, ephrin B2, EPHa2 (ephrine receptor A2), ERBB dimer, estrogen receptor, ETBR (endothelin B receptor), FAP-α (fibroblast activation protein α), fetal AchR (fetal acetylcholine receptor), FBP (folate-binding protein), FCRL5, FR-α (folate receptor α), GCC (guanylyl cyclase C), GD2, GD3, GPC2 (glypican-2), GPC3, gp100 (glycoprotein 100), GPNMB (glycoprotein NMB), GPRC5D (G protein-coupled receptor 5D), HER2, HER3, HER4, hepatitis B surface antigen, HLA-A1 (human leukocyte antigen Al), HLA-A2 (human leukocyte antigen A2),HMW-MAA (Human high molecular weight melanoma-associated antigen), IGF1R (Insulin-like growth factor 1 receptor), Igκ, Igλ, IL-22Ra (IL-22 receptor α), IL-13Ra2 (IL-13 receptor α2), KDR (Kinase insert domain receptor), LI cell adhesion molecule (LI-CAM), Liv-1, LRRC8A (Leucine-rich repeat-containing 8 family member A), Lewis Y, Melanoma-associated antigen (MAGE)-A1, MAGE-A3, MAGE-A6, MART-1 (Melan-A), Mouse cytomegalovirus (MCMV), MCSP (Melanoma-associated chondroitin sulfate proteoglycan), Mesothelin, Mucin 1 (MUC1), MUC16, MHC / peptide complex (e.g., HLA-A complexed with peptides derived from AFP, KRAS, NY-ESO, MAGE-A, and WT1), NCAM (Neural cell adhesion molecule), Necl-4, NKG2D (Natural killer group 2 member D) ligand, NY-ESO, Tumor fetal antigen, PD-1, PD-L1, PRAME (Preferentially expressed antigen of melanoma), Progesterone receptor, PSA (Prostate-specific antigen), PSCA (Prostate stem cell antigen), PSMA (Prostate-specific membrane antigen), ROR1, ROR2, SIRPα (Signal regulatory protein α), SLIT, SLITRK6 (NTRK-like protein 6), STEAP1 (Six-transmembrane epithelial antigen of the prostate 1), Survivin, TAG72 (Tumor-associated glycoprotein 72), TPBG (Trophoblast glycoprotein), Trop-2, VEGFR1 (Vascular endothelial growth factor receptor 1), VEGFR2, and antigens from HIV, HBV, HCV, HPV, and other pathogens can be listed without limitation.,

[0108] In some embodiments, constructs comprising a recombinant cytokine receptor described herein include a cleavable linker. In some embodiments, the cleavable linker is a 2A polypeptide. In some embodiments, a construct comprising a recombinant cytokine receptor includes a nucleotide sequence encoding a P2A linker between the nucleotide sequence encoding the recombinant cytokine receptor and a marker (such as EGFR). In some embodiments, 2A-like sequences or "peptide bond skipping" 2A sequences are derived from, for example, different viruses (such as Thosea asigna). These sequences are sometimes also known as "peptide skip sequences". When this type of sequence is placed within a cis - tron between two polypeptides intended to be separated, the ribosome appears to skip a peptide bond. In the case of the Thosea asigna sequence, the bond between the Gly and Pro amino acids at the carboxy - terminal "P - G - P" is omitted. This can result in 2 - 3 polypeptides remaining (such as an inducible chimeric apoptosis - promoting polypeptide and a chimeric antigen receptor, or for example, a marker polypeptide and an inducible chimeric apoptosis - promoting polypeptide). When this sequence is used, the polypeptide encoded 5' of the 2A sequence can end with an additional amino acid at the carboxy - terminus (including the Gly residue and any upstream residues in the 2A sequence). The peptide encoded 3' of the 2A sequence can end with an additional amino acid at the amino - terminus (including the Pro residue and any downstream residues following the 2A sequence). In some embodiments, the cleavable linker is a 2A polypeptide derived from porcine teschovirus - 1 (P2A). In some embodiments, the 2A co - translational sequence is a 2A - like sequence. In some embodiments, the 2A co - translational sequence is T2A (Thosea asigna virus 2A), F2A (foot - and - mouth disease virus 2A), P2A (porcine teschovirus - 1 2A), BmCPV 2A (cytoplasmic polyhedrosis virus 2A), BmIFV 2A (B. mori infectious flacherie virus 2A), or E2A (equine rhinitis A virus 2A).In some embodiments, the 2A co-translational sequence is T2A-GSG, F2A-GSG, P2A-GSG, or E2A-GSG. In some embodiments, the co-translational sequence is such that 2A is selected from the group consisting of T2A, P2A, and F2A. By "cleavable linker" is meant that the linker is cleaved by any means, including for example non-enzymatic means (such as peptide skipping) or enzymatic methods (see, for example, Donnelly, M. L. 2001, J. Gen. Virol. 82:1013-25, which is incorporated herein by reference in its entirety). In certain embodiments, P2A comprises (or consists of) the sequences disclosed herein. In certain embodiments, P2A comprises (or consists of) the sequences disclosed herein (such as the sequences disclosed in the following examples).

[0109] In certain embodiments, the 2A linker comprises the amino acid sequence of SEQ ID NO: 10 (SGATNFSLLKQAGDVEENPGP). In certain embodiments, the 2A linker further comprises the GSG amino acid sequence at the amino terminus of the polypeptide, and in other embodiments, the 2A linker comprises the GSGPR (SEQ ID NO: 28) amino acid sequence at the amino terminus of the polypeptide. Thus, by the term "2A" sequence, the term can refer to the 2A sequences in the examples described herein, or can also refer to the 2A sequences listed herein that further comprise the GSG or GSGPR (SEQ ID NO: 28) sequence at the amino terminus of the linker.

[0110] In some embodiments, a host cell (e.g., a Treg cell) contains the vector described above. The vector can be introduced into the cell using any suitable method known in the art, including but not limited to DEAE dextran-mediated delivery, calcium phosphate precipitation, cationic lipid-mediated delivery, liposome-mediated transfection, electroporation, microprojectile bombardment, receptor-mediated gene delivery, and delivery mediated by polylysine, histone, chitosan, and peptides. Standard methods for transducing cells for expression of a vector of interest are well known in the art. In some embodiments, the host cell contains a vector comprising an isolated nucleic acid encoding a recombinant cytokine receptor.

[0111] In some embodiments, the present application provides a method of expressing any of the recombinant cytokine receptors described herein, comprising culturing an isolated host cell containing a vector and recovering the recombinant cytokine receptor from the cell culture. The isolated host cell is cultured under conditions that allow expression of the isolated nucleic acid inserted into the vector. Suitable conditions for expression of a polynucleotide can include, without limitation, a suitable medium, a suitable density of host cells in the culture medium, the presence of necessary nutrients, the presence of supplemental factors, a suitable temperature and humidity, and the absence of microbial contaminants. One of ordinary skill in the art can select suitable conditions as appropriate for the purpose of expression.

[0112] 1. Vector In certain aspects, the present disclosure provides a nucleic acid molecule encoding any one or more of the recombinant cytokine receptors described herein. Such nucleic acid molecules can be inserted into a vector (e.g., a viral vector or a non-viral plasmid vector) appropriate for introduction into a host regulatory T cell (Treg) of interest.

[0113] As used herein, the terms "recombinant" or "non-natural" refer to an organism, microorganism, cell, nucleic acid molecule, or vector that contains at least one genetic alteration or has been modified by the introduction of an exogenous nucleic acid molecule, and such alteration or modification has been introduced by genetic engineering. Genetic alterations include, for example, modifications that introduce an expressible nucleic acid molecule encoding a protein, fusion protein, enzyme, the addition, deletion, substitution of other nucleic acid molecules, or other functional disruption of the cell's genetic material. Additional modifications include, for example, non-coding regulatory regions where the modification alters the expression of a gene or operon. In some embodiments, cells obtained from a subject (such as regulatory T cells (Tregs)) are converted into non-natural or recombinant regulatory T cells (Tregs) (e.g., non-natural or recombinant Tregs) by the introduction of a nucleic acid encoding a recombinant cytokine receptor described herein, whereby the cells can express the recombinant cytokine receptor located on the cell surface.

[0114] Vectors encoding the core virus are referred to herein as "viral vectors". There are a number of available viral vectors suitable for use with the compositions of the present disclosure, including those identified for human gene therapy applications (see Pfeifer and Verma, Ann. Rev. Genomics Hum. Genet. 2:177, 2001). Suitable viral vectors include vectors based on RNA viruses (such as retrovirus-derived vectors, e.g., vectors derived from Moloney murine leukemia virus (MLV)), and more complex retrovirus-derived vectors (such as lentivirus-derived vectors). Vectors derived from HIV-1 belong to this category. Other examples include lentiviral vectors derived from HIV-2, FIV, equine infectious anemia virus, SIV, and maedi-visna virus (ovine lentivirus). Methods of using retroviral and lentiviral viral vectors and packaging cells for transducing mammalian host Tregs with virus particles containing a chimeric antigen receptor transgene are known in the art, e.g., U.S. Patent No. 8,119,772; Walchli et al., PLoS One 6:327930, 2011; Zhao et al., J. Immunol. 174:4415, 2005; Engels et al., Hum. Gene Ther. 14:1155, 2003; Frecha et al., Mol. Ther. 18:1748, 2010; and Verhoeyen et al., Methods Mol. Biol. 506:97, 2009, which have been previously described. Retroviral and lentiviral vector constructs and expression systems are also commercially available.

[0115] In some embodiments, the viral vector is used to introduce a non-endogenous nucleic acid sequence encoding a recombinant cytokine receptor. The viral vector can be a retroviral vector or a lentiviral vector. The viral vector can also include a nucleic acid sequence encoding a marker for transduction. Transduction markers for viral vectors are known in the art and include selectable markers (which can confer drug resistance) or detectable markers (such as fluorescent markers or cell surface proteins that can be detected by methods such as flow cytometry). In certain embodiments, the viral vector further includes a genetic marker for transduction that includes green fluorescent protein, the extracellular domain of human CD2, or truncated human EGFR (huEGFRt; see Wang et al., Blood 118:1255, 2011). When the viral vector genome includes multiple nucleic acid sequences that are expressed as separate transcripts in a host cell (such as a T cell, e.g., Treg), the viral vector can also include additional sequences between two (or more) transcripts that enable bicistronic or polycistronic expression. Examples of such sequences used in viral vectors include internal ribosome entry sites (IRES), furin cleavage sites, viral 2A peptides, or any combination thereof.

[0116] Other vectors can also be used for polynucleotide delivery, such as DNA viral vectors, for example, vectors based on adenovirus and vectors based on adeno-associated virus (AAV); vectors derived from herpes simplex virus (HSV) (including amplicon vectors, replication-deficient HSV, and attenuated HSV) (Krisky et al., Gene Ther. 5:1517, 1998).

[0117] Other vectors recently developed for use in gene therapy can also be used by the compositions and methods of the present disclosure. Such vectors include those derived from baculovirus and α-virus (Jolly, D J. 1999. Emerging Viral Vectors. pp 209-40 in Friedmann T. ed. The Development of Human Gene Therapy. New York: Cold Spring Harbor Lab), or plasmid vectors (such as sleeping beauty or other transposon vectors).

[0118] In certain embodiments, hematopoietic progenitor cells or embryonic stem cells are modified to contain a non-endogenous nucleic acid molecule encoding the recombinant cytokine receptor of the present disclosure. Hematopoietic progenitor cells can be derived from or originate from fetal liver tissue, bone marrow, umbilical cord blood, or peripheral blood, and can include induced pluripotent stem cells. Hematopoietic progenitor cells can be from humans, mice, rats, or other mammals.

[0119] In certain embodiments, the host cells transfected to express the recombinant cytokine receptor of the present disclosure are functional Tregs.

[0120] One or more growth factor cytokines that enhance the proliferation of Tregs expressing the recombinant cytokine receptor of the present disclosure can be added to the culture. The cytokine can be human or non-human. Exemplary growth factor cytokines that can be used to enhance Treg proliferation include IL-2, TGFβ, or the like.

[0121] IV. Methods for Amplifying and Culturing Cells In some embodiments, the cells transfected to express the recombinant cytokine receptor of the present disclosure are eukaryotic cells. In some embodiments, the cells transfected to express the recombinant cytokine receptor of the present disclosure are human cells. In some embodiments, the cells transfected to express the recombinant cytokine receptor of the present disclosure are human embryonic kidney (HEK) cells. In certain embodiments, the cells transfected to express the recombinant cytokine receptor of the present disclosure are immune cells. In certain embodiments, the cells transfected to express the recombinant cytokine receptor of the present disclosure are T cells. In certain embodiments, the cells transfected to express the recombinant cytokine receptor of the present disclosure are functional Tregs.

[0122] In some embodiments, Treg cells are isolated from peripheral blood mononuclear (PBMC) cells. In some embodiments, Treg cells are isolated from PBMCs using density gradient centrifugation. In some embodiments, Treg cells are enriched by positive selection. In some embodiments, Treg cells are enriched by positive selection for CD25+. In some embodiments, Treg cells are enriched by positive selection for CD4+CD25+CD127lo cells. In some embodiments, the enrichment occurs by FACS. In some embodiments, Tregs are stimulated with anti-CD3 antibody and / or anti-CD28 antibody on day 0 after positive selection. In some embodiments, Tregs are restimulated with anti-CD3 antibody and / or anti-CD28 antibody on day 9 of culture after positive selection.

[0123] One or more growth factor cytokines that enhance the proliferation of Tregs expressing the recombinant cytokine receptor of the present disclosure can be added to the culture. The cytokine can be a human or non-human cytokine. Exemplary growth factor cytokines that can be used to enhance Treg proliferation include IL-4, IL-7, IL-9, IL-21, or the like. In some embodiments, the cytokine is added to the medium prior to selection. In some embodiments, the cytokine is added to the medium after cell isolation. In some embodiments, the cytokine is added to the medium for approximately 15 to 60 minutes. In some embodiments, the cytokine is added to the medium for approximately 40 minutes. In some embodiments, the cytokine is added to the cell culture approximately every 12 to 60 (such as about 24 to about 48) hours. In some embodiments, the cytokine is added to the medium for the duration of the culture. In some embodiments, the cells are treated with the cytokine and cultured at a cell density of approximately 250,000 to 300,000 cells / mL. In some embodiments, the concentration of the cytokine during cytokine treatment is approximately 0.15 ng / mL to 100 ng / mL. In some embodiments, the concentration of IL-2 during cytokine treatment is approximately 300 IU / mL. In some embodiments, the concentration of IL-2 during cytokine treatment is 300 IU / mL.

[0124] In some embodiments, the cells expressing the recombinant cytokine receptor of the present disclosure are cultured for a time sufficient to induce proliferation or differentiation. The cells are generally maintained in culture for about 3 to about 5 days, about 4 to about 10 days, about 5 to about 20 days, about 10 to about 23 days, about 15 to about 30 days, or about 23 to about 30 days. It will be appreciated that the cells can be maintained for an appropriate amount of time required to achieve the desired result (i.e., the desired cell composition or level of proliferation). For example, to generate a cell composition primarily containing Tregs, the cells can be maintained in culture for about 30 days.

[0125] In some embodiments, the method further comprises detecting one or more Treg markers provided herein. In some embodiments, the method further comprises detecting IL-2 signaling. In some embodiments, the method further comprises detecting phosphorylated STAT-5.

[0126] In some embodiments, the suppressive activity of the transduced Tregs increases upon transduction with the recombinant cytokine receptor provided herein. In some embodiments, the rate of division of conventional (e.g., cytotoxic) T cells is decreased by the transduced Treg cells provided herein. In some embodiments, the rate of division of CD4+ T cells is decreased by the transduced Treg cells provided herein as compared to CD4+ T cells cultured without Tregs. In some embodiments, the rate of division of CD8+ T cells is decreased by the transduced Treg cells provided herein as compared to CD8+ T cells cultured without Tregs. In some embodiments, the activity of cytotoxic T cells is decreased.

[0127] In some embodiments, provided herein is a method of amplifying transduced Treg cells in the absence of IL-2, comprising culturing cells that express the recombinant receptor provided herein. In some embodiments, the cells are cultured in a culture medium containing cytokines other than IL-2. In some embodiments, the cells are cultured in a cell culture medium containing a cytokine that binds to the ED of the recombinant cytokine receptor. In some embodiments, the cells are cultured in a medium containing 2, 3, 4, 5, or more cytokines.

[0128] V. Pharmaceutical Compositions, Manufactured Articles, and Kits Further provided by this application is a pharmaceutical composition comprising cells (e.g., T cells such as Treg cells) that contain the recombinant cytokine receptor described herein.

[0129] The pharmaceutical composition may be suitable for various modes of administration described herein (including, for example, systemic or local administration). In some embodiments, the pharmaceutical composition is formulated for intravenous administration.

[0130] Pharmaceutical compositions used for in vivo administration are generally formulated in full compliance with all Good Manufacturing Practice (GMP) regulations of the U.S. Food and Drug Administration, being sterile and substantially isotonic. Sterilization is readily achieved by filtration through a sterile filtration membrane (e.g., filtration of any solution described herein used for reconstituting, storing Treg cells, etc., or filtration of the pharmaceutical compositions described herein). In some embodiments, the composition is pathogen-free. For injection, the pharmaceutical composition may be in the form of a solution, for example, in a physiologically compatible buffer (Hanks' solution or Ringer's solution).

[0131] In some embodiments, the pharmaceutical composition is suitable for administration to humans. In some embodiments, the pharmaceutical composition is suitable for administration to rodents (e.g., mice, rats) or non-human primates (e.g., cynomolgus monkeys). In some embodiments, the pharmaceutical composition is cryopreserved.

[0132] This application also provides a kit comprising a composition (such as a pharmaceutical composition) described herein, and may further comprise instructions (plural) for a method of using the composition (such as uses described herein). The kits described herein may further comprise other materials desired from a commercial and user perspective (including other buffers, diluents, filters, needles, syringes, and package inserts with instructions for performing any method described herein).

[0133] VI. Method of Treatment In some embodiments, provided herein is a method of treating an immune-related disorder, comprising administering a cell (e.g., a Treg cell) comprising a recombinant cytokine receptor provided herein. In some embodiments, the recombinant cytokine receptor comprises an extracellular domain (ED) and a transmembrane domain (TD), and an intracellular domain (ID) of interleukin-2 receptor beta (IL-2Rβ), wherein the ED does not bind to exogenous IL-2. In some embodiments, the recombinant cytokine receptor used in the method of treating an immune-related disorder is capable of signaling in the absence of exogenous IL-2. In some embodiments, the recombinant cytokine receptor used in the method of treating an immune-related disorder comprises an extracellular domain (ED), a transmembrane domain (TD), and an intracellular domain (ID). In some embodiments, the ED binds to a cytokine other than IL-2. Thus, in some embodiments, provided is a method of treating an immune-related disorder, comprising administering a cell (e.g., a Treg cell) comprising a recombinant cytokine receptor comprising: (I) an extracellular domain (ED) of IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (II) IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (III) an intracellular domain (ID) of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence set forth in SEQ ID NOs: 1-5. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NOs: 1-5. In some embodiments, the cell is an immune cell. In some embodiments, the cell is a lymphocyte. In some embodiments, the cell is a T cell. In some embodiments, the cell is a Treg.

[0134] In some embodiments, a method of treating an immune-related disorder involves administering cells (such as Treg cells, such as any of the Treg cells described herein) comprising a recombinant cytokine receptor comprising an ED of IL-4Rα. In some embodiments, the method involves transducing cells (such as Treg cells) with a vector encoding the recombinant cytokine receptor. In some embodiments, the cells are autologous to the individual being treated. In some embodiments, the individual being treated expresses IL-2. In some embodiments, the ED comprises the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the ED comprises an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to SEQ ID NO: 11. In some embodiments, a method of treating an immune disorder involves transducing cells (such as Treg cells) with a recombinant cytokine receptor that, in the N-terminal to C-terminal direction, comprises (I) an ED of IL-4Rα; (II) a TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (III) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the N-terminal to C-terminal direction, comprises (I) an ED of IL-4Rα; (II) a TD of IL-4Rα or IL-2Rβ; (III) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 1, and the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11.In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence shown in SEQ ID NO: 1 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, and the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 11 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the cell is an immune cell. In some embodiments, the cell is a lymphocyte. In some embodiments, the cell is a T cell. In some embodiments, the cell is a Treg.

[0135] In some embodiments, a method of treating an immune-related disorder comprises administering a cell (e.g., a Treg cell such as any of the Treg cells described herein) comprising a recombinant cytokine receptor comprising an ED of IL-7Rα. In some embodiments, the method comprises transducing a cell (e.g., a Treg cell) with a vector encoding the recombinant cytokine receptor. In some embodiments, the cell is autologous to the individual being treated. In some embodiments, the individual being treated expresses IL-2. In some embodiments, the IL-7Rα ED comprises the amino acid sequence set forth in SEQ ID NO: 12. In some embodiments, the ED comprises an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to SEQ ID NO: 12. In some embodiments, a method of treating an immune-related disorder comprises administering a cell (e.g., a Treg cell) comprising a recombinant cytokine receptor comprising, in the N-terminal to C-terminal direction, (I) an ED of IL-7Rα; (II) a TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (III) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an ED of IL-7Rα; (II) a TD of IL-7Rα or IL-2Rβ; (III) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 2, and the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 12.In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence shown in SEQ ID NO: 2 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto, and the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 12 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto. In some embodiments, the cell is an immune cell. In some embodiments, the cell is a lymphocyte. In some embodiments, the cell is a T cell. In some embodiments, the cell is a Treg.

[0136] In some embodiments, a method of treating an immune-related disorder comprises administering a cell (e.g., a Treg cell such as any of the Treg cells described herein) comprising a recombinant cytokine receptor comprising an ED of IL-9Rα. In some embodiments, the method comprises transducing a cell (e.g., a Treg cell) with a vector encoding the recombinant cytokine receptor. In some embodiments, the cell is autologous to the individual being treated. In some embodiments, the individual being treated expresses IL-2. In some embodiments, the IL-9Rα ED comprises the amino acid sequence set forth in SEQ ID NO: 13. In some embodiments, the ED comprises an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to SEQ ID NO: 13. In some embodiments, a method of treating an immune-related disorder comprises administering a cell (e.g., a Treg cell) comprising a recombinant cytokine receptor that, in the N-terminal to C-terminal direction, comprises (I) an ED of IL-9Rα; (II) a TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (III) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an ED of IL-9Rα; (II) a TD of IL-9Rα or IL-2Rβ; and (III) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 3 or 5, and the recombinant cytokine receptor comprises an ED having an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence set forth in SEQ ID NO: 13.In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence shown in SEQ ID NO: 3 or 5 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto, and the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 13 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto. In some embodiments, the cell is an immune cell. In some embodiments, the cell is a lymphocyte. In some embodiments, the cell is a T cell. In some embodiments, the cell is a Treg.

[0137] In some embodiments, a method of treating an immune-related disorder comprises using a recombinant cytokine receptor comprising an ED of IL-21Rα. In some embodiments, the method comprises transducing a cell (e.g., a Treg cell such as any of the Treg cells described herein) with a vector encoding the recombinant cytokine receptor. In some embodiments, the cell is autologous to the individual being treated. In some embodiments, the individual being treated expresses IL-2. In some embodiments, the IL-21Rα ED comprises the amino acid sequence set forth in SEQ ID NO: 14. In some embodiments, the ED comprises an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to SEQ ID NO: 14. In some embodiments, a method of treating an immune-related disorder comprises using a recombinant cytokine receptor that, in the N-terminal to C-terminal direction, comprises (I) an ED of IL-21Rα; (II) a TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; (III) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor, in the N-terminal to C-terminal direction, comprises (I) an ED of IL-21Rα; (II) a TD of IL-21Rα or IL-2Rβ; (III) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 4, and the recombinant cytokine receptor comprises an ED having an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to the amino acid sequence set forth in SEQ ID NO: 14.In some embodiments, the recombinant cytokine receptor comprises an amino acid sequence shown in SEQ ID NO: 4 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity, and the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 14 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity. In some embodiments, the cell is an immune cell. In some embodiments, the cell is a lymphocyte. In some embodiments, the cell is a T cell. In some embodiments, the cell is a Treg.

[0138] In some embodiments, a method of treating an immune-related disorder comprises administering a cell (e.g., a Treg cell such as any of the Treg cells described herein) comprising a recombinant cytokine receptor comprising an ED of IL-4Rα. In some embodiments, the method comprises transducing a cell (e.g., a Treg cell) with a vector encoding the recombinant cytokine receptor. In some embodiments, the cell is autologous to the individual being treated. In some embodiments, the individual being treated expresses IL-2. In some embodiments, the ED comprises the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the ED comprises an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to SEQ ID NO: 11. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-4 cytokine, (II) an ED of IL-4Rα; (III) a TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (IV) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-4 cytokine; (II) an ED of IL-4Rα; (III) a TD of IL-4Rα or IL-2Rβ; and (IV) an ID of IL-2Rβ. In some embodiments, the IL-4 cytokine is tethered to the ED of IL-4Rα by a polypeptide linker.In some embodiments, the recombinant cytokine receptor to which IL-4 is tethered comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 6, the recombinant cytokine receptor comprises an IL-4 cytokine having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 22, and the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the recombinant cytokine receptor to which IL-4 is tethered comprises an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 6, the recombinant cytokine receptor comprises an IL-4 cytokine having an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 22, and the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity to the amino acid sequence set forth in SEQ ID NO: 11. In some embodiments, the cell is an immune cell. In some embodiments, the cell is a lymphocyte. In some embodiments, the cell is a T cell. In some embodiments, the cell is a Treg.

[0139] In some embodiments, a method of treating an immune-related disorder comprises administering a cell (e.g., a Treg cell such as any of the Treg cells described herein) comprising a recombinant cytokine receptor comprising an ED of IL-7Rα. In some embodiments, the method comprises transducing a cell (e.g., a Treg cell) with a vector encoding the recombinant cytokine receptor. In some embodiments, the cell is autologous to the individual being treated. In some embodiments, the individual being treated expresses IL-2. In some embodiments, the IL-7Rα ED comprises the amino acid sequence set forth in SEQ ID NO: 12. In some embodiments, the ED comprises an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to SEQ ID NO: 12. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-7 cytokine, (II) an ED of IL-7Rα; (III) a TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (IV) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-7 cytokine; (II) an ED of IL-7Rα; (III) a TD of IL-7Rα or IL-2Rβ; and (IV) an ID of IL-2Rβ. In some embodiments, the IL-7 cytokine is tethered to the ED of IL-7Rα by a polypeptide linker.In some embodiments, the recombinant cytokine receptor to which IL-7 is tethered comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 7, and the recombinant cytokine receptor comprises an IL-7 cytokine having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 23, and the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 12. In some embodiments, the recombinant cytokine receptor to which IL-7 is tethered comprises an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 7, and the recombinant cytokine receptor comprises an IL-7 cytokine having an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 23, and the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 12. In some embodiments, the cell is an immune cell. In some embodiments, the cell is a lymphocyte. In some embodiments, the cell is a T cell. In some embodiments, the cell is a Treg.

[0140] In some embodiments, a method of treating an immune-related disorder comprises administering a cell (e.g., a Treg cell such as any of the Treg cells described herein) comprising a recombinant cytokine receptor comprising an ED of IL-9Rα. In some embodiments, the method comprises transducing a cell (e.g., a Treg cell) with a vector encoding the recombinant cytokine receptor. In some embodiments, the cell is autologous to the individual being treated. In some embodiments, the individual being treated expresses IL-2. In some embodiments, the IL-9Rα ED comprises the amino acid sequence set forth in SEQ ID NO: 13. In some embodiments, the ED comprises an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to SEQ ID NO: 13. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-9 cytokine, (II) an ED of IL-9Rα; (III) a TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (IV) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-9 cytokine; (II) an ED of IL-9Rα; (III) a TD of IL-9Rα or IL-2Rβ; and (IV) an ID of IL-2Rβ. In some embodiments, the IL-9 cytokine is tethered to the ED of IL-9Rα by a polypeptide linker.In some embodiments, the recombinant cytokine receptor to which IL-9 is tethered comprises an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 8 or 15, the recombinant cytokine receptor comprises an IL-9 cytokine having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 24, and the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 13. In some embodiments, the recombinant cytokine receptor to which IL-9 is tethered comprises an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 8 or 15, the recombinant cytokine receptor comprises an IL-9 cytokine having an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 24, and the recombinant cytokine receptor comprises an ED having an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 13. In some embodiments, the cell is an immune cell. In some embodiments, the cell is a lymphocyte. In some embodiments, the cell is a T cell. In some embodiments, the cell is a Treg.

[0141] In some embodiments, a method of treating an immune-related disorder comprises administering a cell (e.g., a Treg cell such as any of the Treg cells described herein) comprising a recombinant cytokine receptor comprising an ED of IL-21Rα. In some embodiments, the method comprises transducing a cell (e.g., a Treg cell) with a vector encoding the recombinant cytokine receptor. In some embodiments, the cell is autologous to the individual being treated. In some embodiments, the individual being treated expresses IL-2. In some embodiments, the IL-21Rα ED comprises the amino acid sequence set forth in SEQ ID NO: 14. In some embodiments, the ED comprises an amino acid sequence that is at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% identical to SEQ ID NO: 14. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-21 cytokine, (II) an ED of IL-21Rα; (III) a TD of IL-2Rβ, IL-4Rα, IL-7Rα, IL-9Rα, or IL-21Rα; and (IV) an ID of IL-2Rβ. In some embodiments, the recombinant cytokine receptor comprises, in the N-terminal to C-terminal direction, (I) an IL-21 cytokine; (II) an ED of IL-21Rα; (III) a TD of IL-21Rα or IL-2Rβ; and (IV) an ID of IL-2Rβ.In some embodiments, the recombinant cytokine receptor with IL-21 tethered thereto comprises an amino acid sequence shown in SEQ ID NO: 9 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto, the recombinant cytokine receptor comprises an IL-21 cytokine having an amino acid sequence shown in SEQ ID NO: 25 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto, and the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 14 and an amino acid sequence having at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto. In some embodiments, the recombinant cytokine receptor with IL-21 tethered thereto comprises an amino acid sequence shown in SEQ ID NO: 9 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto, the recombinant cytokine receptor comprises an IL-21 cytokine having an amino acid sequence shown in SEQ ID NO: 25 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto, and the recombinant cytokine receptor comprises an ED having an amino acid sequence shown in SEQ ID NO: 14 and an amino acid sequence having at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or about 100% sequence identity thereto. In some embodiments, the IL-21 cytokine is tethered to the ED of IL-21Rα by a polypeptide linker. In some embodiments, the cell is an immune cell. In some embodiments, the cell is a lymphocyte.In some embodiments, the cell is a T cell. In some embodiments, the cell is a Treg.

[0142] In some embodiments, the recombinant cytokine receptor of the disclosure is expressed in T cells. In some embodiments, one or more recombinant cytokine receptors are expressed in T cells. In some embodiments, the recombinant cytokine receptor can be co-expressed with a chimeric antigen receptor (CAR). In some embodiments, the T cell is a regulatory T cell (Treg). In some embodiments, the Treg is CD4+, CD25+, CD127lo. In some embodiments, the Treg expresses FOXP3 and / or HELIOS. In some embodiments, the recombinant cytokine receptor is expressed in Treg cells.

[0143] The immune pathologies, diseases, disorders, and reactions or responses treated according to the methods and compositions of the invention refer to diseases in which the immune system may contribute to the etiology or be part of the treatment. These reactions include, but are not limited to, cancer, inflammation, autoimmune pathologies, disorders or diseases, and persistent and progressive immune responses to infectious non-self antigens from bacterial, viral (e.g., HCV), fungal, or parasitic organisms that invade and persist within mammals and humans. Such pathologies and disorders include allergies and / or asthma. Allergies and asthma can be caused by sensitization to exogenous antigens or non-self antigens such as pollen, animal dander, and dietary proteins. The source of the triggering exogenous antigen can be plants, fungi, molds, or other ambient contaminants.

[0144] Autoimmunity is defined as a persistent and progressive immune response to non-infectious self-antigens, distinct from infectious non-self antigens from bacterial, viral, fungal, or parasitic organisms that invade and persist within mammals and humans. Autoimmune conditions include graft-versus-host disease, autoimmune polyendocrine syndrome, type 1 diabetes (TIDM), autoimmune gastritis, autoimmune uveitis, autoimmune vasculitis, colitis, thyroiditis, Addison's disease, agammaglobulinemia, alopecia areata, amyloidosis, ankylosing spondylitis, anti-GBM / anti-TBM nephritis, antiphospholipid syndrome, autoimmune hepatitis, autoimmune inner ear disease, axonal and neuronal neuropathy, Behçet's disease, bullous pemphigoid, Castleman disease, celiac disease, Chagas disease, chronic inflammatory demyelinating polyneuropathy (CIDP), chronic recurrent multifocal osteomyelitis, Cicatricial pemphigoid / benign mucous membrane pemphigoid, Cogan syndrome, cold agglutinin disease, congenital heart block, coxsackievirus myocarditis, CREST syndrome, Crohn's disease, dermatitis herpetiformis, dermatomyositis, Devic's disease, discoid lupus, Dressler syndrome, endometriosis, eosinophilic esophagitis, eosinophilic fasciitis, erythema nodosum, essential mixed cryoglobulinemia, Evans syndrome, fibromyalgia, fibrosing alveolitis, giant cell arteritis (temporal arteritis), giant cell myocarditis, glomerulonephritis, Goodpasture syndrome, granulomatosis with polyangiitis, Graves' disease, Guillain-Barré syndrome, Hashimoto's thyroiditis, hemolytic anemia, Henoch-Schönlein purpura, herpes gestationis or pemphigoid gestationis, hypogammaglobulinemia, IgA nephropathy, IgG4-related sclerosing diseases, inclusion body myositis, interstitial cystitis, juvenile arthritis, juvenile diabetes (type 1 diabetes), juvenile myositis, Kawasaki disease, Lambert-Eaton syndrome, leukocytoclastic vasculitis, lichen planus, lichen sclerosus, ligneous conjunctivitis, linear IgA disease, lupus, Lyme disease, Meniere's disease, microscopic polyangiitis, mixed connective tissue disease, Mooren ulcer, Mucha-Habermann disease, multiple sclerosis, myasthenia gravis, myositis, narcolepsy, neuromyelitis optica, neutropenia, ocular cicatricial pemphigoid, optic neuritis, relapsing polychondritis, PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections), paraneoplastic cerebellar degeneration, paroxysmal nocturnal hemoglobinuria, Parry-Romberg syndrome, pars planitis (peripheral uveitis), Persistent and Progressive Immune Response to Non-Infectious Self-Antigens, distinct from infectious non-self antigens from bacterial, viral, fungal, or parasitic organisms that invade and persist within mammals and humans. Autoimmune conditions include graft-versus-host disease, autoimmune polyendocrine syndrome, type 1 diabetes (TIDM), autoimmune gastritis, autoimmune uveitis, autoimmune vasculitis, colitis, thyroiditis, Addison's disease, agammaglobulinemia, alopecia areata, amyloidosis, ankylosing spondylitis, anti-GBM / anti-TBM nephritis, antiphospholipid syndrome, autoimmune hepatitis, autoimmune inner ear disease, axonal and neuronal neuropathy, Behçet's disease, bullous pemphigoid, Castleman disease, celiac disease, Chagas disease, chronic inflammatory demyelinating polyneuropathy (CIDP), chronic recurrent multifocal osteomyelitis, Cicatricial pemphigoid / benign mucous membrane pemphigoid, Cogan syndrome, cold agglutinin disease, congenital heart block, coxsackievirus myocarditis, CREST syndrome, Crohn's disease, dermatitis herpetiformis, dermatomyositis, Devic's disease, discoid lupus, Dressler syndrome, endometriosis, eosinophilic esophagitis, eosinophilic fasciitis, erythema nodosum, essential mixed cryoglobulinemia, Evans syndrome, fibromyalgia, fibrosing alveolitis, giant cell arteritis (temporal arteritis), giant cell myocarditis, glomerulonephritis, Goodpasture syndrome, granulomatosis with polyangiitis, Graves' disease, Guillain-Barré syndrome, Hashimoto's thyroiditis, hemolytic anemia, Henoch-Schönlein purpura, herpes gestationis or pemphigoid gestationis, hypogammaglobulinemia, IgA nephropathy, IgG4-related sclerosing diseases, inclusion body myositis, interstitial cystitis, juvenile arthritis, juvenile diabetes (type 1 diabetes), juvenile myositis, Kawasaki disease, Lambert-Eaton syndrome, leukocytoclastic vasculitis, lichen planus, lichen sclerosus, ligneous conjunctivitis, linear IgA disease, lupus, Lyme disease, Meniere's disease, microscopic polyangiitis, mixed connective tissue disease, Mooren ulcer, Mucha-Habermann disease, multiple sclerosis, myasthenia gravis, myositis, narcolepsy, neuromyelitis optica, neutropenia, ocular cicatricial pemphigoid, optic neuritis, relapsing polychondritis, PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections), paraneoplastic cerebellar degeneration, paroxysmal nocturnal hemoglobinuria, Parry-Romberg syndrome, pars planitis (peripheral uveitis), Personnage-Turner syndrome, pemphigus, peripheral neuropathyPeripheral myelitis, pernicious anemia, POEMS syndrome, polyarteritis nodosa, polymyalgia rheumatica, polymyositis, post-myocardial infarction syndrome, post-pericardiotomy syndrome, primary biliary cirrhosis, primary sclerosing cholangitis, progesterone dermatitis, psoriasis, psoriatic arthritis, pure red cell aplasia, pyoderma gangrenosum, Raynaud's phenomenon, reactive arthritis, reflex sympathetic dystrophy, Reiter's syndrome, relapsing polychondritis, restless legs syndrome, retroperitoneal fibrosis, rheumatic fever, rheumatoid arthritis, sarcoidosis, Schmidt's syndrome, episcleritis, scleroderma, Sjögren's syndrome, sperm and testicular autoimmunity, stiff-person syndrome, subacute bacterial endocarditis, Suzaku syndrome, sympathetic ophthalmia, Takayasu arteritis, temporal arteritis / giant cell arteritis, thrombocytopenic purpura, Troisier-Hanot syndrome, transverse myelitis, ulcerative colitis, undifferentiated connective tissue disease, uveitis, vasculitis, vitiligo, and Wegener's granulomatosis (multivessel granulomatosis) are included. "Autoantigen" or "self-antigen", as used herein, refers to an antigen or epitope that is native to a mammal and is immunogenic in the mammalian disease. One aspect of the present application provides a method for treating immune-related disorders.,

[0145] Cells that can be "allogeneic cells" are isolated from one individual (donor) and injected into another individual, while "autologous cells" refer to cells that are isolated and injected back into the same individual. In some embodiments, the cells are autologous to the individual. In some embodiments, the individual is human. In some embodiments, the individual expresses IL-2. In some embodiments, the cells are T cells. In some embodiments, the cells are Tregs. In some embodiments, Treg cells are isolated from human peripheral blood mononuclear cells (PBMCs). In some embodiments, Treg cells are ex vivo modified with a vector encoding one or more recombinant cytokine receptors. In some embodiments, Treg cells amplify ex vivo in the absence of IL-2. In some embodiments, Treg cells are modified with a nucleic acid or vector encoding a recombinant cytokine receptor. In some embodiments, Treg cells are modified to proliferate in the absence of IL-2. In some embodiments, Treg cells have one or more markers of detected IL-2 signaling. In some embodiments, the marker of detected IL-2 signaling is phosphorylated STAT-5. In some embodiments, the Treg is CD4+, CD25+, CD127lo. In some embodiments, the Treg expresses FOXP3 and / or HELIOS. In some embodiments, Treg cells are administered to the same individual for treating an immune-related disorder.

[0146] In some embodiments, a method of treating an immune-related disorder comprises administering Treg cells to an individual in need of such treatment. In some embodiments, the individual expresses IL-2. In some embodiments, the recombinant cytokine receptor can be co-expressed with a chimeric antigen receptor (CAR). In some embodiments, the Treg is CD4+, CD25+, CD127lo. In some embodiments, the Treg expresses FOXP3 and / or HELIOS.

[0147] In some embodiments, a method of treating an immune-related disorder comprises administering autologous Treg cells to an individual. In some embodiments, the individual is human. In some embodiments, the individual expresses IL-2. In some embodiments, a method of treating an immune-related disorder comprises administering Treg cells isolated from human peripheral blood mononuclear cells (PBMCs). In some embodiments, the Treg cells are ex vivo modified by a vector encoding one or more recombinant cytokine receptors. In some embodiments, the Treg cells are amplified ex vivo in the absence of IL-2. In some embodiments, a method of treating an immune-related disorder comprises administering Treg cells ex vivo modified by a vector encoding one or more recombinant cytokine receptors. In some embodiments, a method of treating an immune-related disorder comprises administering Treg cells amplified ex vivo in the absence of IL-2. In some embodiments, a method of treating an immune-related disorder comprises administering Treg cells modified by a nucleic acid or vector encoding a recombinant cytokine receptor. In some embodiments, a method of treating an immune-related disorder comprises administering Treg cells modified to proliferate in the absence of IL-2. In some embodiments, a method of treating an immune-related disorder comprises administering Treg cells in which one or more markers of IL-2 signaling are detected. In some embodiments, a method of treating an immune-related disorder comprises administering Treg cells in which the detected marker of IL-2 signaling is phosphorylated STAT-5. In some embodiments, a method of treating an immune-related disorder comprises administering Treg cells that are CD4+, CD25+, CD127lo. In some embodiments, a method of treating an immune-related disorder comprises administering Treg cells that express FOXP3 and / or HELIOS. In some embodiments, a method of treating an immune-related disorder comprises administering the Treg cells described herein.

[0148] In some embodiments, a method of treating an immune-related disorder comprises administering Treg cells comprising a recombinant cytokine receptor of the present disclosure. In some embodiments, the suppressive activity of Tregs on CD8+ T cells and / or CD4+ T cells is increased as compared to wild-type Tregs. In some embodiments, the suppressive activity of Tregs on CD8+ T cells and / or CD4+ T cells is increased as compared to wild-type Tregs cultured without IL-2. In some embodiments, the suppressive activity of Tregs on CD8+ T cells and / or CD4+ T cells is increased as compared to unmodified cells cultured without IL-2. In some embodiments, the suppressive activity of Tregs on CD8+ T cells and / or CD4+ T cells cultured without IL-2 is approximately equivalent or about the same as that of unmodified Treg cells cultured with IL-2. In some embodiments, the suppressive activity of Tregs decreases the rate of division of CD4+ T cells and / or CD8+ T cells. In some embodiments, the method further comprises culturing the Treg cells in a composition comprising a cytokine. In some embodiments, the method further comprises culturing the Treg cells in a composition comprising a cognate cytokine. In some embodiments, the method further comprises culturing the Treg cells in a composition comprising one or more additional cytokines other than IL-2.

[0149] In some embodiments, a method of treating an immune-related disorder comprises transducing a cell population with a recombinant cytokine receptor. In some embodiments, a method of treating an immune-related disorder comprises transducing a population of T cells with a recombinant cytokine receptor. In some embodiments, a method of treating an immune-related disorder comprises transducing a population of Treg cells with a recombinant cytokine receptor. In some embodiments, the viability of the cells is increased as compared to untransduced Tregs. In some embodiments, at least about 60-99% of the cells in the population of Treg cells transduced with a recombinant cytokine remain viable in vitro for approximately 7-20 days after transduction. In some embodiments, at least about 60-99% of the cells in the population of Treg cells transduced with a recombinant cytokine remain viable in vitro for approximately 7-14 days after transduction. In some embodiments, at least about 60% of the cells in the population of Treg cells transduced with a recombinant cytokine remain viable in vitro for approximately 7 days after transduction. In some embodiments, the method further comprises culturing the Treg cells in a composition comprising a cytokine. In some embodiments, the method further comprises culturing the Treg cells in a composition comprising a cognate cytokine. In some embodiments, the method further comprises culturing the Treg cells in a composition comprising one or more additional cytokines other than IL-2.

[0150] In some embodiments, a method of treating an immune-related disorder comprises transducing a cell population with a recombinant cytokine receptor. In some embodiments, a method of treating an immune-related disorder comprises transducing a population of T cells with a recombinant cytokine receptor. In some embodiments, a method of treating an immune-related disorder comprises transducing a population of Treg cells with a recombinant cytokine receptor. In some embodiments, the viability of the cells is increased compared to untransduced Tregs. In some embodiments, at least about 60-99% of the cells in a population of Treg cells transduced with a recombinant cytokine can survive in vivo for at least about 3 days or more. In some embodiments, at least about 60-99% of the cells in a population of Treg cells transduced with a recombinant cytokine can survive in vivo for at least about 3 days or more. In some embodiments, at least about 60% of the cells in a population of Treg cells transduced with a recombinant cytokine can survive in vivo for at least about 3 days or more. In some embodiments, a population of Treg cells transduced with a recombinant cytokine can survive in vivo for at least about 1, 2, 3, 5, 6, 8, 10, or 11 months, or at least 1 year or more.

[0151] In some embodiments, a method of treating an immune-related disorder comprises transducing a cell population with a recombinant cytokine receptor. In some embodiments, a method of treating an immune-related disorder comprises transducing a population of T cells with a recombinant cytokine receptor. In some embodiments, a method of treating an immune-related disorder comprises transducing a population of Treg cells with a recombinant cytokine receptor, which results in a cell population containing more viable cells as compared to a composition containing the same population of Treg cells not transduced with the recombinant cytokine receptor. In some embodiments, at least about 60 to 99% of the cells in a population of Treg cells transduced with a recombinant cytokine remain viable in vitro for approximately 7 to 20 days after transduction. In some embodiments, at least about 60 to 99% of the cells in a population of Treg cells transduced with a recombinant cytokine remain viable in vitro for approximately 7 to 14 days after transduction. In some embodiments, at least about 60% of the cells in a population of Treg cells transduced with a recombinant cytokine remain viable in vitro for approximately 7 days after transduction. In some embodiments, the method further comprises culturing the Treg cells in a composition containing a cytokine. In some embodiments, the method further comprises culturing the Treg cells in a composition containing a cognate cytokine.

[0152] In some embodiments, a method of treating an immune-related disorder comprises transducing a cell population with a recombinant cytokine receptor. In some embodiments, a method of treating an immune-related disorder comprises transducing a population of T cells with a recombinant cytokine receptor. In some embodiments, a method of treating an immune-related disorder comprises transducing a population of Treg cells with a recombinant cytokine receptor, which results in a cell population containing more viable cells as compared to a composition containing the same population of Treg cells not transduced with the recombinant cytokine receptor. In some embodiments, at least about 60-99% of the cells in the population of Treg cells transduced with a recombinant cytokine can survive in vivo for at least about 3 days or more. In some embodiments, at least about 60-99% of the cells in the population of Treg cells transduced with a recombinant cytokine can survive in vivo for at least about 3 days or more. In some embodiments, at least about 60% of the cells in the population of Treg cells transduced with a recombinant cytokine can survive in vivo for at least about 3 days or more. In some embodiments, the population of Treg cells transduced with a recombinant cytokine can survive in vivo for at least about 1, 2, 3, 5, 6, 8, 10, or 11 months, or at least 1 year or more.

[0153] In some embodiments, a method of treating an immune-related disorder comprises transducing a population of Treg cells transduced with a recombinant cytokine receptor, and the transduced population of Treg cells amplifies at least 2-fold or more than the same population of Treg cells not transduced with the recombinant cytokine receptor. In some embodiments, a method of treating an immune-related disorder comprises a composition in which the population of Treg cells transduced with a recombinant cytokine receptor amplifies at least 2-fold, and the population of Treg cells transduced with a recombinant cytokine receptor maintains the expression of at least one Treg marker selected from the group consisting of CD4+, CD25+, and CD127lo.

[0154] In some embodiments, the recombinant cytokine receptors of the present disclosure can also be used in combination with a chimeric antigen receptor (CAR). In some embodiments, the modified Tregs comprise a recombinant cytokine receptor and a chimeric antigen.

[0155] VII. Definitions It will be recognized that certain features of the disclosure described in the context of separate embodiments may be provided in combination in a single embodiment. Conversely, various features described in the context of a single embodiment for purposes of brevity may be provided separately or in any suitable subcombination. All combinations of embodiments belonging to a particular method step, reagent, or condition are specifically embraced by the present disclosure, and each and every combination is disclosed herein as if it were individually and explicitly disclosed.

[0156] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It is further pointed out that the claims may be drafted to exclude optional elements. Accordingly, this description serves as antecedent basis for use of exclusive terms, such as "solely," "only," and the like, in connection with the recitation of claim elements, or use of "negative" limitations.

[0157] Reference to a value or parameter herein to "about" refers to the ordinary error range for each respective value known readily to a person of ordinary skill in the art. Reference to a value or parameter herein to "about" encompasses (and describes) aspects relating to that value or parameter itself. For example, a description that refers to "about X" encompasses a description of "X".

[0158] The term "and / or" as used herein is considered to be a specific disclosure of each of two designated features or components, whether or not the other is present. Thus, when the term "and / or" is used in a phrase such as "A and / or B" herein, it is intended to encompass "A and B", "A or B", "A" (alone), as well as "B" (alone). Similarly, when the term "and / or" is used in a phrase such as "A, B, and / or C", the following aspects are intended to be covered: A, B, and C; A, B, or C; A or C; A or B; B or C; A and C; A and B; B and C; A (alone); B (alone); as well as C (alone).

[0159] It is understood that the aspects and embodiments of the invention described herein include aspects and embodiments of "comprising", "consisting of", and "consisting essentially of".

[0160] As used herein, the terms "comprising", "containing", and "including" are used in their open and non-limiting senses.

[0161] With respect to the sequences of the polypeptides and antibodies identified herein, "percent (%) amino acid sequence identity" or "homology" is defined as the percentage of amino acid residues in a candidate sequence that are identical to the amino acid residues in the polypeptides being compared, after aligning the sequences to take into account any conservative substitutions as part of sequence identity. Alignments for the purpose of determining percent amino acid sequence identity can be achieved by various methods within the skill of the art, using, for example, publicly available computer software such as BLAST, BLAST-2, ALIGN, or Megalign (DNASTAR) software. One of ordinary skill in the art can determine appropriate parameters for measuring alignment, including any algorithms necessary to achieve the maximum alignment over the full length of the sequences being compared. However, for the purposes herein, the % amino acid sequence identity values are generated using the sequence comparison computer program ALIGN-2. The ALIGN-2 sequence comparison computer program was written by Genentech, Inc., and the source code has been submitted to the U.S. Copyright Office (Washington D.C., 20559) together with user documentation and is registered under U.S. Copyright Registration No. TXU510087. The ALIGN-2 program is publicly available through Genentech, Inc. (South San Francisco, California). The ALIGN-2 program should be compiled for use on a UNIX® operating system, preferably Digital UNIX® V4.0D. All sequence comparison parameters are set and unvaried by the ALIGN-2 program.

[0162] An "individual" or "subject" is a mammal. Mammals include, but are not limited to, livestock (e.g., cows, sheep, cats, dogs, and horses), primates (e.g., humans and non-human primates such as monkeys and cynomolgus monkeys), rabbits, and rodents (e.g., mice and rats). In some embodiments, the individual or subject is a human.

[0163] The "treatment" or "therapy" of interest refers to any type of intervention or process carried out on a subject, or the administration of an active agent to a subject, for the purpose of curing, ameliorating, alleviating, relieving, inhibiting, decelerating, or preventing the onset, progression, development, severity, or recurrence of a disease, associated symptoms, complications, conditions, or biochemical markers.

[0164] The "effective amount" or "therapeutically effective amount" or "therapeutically effective dosage" of a drug or therapeutic agent is any amount of the drug that, when used alone or in combination with another therapeutic agent, protects the subject against the onset of a disease or demonstrates disease regression by decreasing the severity of disease symptoms, increasing the frequency and duration of disease-free periods, or preventing functional or physical impairment resulting from disease affliction. The ability of a therapeutic agent to promote disease regression can be evaluated using various methods known to those skilled in the art, such as in human subjects during clinical trials, in animal model systems that predict efficacy in humans, or by assay of the activity of the agent in in vitro assays.

[0165] The phrase "pharmaceutically acceptable" indicates that the substance or composition must be chemically and / or toxicologically compatible with the other components that make up the formulation and / or the mammal being treated thereby.

[0166] As used herein, the term "tethered" includes linked, fused, connected, attached, etc., and may also include any method known to those skilled in the art for fusion, linking, connection, attachment, etc. For example, two polypeptide sequences can be "tethered", or otherwise fused, linked, connected, attached, etc., using a polypeptide or peptide linker.

[0167] When described in this specification, any concentration range, percentage range, ratio range, or integer range is to be understood to include any integer value within the recited range, and fractions thereof as appropriate (such as one-tenth and one-hundredth of an integer), unless otherwise indicated. The recitation of endpoints includes the range between all disclosed endpoints. For example, the recitation of 1, 2, or 3 includes the ranges 1 to 2, 2 to 3, and 1 to 3.

[0168] Embodiment 1. A recombinant cytokine receptor comprising an extracellular cytokine receptor domain, a transmembrane domain, and an intracellular IL-2 receptor β chain domain, wherein the extracellular cytokine receptor domain binds to a cytokine other than IL-2. 2. A recombinant cytokine receptor comprising an extracellular cytokine receptor domain, a transmembrane domain, and an intracellular IL-2 receptor β chain domain, wherein the extracellular cytokine receptor domain binds to a cytokine other than IL-2 and is tethered. 3. The recombinant cytokine receptor according to embodiment 1 or 2, wherein the extracellular cytokine receptor domain is selected from the group consisting of an IL-4 extracellular domain, an IL-7 extracellular domain, an IL-9 extracellular domain, and an IL-21 extracellular domain. 4. The recombinant cytokine receptor according to any one of embodiments 2 to 3, wherein the extracellular cytokine receptor domain is tethered to the cytokine by a polypeptide linker. 5. The recombinant cytokine receptor according to embodiment 4, wherein the peptide linker contains glycine residues and serine residues. 6. The recombinant cytokine receptor according to embodiment 1, wherein the extracellular cytokine receptor domain is not tethered to the cytokine. 7. The recombinant cytokine receptor according to any one of embodiments 1 to 6, wherein the cytokine receptor participates in IL-2 signaling in the absence of IL-2. 8. The cytokine receptor according to any one of Embodiments 1 to 7, wherein the transmembrane domain is a transmembrane domain of a cytokine receptor. 9. The recombinant cytokine receptor according to Embodiment 8, wherein the transmembrane domain is a transmembrane domain of an IL-9 receptor, an IL-2 receptor, an IL-4 receptor, an IL-7 receptor, or an IL-21 receptor. 10. The recombinant cytokine receptor according to any one of Embodiments 1 to 9, wherein the intracellular domain comprises an amino acid sequence shown in SEQ ID NO: 20 and an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity. 11. The recombinant cytokine receptor according to any one of Embodiments 1 to 10, wherein the extracellular domain comprises an amino acid sequence shown in SEQ ID NOs: 11 to 14 and an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity. 12. The recombinant cytokine receptor according to any one of Embodiments 1 to 11, wherein the transmembrane domain comprises an amino acid sequence shown in SEQ ID NOs: 16 to 19 and an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity. 13. The recombinant cytokine receptor according to any one of Embodiments 1 to 12, wherein the cytokine receptor comprises an amino acid sequence shown in SEQ ID NOs: 6 to 9 and an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity. 14. A nucleic acid encoding the recombinant cytokine receptor according to any one of Embodiments 1 to 13. 15. A vector comprising the nucleic acid according to Embodiment 14. 16. The vector according to embodiment 15, wherein the vector is a lentiviral vector. 17. The vector according to embodiment 15 or 16, further comprising a marker gene. 18. The vector according to embodiment 17, wherein the marker gene is a transmembrane protein. 19. The vector according to embodiment 18, wherein the transmembrane protein is EGFR. 20. A T cell comprising the recombinant cytokine receptor according to any one of embodiments 1 to 13, the nucleic acid according to embodiment 14, or the vector according to any one of embodiments 15 to 19. 21. The T cell according to embodiment 20, wherein the T cell is a regulatory T cell (Treg), and the Treg is CD4+, CD25+, and CD127lo. 22. The T cell according to embodiment 21, wherein the Treg expresses FOX3P and / or HELIOS. 23. The T cell according to any one of embodiments 20 to 22, further comprising a chimeric antigen receptor (CAR). 24. A composition comprising the nucleic acid according to embodiment 14, the vector according to any one of embodiments 15 to 20, or the T cell according to any one of embodiments 21 to 23. 25. A method for treating an immune-related disorder, comprising administering the T cell according to any one of embodiments 20 to 23 or the composition according to embodiment 24 to an individual in need of the T cell or the composition. 26. The method according to embodiment 25, wherein the cells are autologous to the individual. 27. The method according to any one of embodiments 25 to 26, wherein the individual is a human. 28. A method for amplifying the transduced Treg cells in the absence of IL-2, comprising introducing the nucleic acid according to embodiment 14 or the vector according to any one of embodiments 15 to 19 into Treg cells and culturing the cells in the absence of IL-2. The method according to embodiment 28, further comprising detecting at least one Treg marker selected from the group consisting of CD4+, CD25+, and CD127. The method according to embodiment 29, further comprising detecting FOXP3 and / or HELIOS. The method according to any one of embodiments 28 to 30, wherein the Treg cells are capable of proliferating in the absence of IL-2. The method according to any one of embodiments 28 to 31, wherein one or more markers of IL-2 signaling are detected. The method according to any one of embodiments 28 to 32, wherein one or more markers of IL-2 signaling include phosphorylated STAT5. The method according to any one of embodiments 28 to 33, wherein the suppressive activity of Tregs against CD8+ T cells and / or CD4+ T cells is increased. The method according to embodiment 34, wherein the rate of division of CD4+ T cells and / or CD8+ T cells is decreased. The method according to any one of embodiments 28 to 35, wherein the relative amount of Treg cells in a composition comprising a population of Treg cells transduced with a recombinant cytokine receptor increases over time. The method according to any one of embodiments 28 to 36, wherein a composition comprising a population of Treg cells transduced with the recombinant cytokine receptor contains more viable cells compared to a composition comprising a population of the same Treg cells not transduced with the recombinant cytokine receptor. The method according to embodiment 36 or 37, wherein at least 60% of the cells in the population of Treg cells transduced with the recombinant cytokine remain viable for 7 days after transduction. The method according to any one of embodiments 28 to 38, further comprising culturing the Treg cells in a composition containing the cytokine. The method according to any one of embodiments 28 to 39, further comprising culturing Treg cells in a composition comprising one or more additional cytokines other than IL-2. 41. The method according to any one of embodiments 28 to 40, wherein the population of Treg cells transduced with the recombinant cytokine receptor amplifies at least 2-fold more than the population of the same Treg cells not transduced with the recombinant cytokine receptor. 42. The method according to any one of embodiments 28 to 41, wherein the population of Treg cells transduced with the recombinant cytokine receptor amplifies at least 2-fold, and the population of Treg cells transduced with the recombinant cytokine receptor maintains the expression of at least one Treg marker selected from the group consisting of CD4+, CD25+, and CD127lo. 43. A recombinant cytokine receptor comprising an extracellular cytokine receptor domain, a transmembrane domain, and an intracellular IL-2 receptor β chain domain, wherein the extracellular cytokine receptor domain is capable of binding to a cytokine other than IL-2. 44. A recombinant cytokine receptor comprising an extracellular cytokine receptor domain, a transmembrane domain, and an intracellular IL-2 receptor β chain domain, wherein the extracellular cytokine receptor domain is capable of binding to a cytokine other than IL-2 and is tethered. 45. The recombinant cytokine receptor according to embodiment 43 or embodiment 44, wherein the extracellular cytokine receptor domain is selected from the group consisting of an IL-4 extracellular domain, an IL-7 extracellular domain, an IL-9 extracellular domain, and an IL-21 extracellular domain. 46. The recombinant cytokine receptor according to embodiment 44 or embodiment 45, wherein the extracellular cytokine receptor domain is tethered to the cytokine by a polypeptide linker. 47. The recombinant cytokine receptor according to embodiment 46, wherein the polypeptide linker comprises glycine residues and serine residues. 48. The recombinant cytokine receptor according to embodiment 43 or embodiment 45, wherein the extracellular cytokine receptor domain is not tethered to the cytokine. 49. The recombinant cytokine receptor according to any one of embodiments 43 to 48, wherein the recombinant cytokine receptor participates in IL-2 signaling in the absence of IL-2. 50. The cytokine receptor according to any one of embodiments 43 to 49, wherein the transmembrane domain is the transmembrane domain of a cytokine receptor. 51. The recombinant cytokine receptor according to embodiment 50, wherein the transmembrane domain is the transmembrane domain of an IL-9 receptor, an IL-2 receptor, an IL-4 receptor, an IL-7 receptor, or an IL-21 receptor. 52. The recombinant cytokine receptor according to any one of embodiments 43 to 51, wherein the TM and the ED are from the same cytokine receptor. 53. The recombinant cytokine receptor according to any one of embodiments 43 to 5, wherein the intracellular domain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20. 54. The recombinant cytokine receptor according to any one of embodiments 43 to 53, wherein the extracellular domain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NOs: 11 to 14 or 21. 55. The recombinant cytokine receptor according to any one of embodiments 43 to 54, wherein the transmembrane domain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NOs: 16 to 19. 56. The intracellular domain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20; The extracellular domain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NOs: 11-14; and / or The transmembrane domain comprises an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NOs: 16-19, The recombinant cytokine receptor according to any one of Embodiments 43 to 55. 57. The recombinant cytokine receptor is a) an IL-4Rα extracellular domain, an IL-4Rα transmembrane domain, and an IL-2Rβ intracellular domain; b) an IL-4Rα extracellular domain, an IL-2Rβ transmembrane domain, and an IL-2Rβ intracellular domain; c) an IL-7Rα extracellular domain, an IL-7Rα transmembrane domain, and an IL-2Rβ intracellular domain; d) an IL-7Rα extracellular domain, an IL-2Rβ transmembrane domain, and an IL-2Rβ intracellular domain; e) an IL-9Rα extracellular domain, an IL-9Rα transmembrane domain, and an IL-2Rβ intracellular domain; f) an IL-9Rα extracellular domain, an IL-2Rβ transmembrane domain, and an IL-2Rβ intracellular domain; g) an IL-21Rα extracellular domain, an IL-21Rα transmembrane domain, and an IL-2Rβ intracellular domain; or h) an IL-21Rα extracellular domain, an IL-2Rβ transmembrane domain, and an IL-2Rβ intracellular domain The recombinant cytokine receptor according to any one of Embodiments 43 to 56, comprising 58.a) the intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 16, and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 11; or b) the intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 17, and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 12; or c) the intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 18, and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 13; or d) the intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 21, and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 13; or e) the intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 19, and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 14; or f) the intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 16, the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 11, and the cytokine comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 22; or g) the intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 17, the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 12, and the cytokine comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 23; h) the intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 18, the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 13, and the cytokine comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 24; i) the intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 21, the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 13, and the cytokine comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 24; or j) the intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 19, the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 14, and the cytokine comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 25; The recombinant cytokine receptor according to any one of Embodiments 43 to 57. 59. The recombinant cytokine receptor according to any one of embodiments 43, 45, and 48 to 58, wherein the recombinant cytokine receptor comprises an amino acid sequence shown in SEQ ID NOs: 1 to 5 and an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity. 60. The recombinant cytokine receptor according to any one of embodiments 43 to 47 and 49 to 59, wherein the recombinant cytokine receptor comprises an amino acid sequence shown in SEQ ID NOs: 6 to 9 or 15 and an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity. 61. A nucleic acid encoding the recombinant cytokine receptor according to any one of embodiments 43 to 60. 62. A vector comprising the nucleic acid according to embodiment 61. 63. The vector according to embodiment 62, wherein the vector is a lentiviral vector. 64. The vector according to embodiment 62 or 63, further comprising a marker gene. 65. The vector according to embodiment 64, wherein the marker gene is a transmembrane protein. 66. The vector according to embodiment 65, wherein the transmembrane protein is EGFR. 67. A T cell comprising the recombinant cytokine receptor according to any one of embodiments 43 to 60, the nucleic acid according to embodiment 61, or the vector according to any one of embodiments 62 to 66. 68. The T cell according to embodiment 67, wherein the T cell is a regulatory T cell (Treg), and the Treg is CD4+, CD25+, and CD127lo. 69. The T cell according to embodiment 68, wherein the Treg expresses FOX3P and / or HELIOS. 70. The T cell according to any one of embodiments 67 to 69, further comprising a chimeric antigen receptor (CAR). 71. A composition comprising the nucleic acid according to Embodiment 61, the vector according to any one of Embodiments 62 to 66, or the T cell according to any one of Embodiments 67 to 70. 72. A method for amplifying the Treg cells in the absence of IL-2, comprising introducing the nucleic acid according to Embodiment 61 or the vector according to any one of Embodiments 62 to 66 into the Treg cells and culturing the cells in vitro in the absence of IL-2. 73. The method according to Embodiment 72, further comprising detecting at least one Treg marker selected from the group consisting of CD4+, CD25+, and CD127. 74. The method according to Embodiment 73, further comprising detecting FOXP3 and / or HELIOS. 75. The method according to any one of Embodiments 72 to 74, wherein the Treg cells are capable of proliferating in the absence of IL-2. 76. The method according to any one of Embodiments 72 to 75, wherein one or more markers of IL-2 signaling are detected. 77. The method according to any one of Embodiments 7...

Claims

1. Regulatory T cells (Treg) containing recombinant cytokine receptors, wherein the recombinant cytokine receptors are The Treg comprises an extracellular cytokine receptor domain (ED), a transmembrane domain (TM), and an intracellular IL-2 receptor β-chain domain, wherein the extracellular cytokine receptor domain binds to cytokines other than IL-2.

2. The Treg according to claim 1, wherein the extracellular cytokine receptor domain is selected from the group consisting of an IL-4 extracellular domain, an IL-7 extracellular domain, an IL-9 extracellular domain, and an IL-21 extracellular domain.

3. The Treg according to claim 1, wherein the extracellular cytokine receptor domain is not tethered to the cytokine.

4. The Treg according to claim 1, wherein the recombinant cytokine receptor participates in IL-2 signaling in the absence of IL-2.

5. The Treg according to claim 1, wherein the transmembrane domain is the transmembrane domain of a cytokine receptor.

6. The Treg according to claim 5, wherein the transmembrane domain is the transmembrane domain of an IL-9 receptor, an IL-2 receptor, an IL-4 receptor, an IL-7 receptor, or an IL-21 receptor.

7. The Treg according to claim 1, wherein the TM and ED are from the same cytokine receptor.

8. The intracellular domain includes an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with the amino acid sequence shown in Sequence ID No. 20; and / or The extracellular domain includes an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with the amino acid sequences shown in SEQ ID NOs: 11-14; and / or The transmembrane domain includes an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NOs: 16-19 or 21. The Treg according to claim 1.

9. The recombinant cytokine receptor, a) IL-4Rα extracellular domain, IL-4Rα transmembrane domain, and IL-2Rβ intracellular domain; b) IL-4Rα extracellular domain, IL-2Rβ transmembrane domain, and IL-2Rβ intracellular domain; c) IL-7Rα extracellular domain, IL-7Rα transmembrane domain, and IL-2Rβ intracellular domain; d) IL-7Rα extracellular domain, IL-2Rβ transmembrane domain, and IL-2Rβ intracellular domain; e) IL-9Rα extracellular domain, IL-9Rα transmembrane domain, and IL-2Rβ intracellular domain; f) IL-9Rα extracellular domain, IL-2Rβ transmembrane domain, and IL-2Rβ intracellular domain; g) IL-21Rα extracellular domain, IL-21Rα transmembrane domain, and IL-2Rβ intracellular domain; or h) IL-21Rα extracellular domain, IL-2Rβ transmembrane domain, and IL-2Rβ intracellular domain The Treg according to claim 1, including the Treg.

10. a) The intracellular domain contains an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20; the transmembrane domain contains an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 16; and the extracellular domain contains an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 11; b) The intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 17, and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 12; c) The intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20; the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 18; and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 13; d) The intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 21, and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 13; or e) The intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 19, and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO:

14. The Treg according to claim 1.

11. The Treg according to claim 1, wherein the recombinant cytokine receptor comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 1 to 5 and an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity.

12. The Treg according to claim 1, wherein the Treg is CD4+, CD25+, and CD127lo, and optionally the Treg expresses FOXP3 and / or HELIOS.

13. The Treg according to claim 1, further comprising a chimeric antigen receptor (CAR).

14. A pharmaceutical composition for the treatment of immune-related disorders in an individual, comprising the Treg described in any one of claims 1 to 13.

15. The pharmaceutical composition according to claim 14, wherein the Treg cells are of autologous origin to the individual, and optionally the individual is human.

16. The pharmaceutical composition according to claim 14, wherein the Treg cells prevent, alleviate, or cure the immune-related disorder.

17. A recombinant cytokine receptor comprising an extracellular cytokine receptor domain (ED), a transmembrane domain (TM), and an intracellular IL-2 receptor β-chain domain, wherein the extracellular cytokine receptor domain is capable of binding to cytokines other than IL-2.

18. The recombinant cytokine receptor according to claim 17, wherein the extracellular cytokine receptor domain is selected from the group consisting of an IL-4 extracellular domain, an IL-7 extracellular domain, an IL-9 extracellular domain, and an IL-21 extracellular domain.

19. The recombinant cytokine receptor according to claim 17, wherein the extracellular cytokine receptor domain is not tethered to the cytokine.

20. The recombinant cytokine receptor according to claim 17, wherein the recombinant cytokine receptor participates in IL-2 signaling in the absence of IL-2.

21. The recombinant cytokine receptor according to claim 17, wherein the transmembrane domain is the transmembrane domain of a cytokine receptor, and optionally, the transmembrane domain is the transmembrane domain of an IL-9 receptor, an IL-2 receptor, an IL-4 receptor, an IL-7 receptor, or an IL-21 receptor.

22. The recombinant cytokine receptor according to claim 17, wherein the TM and ED are derived from the same cytokine receptor.

23. The intracellular domain includes an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with the amino acid sequence shown in Sequence ID No. 20; The extracellular domain includes an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with the amino acid sequences shown in SEQ ID NOs: 11-14; and / or The transmembrane domain includes an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NOs: 16-19 or 21. The recombinant cytokine receptor according to claim 17.

24. The recombinant cytokine receptor, a) IL-4Rα extracellular domain, IL-4Rα transmembrane domain, and IL-2Rβ intracellular domain; b) IL-4Rα extracellular domain, IL-2Rβ transmembrane domain, and IL-2Rβ intracellular domain; c) IL-7Rα extracellular domain, IL-7Rα transmembrane domain, and IL-2Rβ intracellular domain; d) IL-7Rα extracellular domain, IL-2Rβ transmembrane domain, and IL-2Rβ intracellular domain; e) IL-9Rα extracellular domain, IL-9Rα transmembrane domain, and IL-2Rβ intracellular domain; f) IL-9Rα extracellular domain, IL-2Rβ transmembrane domain, and IL-2Rβ intracellular domain; g) IL-21Rα extracellular domain, IL-21Rα transmembrane domain, and IL-2Rβ intracellular domain; or h) IL-21Rα extracellular domain, IL-2Rβ transmembrane domain, and IL-2Rβ intracellular domain A recombinant cytokine receptor according to claim 17, comprising:

25. a) The intracellular domain contains an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20; the transmembrane domain contains an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 16; and the extracellular domain contains an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 11; b) The intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 17, and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 12; c) The intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20; the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 18; and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 13; d) The intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 21, and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 13; or e) The intracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 20, the transmembrane domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO: 19, and the extracellular domain comprises an amino acid sequence having at least 80%, at least 90%, at least 95%, at least 99%, or 100% sequence identity with the amino acid sequence shown in SEQ ID NO:

14. The recombinant cytokine receptor according to claim 17.

26. The recombinant cytokine receptor according to claim 17, wherein the recombinant cytokine receptor comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 1 to 5 and an amino acid sequence having at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity.

27. A nucleic acid encoding a recombinant cytokine receptor according to any one of claims 17 to 26.

28. A vector comprising the nucleic acid described in claim 27.

29. A method for amplifying Treg cells in the absence of IL-2, comprising introducing the nucleic acid described in claim 27 into Treg cells and culturing the cells in the absence of IL-2.

30. The method according to claim 29, further comprising detecting at least one Treg marker selected from the group consisting of CD4+, CD25+, and CD127, and optionally further comprising detecting FOXP3 and / or HELIOS.

31. The method according to claim 29, wherein the Treg cells are capable of proliferating by division in the absence of IL-2.

32. The method according to claim 29, wherein one or more markers of endogenous IL-2 signaling are detected, and optionally, the one or more markers of endogenous IL-2 signaling include phosphorylated STAT-5.

33. The method according to claim 29, wherein the method generates Treg cells containing recombinant cytokine receptors, i. The in vitro and / or in vivo inhibitory activity of the Treg against CD8+ T cells and / or CD4+ T cells is increased compared to the control Treg; ii. The rate of division of CD4+ T cells and / or CD8+ T cells when cultured in the presence of Treg is reduced compared to the rate of division of CD4+ T cells and / or CD8+ T cells when cultured without Treg; iii. The relative amount of Treg cells in a composition containing a population of Treg cells transduced by recombinant cytokine receptors increases over time; iv. A composition containing a population of Treg cells transduced by the recombinant cytokine receptor contains more viable cells than a composition containing the same population of Treg cells that are not transduced by the recombinant cytokine receptor; v. At least 60% of the cells in the population of Treg cells transduced by the recombinant cytokine remain viable in vitro for 7 days after transduction; vi. The level of Treg cell mitosis increases once or multiple times in vitro and / or in vivo following restimulation; vii. The IL-10 cytokine levels produced in vitro and / or in vivo by the aforementioned Treg are increased compared to the control Treg; viiii. The IFN-γ cytokine levels produced in vitro and / or in vivo by the aforementioned Treg are increased compared to the control Treg; And / or ix. The Gr-B cytokine levels produced in vitro and / or in vivo by the aforementioned Treg are increased compared to the control Treg. The aforementioned method.

34. The method according to claim 29, further comprising culturing the Treg cells in a composition comprising the cytokine, and optionally further comprising culturing the Treg cells in a composition comprising one or more additional cytokines other than IL-2.

35. The method according to claim 29, wherein the population of Treg cells transduced by the recombinant cytokine receptor is amplified at least twice as much as the same population of Treg cells not transduced by the recombinant cytokine receptor, and optionally, the population of Treg cells transduced by the recombinant cytokine receptor is amplified at least twice, and the population of Treg cells transduced by the recombinant cytokine receptor maintains the expression of at least one Treg marker selected from the group consisting of CD4+, CD25+, and CD127lo.

36. The pharmaceutical composition according to claim 14, wherein the individual expresses IL-2.

Images