Engineered Anti-il-2 antibodies

Abstract

Kits for combination therapy are provided.SOLUTION: Provided is a kit for combination therapy comprising an anti-IL-2 antibody or a pharmaceutical composition comprising the same, IL-2 or a pharmaceutical composition comprising the same, and an immune checkpoint inhibitor or a pharmaceutical composition comprising the same. The immune checkpoint inhibitor is a programmed cell death ligand 1 (PDL-1) checkpoint inhibitor, or a programmed cell death protein 1 (PD-1), optionally, the PDL-1 checkpoint inhibitor is selected from avelumab, atezolizumab, durvalumab, segmariumab, and enbufolimab, and the PD-1 checkpoint inhibitor is selected from nivolumab, pembrolizumab, cemiplimab, camrelizumab, zingeberilumab, tislelizumab, sintilimab, teriplizumab, prologolimab, penprimumab and the like.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 62 / 977,292, filed February 16, 2020, and U.S. Provisional Patent Application No. 63 / 139,315, filed January 20, 2021, the entire disclosures of both of which are incorporated herein by reference.

[0002] (Sequence Listing Statement) This application contains a Sequence Listing, the entirety of which is incorporated herein by reference.

[0003] (Technical field) The present disclosure relates generally to the field of antibodies. In one embodiment, the present disclosure relates to the production and use of engineered anti-IL-2 antibodies that confer altered receptor binding specificity to IL-2. [Background technology]

[0004] Interleukin-2 (IL-2) is a 15.4 kDa type I cytokine with a four-helical bundle structure. Since its discovery more than 30 years ago, its importance in regulating the immune system has been repeatedly described. IL-2 is primarily produced and secreted by antigen-activated CD4+ T cells. To a lesser extent, IL-2 is also produced by CD8+ T cells, natural killer (NK) cells, dendritic cells, and mast cells.

[0005] IL-2 signaling has two opposing effects. IL-2 can enhance immune responses by activating and expanding effector cells. IL-2 can also downregulate immune responses by activating and expanding CD4+ regulatory T (Treg) cells. To promote these functions, IL-2 mediates its effects by binding to two types of IL-2 receptors: (i) a trimeric IL-2 receptor consisting of the IL-2Rα (CD25), IL-2Rβ (CD122), and IL-2Rγ (γc, CD132) common chains; and (ii) a dimeric IL-2 receptor consisting only of the IL-2Rβ and IL-2Rγ subunits. Both the dimeric and trimeric receptors can transmit IL-2 binding signals via the STAT5 pathway. However, IL-2 binds 100-fold more tightly to the αβγ trimeric receptor than to the βγ dimeric receptor. hIL-2 has demonstrated a binding affinity of approximately 10 pM to the αβγ trimeric receptor and 1 nM to the βγ dimeric receptor.

[0006] The difference in binding affinity of IL-2 to dimeric and trimeric receptors is one of the important mechanisms maintaining immunological homeostasis in vivo. Activation of the trimeric receptor is associated with FoxP3-mediated transcription in Tregs, which express a higher number of αβγ trimeric receptors on their membranes. In contrast, binding of IL-2 to the βγ dimeric receptor is associated with activation of NK cells and memory phenotype (MP) CD8+ cells, which express relatively high levels of βγ dimeric receptors and very low levels of αβγ trimeric receptors. Because natural levels of IL-2 are relatively low under normal physiological conditions, its primary function appears to be to promote immune tolerance by acting as an activation and proliferation factor for Tregs. On the other hand, upon immune system activation, IL-2 levels increase, and IL-2 can then bind to the βγ dimeric receptor to promote the activation and proliferation of memory phenotype effector T cells (MP) CD8+ and NK cells.

[0007] Since the early 1990s, high-dose IL-2 therapy has been used to treat melanoma and metastatic renal cell carcinoma, with response rates ranging from 10% to 15%. While effective, this approach has not been adopted for other cancers because IL-2-dependent side effects, such as potentially fatal vascular leak syndrome (VLS), preclude many patients from this treatment approach. The short half-life of administered IL-2 necessitates very frequent administration, resulting in repeated spikes in circulating IL-2 levels and exacerbating side effects. Finally, wild-type IL-2 is not selective and may promote undesired activation of Treg cells.

[0008] Certain antibodies have been found to bind IL-2 and modulate its binding to the βγ dimeric IL-2 receptor or the αβγ trimeric IL-2 receptor. IL-2 complexed with such antibodies has a relatively long half-life, and this IL-2 complex activates specific subsets of effector or immune cells. For example, a complex of the S4B6 antibody (mouse) with IL-2 selectively activates mouse effector cells in vivo. Furthermore, a complex of the JES6.1 antibody (mouse) with IL-2 selectively activates mouse T regulatory cells in vivo. The mechanism of regulation by the JES6.1 antibody has been elucidated. It has been shown that a complex of JES6.1 and mIL-2 binds to CD25 but not CD122 in vitro.

[0009] Increased IL-2 levels are thought to be involved in viral infection. SARS-CoV-2 is a positive-strand RNA virus in the respiratory coronavirus family. The virus enters the host by binding to angiotensin-converting enzyme 2 (ACE2) on lung and gastrointestinal tissues. The course of infection is characterized by an incubation period of approximately 7–14 days, followed by symptoms of dry cough, fever, and shortness of breath. Up to 20% of symptomatic individuals develop severe symptoms, and an average of 3% die from pulmonary failure. Previous studies of members of the coronavirus family have demonstrated that coronavirus infection induces an increase in regulatory T lymphocytes, which may contribute to delayed viral clearance. More recent studies of COVID-19 patients have found that ICU patients have higher levels of IL-2, IL-7, IL-10, GSCF, IP10, MCP1, MIP1A, and TNF-α than non-ICU patients, suggesting an immunopathological role in severe disease. A search for direct evidence of altered leukocyte homeostasis using immunological characterization of peripheral blood leukocytes from patients infected with SARS-CoV-2 revealed that in COVID-19, as in some chronic infections, impaired CD4+ T cell function promotes CD8+ T cell hyperactivation and subsequent exhaustion. Perturbations of these T cell subsets could ultimately compromise host antiviral immunity. Therefore, therapies that slow viral replication or enhance immune responses to eliminate viral load while also reducing some of the associated immunopathology would be of great benefit.

[0010] The immune response to viruses consists of both the innate and adaptive immune systems. The innate immune system senses viral RNA / DNA using Toll-like receptors (TLRs) and retinoic acid-inducible gene I (RIG-I) proteins and induces an early response. This early response includes the production of antiviral cytokines (e.g., interferon-α), the production of chemokines that guide the immune system to the site of infection, and the recruitment of macrophages and dendritic cells. Natural killer (NK) cells (innate lymphocytes) directly kill virus-infected cells in the absence of MHC class I expression. This can also occur if the virus interferes with the MHC class I presentation system.

[0011] In addition, during infection response, NK cells produce interferon-γ (IFN-γ), thereby increasing the expression of MHC class I on cells and enhancing the adaptive immune system's response potential. The adaptive immune system consists of T cells (CD4 and CD8) and B cells. CD4+ T cells recognize viral antigens in the context of MHC-II on antigen-presenting cells, amplify the immune response (via cytokines), induce B cell class switching, and subsequently produce antiviral antibodies. Activation of CD4 cells, particularly Th1 cells, releases IFN-γ, thereby promoting the presentation of viral antigens. CD8+ T cells exert a direct lytic effect on virus-infected cells presenting viral peptides in the context of MHC-I. The initial induction phase of the immune response typically takes 7–10 days to expand the T cell population and produce the cells necessary to eliminate the virus.

[0012] IL-2 is a key mediator of T cell and NK cell proliferation and activation. IL-2 is generally believed to play a key role in the secondary signaling required for T cell activation. Regarding the expression of dimeric (βγ) and trimeric (αβγ) IL-2 receptor complexes, the trimeric receptor containing CD25 (α subunit) is highly expressed on regulatory T cells and subsets of activated, short-lived cytotoxic effector T cells, whereas the dimeric receptor exhibits lineage selectivity in that it is found on naive T cells, memory T cells, and NK cells. Thus, naive T cells, memory T cells, and NK cells can receive signals via IL-2 bound to the dimeric receptor. Regulatory T cells rely on the high-affinity trimeric receptor complex to enhance their function, which involves sequestering IL-2 from binding to memory and naive T cells, thereby reducing the function of these cell populations. The mechanism of IL-2 action is shown in Figure 1.

[0013] Effector T cell subsets also express the trimeric IL-2 receptor complex. These cells are highly active, but IL-2 binding to these subsets induces activation-induced cell death (AICD). Furthermore, CD25 has been shown to be expressed on pulmonary and vascular endothelium. This expression correlates with pulmonary edema and vascular leakage in a mouse model treated with high-dose IL-2 therapy. It has been suggested that CD25 expression on lung cells contributes to the pulmonary toxicity of high-dose IL-2 therapy. Furthermore, while pulmonary endothelial cells express CD25 under steady-state conditions, the expression level of CD25 on pulmonary endothelial cells increases in vivo after IL-2 injection in mice. It has been shown that IL-2-induced pulmonary edema and vascular leak syndrome can be prevented by knocking out CD25 on non-immune cells or by blocking the CD25-binding epitope of IL-2 using immunoconjugates of IL-2 and anti-IL-2 antibodies (IL-2 / mAb). It has also been demonstrated that administration of high doses of IL-2 to mice that have been genetically engineered to deplete T and B cells and then sublethally irradiated to eliminate remaining immune cells (NK, monocytes, DCs, and granulocytes) results in severe pulmonary edema, indicative of the absence of immune components.

[0014] Much research has explored the dual role of IL-2 in the lung's ability to clear viral infections. IL-2 has been shown to be necessary for the proliferation of CD8+ T cells required for viral clearance. IL-2 has also been shown to mediate pulmonary edema. For example, in a murine influenza model of pulmonary infection with influenza virus, it has been demonstrated that memory CD4+ T cells produce high levels of IL-2, and the presence of this IL-2 exacerbates the disease. Regulatory T cells are important for reducing pathological damage to lung tissue during viral infection. One mechanism by which Tregs control CD8+ effector cells has been hypothesized and demonstrated to be through high-affinity consumption of IL-2 via the CD25 trimeric receptor on Tregs. This may actually remove IL-2 from proliferating effector cells, limiting their effectiveness and potentially reducing viral clearance. Tregs also appear to limit the effects of IL-2 on the pulmonary endothelium by sequestering IL-2 from CD25+ endothelial cells. The outcome depends on the Teff / Treg ratio. High levels of Teff (effector T cells) lead to viral clearance, but can also lead to excessive levels of IL-2 secreted by immune-activated cells, which can cause pulmonary edema. In contrast, high Treg proliferation reduces pulmonary edema pathology, but can also reduce viral clearance and prolong viral infection.

[0015] Recent data from COVID-19 patients suggest that higher viral loads are associated with poorer outcomes. Therefore, reduced viral clearance is thought to be associated with worse outcomes. In a mouse model, the role of Tregs in reduced viral clearance was demonstrated using an influenza A virus (IAV) infection model. Mice infected with IAV had higher levels of Tregs in the lungs, spleen, and lymph nodes, and higher viral loads in lung tissue. This was observed even 6 weeks after the onset of infection. These findings suggest that influenza A induces Treg proliferation to evade immune clearance. To evaluate whether a boosted immune response could increase clearance of IAV infection in the lungs, researchers infected IAV-infected mice with lymphocytic choriomeningitis virus (LCMV), which induces a vigorous cytotoxic T lymphocyte response. Furthermore, the extensive immune response in IAV-infected lungs led to pulmonary edema and extensive lung tissue damage. On the other hand, treatment of IAV-infected mice with anti-CD25 blocking antibodies before LCMV challenge protected them from severe pulmonary edema. These data demonstrate that enhancing immune responses in the setting of delayed viral clearance by Tregs can induce viral clearance. Additionally, blocking IL-2 binding to CD25+ cells reduces the risk of immune-mediated pulmonary edema during viral clearance.

[0016] IL-2 administered as monotherapy has been shown to enhance antiviral immune responses. We examined the effects of IL-2 therapy on the proliferation, contraction, and memory phases of T cells in LCMV-infected mice. We found that IL-2 therapy during the proliferation phase was detrimental to the survival of rapidly dividing effector T cells, which transiently upregulated CD25 expression. These effector T cells were subsequently induced to undergo activation-induced cell death (AICD). In contrast, IL-2 therapy was highly effective during the contraction phase, resulting in the survival and activation of virus-specific T cells. IL-2 therapy was also observed to promote the activation and proliferation of resting memory T cells. However, IL-2 therapy has drawbacks. Due to its short half-life, multiple administrations are required, such as daily loading doses followed by weekly administrations, which increases the risk of associated adverse events and increased immunogenicity. In addition, exogenous administration of high-dose IL-2 is expected to bind to CD25-positive endothelial cells. In fact, pulmonary edema and vascular leak syndrome are major serious adverse events of high-dose IL-2 therapy in oncology. The development of technologies to overcome these problems is crucial for the use of IL-2 as a therapeutic agent.

[0017] Those skilled in the art will recognize that the principles discussed above with respect to IL-2 and the treatment of viral infections are equally applicable to IL-2 and the treatment of bacterial infections or the treatment of cancer.

[0018] Advances in the field of biomolecular engineering have provided researchers with unprecedented opportunities to apply molecular design strategies to modify naturally occurring proteins and generate new molecules for the treatment of targeted diseases. In some areas, the development of immunotherapeutic agents, such as cytokine-based and antibody-based drugs, has been driven by advanced technologies and insights from protein engineering. Thus, there is a need for the development of engineered anti-IL-2 antibodies that can be used to modulate the function of IL-2 in specific disease states, such as, but not limited to, viral infections, bacterial infections, and cancer. Summary of the Invention [Means for solving the problem]

[0019] In one aspect of the disclosure, there is provided an isolated anti-IL-2 antibody comprising a heavy chain variable region (VH) and a light chain variable region (VL), The heavy chain variable region (VH) contains heavy chain complementarity determining regions (HCDRs): HCDR1, HCDR2, and HCDR3; The light chain variable region (VL) contains light chain complementarity determining regions (LCDRs) LCDR1, LCDR2, and LCDR3; The amino acid sequences of the heavy chain complementarity determining region (HCDR) and the light chain complementarity determining region (LCDR) are: (a) HCDR1 comprises the amino acid sequence of SEQ ID NO: 38, HCDR2 comprises the amino acid sequence of SEQ ID NO: 39, HCDR3 comprises the amino acid sequence of SEQ ID NO: 40, LCDR1 comprises the amino acid sequence of SEQ ID NO: 41, LCDR2 comprises the amino acid sequence of SEQ ID NO: 42, and LCDR3 comprises the amino acid sequence of SEQ ID NO: 43; or (b) HCDR1 comprises the amino acid sequence of SEQ ID NO: 44, HCDR2 comprises the amino acid sequence of SEQ ID NO: 45, HCDR3 comprises the amino acid sequence of SEQ ID NO: 46, LCDR1 comprises the amino acid sequence of SEQ ID NO: 47, LCDR2 comprises the amino acid sequence of SEQ ID NO: 48, and LCDR3 comprises the amino acid sequence of SEQ ID NO: 49; or (c) HCDR1 comprises the amino acid sequence of SEQ ID NO: 50, HCDR2 comprises the amino acid sequence of SEQ ID NO: 51, HCDR3 comprises the amino acid sequence of SEQ ID NO: 52, LCDR1 comprises the amino acid sequence of SEQ ID NO: 53, LCDR2 comprises the amino acid sequence of SEQ ID NO: 54, and LCDR3 comprises the amino acid sequence of SEQ ID NO: 55; or (d) HCDR1 comprises the amino acid sequence of SEQ ID NO: 56, HCDR2 comprises the amino acid sequence of SEQ ID NO: 57, HCDR3 comprises the amino acid sequence of SEQ ID NO: 58, LCDR1 comprises the amino acid sequence of SEQ ID NO: 59, LCDR2 comprises the amino acid sequence of SEQ ID NO: 60, and LCDR3 comprises the amino acid sequence of SEQ ID NO: 61; or (e) An antibody is provided, wherein HCDR1 comprises the amino acid sequence of SEQ ID NO: 62, HCDR2 comprises the amino acid sequence of SEQ ID NO: 63, HCDR3 comprises the amino acid sequence of SEQ ID NO: 64, LCDR1 comprises the amino acid sequence of SEQ ID NO: 65, LCDR2 comprises the amino acid sequence of SEQ ID NO: 66, and LCDR3 comprises the amino acid sequence of SEQ ID NO: 67.

[0020] In another related aspect, the amino acid sequences of the heavy chain variable region (VH) and light chain variable region (VL) are: (a) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 10 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 11; or (b) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 12 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 13; or (c) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 14 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 15; or (d) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 16 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 17; or (e) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 18 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 19; or (f) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 20 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 21; or (g) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 22 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 23; or (h) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 24 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 25; or (i) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 26 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 27, or (j) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 36, and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 37.

[0021] In another related aspect, the antibody of the disclosure comprises an IgG, IgA, IgM, IgE, IgD, Fv, scFv, Fab, F(ab')2, minibody, diabody, triabody, nanobody, or single domain antibody.

[0022] In another related aspect, an antibody of the disclosure comprises a heavy chain having a mutation that reduces binding to an Fcγ receptor. In yet another related aspect, an antibody of the disclosure comprises a heavy chain sequence and a light chain sequence, wherein the heavy chain sequence and the light chain sequence comprise (a) the heavy chain sequence set forth in SEQ ID NO: 68 and the light chain sequence set forth in SEQ ID NO: 69, (b) the heavy chain sequence set forth in SEQ ID NO: 70 and the light chain sequence set forth in SEQ ID NO: 71, or (c) the heavy chain sequence set forth in SEQ ID NO: 72 and the light chain sequence set forth in SEQ ID NO: 73.

[0023] In one aspect of the present disclosure, a composition is provided comprising the antibody of the present disclosure and a pharmaceutically acceptable carrier. In another related aspect, the composition of the present disclosure is formulated to have a pH value of about pH 5.0 to 6.0 and comprises a buffer selected from a histidine buffer and a citrate buffer. In yet another related aspect, the composition of the present disclosure further comprises at least one of sucrose, methionine, or PS80, or any combination thereof. In yet another related aspect, the composition of the present disclosure further comprises IL-2.

[0024] In one aspect of the disclosure, there is provided an isolated polynucleotide sequence encoding the heavy chain variable region (VH) of an anti-IL-2 antibody, wherein the amino acid sequence of the heavy chain variable region (VH) comprises the amino acid sequence set forth in SEQ ID NO: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36. In another related aspect, there is provided a vector comprising the isolated polynucleotide sequence encoding the heavy chain variable region (VH) of an anti-IL-2 antibody, wherein the amino acid sequence of the heavy chain variable region (VH) comprises the amino acid sequence set forth in SEQ ID NO: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36. In yet another related aspect, a host cell is provided that comprises a vector comprising an isolated polynucleotide sequence encoding a heavy chain variable region (VH) of an anti-IL-2 antibody, wherein the amino acid sequence of the heavy chain variable region (VH) comprises the amino acid sequence set forth in SEQ ID NO: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36.

[0025] In one aspect of the disclosure, there is provided an isolated polynucleotide sequence encoding the light chain variable region (VL) of an anti-IL-2 antibody, wherein the amino acid sequence of the light chain variable region (VL) comprises the amino acid sequence set forth in SEQ ID NO: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37. In another related aspect, there is provided a vector comprising the isolated polynucleotide sequence encoding the light chain variable region (VL) of an anti-IL-2 antibody, wherein the amino acid sequence of the light chain variable region (VL) comprises the amino acid sequence set forth in SEQ ID NO: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37. In yet another related aspect, a host cell is provided that comprises a vector comprising an isolated polynucleotide sequence encoding a light chain variable region (VL) of an anti-IL-2 antibody, wherein the amino acid sequence of the light chain variable region (VL) comprises the amino acid sequence set forth in SEQ ID NO: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37.

[0026] In one aspect of the disclosure, there is provided an isolated polynucleotide sequence encoding an anti-IL-2 antibody scFv, wherein the isolated polynucleotide sequence is set forth in SEQ ID NO: 1, 2, 3, 4, 5, 31, 32, 33, 34, or 35. In another related aspect, there is provided a vector comprising the isolated polynucleotide sequence encoding an anti-IL-2 antibody scFv, wherein the isolated polynucleotide sequence is set forth in SEQ ID NO: 1, 2, 3, 4, 5, 31, 32, 33, 34, or 35. In yet another related aspect, there is provided a host cell comprising a vector comprising the isolated polynucleotide sequence encoding an anti-IL-2 antibody scFv, wherein the isolated polynucleotide sequence is set forth in SEQ ID NO: 1, 2, 3, 4, 5, 31, 32, 33, 34, or 35.

[0027] In one aspect of the present disclosure, there is provided a method of treating a disease or condition in a subject, the method comprising administering to the subject a composition comprising an anti-IL-2 antibody of the present disclosure, wherein the antibody promotes the differentiation and growth of a subset of immune cells and reduces undesirable effects caused by IL-2, thereby treating the disease or condition in the subject.

[0028] In another related aspect, the compositions of the disclosure comprise an anti-IL-2 antibody and IL-2, or an anti-IL-2 antibody complexed with IL-2.

[0029] In another related aspect, the disease comprises a viral infection, a bacterial infection, or cancer. In yet another related aspect, the viral infection is caused by SARS-CoV-2; norovirus; rotavirus; hepatitis A, B, C, D, or E virus; rabies virus; West Nile virus; enterovirus; echovirus; coxsackievirus; herpes simplex virus (HSV); HSV-2; varicella-zoster virus; mosquito-borne virus; arbovirus; St. Louis encephalitis virus; California encephalitis virus; lymphocytic choriomeningitis virus; human immunodeficiency virus (HIV); poliovirus; Zika virus; rubella virus; cytomegalovirus; human papillomavirus (HPV); enterovirus D68; severe acute respiratory syndrome (SARS) coronavirus; Middle East respiratory syndrome coronavirus; Epstein-Barr virus; influenza virus; respiratory syncytial virus; polyomavirus, including JC virus; BK virus; Ebola virus; dengue virus; or any combination thereof.

[0030] In another related aspect, the condition comprises a weakened immune system and treating the condition comprises prophylactically boosting the immune system. In yet another related aspect, the condition comprises IL-2 induced pulmonary edema or IL-2 induced vascular leakage.

[0031] In another related aspect, the condition comprises a genetic predisposition that increases the likelihood of cancer in the subject. In yet another related aspect, the genetic predisposition comprises an alteration in the expression or activity of a gene product, wherein the gene comprises a tumor suppressor gene, a mismatch repair (MMR) gene, or a combination thereof. In yet another related aspect, the genetic predisposition comprises an alteration in the expression or activity of a gene product, wherein the gene comprises BRCA1, BRAC2, MLH1, MSH2, MSH6, PMS1, PMS2, TP53, CHEK2, or any combination thereof.

[0032] In another related embodiment, the immune cells are selected from the group consisting of naive T cells, memory T cells, CD8 +The cells include one or more of T cells, NK cells, or natural killer T cells.

[0033] In yet another related aspect, the undesirable effects caused by IL-2 include the activation of regulatory T cells, CD25 + These include one or more of T effector cell apoptosis, IL-2-induced pulmonary edema, IL-2-induced pneumonia, or IL-2-induced vascular leakage.

[0034] In yet another related embodiment, the anti-IL-2 antibody inhibits binding of IL-2 to CD25.

[0035] In yet another related embodiment, the subject is further treated with one or more immune checkpoint inhibitors that target one or more immune checkpoints. In yet another related embodiment, the subject is treated with the immune checkpoint inhibitor concurrently with, prior to, or after treatment with an anti-IL-2 antibody. In yet another related embodiment, the immune checkpoints include PD-1, PDL-1, CTLA-4, TIGIT, TIM-3, B7-H3, CD73, LAG3, CD27, CD70, 4-1BB, GITR, OX40, SIRP-α (CD47), CD39, ILDR2, VISTA, BTLA, VTCN-1, or any combination thereof.

[0036] In one aspect of the disclosure, there is provided a method of immunizing a subject, the method comprising administering a vaccine comprising an adjuvant, the adjuvant comprising an IL-2 antibody adjuvant, the IL-2 antibody adjuvant comprising an anti-IL-2 antibody of claim 1. In another related aspect, the IL-2 antibody adjuvant comprises an anti-IL-2 antibody and IL-2, or an anti-IL-2 antibody complexed with IL-2. In yet another related aspect, the subject has a weakened immune system.

[0037] In another related aspect, the subject has a genetic predisposition that increases the likelihood of cancer in the subject. In yet another related aspect, the genetic predisposition comprises an alteration in the expression or activity of a gene product, wherein the gene comprises a tumor suppressor gene, a mismatch repair (MMR) gene, or a combination thereof. In yet another related aspect, the genetic predisposition comprises an alteration in the expression or activity of a gene product, wherein the gene comprises BRCA1, BRAC2, MLH1, MSH2, MSH6, PMS1, PMS2, TP53, CHEK2, or any combination thereof. [Brief explanation of the drawings]

[0038] This patent or application contains at least one color drawing. Copies of this patent or patent application publication with color drawing(s) will be provided by the Patent and Trademark Office upon request and payment of the necessary fee.

[0039] The engineered anti-IL-2 antibodies of the present disclosure, together with their objects, features, and advantages, both as to how to make and use them, can best be understood by reference to the following detailed description.

[0040] [Figure 1] FIG. 1 is a schematic diagram illustrating the mechanism of action of IL-2 and its dual role in regulating immune responses. [Figure 2] FIG. 2 is a schematic diagram showing anti-IL-2 antibody-directed immunotherapy. [Figure 3A] Figures 3A and 3B are schematic diagrams showing the progression of COVID-19 infection and potential anti-IL-2 therapy as an adjuvant intervention. Figure 3A is adapted from Shi Y et al., (2020) COVID-19 infection: the perspectives on immune responses. Cell Death & Differentiation volume 27, pages 1451-1454 (doi:10.1038 / s41418-020-0530-3), Fig. 1. [Figure 3B]Figures 3A and 3B are schematic diagrams showing the progression of COVID-19 infection and potential anti-IL-2 therapy as an adjuvant intervention. [Figure 4A] FIG. 4A shows a representative SPR sensorgram of the JES6.1 antibody binding to human IL-2. [Figure 4B] FIG. 4B shows a representative SPR sensorgram of the JES6.1 antibody binding to mouse IL-2. [Figure 4C] FIG. 4C shows a representative SPR sensorgram of the JES6.1RMC antibody binding to human IL-2. [Figure 4D] FIG. 4D shows a representative SPR sensorgram of the JES6.1RMC antibody binding to mouse IL-2. [Figure 5A] Figures 5A-5C show the IL-2 binding results for YSD clones expressing the JES6.1 antibody in scFv format. Fluorescence levels on the X-axis correspond to the Jes6.1 scFv expression level, and fluorescence levels on the Y-axis correspond to the binding of human or mouse IL-2. Figure 5A shows a negative control without IL-2. [Figure 5B] FIG. 5B shows the JES6.1YSD clone containing 1000 nM human IL-2. [Figure 5C] FIG. 5C shows YSD expressing mouse IL-2 incubated with 100 nM labeled JES6.1. [Figure 6A] Figure 6A shows the binding of isolated yeast surface-displayed clones to IL-2 (0.1 nM). Mean fluorescence intensity (Em 655 nM) was normalized to yeast surface expression. Negative YSD clones were labeled with 500 nM hIL-2. [Figure 6B] Figure 6B shows nonspecific binding of YSD clones to a mixture of OX40 / PD-1 / TNFR2. Clones were labeled with 500 nM of the mixture. A TNFR2-binding yeast clone was used as a positive control. [Figure 7]Figure 7 shows the purification of BDG17.023 IgG. The antibody was run at 0.5 ml / min in PBS buffer on a GE Superdex 200 with a 10 / 300 gradient (CV = 25 ml). The first peak (0.38 CV) corresponds to typical aggregates, while the second peak (0.51 CV) with a retention of approximately 12.9 ml is characteristic of normal human IgG. [Figure 8A] FIG. 8A shows the binding kinetics of BDG17.023 IgG to hIL-2. [Figure 8B] FIG. 8B shows the binding kinetics of BDG17.023 IgG to mIL-2. [Figure 9] Figure 9 shows SPR response traces of receptor recognition by the BDG17.023 / IL-2 complex. BDG17.023 was immobilized on a CM5 chip, and hIL-2 (60 RU), CD122 (20 RU), and CD25 (0 RU) were flowed through as indicated by the arrows. [Figure 10A] Figures 10A-10D show splenic immune cell populations from mice treated with JES6.1 / mIL-2 complexes and BDG17.023 / hIL-2 complexes. Figure 10A shows the percentage of immune cell populations from mice treated with JES6.1 / mIL-2 complexes. [Figure 10B] FIG. 10B shows the memory phenotype effector T cell (MP) CD8+ / Treg ratio in mice treated with JES6.1 / mIL-2 complex. [Figure 10C] FIG. 10C shows the percentage of immune cell populations from mice treated with BDG17.023 / hIL-2 complexes. [Figure 10D] FIG. 10D shows the MPCD8+ / Treg ratio in mice treated with BDG17.023 / hIL-2 complexes. [Figure 11] Figure 11 shows an alignment of the amino acid sequences of the heavy chain variable regions of JES6.1 clone 1 (17.021), clone 2 (17.022), clone 4 (17.023), clone 5 (17.030), and clone 6 (17.035). [Figure 12]Figure 12 shows an alignment of the amino acid sequences of the light chain variable regions of JES6.1 clone 1 (17.021), clone 2 (17.022), clone 4 (17.023), clone 5 (17.030), and clone 6 (17.035). [Figure 13A] Figure 13A shows an alignment of the amino acid sequences of the heavy chain variable regions of humanized clones 17.014, 17.038, 17.043, 17.053, and 17.054. Black triangles indicate the positions of the IMGT CDRs. Bold / italic indicates the positions of the ABRs and CDRs, respectively. [Figure 13B] Figure 13B shows an alignment of the amino acid sequences of the light chain variable regions of humanized clones 17.014, 17.038, 17.043, 17.053, and 17.054. Black triangles indicate the positions of the IMGT CDRs. Bold / italic indicates the positions of the ABRs / CDRs, respectively. [Figure 14A] Figures 14A to 14G show the binding kinetics of each antibody to human IL-2. Surface plasmon resonance (SPR) sensorgrams traced the binding kinetics of the anti-IL-2 antibody clone BDG17.038 to human IL-2. The binding kinetics of BDG17.038 was measured by the multi-cycle method. [Figure 14B] Surface plasmon resonance (SPR) sensorgrams traced the binding kinetics of BDG17.043, an anti-IL-2 antibody clone, to human IL-2. The binding kinetics of BDG17.043 was measured by the multi-cycle method. [Figure 14C] Surface plasmon resonance (SPR) sensorgrams traced the binding kinetics of BDG17.053, an anti-IL-2 antibody clone, to human IL-2. The binding kinetics of BDG17.053 was measured by the single-cycle method. [Figure 14D]Surface plasmon resonance (SPR) sensorgrams traced the binding kinetics of BDG17.054, an anti-IL-2 antibody clone, to human IL-2. The binding kinetics of BDG17.054 was measured by the single-cycle method. [Figure 14E] Surface plasmon resonance (SPR) sensorgrams traced the binding kinetics of BDG17.066, an anti-IL-2 antibody clone, to human IL-2. The binding kinetics of BDG17.066 was measured by the multi-cycle method. [Figure 14F] Surface plasmon resonance (SPR) sensorgrams traced the binding kinetics of BDG17.067, an anti-IL-2 antibody clone, to human IL-2. The binding kinetics of BDG17.067 was measured by the multi-cycle method. [Figure 14G] Surface plasmon resonance (SPR) sensorgrams traced the binding kinetics of BDG17.069, an anti-IL-2 antibody clone, to human IL-2. The binding kinetics of BDG17.069 was measured by the multi-cycle method. [Figure 15A] 15A and 15B show the binding kinetics of each antibody to cynomolgus monkey IL-2. Surface plasmon resonance (SPR) sensorgrams traced the binding kinetics of the anti-IL-2 antibody clone BDG17.067 to cynomolgus monkey IL-2. [Figure 15B] Surface plasmon resonance (SPR) sensorgrams traced the binding kinetics of BDG17.069, an anti-IL-2 antibody clone, to cynomolgus monkey IL-2. [Figure 16A] Figures 16A-16G show the results of differential scanning fluorescence (DSF) analysis of the melting temperatures of each IgG. The light green dashed line indicates Tonset, and the thick green dashed line indicates Tm1 and, where applicable, Tm2. The anti-IL-2 clone analyzed was BDG17.038. [Figure 16B] The anti-IL-2 clone analyzed is BDG17.043. [Figure 16C]The anti-IL-2 clone analyzed is BDG17.053. [Figure 16D] The anti-IL-2 clone analyzed is BDG17.054. [Figure 16E] The anti-IL-2 clone analyzed is BDG17.066. [Figure 16F] The anti-IL-2 clone analyzed is BDG17.067. [Figure 16G] The anti-IL-2 clone analyzed is BDG17.069. [Figure 17A] Figures 17A and 17B show the receptor discrimination of each antibody / IL-2 complex by SPR response tracing. Antibodies were immobilized on a CM5 chip, and hIL-2, CD122, and CD25 were streamed as indicated by the arrows. Figure 17A shows the general sequence of compound injection onto the SPR chip, depicting sequential anti-IL-2 antibodies complexed with human IL-2 (hIL2), which bind to CD122 but not CD25. [Figure 17B] Figure 17G shows the SPR response of BDG17.038. [Figure 17C] Figure 17C shows the SPR response of BDG17.043. [Figure 17D] Figure 17D shows the SPR response of BDG17.054. [Figure 17E] Figure 17E shows the SPR response of BDG17.066. [Figure 17F] Figure 17F shows the SPR response of BDG17.067. [Figure 17G] Figure 17G shows the SPR response of BDG17.069. [Figure 18A-1]Figure 18A shows that anti-human IL-2 antibodies (clone 17.043 and clone 17.054) exhibit potent immunostimulatory effects in vivo. Anti-IL-2 antibody / hIL-2 complexes increase effector cell populations but have no effect on regulatory T cells. Figure 18A shows an example in which C57BL / 6 mice were treated daily for 4 days with anti-IL-2 antibodies (10 μg) pre-complexed with 0.5 μg hIL-2. Splenocytes were isolated on day 5, and immune cell populations were analyzed by flow cytometry. Average values ​​for each experimental group are shown (n = 6 per group). Lymphocytes were gated according to side scatter and forward scatter parameters, and subsequent immune cell subpopulations were gated as follows: Tregs (CD45+, CD3+, CD4+, CD25+, FoxP3+), CD8 T cells (CD45+, CD3+, CD8+, CD122+, CD25-), NKT cells (CD45+, CD3+, CD49b+, NK1.1+), and NK cells (CD45+, CD3-, CD49b+, NK1.1+). [Figure 18A-2] Figure 18A shows that anti-human IL-2 antibodies (clone 17.043 and clone 17.054) exhibit potent immunostimulatory effects in vivo. Anti-IL-2 antibody / hIL-2 complexes increase effector cell populations but have no effect on regulatory T cells. Figure 18A shows an example in which C57BL / 6 mice were treated daily for 4 days with anti-IL-2 antibodies (10 μg) pre-complexed with 0.5 μg hIL-2. Splenocytes were isolated on day 5, and immune cell populations were analyzed by flow cytometry. Average values ​​for each experimental group are shown (n = 6 per group). Lymphocytes were gated according to side scatter and forward scatter parameters, and subsequent immune cell subpopulations were gated as follows: Tregs (CD45+, CD3+, CD4+, CD25+, FoxP3+), CD8 T cells (CD45+, CD3+, CD8+, CD122+, CD25-), NKT cells (CD45+, CD3+, CD49b+, NK1.1+), and NK cells (CD45+, CD3-, CD49b+, NK1.1+). [Figure 18B-1]Figure 18B shows that anti-human IL-2 antibodies (clone 17.043 and clone 17.054) exhibit potent immunostimulatory effects in vivo. Anti-IL-2 antibody / hIL-2 complexes increase effector cell populations but have no effect on regulatory T cells. Figure 18B shows an example of C57BL / 6 mice receiving daily injections of anti-IL-2 antibodies (25 μg) pre-complexed with 1.25 μg hIL-2 for 4 days. Splenocytes were isolated on day 5, and immune cell populations were analyzed by flow cytometry. Average values ​​for each experimental group are shown (n = 6 per group). Lymphocytes were gated according to side scatter and forward scatter parameters, and subsequent immune cell subpopulations were gated as follows: Tregs (CD45+, CD3+, CD4+, CD25+, FoxP3+), CD8 T cells (CD45+, CD3+, CD8+, CD122+, CD25-), NKT cells (CD45+, CD3+, CD49b+, NK1.1+), and NK cells (CD45+, CD3-, CD49b+, NK1.1+). [Figure 18B-2] Figure 18B shows that anti-human IL-2 antibodies (clone 17.043 and clone 17.054) exhibit potent immunostimulatory effects in vivo. Anti-IL-2 antibody / hIL-2 complexes increase effector cell populations but have no effect on regulatory T cells. Figure 18B shows an example of C57BL / 6 mice receiving 25 μg of anti-IL-2 antibody pre-complexed with 1.25 μg of hIL-2 daily for 4 days. Splenocytes were isolated on day 5, and immune cell populations were analyzed by flow cytometry. Average values ​​for each experimental group (n = 6 per group) are shown. Lymphocytes were gated according to side scatter and forward scatter parameters, and subsequent immune cell subpopulations were gated as follows: Tregs (CD45+, CD3+, CD4+, CD25+, FoxP3+), CD8 T cells (CD45+, CD3+, CD8+, CD122+, CD25-), NKT cells (CD45+, CD3+, CD49b+, NK1.1+), and NK cells (CD45+, CD3-, CD49b+, NK1.1+). [Figure 19A]Figures 19A and 19B show that anti-human IL-2 antibodies (clone 17.043 and clone 17.054) exhibit potent dose-dependent immunostimulatory effects in vivo. Figure 19A shows an example of C57BL / 6 healthy mice receiving daily administration of anti-IL-2 antibody / hIL-2 complexes (25 μg / 1.25 μg, respectively) for 4 days. On day 5, splenocytes were isolated, and immune cell populations were analyzed by flow cytometry. Lymphocytes were gated according to side scatter and forward scatter parameters, and subsequent immune cell subpopulations were gated as follows: Tregs (CD45+, CD3+, CD4+, CD25+, FoxP3+), CD8 T cells (CD45+, CD3+, CD8+, CD122+, CD25-), NKT cells (CD45+, CD3+, CD49b+, NK1.1+), and NK cells (CD45+, CD3-, CD49b+, NK1.1+). [Figure 19B] Figures 19A and 19B show that anti-human IL-2 antibodies (clone 17.043 and clone 17.054) exhibit potent dose-dependent immunostimulatory effects in vivo. Figure 19B shows that anti-human IL-2 antibodies exhibit potent in vivo immunostimulatory effects in a dose-dependent manner. Healthy C57BL / 6 mice were administered increasing doses of anti-IL-2 antibody / hIL-2 complexes daily. On day 5, splenocytes were isolated, and immune cell populations were analyzed by flow cytometry. Lymphocytes were gated according to side scatter and forward scatter parameters, and subsequent immune cell subpopulations were gated as follows: Tregs (CD45+, CD3+, CD4+, CD25+, FoxP3+), CD8 T cells (CD45+, CD3+, CD8+, CD122+, CD25-), NKT cells (CD45+, CD3+, CD49b+, NK1.1+), and NK cells (CD45+, CD3-, CD49b+, NK1.1+). [Figure 20A]Figures 20A and 20B show that anti-human IL-2 antibodies (clone 17.043 and clone 17.054) demonstrate a safe administration regimen in vivo. Figure 20A shows an example in which healthy C57BL / 6 mice were administered anti-IL-2 antibody / hIL-2 complexes (10 μg / 0.5 μg, respectively) daily for four days. After the experiment, the mice were weighed, and the weight change rate relative to the weight of each mouse at the start of the study was calculated. The average percent body weight (BW) change for each experimental group (n=6 per group) is shown. [Figure 20B] Figures 20A and 20B show that anti-human IL-2 antibodies (clone 17.043 and clone 17.054) demonstrate a safe administration regimen in vivo. Figure 20B shows an example in which healthy C57BL / 6 mice were administered anti-IL-2 antibody / hIL-2 complexes (25 μg / 1.25 μg, respectively) daily for four days. After the experiment, the mice were weighed, and the weight change rate relative to the weight of each mouse at the start of the study was calculated. The average percent body weight (BW) change for each experimental group (n=6 per group) is shown. [Figure 21A] Figures 21A and 21B show that anti-IL-2 antibodies (clone 17.043 and clone 17.054) inhibit tumor growth in an I / O-resistant tumor model with an acceptable safety profile. On day 0, C57BL / 6 healthy mice were inoculated with B16F10 melanoma tumor cells. On day 5, mice were randomized into experimental groups (n = 10 per group) and administered anti-IL-2 antibody / hIL-2 complexes (20 μg / 1 μg, respectively) or PBS daily for 4 days. Figure 21A shows the change in tumor volume for each experimental group. The percentage weight change was calculated relative to the weight of each mouse at the start of the study. [Figure 21B]Figures 21A and 21B show that anti-IL-2 antibodies (clone 17.043 and clone 17.054) inhibit tumor growth in an I / O-resistant tumor model with an acceptable safety profile. On day 0, C57BL / 6 healthy mice were inoculated with B16F10 melanoma tumor cells. On day 5, mice were randomized into experimental groups (n = 10 per group) and administered anti-IL-2 antibody / hIL-2 complexes (20 μg / 1 μg, respectively) or PBS daily for 4 days. Figure 21B shows the change in body weight for each experimental group. The percentage change in body weight was calculated relative to the weight of each mouse at the start of the study. [Figure 22A] Figures 22A-22G show the results of analyzing different formulations of the anti-IL-2 antibody clone BDG17.069. Figure 22A shows BDG17.069 parameters at T=0. [Figure 22B] FIG. 22B shows the appearance, pH, protein concentration, and sub-visual particle formation of BDG17.069 after 1 and 2 weeks of incubation at T=0 and 40° C. [Figure 22C] FIG. 22C shows SEC, caliper SDS, and capillary isoelectric focusing analyses of BDG17.069 after 1 and 2 weeks of incubation at T=0 and 40° C. [Figure 22D] FIG. 22D shows the appearance, pH, protein concentration, and subvisible particle formation of BDG17.069 at T=0 and after 3 days of stirring at 300 rpm. [Figure 22E] FIG. 22E shows SEC, caliper SDS, and capillary isoelectric focusing analyses of BDG17.069 at T=0 and after 3 days of stirring at 300 rpm. [Figure 22F] FIG. 22F shows the appearance, pH, protein concentration, and subvisible particle formation of BDG17.069 at T=0 and after 5 cycles of freeze / thaw. [Figure 22G] Figure 22G shows SEC, caliper SDS, and capillary isoelectric focusing analysis of BDG17.069 at T=0 and after 5 cycles of freeze / thaw. DETAILED DESCRIPTION OF THE INVENTION

[0041] The present disclosure provides engineered anti-human IL-2 antibodies that bind to human IL-2 with high affinity (e.g., 12.7 pM-48 pM) to a predefined binding epitope. The antibodies bind IL-2 in a manner that completely blocks CD25 binding while preserving IL-2 binding to CD122, thereby modulating the immune response to immunostimulation by directly activating and expanding effector cells without interacting with CD25-expressing cells (e.g., regulatory T cells, short-lived cytotoxic T cells, pulmonary endothelial cells, and vascular endothelial cells). Thus, the antibody / IL-2 complex promotes a robust immune response that eliminates viral load or tumors by expanding and activating effector cells such as NK cells, central memory T cells (memory T cells), and virus- or tumor-specific T cells, while suppressing IL-2 activation-induced cell death of short-lived CD25+ cytotoxic T cells, which are important for virus / tumor elimination. The antibody / IL-2 complex may also reduce immunosuppression caused by regulatory mechanisms of the immune system. Furthermore, the antibody / IL-2 complexes will block undesired interactions of IL-2 with vascular and pulmonary CD25-expressing cells, thereby preventing the severe syndromes of IL-2-induced vascular leakage and IL-2-induced pulmonary edema frequently seen in models of viral pulmonary infection. In some embodiments, the activity of the engineered anti-IL-2 antibodies described herein depends on the predefined epitope to which they are designed to bind.

[0042] Those skilled in the art will understand that in certain embodiments, the term "anti-IL-2 antibody" as used herein is interchangeable with the term "anti-human IL-2 antibody," all of which have the same properties and meaning. Similarly, as used throughout, in certain embodiments, the term "IL-2" is interchangeable with the term "human IL-2," all of which have the same properties and meaning.

[0043] In some embodiments, the anti-human IL-2 antibodies described herein inhibit IL-2 binding to the IL-2 receptor alpha (IL-2Rα, i.e., CD25) subunit and, therefore, inhibit binding to the trimeric IL-2Rαβγ receptor. In some embodiments, anti-IL-2 antibodies that inhibit IL-2 binding to the trimeric IL-2 receptor (IL-2Rαβγ) do not inhibit IL-2 binding to the dimeric IL-2 receptor (IL-2Rβγ).

[0044] Figure 2 is a schematic diagram of anti-IL-2 antibody-directed immunotherapy. Targeting IL-2 to various cell populations can be used to modulate immune responses toward immunosuppression or immune activation. The anti-human IL-2 antibodies disclosed herein are designed to bind with high affinity to an IL-2 epitope that inhibits IL-2 binding to CD25. As a result, IL-2 targets regulatory T cells or short-lived CD8 T cells that express high levels of CD25. + By blocking binding to cytotoxic T cells but preferentially binding to effector T cells, it enhances the immune response to improve viral or bacterial clearance. Furthermore, it also inhibits IL-2 binding to CD25-expressing endothelial cells, which would prevent IL-2-induced pulmonary edema and IL-2-induced vascular leakage.

[0045] In one embodiment, the present disclosure provides a method for treating a disease (e.g., a viral infection, a bacterial infection, or cancer) or condition (e.g., an undesirable condition caused by IL-2, such as, but not limited to, pulmonary edema) with an anti-IL-2 antibody designed to enhance T cell immune responses and prevent the severe edema syndrome of IL-2-induced acute pneumonia. The anti-IL-2 antibody specifically binds human IL-2 with high affinity at a predefined epitope that inhibits IL-2 binding to the α chain (CD25) of the IL-2 receptor, while sparing binding to the receptor's primary signaling β and γ chain complex (CD122 / CD132). As a result, in the presence of such an antibody, IL-2 is directed to immune cells responsible for viral / tumor elimination and away from cells that dampen the immune response or cause edema. Through the formation of this IL-2 / antibody immune complex, IL-2 specifically binds to and activates naive T lymphocytes, memory T lymphocytes, NK cells, and natural killer T lymphocytes, while also activating regulatory T cells and the short-lived CD25 + This suppresses the apoptosis of cytotoxic T effector cells. Overall, this ultimately results in an effective immune response, such as the elimination of viruses or tumors. Furthermore, this treatment can prevent toxicity caused by IL-2 binding to endothelial CD25-expressing cells. Therefore, in one embodiment, targeting IL-2 with the anti-IL-2 antibodies disclosed herein would be an effective treatment for respiratory diseases caused by viral or bacterial infections. In another embodiment, treatment with the anti-IL-2 antibodies disclosed herein would be effective in preventing toxicity caused by IL-2 binding to endothelial CD25-expressing cells, such as pulmonary edema or IL-2-induced vascular leakage. More importantly, enhancing IL-2 immune stimulation toward general immune activation and proliferation of immune effector cells independent of specific pathogens (e.g., viral antigens) is an effective strategy against future viral or bacterial pandemics caused by unknown pathogens (Figures 3A and 3B).

[0046] In one embodiment, the methods disclosed herein may be useful against infection caused by SARS-CoV-2. SARS-CoV-2 binds to angiotensin-converting enzyme 2 in lung cells, allowing viral entry and replication. The immune response to pulmonary viral infections is composed of both innate and adaptive immune responses. As with many respiratory viruses, clearance of SARS-CoV-2 from the lungs is expected to depend on a T cell immune response. The cytokine IL-2 is important for T cell proliferation and plays a key role in the immune response to viruses. However, IL-2 binds to endothelial CD25-expressing cells, resulting in prostimulatory effects as well as side effects such as pulmonary edema and vascular leak syndrome.

[0047] Figures 3A and 3B are schematic diagrams illustrating the progression of COVID-19 infection and the potential of anti-IL-2 therapy as an adjuvant intervention. Figure 3A shows that invaded SARS-CoV-2 causes non-severe symptoms and induces a protective immune response after an incubation period. Successful clearance of the infection depends on the health of the infected individual. While individuals with a weak immune response to the virus have difficulty clearing it, those with an overly strong immune response may develop pulmonary edema and other cytokine-induced side effects. Therefore, strategies to enhance the immune response and prevent pulmonary edema are desirable. While high concentrations of IL-2 are beneficial, especially for early viral clearance, high concentrations of IL-2 can also cause IL-2-induced pulmonary edema and vascular leakage due to the interaction of IL-2 with CD25-expressing endothelial cells. Figure 3B shows that anti-human IL-2 antibodies designed to bind and block the CD25 / IL-2 interaction are predicted to improve viral clearance by promoting the proliferation of immune effector cells and reduce the negative effects of IL-2 binding to CD25 expressed on endothelial cells, thereby preventing IL-2-induced pulmonary edema and IL-2-induced vascular leakage.

[0048] Figure 1 shows a schematic of the mechanism of action of IL-2 and its dual role in regulating immune responses. The left panel shows that IL-2 consists of three epitope binding sites (α, β, and γ) that interact with multiple forms of the IL2-R (CD25, CD122, and CD132) with different affinities. The right panel shows that different IL-2R complexes are expressed on different T cell populations, and their different affinities for IL2 allow immunosuppression under conditions of low local IL-2 concentrations and immunostimulation when local IL-2 concentrations are increased.

[0049] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the antibodies disclosed herein. However, it will be understood by those skilled in the art that the preparation and use of the antibodies disclosed herein may, in some instances, be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the disclosure provided herein.

[0050] Throughout this application, various references or publications are cited. The disclosures of these references and publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art to which this invention pertains.

[0051] As used herein, the term "antibody" is used interchangeably with the term "immunoglobulin," all having the same properties and meaning. An antibody binding domain or antigen-binding site can be a fragment of an antibody or a genetically engineered product of one or more fragments of an antibody, which fragment is responsible for specific binding to a target antigen. "Specific binding" means selective binding to the antigen of interest and the ability to distinguish from unwanted or nonspecific interactions. For example, an antibody is said to specifically bind to an IL-2 epitope if the equilibrium dissociation constant is 10 M or less, 10 M or less, or 10 M or less (equilibrium dissociation constant ≦10, 10, or 10 M). In some embodiments, the equilibrium dissociation constant can be 10 M or less or 10 M or less (equilibrium dissociation constant ≦10, 10, or 10 M). In some further embodiments, the equilibrium dissociation constant may be 10 M or less, 10 M or less, or 10 M or less (equilibrium dissociation constant ≦10, 10, or 10 M). In some embodiments, the equilibrium dissociation constant may be in the range of 10 M to 10 M or less (equilibrium dissociation constant ≦10 M to 10 M).

[0052] As used herein, the term "antibody" includes antibody fragments that retain binding specificity, including, but not limited to, IgG, heavy chain variable regions (VH), light chain variable regions (VL), Fab fragments, F(ab')2 fragments, scFv fragments, Fv fragments, nanobodies, minibodies, diabodies, triabodies, tetrabodies, and single domain antibodies (see, e.g., Hudson and Souriau, Nature Med. 9: 129-134 (2003)). Also included are humanized antibodies, primatized antibodies, and chimeric antibodies, as these terms are commonly understood in the art.

[0053] As used herein, the term "heavy chain variable region (VH)" is used interchangeably with the term "VH domain" or "VH," all having the same meaning and properties. As used herein, the term "light chain variable region (VL)" is used interchangeably with the term "VL domain" or "VL," all having the same meaning and properties. Those skilled in the art will recognize that a "heavy chain variable region (VH)" or "VH" for an antibody encompasses a fragment of a heavy chain comprising three complementarity-determining regions (CDRs) interposed between adjacent stretches, also known as framework regions. Framework regions are more highly conserved than complementarity-determining regions (CDRs) and form a scaffold to support the complementarity-determining regions (CDRs). Similarly, those skilled in the art will recognize that a "light chain variable region (VL)" or "VL" for an antibody encompasses a fragment of a light chain comprising three complementarity-determining regions (CDRs) interposed between framework regions.

[0054] As used herein, the term "complementarity-determining region" or "CDR" refers to the hypervariable region of a heavy chain variable region (VH) or a light chain variable region (VL). Starting from the N-terminus, each heavy or light chain polypeptide has three complementarity-determining regions (CDRs), designated "CDR1," "CDR2," and "CDR3." Crystal structure analyses of many antigen-antibody complexes have revealed that amino acid residues in the complementarity-determining regions (CDRs) form extensive contacts with the bound antigen, with the most extensive antigen contact occurring with CDR3 of the heavy chain. Thus, the complementarity-determining region (CDR) is primarily responsible for the specificity of an antigen-binding site. In one embodiment, the antigen-binding site comprises six complementarity-determining regions (CDRs), including CDRs from each of the heavy chain variable region (VH) and the light chain variable region (VL).

[0055] As used herein, the term "framework region" or "FR" refers to the four contiguous amino acid sequences that form the complementarity-determining regions (CDRs) of a heavy chain variable region (VH) or a light chain variable region (VL). While some FR residues contact a bound antigen, the FR residues are primarily responsible for folding the variable region into the antigen-binding site. In some embodiments, the FR residues responsible for folding the variable region include those immediately adjacent to the complementarity-determining regions (CDRs). Within the FRs, certain amino acid residues and certain structural features are highly conserved. In this regard, all variable region sequences contain an internal disulfide loop of approximately 90 amino acid residues. When the variable region folds into the antigen-binding site, the complementarity-determining regions (CDRs) are represented as protruding loop motifs that form the antigen-binding surface. It is generally recognized that FRs contain conserved structural regions that constrain the folded shape of the CDR loops to a particular "canonical" structure, regardless of the exact amino acid sequence of the CDRs. Furthermore, certain FR residues are known to participate in non-covalent interdomain contacts that stabilize the interaction between the heavy and light chains of an antibody.

[0056] Wu and Kabat (Tai Te Wu, Elvin A. Kabat. "An analysis of the sequences of the variable regions of Benefit Jones proteins and myeloma light chains and their implications for antibody complementarity", Journal of Experimental Medicine, 132, 2, 8 (1970); Kabat EA, Wu TT, Bilofsky H, Reid-Miller M, Perry H. "Sequence of proteins of immunological interest", Bethesda: National Institutes of Health; 1983. 323 (1983)) pioneered the alignment of antibody peptide sequences, and their contributions in this regard were significant. First, by examining the sequence similarity between variable domains, they identified corresponding residues that are more or less homologous in all antibodies of all vertebrate species, as long as they have similar three-dimensional structures, play similar functional roles, interact similarly with neighboring residues, and exist in a similar chemical environment. Second, they devised a peptide sequence numbering system in which identical position numbers are assigned to homologous immunoglobulin residues. Those skilled in the art can unambiguously assign what are now commonly called Kabat numbering to any variable domain sequence without relying on any experimental data other than the sequence itself. Third, Kabat and Wu calculated the variability of each Kabat-numbered sequence position, meaning that a small or large number of amino acids can be found when variable domain sequences are aligned. They determined that three contiguous regions of high variability are embedded within four contiguous regions of low variability. Kabat and Wu formally identified the residues that make up these variable regions and linked them to the chemical complementarity between antibody and antigen, naming them "complementarity-determining regions" (CDRs).The remaining less variable regions, which are not involved in antigen recognition but are involved in the three-dimensional folding of the variable regions, are now called "framework regions." Fourth, Kabat and Wu established public databases of antibody peptide and nucleic acid sequences that are still maintained today and are well known to those skilled in the art.

[0057] Chothia and coworkers (Cyrus Chothia, Arthur M. Lesk. Canonical structures for the hypervariable regions of immunoglobulins. Journal of Molecular Biology, 196, 4, 8 (1987)) discovered that certain subregions within the Kabat complementarity-determining regions (CDRs) have nearly identical peptide backbone structures despite great diversity at the amino acid sequence level. These subregions are designated L1, L2, and L3, or H1, H2, and H3, where "L" and "H" indicate the light chain and heavy chain regions, respectively. These regions are sometimes referred to as Chothia complementarity-determining regions (CDRs), with boundaries that overlap with the Kabat CDRs.

[0058] Recent studies have shown that virtually all antibody-binding residues are contained in structural consensus regions (Kunik, V. et al., PloS Computational Biology 8(2): el002388 (February 2012)). In some embodiments, these regions are referred to as antibody-binding regions. It has also been shown that these regions can be identified from antibody sequences. For this purpose, "Paratome," an implementation of a structural approach to identify antibody structural consensus, was used (Ofran, Y. et al., J. Immunol. 757:6230-6235 (2008)). While the residues identified by Paratome encompass virtually the entire antibody-binding site, they miss a significant portion of the complementarity-determining regions (CDRs) identified by commonly used CDR identification tools. Antibody-binding residues identified by Paratome but not by common CDR identification methods are referred to as Paratome-unique residues. Similarly, antibody-binding residues identified by common complementarity-determining region (CDR) identification methods but not by Paratome are called CDR-unique residues. Paratome-unique residues contribute significantly to the energy of antibody-antigen interactions, whereas the contribution of CDR-unique residues is significantly smaller. These results further confirm the identification of the antigen-binding site.

[0059] IMGT is the international ImMunoGeneTics information system (see Nucleic Acids Res. 2015 Jan; 43 (Database issue): D413-22. doi: 10.1093 / nar / gku1056. Epub 2014 Nov 5 Free article. PMID: 25378316 LIGM:441 and Dev Comp Immunol. 2003 Jan;27(1):55-77). IMGT is a unique numbering system for immunoglobulin and T-cell receptor variable domains and Ig superfamily V-like domains (Lefranc et al., Dev Comp Immunol. 27: 55-77 (2003)). IMGT provides a unified numbering system for IG and TcR variable domain sequences based on the alignment of five or more of these sequences, taking into account the Kabat definitions of FRs and complementarity-determining regions (CDRs), structural data, and Chothia's characterization of hypervariable loops. IMGT is considered to be a universal numbering scheme for antibodies and is well known in the art.

[0060] In some embodiments, the IMGT analysis system is used to identify potential mutated amino acid positions in the heavy chain variable region (VH) and light chain variable region (VL) domains. In some embodiments, the Paratome analysis system is used to identify potential mutated amino acid positions in the heavy chain variable region (VH) and light chain variable region (VL) domains. In some embodiments, the Kabat analysis system is used to identify potential mutated amino acid positions in the heavy chain variable region (VH) and light chain variable region (VL) domains. In some embodiments, the Clothia analysis system is used to identify potential mutated amino acid positions in the heavy chain variable region (VH) and light chain variable region (VL) domains.

[0061] In describing the mutated amino acid positions present in the heavy chain variable region (VH) and light chain variable region (VL) domains, in some embodiments, IMGT numbering is used. In describing the mutated amino acid positions present in the heavy chain variable region (VH) and light chain variable region (VL) domains, in some embodiments, Paratome numbering is used. In describing the mutated amino acid positions present in the heavy chain variable region (VH) and light chain variable region (VL) domains, in some embodiments, Kabat numbering is used. In describing the mutated amino acid positions present in the heavy chain variable region (VH) and light chain variable region (VL) domains, in some embodiments, Clothia numbering is used.

[0062] Antigen-binding sequences are typically located within the heavy chain variable region (VH) and light chain variable region (VL) of an antibody. For example, these heavy chain variable regions (VH) and light chain variable regions (VL) may be manipulated to create new binding sites, e.g., to create antibodies or fragments thereof that bind to different antigens or different epitopes of the same antigen. In some embodiments, as described herein, a new binding site for a second antigen is created by manipulating the heavy chain variable region (VH) sequence, the heavy chain variable region (VH) sequence, or both.

[0063] Antibodies may have various domains or exist in various forms, including, but not limited to, complementarity determining regions (CDRs), variable regions (Fv), heavy chain variable region (VH) domains, light chain variable region (VL) domains, single chain variable region (scFv), and Fab fragments.

[0064] Those skilled in the art will appreciate that an scFv is a fusion polypeptide comprising the heavy chain variable region (VH) and light chain variable region (VL) of an immunoglobulin linked by a short linker peptide, which may have, for example, from 10 to about 25 amino acids.

[0065] Those skilled in the art will also understand that the term "Fab" in reference to an antibody generally includes the portion of an antibody consisting of a single light chain (both variable and constant regions) linked by a disulfide bond to the variable region and first constant region of a single heavy chain, while F(ab')2 includes a fragment of a light chain comprising the heavy chain variable region (VH) domain and the light chain variable region (VL) domain.

[0066] In some embodiments, antibodies include whole antibody molecules, including monoclonal and polyclonal antibodies. In some embodiments, antibodies include one or more antibody fragments that retain binding specificity, such as, but not limited to, heavy chain variable region (VH) fragments, light chain variable region (VL) fragments, Fab fragments, F(ab')2 fragments, scFv fragments, Fv fragments, minibodies, diabodies, triabodies, and tetrabodies.

[0067] Engineered anti-IL-2 antibodies

[0068] In one embodiment, the present disclosure provides engineered anti-IL-2 antibodies obtained by introducing amino acid mutations into a parent anti-IL-2 antibody. In one embodiment, one or more amino acid mutations are introduced in the CDR region. In another embodiment, one or more amino acid mutations are introduced within the framework (FR) region. In yet another embodiment, amino acid mutations are introduced in both the CDR and framework (FR) regions. One skilled in the art could readily introduce amino acid mutations into an anti-IL-2 antibody and then test the resulting modified antibody for altered binding to IL-2 by employing a variety of standard techniques known in the art. While standard techniques can be used, the binding pattern of a newly engineered antibody is unpredictable, and analysis is required to determine functionality.

[0069] In some embodiments, the present disclosure provides polypeptides comprising VH and VL domains that can be dimerized under appropriate conditions. For example, the VH and VL domains can be combined in an appropriate buffer and dimerized through appropriate interactions, such as hydrophobic interactions. In another embodiment, the VH and VL domains can be combined in an appropriate buffer containing an enzyme and / or cofactor that can promote dimerization of the VH and VL domains. In another embodiment, the VH and VL domains can be combined in an appropriate medium that allows them to react with each other in the presence of appropriate reagents and / or catalysts.

[0070] In some embodiments, the VH and VL domains are comprised within a longer polypeptide sequence, such as, but not limited to, a constant region, hinge region, linker region, Fc region, or disulfide bond region, or any combination thereof. A constant domain is an immunoglobulin fold unit of the constant portion of an immunoglobulin molecule, also referred to as a domain of the constant region (e.g., CH1, CH2, CH3, CH4, Ck, Cl). In some embodiments, the longer polypeptide may comprise multiple copies of one or both of the VH and VL domains generated by the methods disclosed herein, for example, when the polypeptides generated herein are used to form diabodies or triabodies.

[0071] In some embodiments, the Fc region comprises at least one mutation that reduces Fc-gamma binding, i.e., binding to Fcγ receptors (FcγRs). In some embodiments, the reduced binding is abolished, such that binding to Fcγ receptors is detectable. In some embodiments, the reduced binding reduces binding affinity to Fcγ receptors. In some embodiments, the reduced binding reduces the on-rate to Fcγ receptors. In some embodiments, the reduced binding reduces the off-rate to Fcγ receptors. In some embodiments, the mutation comprises an L234A, L235A mutation, also known as a LALA mutation. In some embodiments, the mutation that reduces Fc-gamma binding comprises a P329G mutation in addition to the L234A, L235A mutation. In some embodiments, the antibody described herein comprises a heavy chain comprising a mutation that reduces binding to Fcγ receptors.

[0072] In one embodiment, the present disclosure provides an engineered (or modified) anti-IL-2 antibody comprising a heavy chain variable region (VH) having the sequence of one of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36. In one embodiment, the engineered antibody may comprise an IgG, IgA, IgM, IgE, IgD, Fv, scFv, Fab, or F(ab')2. The IgG may be of the IgG1, IgG2, IgG3, or IgG4 subclass. In another embodiment, the engineered antibody may comprise a minibody, diabody, triabody, nanobody, or single domain antibody.

[0073] In one embodiment, the present disclosure provides an engineered (or modified) anti-IL-2 antibody comprising a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37. In one embodiment, the engineered antibody may comprise an IgG, IgA, IgM, IgE, IgD, Fv, scFv, Fab, or F(ab')2. The IgG may be of the IgG1, IgG2, IgG3, or IgG4 subclass. In another embodiment, the engineered antibody may comprise a minibody, diabody, triabody, nanobody, or single domain antibody.

[0074] In one embodiment, the present disclosure provides an engineered (or modified) anti-IL-2 antibody comprising a heavy chain variable region (VH) and a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 10 and 11, 12 and 13, 14 and 15, 16 and 17, 18 and 19, 20 and 21, 22 and 23, 24 and 25, 26 and 27, or 36 and 37. In one embodiment, the engineered anti-IL-2 antibody comprises the sequences of SEQ ID NOs: 10 and 11. In one embodiment, the engineered anti-IL-2 antibody comprises the sequences of SEQ ID NOs: 12 and 13. In one embodiment, the engineered anti-IL-2 antibody comprises the sequences of SEQ ID NOs: 14 and 15. In one embodiment, the engineered anti-IL-2 antibody comprises the sequences of SEQ ID NOs: 16 and 17. In one embodiment, the engineered anti-IL-2 antibody comprises the sequences of SEQ ID NOs: 18 and 19. In one embodiment, the engineered anti-IL-2 antibody comprises the sequences of SEQ ID NOs: 20 and 21. In one embodiment, the engineered anti-IL-2 antibody comprises the sequences of SEQ ID NOs: 22 and 23. In one embodiment, the engineered anti-IL-2 antibody comprises the sequences of SEQ ID NOs: 24 and 25. In one embodiment, the engineered anti-IL-2 antibody comprises the sequences of SEQ ID NOs: 26 and 27. In one embodiment, the engineered anti-IL-2 antibody comprises the sequences of SEQ ID NOs: 36 and 37.

[0075] In some embodiments, the isolated anti-IL-2 antibody comprises a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) comprises heavy chain complementarity determining regions (HCDRs) HCDR1, HCDR2, and HCDR3, and the light chain variable region (VL) comprises light chain complementarity determining regions (LCDRs) LCDR1, LCDR2, and LCDR3, and the amino acid sequences of the heavy chain complementarity determining regions (HCDRs) and light chain complementarity determining regions (LCDRs) are: (a) HCDR1 comprises the amino acid sequence of SEQ ID NO: 38, and HCDR2 comprises the sequence 39, wherein HCDR3 comprises the amino acid sequence of SEQ ID NO: 40, LCDR1 comprises the amino acid sequence of SEQ ID NO: 41, LCDR2 comprises the amino acid sequence of SEQ ID NO: 42, and LCDR3 comprises the amino acid sequence of SEQ ID NO: 43, or (b) HCDR1 comprises the amino acid sequence of SEQ ID NO: 44, HCDR2 comprises the amino acid sequence of SEQ ID NO: 45, HCDR3 comprises the amino acid sequence of SEQ ID NO: 46, LCDR1 comprises the amino acid sequence of SEQ ID NO: 47, and LCDR2 comprises the amino acid sequence of SEQ ID NO: 48, and and LCDR3 comprises the amino acid sequence of SEQ ID NO: 49, or (c) HCDR1 comprises the amino acid sequence of SEQ ID NO: 50, HCDR2 comprises the amino acid sequence of SEQ ID NO: 51, and HCDR3 comprises the amino acid sequence of SEQ ID NO: 52, LCDR1 comprises the amino acid sequence of SEQ ID NO: 53, LCDR2 comprises the amino acid sequence of SEQ ID NO: 54, and LCDR3 comprises the amino acid sequence of SEQ ID NO: 55, or (d) HCDR1 comprises the amino acid sequence of SEQ ID NO: 56, HCDR2 comprises the amino acid sequence of SEQ ID NO: 57, and HCDR3 comprises the amino acid sequence of SEQ ID NO: 58. wherein LCDR1 comprises the amino acid sequence of SEQ ID NO: 59, LCDR2 comprises the amino acid sequence of SEQ ID NO: 60, and LCDR3 comprises the amino acid sequence of SEQ ID NO: 61, or (e) HCDR1 comprises the amino acid sequence of SEQ ID NO: 62, HCDR2 comprises the amino acid sequence of SEQ ID NO: 63, HCDR3 comprises the amino acid sequence of SEQ ID NO: 64, LCDR1 comprises the amino acid sequence of SEQ ID NO: 65, LCDR2 comprises the amino acid sequence of SEQ ID NO: 66, and LCDR3 comprises the amino acid sequence of SEQ ID NO: 67.

[0076] In some embodiments, the amino acid sequences of the heavy chain variable region (VH) and the light chain variable region (VL) are such that the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 10 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 11; the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 12 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 13; the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 14 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 15; the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 16 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 17; or the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 18 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 19. ) comprises the amino acid sequence of SEQ ID NO: 19, or the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 20 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 21, or the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 22 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 23, or the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 24 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 25, or the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 26 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 27, or the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 36 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 37.

[0077] In some embodiments, the antibody comprises a heavy chain sequence and a light chain sequence, wherein the heavy chain sequence is set forth in SEQ ID NO: 68 and the light chain sequence is set forth in SEQ ID NO: 69, the heavy chain sequence is set forth in SEQ ID NO: 70 and the light chain sequence is set forth in SEQ ID NO: 71, or the heavy chain sequence is set forth in SEQ ID NO: 72 and the light chain sequence is set forth in SEQ ID NO: 73.

[0078] In one embodiment, the engineered antibody can be an IgG, IgA, IgM, IgE, IgD, Fv, scFv, Fab, or F(ab')2. The IgG can be of the IgG1, IgG2, IgG3, or IgG4 subclass. In another embodiment, the engineered antibody can be part of a minibody, diabody, triabody, nanobody, or single domain antibody.

[0079] In one embodiment, the present disclosure also provides an isolated polynucleotide sequence encoding the heavy chain variable region (VH) of an anti-IL-2 antibody, wherein the amino acid sequence of the heavy chain variable region (VH) comprises the amino acid sequence set forth in SEQ ID NO: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36. In another embodiment, the present disclosure also provides a vector comprising the above-described polynucleotide sequence. Taking into account the amino acid sequences disclosed herein, one skilled in the art would be able to easily construct a vector or plasmid encoding the amino acid sequence. In another embodiment, the present disclosure also provides a host cell comprising the vector provided herein. One skilled in the art would be able to easily select an appropriate host cell depending on the application and experimental conditions, and cause the host cell to carry and / or express the above-described polynucleotide sequence.

[0080] In one embodiment, the present disclosure also provides an isolated polynucleotide sequence encoding the light chain variable region (VL) of an anti-IL-2 antibody, wherein the amino acid sequence of the light chain variable region (VL) comprises the amino acid sequence set forth in SEQ ID NO: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37. In another embodiment, the present disclosure also provides a vector comprising the above-described polynucleotide sequence. Taking into account the amino acid sequences disclosed herein, one skilled in the art would be able to easily construct a vector or plasmid encoding the amino acid sequence. In another embodiment, the present disclosure also provides a host cell comprising the vector provided herein. One skilled in the art would be able to easily select an appropriate host cell depending on the application and experimental conditions, and cause it to harbor and / or express the above-described polynucleotide sequence.

[0081] Given the sequences of the heavy chain variable region (VH) and light chain variable region (VL) disclosed herein, one of skill in the art would readily be able to employ standard techniques known in the art to construct an anti-IL-2 scFv. In one embodiment, the polynucleotide sequence encoding such an anti-IL-2 scFv may have the sequence of one of SEQ ID NOs: 1-5, or one of SEQ ID NOs: 31-35.

[0082] In some embodiments, the isolated polynucleotide sequence disclosed herein encoding the heavy chain variable region (VH) of an anti-IL-2 antibody comprises the heavy chain variable region (VH) amino acid sequence set forth in any of the amino acid sequences of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36. In some embodiments, a vector comprises the polynucleotide sequence of any of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36. In some embodiments, a host cell comprises a vector comprising the polynucleotide sequence of any of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36.

[0083] In some embodiments, the isolated polynucleotide sequence disclosed herein encoding the light chain variable region (VL) of an anti-IL-2 antibody comprises the light chain variable region (VL) amino acid sequence set forth in any of the amino acid sequences of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37. In some embodiments, a vector comprises the polynucleotide sequence of any of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37. In some embodiments, a host cell comprises a vector comprising the polynucleotide sequence of any of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37. In some embodiments, the isolated polynucleotide sequence encodes an anti-IL-2 scFv, and the polynucleotide sequence is set forth in SEQ ID NO: 1, 2, 3, 4, 5, 31, 32, 33, 34, or 35. In some embodiments, the vector comprises an isolated polynucleotide sequence encoding an anti-IL-2 scFv, wherein the polynucleotide sequence is set forth in SEQ ID NO: 1, 2, 3, 4, 5, 31, 32, 33, 34, or 35. In some embodiments, the host cell comprises a vector comprising an isolated polynucleotide sequence encoding an anti-IL-2 scFv, wherein the polynucleotide sequence is set forth in SEQ ID NO: 1, 2, 3, 4, 5, 31, 32, 33, 34, or 35.

[0084] In another embodiment, the present disclosure also provides an isolated anti-IL-2 antibody, wherein the antibody comprises a heavy chain variable region (VH) having complementarity-determining regions (CDR1, CDR2, and CDR3). In one embodiment, CDR1, CDR2, and CDR3 comprise the amino acid sequences of SEQ ID NOs: 38-40, 34-46, 34-46, 50-52, 56-58, or 62-64, respectively. In one embodiment, the antibody can be an IgG, IgA, IgM, IgE, IgD, Fv, scFv, Fab, F(ab'), minibody, diabody, triabody, nanobody, or single-domain antibody. The IgG can be IgG1, IgG2, IgG3, or IgG4. In one embodiment, the present disclosure also encompasses a composition comprising the above-described antibody and a pharmaceutically acceptable carrier.

[0085] In another embodiment, the present disclosure also provides an isolated anti-IL-2 antibody, wherein the antibody comprises a light chain variable region (VL) having complementarity-determining regions (CDR1, CDR2, and CDR3). In one embodiment, CDR1, CDR2, and CDR3 comprise the amino acid sequences of SEQ ID NOs: 41-43, 47-49, 53-55, 59-61, or 65-67, respectively. In one embodiment, the antibody can be an IgG, IgA, IgM, IgE, IgD, Fv, scFv, Fab, F(ab'), minibody, diabody, triabody, nanobody, or single-domain antibody. The IgG can be IgG1, IgG2, IgG3, or IgG4. In one embodiment, the present disclosure also encompasses a composition comprising the above-described antibody and a pharmaceutically acceptable carrier.

[0086] In another embodiment, the disclosure also provides an isolated anti-IL-2 antibody, the antibody comprising a heavy chain variable region (VH) having complementarity determining regions (CDR1, CDR2, and CDR3) and a light chain variable region (VL) having complementarity determining regions (CDR1, CDR2, and CDR3). In one embodiment, the complementarity determining regions (CDR1, CDR2, and CDR3) of the heavy chain variable region (VH) comprise the amino acid sequences of SEQ ID NOs: 38-40, 44-46, 50-52, 56-58, or 62-64, respectively. In one embodiment, the complementarity determining regions (CDR1, CDR2, and CDR3) of the light chain variable region (VL) comprise the amino acid sequences of SEQ ID NOs: 41-43, 47-49, 53-55, 59-61, or 65-67, respectively. In one embodiment, the antibody can be an IgG, IgA, IgM, IgE, IgD, Fv, scFv, Fab, F(ab')2, minibody, diabody, triabody, nanobody, or single domain antibody. The IgG can be an IgG1, IgG2, IgG3, or IgG4. In one embodiment, the present disclosure also encompasses a composition comprising the above-described antibody and a pharmaceutically acceptable carrier.

[0087] Pharmaceutical Composition

[0088] In some embodiments, compositions for therapeutic use are disclosed herein. In some embodiments, the compositions described herein comprise an anti-IL-2 antibody disclosed herein and a pharmaceutically acceptable carrier.

[0089] As used herein, the terms "composition" and "pharmaceutical composition" all have the same nature and meaning and may be used interchangeably in some embodiments. Disclosed herein, in some embodiments, are pharmaceutical compositions for the treatment of conditions or diseases as described herein.

[0090] In some embodiments, disclosed herein are pharmaceutical compositions for use in combination therapy.

[0091] In another embodiment, disclosed herein is a composition for use in treating a disease or condition in a subject. In some embodiments, the disease comprises a viral infection, a bacterial infection, or cancer. In some embodiments, the condition comprises an IL-2-induced condition. In some embodiments, the IL-2-induced condition comprises IL-2-induced pulmonary edema or IL-2-induced vascular leakage.

[0092] The heavy chain variable region (VH) and light chain variable region (VL) polypeptides disclosed herein can be administered to a subject (e.g., a human or animal) alone or in combination with a carrier, i.e., a pharmaceutically acceptable carrier. Pharmaceutically acceptable means a material that may be administered to a subject without causing undesired biological effects or interacting in a deleterious manner with any of the other components of the pharmaceutical composition in which it is contained. As is well known to those skilled in the art, the carrier will be selected to minimize any degradation of the polypeptides disclosed herein and to minimize any adverse side effects in the subject. Pharmaceutical compositions may be prepared by methodology well known in the pharmaceutical arts.

[0093] The pharmaceutical compositions comprising the polypeptides disclosed herein can be administered in any suitable manner (e.g., to a mammal, cell, or tissue) depending on whether local or systemic treatment is desired. For example, the compositions can be administered topically (e.g., intraocularly, intravaginally, intrarectally, intranasally, transdermally, etc.), orally, by inhalation, or parenterally (including by intravenous infusion or subcutaneous, intrapleural, intraperitoneal, intradermal, or intramuscular injection). Local intranasal administration refers to delivery of the composition into the nose and nasal cavity through one or both nostrils. The compositions can be delivered by a spray or droplet mechanism or by aerosolization. Delivery can also be directed to any region of the respiratory system (e.g., lungs) by intubation. Alternatively, administration can be intratumoral, e.g., by local or intravenous injection.

[0094] When the composition is administered parenterally, administration is generally carried out by injection.Injectables can be prepared in conventional forms, such as liquid solution or suspension, solid form suitable for suspending in liquid before injection, or emulsion.In addition, oral administration can include the preparation of a sustained release or sustained release system to maintain a constant dosage.

[0095] In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises a heavy chain variable region (VH) having the sequence of one of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises a heavy chain variable region (VH) and a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 10 and 11, SEQ ID NOs: 12 and 13, SEQ ID NOs: 14 and 15, SEQ ID NOs: 16 and 17, SEQ ID NOs: 18 and 19, SEQ ID NOs: 20 and 21, SEQ ID NOs: 22 and 23, SEQ ID NOs: 24 and 25, SEQ ID NOs: 26 and 27, or SEQ ID NOs: 36 and 37. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises a heavy chain variable region (VH) domain comprising CDR1, CDR2, and CDR3 regions comprising the amino acid sequences of SEQ ID NOs: 38-40, respectively, SEQ ID NOs: 44-46, respectively, SEQ ID NOs: 50-52, respectively, SEQ ID NOs: 56-58, respectively, or SEQ ID NOs: 62-64, respectively. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises a light chain variable region (VL) domain comprising CDR1, CDR2, and CDR3 regions comprising the amino acid sequences of SEQ ID NOs: 41-43, respectively, SEQ ID NOs: 47-49, respectively, SEQ ID NOs: 53-55, respectively, SEQ ID NOs: 59-61, respectively, or SEQ ID NOs: 65-67, respectively. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises a heavy chain variable region (VH) domain comprising CDR1, CDR2, and CDR3 regions comprising the amino acid sequences of SEQ ID NOs: 38-40, 44-46, 50-52, 56-58, or 62-64, respectively, and a light chain variable region (VL) domain comprising CDR1, CDR2, and CDR3 regions comprising the amino acid sequences of SEQ ID NOs: 41-43, 47-49, 53-55, 59-61, or 65-67, respectively.

[0096] In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises any of clones BDG17.014, BDG17.023, BDG17.038, BDG17.043, BDG17.053, BDG17.054, BDG17.066, BDG17.067, and BDG17.069. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises anti-IL-2 antibody clone BDG17.014. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises anti-IL-2 antibody clone BDG17.023. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises anti-IL-2 antibody clone BDG17.038. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises anti-IL-2 antibody clone BDG17.043. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises anti-IL-2 antibody clone BDG17.053. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises anti-IL-2 antibody clone BDG17.054. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises anti-IL-2 antibody clone BDG17.066. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises anti-IL-2 antibody clone BDG17.067. In some embodiments, the composition comprises an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises anti-IL-2 antibody clone BDG17.069.

[0097] In some embodiments, the composition comprises an anti-IL-2 antibody and a pharmaceutically acceptable carrier. In some embodiments, the composition comprises an anti-IL-2 antibody, IL-2, and a pharmaceutically acceptable carrier. In some embodiments, the composition comprises an anti-IL-2 antibody complexed with IL-2 and a pharmaceutically acceptable carrier.

[0098] In some embodiments, the anti-IL-2 antibody and IL-2 are contained in the same composition. In some embodiments, the anti-IL-2 antibody and IL-2 are contained in different compositions. In some embodiments, the combination of an anti-IL-2 antibody and IL-2, or a composition thereof, is administered simultaneously. In some embodiments, the combination of an anti-IL-2 antibody and IL-2, or a composition thereof, is administered simultaneously. In some embodiments, the administration of the combination of an anti-IL-2 antibody and IL-2, or a composition thereof, comprises administering the anti-IL-2 antibody or a composition thereof before administering IL-2 or a composition thereof. In some embodiments, the administration of the combination of an anti-IL-2 antibody and IL-2, or a composition thereof, comprises administering the anti-IL-2 antibody or a composition thereof after administering IL-2 or a composition thereof.

[0099] Those skilled in the art will understand that a "pharmaceutical composition" can include a preparation of one or more active ingredients described herein with other chemical components, such as physiologically suitable carriers and excipients. The purpose of a pharmaceutical composition is to facilitate administration of an active agent, such as, but not limited to, an antibody or compound, to an organism.

[0100] In some embodiments, disclosed herein are pharmaceutical compositions for therapeutic use in treating a subject with a weakened immune system. In some embodiments, disclosed herein are pharmaceutical compositions for therapeutic use in treating a subject suffering from a viral infection, a bacterial infection, or cancer. In some embodiments, disclosed herein are pharmaceutical compositions for use as part of a combination therapy for treating a subject with a weakened immune system. In some embodiments, disclosed herein are pharmaceutical compositions for use as part of a combination therapy for treating a subject suffering from a viral infection, a bacterial infection, or cancer.

[0101] Those skilled in the art will understand that the phrases "physiologically acceptable carrier," "pharmaceutically acceptable carrier," "physiologically acceptable excipient," and "pharmaceutically acceptable excipient" may be used interchangeably and can encompass a carrier, excipient, or diluent that is not significantly irritating to an organism and does not abrogate the biological activity and properties of the administered active ingredient.

[0102] Those skilled in the art will understand that "excipients" can include inert substances added to a pharmaceutical composition to further facilitate administration of an active ingredient. In some embodiments, excipients include calcium carbonate, calcium phosphate, various sugars and types of starch, cellulose derivatives, gelatin, vegetable oils, and polyethylene glycols.

[0103] Techniques for drug formulation and administration are described in the most recent edition of "Remington's Pharmaceutical Sciences," Mack Publishing Co., Easton, Pa., which is incorporated herein by reference.

[0104] In some embodiments, the compositions disclosed herein comprise therapeutic compositions. In some embodiments, the compositions disclosed herein have a therapeutic effect.

[0105] Combination therapy

[0106] In some embodiments, the anti-IL-2 antibody or composition thereof is used in combination with an immune checkpoint inhibitor. In some embodiments, the term "immune checkpoint inhibitor" encompasses any compound or molecule that can inhibit the function of a checkpoint protein. In some embodiments, the term "immune checkpoint inhibitor" encompasses any compound or molecule that targets an immune checkpoint protein. Those skilled in the art will appreciate that "immune checkpoints" are important regulators of the immune system that, when stimulated, can attenuate the immune response to an immunological stimulus. Checkpoint inhibitors can restore immune system function by blocking inhibitory checkpoints. In some embodiments, the one or more checkpoint inhibitors comprise an immune checkpoint inhibitor.

[0107] Those skilled in the art will understand that the terms "immune checkpoint inhibitor" (ICI), "checkpoint inhibitor," and the like are used interchangeably herein, all having the same properties and meaning, and that immune checkpoint inhibitors encompass compounds that inhibit the activity or regulatory mechanisms of the immune system. Immune system checkpoints, or immune checkpoints generally, are inhibitory pathways in the immune system that act to regulate the duration and magnitude of physiological immune responses to maintain self-tolerance or minimize collateral tissue damage. Checkpoint inhibitors can inhibit immune system checkpoints by inhibiting the activity of proteins within the pathway.

[0108] Targets of immune checkpoint inhibitors include, but are not limited to, PD-1, PDL-1, CTLA-4, TIGIT, TIM-3, B7-H3, CD73, LAG3, CD27, CD70, 4-1BB, GITR, OX40, SIRP-α (CD47), CD39, ILDR2, VISTA, BTLA, and VTCN-1. In some embodiments, anti-IL-2 antibody therapy is used in combination with an immune checkpoint inhibitor, and the targets of the immune checkpoint inhibitor include PD-1, PDL-1, CTLA-4, TIGIT, TIM-3, B7-H3, CD73, LAG3, CD27, CD70, 4-1BB, GITR, OX40, SIRP-α (CD47), CD39, ILDR2, VISTA, BTLA, VTCN-1, or any combination thereof.

[0109] Checkpoint inhibitors include antibodies or antigen-binding fragments thereof, other binding proteins, biotherapeutics, or small molecules that bind to, block, or inhibit one or more of PD-1, PDL-1, CTLA-4, TIGIT, TIM-3, B7-H3, CD73, LAG3, CD27, CD70, 4-1BB, GITR, OX40, SIRP-α (CD47), CD39, ILDR2, VISTA, BTLA, or VTCN-1. Exemplary checkpoint inhibitors include, but are not limited to, those listed in Table 1 below.

[0110] [Table 1-1]

[0111] [Table 1-2]

[0112] [Table 1-3]

[0113] In some embodiments, the checkpoint inhibitor comprises a PD-1 inhibitor. In some embodiments, the checkpoint inhibitor comprises a PDL-1 inhibitor. In some embodiments, the checkpoint inhibitor comprises a CTLA-4 inhibitor. In some embodiments, the checkpoint inhibitor comprises a TIGIT inhibitor. In some embodiments, the checkpoint inhibitor comprises a TIM-3 inhibitor. In some embodiments, the checkpoint inhibitor comprises a B7-H3 inhibitor. In some embodiments, the checkpoint inhibitor comprises a CD73 inhibitor. In some embodiments, the checkpoint inhibitor comprises a LAG3 inhibitor. In some embodiments, the checkpoint inhibitor comprises a CD27 inhibitor. In some embodiments, the checkpoint inhibitor comprises a CD70 inhibitor. In some embodiments, the checkpoint inhibitor comprises a 4-1BB inhibitor. In some embodiments, the checkpoint inhibitor comprises a GITR inhibitor. In some embodiments, the checkpoint inhibitor comprises an OX40 inhibitor. In some embodiments, the checkpoint inhibitor comprises a SIRP-α (CD47) inhibitor. In some embodiments, the checkpoint inhibitor comprises a CD39 inhibitor. In some embodiments, the checkpoint inhibitor comprises an ILDR2 inhibitor. In some embodiments, the checkpoint inhibitor comprises a VISTA inhibitor. In some embodiments, the checkpoint inhibitor comprises a BTLA inhibitor. In some embodiments, the checkpoint inhibitor comprises a VTCN-1 inhibitor.

[0114] In some embodiments, the checkpoint inhibitors comprise a combination of a PD-1 inhibitor, a PDL-1 inhibitor, a CTLA-4 inhibitor, a TIGIT inhibitor, a TIM-3 inhibitor, a B7-H3 inhibitor, a CD73 inhibitor, a LAG3 inhibitor, a CD27 inhibitor, a CD70 inhibitor, a 4-1BB inhibitor, a GITR inhibitor, an OX40 inhibitor, a SIRP-α (CD47) inhibitor, a CD39 inhibitor, an ILDR2 inhibitor, a VISTA inhibitor, a BTLA inhibitor, and a VTCN-1 inhibitor. In some embodiments, the checkpoint inhibitors comprise at least two checkpoint inhibitors selected from a PD-1 inhibitor, a PDL-1 inhibitor, a CTLA-4 inhibitor, a TIGIT inhibitor, a TIM-3 inhibitor, a B7-H3 inhibitor, a CD73 inhibitor, a LAG3 inhibitor, a CD27 inhibitor, a CD70 inhibitor, a 4-1BB inhibitor, a GITR inhibitor, an OX40 inhibitor, a SIRP-α (CD47) inhibitor, a CD39 inhibitor, an ILDR2 inhibitor, a VISTA inhibitor, a BTLA inhibitor, and a VTCN-1 inhibitor.

[0115] In some embodiments, pharmaceutical compositions for use in the combination therapies described herein comprise an effective amount of a checkpoint inhibitor described herein and a pharmaceutically acceptable carrier.

[0116] In some embodiments, the compositions disclosed herein comprise a checkpoint inhibitor and a pharmaceutically acceptable carrier. In some embodiments, the compositions disclosed herein comprise a combination of a checkpoint inhibitor and a pharmaceutically acceptable carrier. In some embodiments, the compositions comprise a checkpoint inhibitor, including a PD-1 inhibitor, a PDL-1 inhibitor, a CTLA-4 inhibitor, a TIGIT inhibitor, a TIM-3 inhibitor, a B7-H3 inhibitor, a CD73 inhibitor, a LAG3 inhibitor, a CD27 inhibitor, a CD70 inhibitor, a 4-1BB inhibitor, a GITR inhibitor, an OX40 inhibitor, a SIRP-α (CD47) inhibitor, a CD39 inhibitor, an ILDR2 inhibitor, a VISTA inhibitor, a BTLA inhibitor, or a VTCN-1 inhibitor. In some embodiments, the checkpoint inhibitors comprise at least two checkpoint inhibitors selected from a PD-1 inhibitor, a PDL-1 inhibitor, a CTLA-4 inhibitor, a TIGIT inhibitor, a TIM-3 inhibitor, a B7-H3 inhibitor, a CD73 inhibitor, a LAG3 inhibitor, a CD27 inhibitor, a CD70 inhibitor, a 4-1BB inhibitor, a GITR inhibitor, an OX40 inhibitor, a SIRP-α (CD47) inhibitor, a CD39 inhibitor, an ILDR2 inhibitor, a VISTA inhibitor, a BTLA inhibitor, or a VTCN-1 inhibitor; and a pharmaceutically acceptable carrier. In some embodiments, the composition comprises at least two checkpoint inhibitors selected from a PD-1 inhibitor, a PDL-1 inhibitor, a CTLA-4 inhibitor, a TIGIT inhibitor, a TIM-3 inhibitor, a B7-H3 inhibitor, a CD73 inhibitor, a LAG3 inhibitor, a CD27 inhibitor, a CD70 inhibitor, a 4-1BB inhibitor, a GITR inhibitor, an OX40 inhibitor, a SIRP-α (CD47) inhibitor, a CD39 inhibitor, an ILDR2 inhibitor, a VISTA inhibitor, a BTLA inhibitor, and a VTCN-1 inhibitor.In some embodiments, the checkpoint inhibitors comprise at least two checkpoint inhibitors selected from a PD-1 inhibitor, a PDL-1 inhibitor, a CTLA-4 inhibitor, a TIGIT inhibitor, a TIM-3 inhibitor, a B7-H3 inhibitor, a CD73 inhibitor, a LAG3 inhibitor, a CD27 inhibitor, a CD70 inhibitor, a 4-1BB inhibitor, a GITR inhibitor, an OX40 inhibitor, a SIRP-α (CD47) inhibitor, a CD39 inhibitor, an ILDR2 inhibitor, a VISTA inhibitor, a BTLA inhibitor, and a VTCN-1 inhibitor; and a pharmaceutically acceptable carrier.

[0117] In some embodiments, when more than one checkpoint inhibitor is used in the methods of treatment described herein, each checkpoint inhibitor is contained in a separate composition, hi some embodiments, when more than one checkpoint inhibitor is used in the methods of treatment described herein, the checkpoint inhibitors are contained in the same composition.

[0118] In some embodiments, the combination therapy comprises the use of an anti-IL-2 antibody or composition thereof described herein and a checkpoint inhibitor or composition thereof. In some embodiments, the combination therapy comprises the use of an anti-IL-2 antibody or composition thereof described herein and IL-2 and a checkpoint inhibitor or composition thereof. In some embodiments, the combination therapy comprises the use of an anti-IL-2 antibody or composition thereof complexed with IL-2 described herein and a checkpoint inhibitor or composition thereof.

[0119] In some embodiments, the combination therapy comprises the use of an anti-IL-2 antibody or composition thereof described herein and at least two checkpoint inhibitors or compositions thereof. In some embodiments, the combination therapy comprises the use of an anti-IL-2 antibody or composition thereof described herein, and IL-2 and at least two checkpoint inhibitors or compositions thereof. In some embodiments, the combination therapy comprises the use of an anti-IL-2 antibody or composition thereof complexed with IL-2 described herein and at least two checkpoint inhibitors or compositions thereof.

[0120] In some embodiments, the combination therapy includes a second composition comprising one or more checkpoint inhibitors, as described herein.

[0121] In some embodiments of the combination therapy, the anti-IL-2 antibody and IL-2 are in the same composition as the checkpoint inhibitor, while in some embodiments, the anti-IL-2 antibody and IL-2 are in different compositions from each other and from the checkpoint inhibitor.

[0122] In some embodiments of the combination therapy, the order of administration of the anti-IL-2 antibody or composition thereof and the checkpoint inhibitor or composition thereof may be any order. In some embodiments of the combination therapy, the order of administration of the anti-IL-2 antibody or composition thereof, IL-2 or composition thereof, and the checkpoint inhibitor or composition thereof may be any order. For example, without limitation, the anti-IL-2 antibody may be administered before, simultaneously with, or after the administration of the checkpoint inhibitor. Similarly, the combination of the anti-IL-2 antibody and IL-2 may be administered before, simultaneously with, or after the administration of the checkpoint inhibitor. In some embodiments, the anti-IL-2 antibody may be administered before, simultaneously with, or after the administration of at least two checkpoint inhibitors. Similarly, the combination of the anti-IL-2 antibody and IL-2 may be administered before, simultaneously, or after the administration of at least two checkpoint inhibitors.

[0123] In some embodiments, administering the combination therapy with a checkpoint inhibitor comprises simultaneous administration of an anti-IL-2 antibody, or composition thereof, and a checkpoint inhibitor. In some embodiments, administering the combination therapy with a checkpoint inhibitor comprises simultaneous administration of an anti-IL-2 antibody and IL-2, or a composition thereof, and a checkpoint inhibitor. In some embodiments, administering the combination therapy with a checkpoint inhibitor comprises pre-administering an anti-IL-2 antibody, or composition thereof, before administration of the checkpoint inhibitor. In some embodiments, administering the combination therapy with a checkpoint inhibitor comprises pre-administering an anti-IL-2 antibody and IL-2, or a composition thereof, before administration of the checkpoint inhibitor. In some embodiments, administering the combination therapy with a checkpoint inhibitor comprises administering the anti-IL-2 antibody, or composition thereof, with a delay after administration of the checkpoint inhibitor. In some embodiments, administering the combination therapy with a checkpoint inhibitor comprises administering the anti-IL-2 antibody, or composition thereof, with a delay after administration of the checkpoint inhibitor.

[0124] In some embodiments, the combination therapy comprises the use of an anti-IL-2 antibody comprising a heavy chain variable region (VH) having the sequence of one of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36, and a checkpoint inhibitor. In some embodiments, the combination therapy comprises the use of an anti-IL-2 antibody comprising a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37, and a checkpoint inhibitor. In some embodiments, the combination therapy comprises the use of an anti-IL-2 antibody comprising a heavy chain variable region (VH) and a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 10 and 11, SEQ ID NOs: 10 and 11, SEQ ID NOs: 12 and 13, SEQ ID NOs: 14 and 15, SEQ ID NOs: 16 and 17, SEQ ID NOs: 18 and 19, SEQ ID NOs: 20 and 21, SEQ ID NOs: 22 and 23, SEQ ID NOs: 24 and 25, SEQ ID NOs: 26 and 27, or SEQ ID NOs: 36 and 37, and a checkpoint inhibitor. In some embodiments, the combination therapy comprises the use of an anti-IL-2 antibody comprising a heavy chain variable region (VH) domain comprising CDR1, CDR2, and CDR3 regions comprising the amino acid sequences of SEQ ID NOs: 38-40, respectively, SEQ ID NOs: 44-46, respectively, SEQ ID NOs: 50-52, respectively, SEQ ID NOs: 56-58, respectively, or SEQ ID NOs: 62-64, respectively. In some embodiments, the combination therapy comprises the use of an anti-IL-2 antibody comprising a light chain variable region (VL) domain and a checkpoint inhibitor, wherein the light chain variable region (VL) domain comprises CDR1, CDR2, and CDR3 regions comprising the amino acid sequences of SEQ ID NOs: 41-43, respectively, SEQ ID NOs: 47-49, respectively, SEQ ID NOs: 53-55, respectively, SEQ ID NOs: 59-61, respectively, or SEQ ID NOs: 65-67, respectively.In some embodiments, the combination therapy comprises the use of a checkpoint inhibitor and an anti-IL-2 antibody comprising a heavy chain variable region (VH) domain and a light chain variable region (VL) domain, wherein the heavy chain variable region (VH) domain comprises CDR1, CDR2, and CDR3 regions comprising the amino acid sequences of SEQ ID NOs: 38-40, respectively, SEQ ID NOs: 44-46, respectively, SEQ ID NOs: 50-52, respectively, SEQ ID NOs: 56-58, respectively, or SEQ ID NOs: 62-64, respectively, and the light chain variable region (VL) domain comprises CDR1, CDR2, and CDR3 regions comprising the amino acid sequences of SEQ ID NOs: 41-43, respectively, SEQ ID NOs: 47-49, respectively, SEQ ID NOs: 53-55, respectively, SEQ ID NOs: 59-61, respectively, or SEQ ID NOs: 65-67, respectively.

[0125] In some embodiments, the combination therapy comprises the use of a checkpoint inhibitor and an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises any of clones BDG17.014, BDG17.023, BDG17.038, BDG17.043, BDG17.053, BDG17.054, BDG17.066, BDG17.067, and BDG17.069. In some embodiments, the combination therapy comprises the use of a checkpoint inhibitor and an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises clone BDG17.014. In some embodiments, the combination therapy comprises the use of a checkpoint inhibitor and an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises clone BDG17.023. In some embodiments, the combination therapy comprises the use of a checkpoint inhibitor and an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises clone BDG17.038. In some embodiments, the combination therapy comprises the use of a checkpoint inhibitor and an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises clone BDG17.043. In some embodiments, the combination therapy comprises the use of a checkpoint inhibitor and an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises clone BDG17.053. In some embodiments, the combination therapy comprises the use of a checkpoint inhibitor and an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises clone BDG17.054. In some embodiments, the combination therapy comprises the use of a checkpoint inhibitor and an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises clone BDG17.066. In some embodiments, the combination therapy comprises the use of a checkpoint inhibitor and an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises clone BDG17.067. In some embodiments, the combination therapy comprises the use of a checkpoint inhibitor and an anti-IL-2 antibody, wherein the anti-IL-2 antibody comprises clone BDG17.069.

[0126] combination

[0127] Pharmaceutical compositions disclosed herein containing anti-IL-2 antibodies, combinations of anti-IL-2 antibodies and IL-2, or checkpoint inhibitors can be conveniently provided as sterile liquid formulations, such as isotonic aqueous solutions, suspensions, emulsions, dispersions, or viscous compositions, which may be buffered to a selected pH. Liquid formulations are typically easier to prepare than gels, other viscous compositions, and solid compositions. Furthermore, liquid compositions are somewhat more convenient to administer, particularly by injection. Viscous compositions, on the other hand, can be formulated within an appropriate viscosity range to extend contact time with specific tissues. Liquid or viscous compositions can contain a carrier, which can be a solvent or dispersion medium, including, for example, water, saline, phosphate-buffered saline, polyols (e.g., glycerol, propylene glycol, liquid polyethylene glycol, etc.), and suitable mixtures thereof.

[0128] Sterile injectable solutions can be prepared by incorporating the anti-IL-2 antibody, anti-IL-2 antibody and IL-2 combination, or checkpoint inhibitor described herein and utilized in practicing the methods disclosed herein into the required amount of an appropriate solvent, along with various amounts of other ingredients, as needed. Such formulations may be mixed with a suitable carrier, diluent, or excipient, such as sterile water, saline, glucose, dextrose, or the like. The formulations may also be lyophilized. Depending on the route of administration and the desired preparation, the formulations may contain auxiliary substances such as wetting agents, dispersing agents, or emulsifying agents (e.g., methylcellulose), pH buffering agents, gelling or viscosity-enhancing agents, preservatives, flavoring agents, coloring agents, and the like. Reference may be made to standard texts, such as "REMINGTON'S PHARMACEUTICAL SCIENCE," 17th ed., 1985, incorporated herein by reference, to prepare suitable preparations without undue experimentation.

[0129] Various additives can be added to enhance the stability and sterility of the formulation, including antimicrobial preservatives, antioxidants, chelating agents, and buffers. Prevention of the action of microorganisms can be ensured by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, etc. The absorption of injectable pharmaceuticals can be prolonged by the use of agents delaying absorption, for example, aluminum monostearate and gelatin.

[0130] In certain embodiments, the terms "pharmaceutical composition," "composition," and "formulation" have the same meaning and quality and are used interchangeably.

[0131] The compositions or formulations described herein can be isotonic, i.e., have the same osmotic pressure as blood and tears. The desired isotonicity of the compositions disclosed herein can be achieved using sodium chloride or other pharmaceutically acceptable agents, such as dextrose, boric acid, sodium tartrate, propylene glycol, or other inorganic or organic solutes. Sodium chloride is preferably used, especially for buffers containing sodium ions.

[0132] The viscosity of the composition can be maintained at a selected level, if necessary, using a pharmaceutically acceptable thickening agent. Methylcellulose is preferred because it is readily and economically available and easy to work with.

[0133] Other suitable thickening agents include, for example, xanthan gum, carboxymethylcellulose, hydroxypropylcellulose, carbomer, etc. The preferred concentration of the thickening agent depends on the thickening agent selected. The key is to use an amount that achieves the selected viscosity. Obviously, the selection of appropriate carriers and other additives will depend on the exact route of administration and the nature of the particular dosage form (e.g., liquid dosage form, etc.) (e.g., whether the composition is to be formulated into a solution, suspension, gel, or other liquid dosage form, such as a time-release formulation or liquid-fill formulation).

[0134] In some embodiments, the composition is formulated to have a pH value of about pH 5.0-6.0. In some embodiments, the composition is formulated to have a pH value of about pH 5.0-7.0. In some embodiments, the composition is formulated to have a pH value of about pH 5.0-6.5. In some embodiments, the composition is formulated to have a pH value of about pH 5.0-5.5. In some embodiments, the composition is formulated to have a pH value of about pH 5.5-6.0. In some embodiments, the composition is formulated to have a pH value of about pH 5.5-6.5. In some embodiments, the composition is formulated to have a pH value of about pH 5.0. In some embodiments, the composition is formulated to have a pH value of about pH 5.5. In some embodiments, the composition is formulated to have a pH value of about pH 6.0. In some embodiments, the composition is formulated to have a pH value of about pH 6.5.

[0135] In some embodiments, the composition is formulated to have a pH value of about pH 5.0 to 6.0 and comprises a buffer. In some embodiments, the buffer comprises a pharmaceutically acceptable buffer. In some embodiments, the composition comprises a histidine buffer or a citrate buffer. In some embodiments, the composition comprises a histidine buffer. In some embodiments, the composition comprises a citrate buffer.

[0136] In some embodiments, the composition is formulated to have a pH value of about pH 5.0-6.0 and comprises a buffer selected from a histidine buffer and a citrate buffer. In some embodiments, the composition is formulated to have a pH value of about pH 5.0-6.0 and comprises a histidine buffer. In some embodiments, the composition is formulated to have a pH value of about pH 5.0-6.0 and comprises a citrate buffer.

[0137] In some embodiments, the composition further comprises at least one of sucrose, methionine, or PS80, or any combination thereof. In some embodiments, the composition further comprises sucrose. In some embodiments, the composition further comprises methionine. In some embodiments, the composition further comprises PS80.

[0138] In some embodiments, a composition comprises an anti-IL-2 antibody disclosed herein, formulated to a pH value of about pH 5.0 to 6.0, and comprising a buffer selected from a histidine buffer and a citrate buffer, and in some embodiments, the composition further comprises IL-2.

[0139] Those skilled in the art will recognize that the components of a composition or formulation should be selected to be chemically inert and not affect the viability or efficacy of the early apoptotic cell populations described herein for use in the methods disclosed herein. This should not be a problem for those skilled in chemical and pharmaceutical principles or issues; i.e., given the present disclosure and the documents cited herein, problems can be easily circumvented by reference to standard texts or by simple experimentation (without undue experimentation).

[0140] How to use

[0141] In one embodiment, the present disclosure provides a method for producing a heavy chain variable region (VH) of an anti-IL-2 antibody, the method comprising culturing a host cell under conditions conducive to expression of a vector encoding the heavy chain variable region (VH), thereby producing the heavy chain variable region (VH) of the anti-IL-2 antibody.

[0142] In one embodiment, the present disclosure provides a method for producing a light chain variable region (VL) of an anti-IL-2 antibody, the method comprising culturing a host cell under conditions conducive to expression of a vector encoding the light chain variable region (VL), thereby producing the light chain variable region (VL) of the anti-IL-2 antibody.

[0143] The heavy chain variable region (VH) and / or light chain variable region (VL) polypeptides disclosed herein are used in therapeutic methods. In one embodiment, the polypeptides of the present disclosure can be used as immunotherapeutic agents, for example, for the differentiation and activation of immune cells as described herein.

[0144] The exact amount of the polypeptide of the present invention or a composition thereof required to elicit the desired effect will vary from subject to subject, depending on the species, age, sex, weight, and general condition of the subject, the particular polypeptide, the route of administration, and whether other drugs are included in the regimen. Therefore, it is not possible to specify an exact amount for every composition. However, one of ordinary skill in the art can determine an appropriate amount through routine experimentation. Dosages vary, and the polypeptide can be administered in one or more doses (e.g., two or more, three or more, four or more, or five or more) per day for one or more days. Guidance on selecting the appropriate dose of an antibody can be readily found in the literature.

[0145] In some embodiments of the methods of using anti-IL-2 antibodies disclosed herein, the subject comprises a mammalian subject. In some embodiments, the subject comprises a human subject. In some embodiments, the subject comprises a subject with an immunocompromised problem. In some embodiments, treating an immunocompromised subject comprises prophylactic treatment.

[0146] In one embodiment, the present disclosure provides a method for promoting the differentiation and growth of immune cells in a subject, the method comprising: preparing a composition comprising an anti-IL-2 antibody disclosed herein; and administering the composition to the subject, thereby promoting the differentiation and growth of immune cells in the subject. In one embodiment, the present disclosure provides a method for promoting the differentiation and growth of immune cells in a subject, the method comprising: preparing a composition comprising an anti-IL-2 antibody disclosed herein and IL-2; and administering the composition to the subject, thereby promoting the differentiation and growth of immune cells in the subject. In one embodiment, the subject can be an animal or a human. In one embodiment, the immune cells are CD8 + It may be a T cell or an NK cell.

[0147] In some embodiments, a method of treating a disease or condition in a subject is disclosed, comprising administering to the subject a composition comprising an anti-IL-2 antibody of the present disclosure, wherein the antibody promotes the differentiation and growth of a subset of immune cells and reduces undesirable effects caused by IL-2, thereby treating the disease or condition in the subject. In some embodiments, the method of treating a disease of the present disclosure comprises the use of a composition comprising an anti-IL-2 antibody and IL-2, or an anti-IL-2 antibody complexed with IL-2. In some embodiments, the method of treating a disease comprises treating a viral infection, a bacterial infection, or cancer. In some embodiments, the method of treating a condition comprises treating a weakened immune system and prophylactically boosting the immune system.

[0148] In some embodiments of the methods for treating a disease or condition, the condition comprises a genetic predisposition that increases the likelihood of cancer in the subject. In some embodiments, the genetic predisposition comprises an alteration in the expression or activity of a gene product. In some embodiments, the genetic predisposition that increases the likelihood of cancer comprises a mutation in a tumor suppressor gene, a mismatch repair (MMR) gene, or a combination thereof.

[0149] By way of non-limiting example, many hereditary cancers are known in the art, such as, but not limited to, hereditary breast and ovarian cancer (HBOC) syndrome, Lynch syndrome (hereditary nonpolyposis colorectal cancer), and Li-Fraumeni syndrome.

[0150] In some embodiments, a genetic predisposition increases the likelihood of HBOC. HBOC is associated with mutations in the RAC1 and BRAC2 genes. HBOC is associated with various cancers, including but not limited to breast cancer, fallopian tube cancer, primary peritoneal cancer, male breast cancer, pancreatic cancer, and prostate cancer. In some embodiments, a genetic predisposition increases the likelihood of any one or a combination of breast cancer, ovarian cancer, fallopian tube cancer, primary peritoneal cancer, male breast cancer, pancreatic cancer, and prostate cancer.

[0151] In some embodiments, a genetic predisposition increases the likelihood of hereditary nonpolyposis colorectal cancer (HNPCC). HNPCC is associated with mutations in genes such as, but not limited to, MLH1, MSH2, MSH6, PMS1, and PMS2. HNPCC is associated with an increased risk of developing endometrial cancer and cancers of the ovaries, stomach, small intestine, pancreas, kidney, brain, ureter, and bile duct. In some embodiments, a genetic predisposition increases the likelihood of any of hereditary nonpolyposis colorectal cancer, ovarian cancer, stomach cancer, small intestine cancer, pancreatic cancer, kidney cancer, brain cancer, ureter cancer, and bile duct cancer.

[0152] In some embodiments, the genetic predisposition increases the likelihood of Li-Fraumeni syndrome. Li-Fraumeni syndrome occurs in genes such as, but not limited to, TP53 and CHEK2, or a combination thereof. Li-Fraumeni syndrome is associated with cancers such as sarcoma, osteosarcoma, soft tissue sarcoma, leukemia, brain (central nervous system) cancer, adrenocortical carcinoma, and breast cancer, or a combination thereof. In some embodiments, the genetic predisposition increases the likelihood of any one or a combination of sarcoma, osteosarcoma, soft tissue sarcoma, leukemia, brain (central nervous system) cancer, adrenocortical carcinoma, and breast cancer.

[0153] In some embodiments, the condition treated in the subject comprises treating a subject with a genetic predisposition comprising an alteration in the expression or activity of a gene product, wherein the gene comprises BRCA1, BRAC2, MLH1, MSH2, MSH6, PMS1, PMS2, TP53, CHEK2, or any combination thereof.

[0154] As described herein, the disclosed conjugates of IL-2 and anti-IL-2 antibodies induce memory phenotype effector T cells (MPs) CD8 + showed a significant effect in inducing proliferation of CD4 and NK cells. + The effect on Tregs was minimal. Thus, the engineered anti-IL-2 antibodies disclosed herein may be useful in modulating immune cell populations and inducing the proliferation and differentiation of specific immune effector cells. In one embodiment, such proliferation and differentiation of immune effector cells results in robust activation of the immune system and is useful for treating tumors. In some embodiments, the treatment includes treatment of solid tumors. In some embodiments, the treatment includes treatment of non-solid tumors. In some embodiments, the treatment includes treatment of solid or non-solid tumors, such as, but not limited to, melanoma, renal cell carcinoma, small cell lung cancer, or other cancerous conditions. In another embodiment, the methods disclosed herein are useful for treating viral or bacterial infections. In another embodiment, the methods disclosed herein are useful for treating or preventing conditions caused by IL-2 binding to endothelial CD25-expressing cells, such as, for example, pulmonary edema or IL-2-induced vascular leakage.

[0155] In some embodiments of the methods of treating a disease or condition, the immune cells exhibiting differentiated growth include naive T cells, memory T cells, CD8 + In some embodiments of the methods of treating a disease or condition, the undesirable effects caused by IL-2 include one or more of the following: activation of regulatory T cells, CD25 T cells, NK cells, or natural killer T cells. +In some embodiments of the method of treating a disease or condition, the anti-IL-2 antibody inhibits binding of IL-2 to CD25.

[0156] In some embodiments, the treatment of cancer includes maintenance treatment. In some embodiments, the maintenance treatment is administered to maintain the absence of cancer or tumor. In some embodiments, the maintenance treatment is administered to maintain the absence of metastasis of cancer or tumor. In some embodiments, the maintenance treatment is administered to inhibit metastasis of cancer or tumor. In some embodiments, the maintenance treatment is administered to maintain the absence of growth of cancer or tumor. In some embodiments, the maintenance treatment is administered to inhibit growth of cancer or tumor.

[0157] In some embodiments, treating cancer includes, but is not limited to, prophylactic treatment, such as for subjects with genetic markers that are at high risk for developing cancer. In some embodiments, the genetic marker comprises a mutation in the BRCA1 gene.

[0158] In some embodiments of the method of promoting the differentiation and growth of immune cells in a subject, the method comprises preparing and administering a composition comprising an anti-IL-2 antibody disclosed herein.

[0159] In some embodiments of the method for promoting the differentiation and growth of immune cells in a subject, the method comprises preparing and administering a composition comprising an anti-IL-2 antibody and IL-2 disclosed herein, wherein the administration of the combination of the anti-IL-2 antibody and IL-2, or a composition thereof, is simultaneous. In some embodiments of the method for promoting the differentiation and growth of immune cells in a subject, the method comprises preparing and administering a composition comprising an anti-IL-2 antibody and IL-2, wherein the administration of the anti-IL-2 antibody and IL-2, or a composition thereof, comprises administering the anti-IL-2 antibody or composition thereof before the administration of the IL-2 or composition thereof. In some embodiments of the method for promoting the differentiation and growth of immune cells in a subject, the method comprises preparing and administering a composition comprising an anti-IL-2 antibody and IL-2, wherein the administration of the anti-IL-2 antibody and IL-2, or a composition thereof, comprises administering the anti-IL-2 antibody or composition thereof after the administration of the IL-2 or composition thereof.

[0160] In some embodiments, the present disclosure provides a method of treating a subject having a disease or condition by inducing the differentiation and growth of immune cells. In one embodiment, the disease can be a viral infection, a bacterial infection, or cancer. In one embodiment, the condition can be IL-2-induced pulmonary edema or IL-2-induced vascular leakage. The method includes the steps of (a) preparing a composition comprising an anti-IL-2 antibody disclosed herein, and (b) administering to the subject the composition obtained by step (a), thereby treating the subject by inducing the differentiation and growth of immune cells in the subject. In some embodiments, any of the engineered anti-IL-2 antibodies disclosed herein are used in a method of treatment as described herein.

[0161] In some embodiments, the present disclosure provides a method for treating a subject having a disease or condition by inducing the differentiation and growth of immune cells. In one embodiment, the disease can be a viral infection, a bacterial infection, or cancer. In one embodiment, the condition can be IL-2-induced pulmonary edema or IL-2-induced vascular leakage. The method includes the steps of (a) preparing a composition comprising an anti-IL-2 antibody disclosed herein and IL-2, and (b) administering the composition obtained by step (a) to the subject, thereby treating the subject by inducing the differentiation and growth of immune cells in the subject. In addition to promoting the expansion of a subset of immune effector cells, the antibody / IL-2 complex will also reduce undesirable effects caused by IL-2 (e.g., IL-2-induced pulmonary edema or IL-2-induced vascular leakage). In one embodiment, the subject can be an animal or a human. In some embodiments, any of the engineered anti-IL-2 antibodies disclosed herein are used in a method of treatment, as described herein.

[0162] In one embodiment, the disclosure provides a method of treating a disease or condition in a subject (e.g., an animal or a human), comprising administering to the subject a composition comprising an anti-IL-2 antibody, wherein the antibody promotes the proliferation of a subset of immune cells and reduces undesirable effects caused by IL-2, thereby treating the disease or condition in the subject. In some embodiments of the method of treating a disease or condition in a subject, the method comprises preparing and administering a composition comprising an anti-IL-2 antibody disclosed herein and administering a composition comprising the anti-IL-2 antibody. In one embodiment, the composition comprises an anti-IL-2 antibody disclosed herein and IL-2, or the composition comprises an anti-IL-2 antibody complexed with IL-2.

[0163] In some embodiments of the method for treating a disease or condition in a subject, the method comprises preparing and administering a composition comprising an anti-IL-2 antibody and IL-2 disclosed herein, wherein the administration of the combination of the anti-IL-2 antibody and IL-2, or a composition thereof, is simultaneous. In some embodiments of the method for treating a disease or condition in a subject, the method comprises preparing and administering a composition comprising an anti-IL-2 antibody and IL-2, wherein the administration of the anti-IL-2 antibody and IL-2, or a composition thereof, comprises administering the anti-IL-2 antibody or composition thereof before the administration of the IL-2 or composition thereof. In some embodiments of the method for treating a disease or condition in a subject, the method comprises preparing and administering a composition comprising an anti-IL-2 antibody and IL-2, wherein the administration of the anti-IL-2 antibody and IL-2, or a composition thereof, comprises administering the anti-IL-2 antibody or composition thereof after the administration of the IL-2 or composition thereof.

[0164] In one embodiment, the method of treatment will be effective in treating conditions such as IL-2-induced pulmonary edema, or IL-2-induced vascular leakage, hi another embodiment, the method of treatment will be effective in treating pulmonary edema (mild or chronic) resulting from viral or bacterial infection.

[0165] In one embodiment, the disease may be a viral infection, a bacterial infection, cancer, an autoimmune disease, or an immune disorder. In one embodiment, the disease may be an upper respiratory tract viral infection, an early stage pulmonary infection, or an end-stage pulmonary infection. Many diseases and cancers are known to be caused by viruses. Examples of disease-causing viruses include, but are not limited to, norovirus; rotavirus; hepatitis A, B, C, D, or E virus; rabies virus, West Nile virus, enterovirus, echovirus, coxsackievirus, herpes simplex virus (HSV), HSV-2, varicella-zoster virus, mosquito-borne virus, arbovirus, St. Louis encephalitis virus, California encephalitis virus, lymphocytic choriomeningitis virus, human immunodeficiency virus (HIV), poliovirus, Zika virus, rubella virus, cytomegalovirus, human papillomavirus (HPV), enterovirus D68, severe acute respiratory syndrome (SARS) coronavirus, Middle East respiratory syndrome coronavirus, SARS coronavirus 2, Epstein-Barr virus, influenza virus, respiratory syncytial virus, polyomavirus (e.g., JC virus, BK virus), Ebola virus, dengue virus, or a combination thereof. In one embodiment, the viral infection is caused by SARS CoV-2. In another embodiment, the cancer may be, for example, but not limited to, melanoma or renal cell carcinoma.

[0166] In one embodiment, the immune cells expanded by treatment with an anti-IL-2 antibody include naive T cells, memory T cells, CD8 + In one embodiment, treatment with an anti-IL-2 antibody may be associated with activation of regulatory T cells, CD25 + One or more undesirable effects caused by IL-2 are reduced, such as apoptosis of T effector cells, pulmonary edema, pneumonia, and IL-2-induced vascular leakage.

[0167] In one embodiment, the anti-IL-2 antibody administered in the above method is an engineered or modified anti-IL-2 antibody capable of inhibiting binding of IL-2 to CD25. In some embodiments, the engineered or modified anti-IL-2 antibody comprises a heavy chain variable region (VH) having the sequence of one of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36. In some embodiments, the engineered or modified anti-IL-2 antibody comprises a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37. In some embodiments, the engineered or modified anti-IL-2 antibody comprises a heavy chain variable region (VH) and a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 10 and 11, SEQ ID NOs: 12 and 13, SEQ ID NOs: 14 and 15, SEQ ID NOs: 16 and 17, SEQ ID NOs: 18 and 19, SEQ ID NOs: 20 and 21, SEQ ID NOs: 22 and 23, SEQ ID NOs: 24 and 25, SEQ ID NOs: 26 and 27, or SEQ ID NOs: 36 and 37.

[0168] In another embodiment, the engineered or modified anti-IL-2 antibody comprises a heavy chain variable region (VH) having complementarity determining regions (CDR1, CDR2, and CDR3). In one embodiment, the complementarity determining regions (CDR1, CDR2, and CDR3) of the heavy chain variable region (VH) comprise the amino acid sequences of SEQ ID NOs: 38-40, respectively, SEQ ID NOs: 44-46, respectively, SEQ ID NOs: 50-52, respectively, SEQ ID NOs: 56-58, respectively, or SEQ ID NOs: 62-64, respectively.

[0169] In another embodiment, the engineered or modified anti-IL-2 antibody comprises a light chain variable region (VL) having complementarity determining regions (CDR1, CDR2, and CDR3). In one embodiment, the complementarity determining regions (CDR1, CDR2, and CDR3) of the light chain variable region (VL) comprise the amino acid sequences of SEQ ID NOs: 41-43, respectively, SEQ ID NOs: 47-49, respectively, SEQ ID NOs: 53-55, respectively, SEQ ID NOs: 59-61, respectively, or SEQ ID NOs: 65-67, respectively.

[0170] In some embodiments, the engineered anti-IL-2 antibody can be an IgG, IgA, IgM, IgE, IgD, Fv, scFv, Fab, or F(ab')2. The IgG can be an IgG1, IgG2, IgG3, or IgG4 subclass. In some embodiments, the engineered anti-IL-2 antibody can be part of a minibody, diabody, triabody, nanobody, or single domain antibody.

[0171] In some embodiments, polynucleotide sequences encoding engineered anti-IL-2 antibodies are used in methods of treating a subject having a disease or condition described herein, wherein the polynucleotide sequences encode an antibody comprising a heavy chain variable region (VH) having the amino acid sequence of one of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36. In some embodiments, polynucleotide sequences encoding engineered anti-IL-2 antibodies are used in methods of treating a subject having a disease or condition described herein, wherein the polynucleotide sequences encode an antibody comprising a light chain variable region (VL) having the amino acid sequence of one of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37. In some embodiments, a polynucleotide sequence encoding an engineered anti-IL-2 antibody is used in a method of treating a subject having a disease or condition described herein, wherein the polynucleotide sequence encodes an antibody comprising a heavy chain variable region (VH) and a light chain variable region (VL) having the amino acid sequence of one of SEQ ID NOs: 10 and 11, SEQ ID NOs: 12 and 13, SEQ ID NOs: 14 and 15, SEQ ID NOs: 16 and 17, SEQ ID NOs: 18 and 19, SEQ ID NOs: 20 and 21, SEQ ID NOs: 22 and 23, SEQ ID NOs: 24 and 25, SEQ ID NOs: 26 and 27, or SEQ ID NOs: 36 and 37.

[0172] In some embodiments of the methods of using polynucleotides to treat the above-described diseases or conditions, the polynucleotide encodes an engineered anti-IL-2 antibody that can be an IgG, IgA, IgM, IgE, IgD, Fv, scFv, Fab, or F(ab')2. The IgG can be an IgG1, IgG2, IgG3, or IgG4 subclass. In some embodiments, the polynucleotide encodes an engineered anti-IL-2 antibody that is part of a minibody, diabody, triabody, nanobody, or single domain antibody.

[0173] In some embodiments, a polynucleotide sequence encoding an engineered anti-IL-2 antibody is used in a method of treating a subject having a disease or condition described herein, wherein the polynucleotide sequence comprises one of SEQ ID NOs: 1, 2, 3, 4, 5, 31, 32, 33, 34, or 35.

[0174] In some embodiments of the methods of treating a subject having a disease or condition described herein, the immune effector cells activated by the treatment are CD8 + In one embodiment, the anti-IL-2 antibodies disclosed herein, or the conjugates of the anti-IL-2 antibodies disclosed herein with IL-2, are MP CD8 + showed a significant effect in inducing proliferation of CD4 cells and NK cells. + The effect on Tregs was very small. + There was no effect on Tregs.

[0175] In some embodiments, the methods of use of the anti-IL-2 antibodies disclosed herein provide a pro-stimulatory effect. Those skilled in the art will appreciate that the use of the anti-IL-2 antibodies described and exemplified herein (e.g., in Example 1) clearly demonstrates a pro-stimulatory effect, as opposed to an anti-stimulatory or pro-regulatory effect.

[0176] In some embodiments, the use of an engineered or modified anti-IL-2 antibody comprising a heavy chain variable region (VH) having the sequence of one of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36 provides a stimulatory immune effect in a subject in need thereof. In some embodiments, the use of an engineered or modified anti-IL-2 antibody comprising a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37 provides a stimulatory immune effect in a subject in need thereof. In some embodiments, the use of an engineered or modified anti-IL-2 antibody comprising a heavy chain variable region (VH) and a light chain variable region (VL) having one of the sequences of SEQ ID NOs: 10 and 11, 12 and 13, 14 and 15, 16 and 17, 18 and 19, 20 and 21, 22 and 23, 24 and 25, 26 and 27, or 36 and 37 provides a stimulatory immune effect in a subject in need thereof. In some embodiments, the use comprises the use of an anti-IL-2 antibody. In some embodiments, the use comprises the use of an anti-IL-2 antibody and IL-2. In some embodiments, the use comprises the use of a complex of an anti-IL-2 antibody and IL-2.

[0177] In some embodiments, the use of engineered or modified anti-IL-2 antibodies comprising a heavy chain variable region (VH) having the sequence of one of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36 provides a pro-stimulatory immune effect in a subject in need thereof, as opposed to an anti-stimulatory or pro-regulatory effect. In some embodiments, the use of engineered or modified anti-IL-2 antibodies comprising a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37 provides a pro-stimulatory immune effect in a subject in need thereof, as opposed to an anti-stimulatory or pro-regulatory effect. In some embodiments, the use of an engineered, i.e., modified, anti-IL-2 antibody comprising a heavy chain variable region (VH) and a light chain variable region (VL) having one of the sequences of SEQ ID NOs: 10 and 11, 12 and 13, 14 and 15, 16 and 17, 18 and 19, 20 and 21, 22 and 23, 24 and 25, 26 and 27, or 36 and 37 provides a pro-stimulatory immune effect in a subject in need thereof, as opposed to an anti-stimulatory or pro-regulatory effect. In some embodiments, the use comprises the use of an anti-IL-2 antibody. In some embodiments, the use comprises the use of an anti-IL-2 antibody and IL-2. In some embodiments, the use comprises the use of a complex of an anti-IL-2 antibody and IL-2.

[0178] In some embodiments, the use of anti-IL-2 antibodies comprising heavy chain variable regions (VH) comprising complementarity determining regions (CDR1, CDR2, and CDR3) set forth in the amino acid sequences of SEQ ID NOs: 38-40, 44-46, 50-52, 56-58, or 62-64, respectively, provides a stimulatory and immunological effect in a subject in need thereof. In some embodiments, the use of anti-IL-2 antibodies comprising light chain variable regions (VL) comprising complementarity determining regions (CDR1, CDR2, and CDR3) set forth in the amino acid sequences of SEQ ID NOs: 41-43, 47-49, 53-55, 59-61, or 65-67, respectively, provides a stimulatory and immunological effect in a subject in need thereof. In some embodiments, the use of an anti-IL-2 antibody comprising a heavy chain variable region (VH) comprising the complementarity determining regions (CDR1, CDR2, and CDR3) of the heavy chain variable region (VH) set forth in the amino acid sequence of SEQ ID NOs: 38-40, 44-46, 50-52, 56-58, or 62-64, respectively, and a light chain variable region (VL) comprising the complementarity determining regions (CDR1, CDR2, and CDR3) of the light chain variable region (VL) set forth in the amino acid sequence of SEQ ID NOs: 41-43, 47-49, 53-55, 59-61, or 65-67, respectively, provides a stimulatory immune effect in a subject in need thereof. In some embodiments, the use comprises the use of an anti-IL-2 antibody. In some embodiments, the use comprises the use of an anti-IL-2 antibody and IL-2. In some embodiments, the use comprises the use of a complex of an anti-IL-2 antibody and IL-2.

[0179] In some embodiments, the use of anti-IL-2 antibodies comprising heavy chain variable regions (VH) comprising complementarity determining regions (CDR1, CDR2, and CDR3) set forth in the amino acid sequences of SEQ ID NOS: 38-40, 44-46, 50-52, 56-58, or 62-64, respectively, provides a pro-stimulatory immune effect in a subject in need thereof, as opposed to an anti-stimulatory or pro-regulatory effect. In some embodiments, the use of anti-IL-2 antibodies comprising light chain variable regions (VL) comprising complementarity determining regions (CDR1, CDR2, and CDR3) set forth in the amino acid sequences of SEQ ID NOS: 41-43, 47-49, 53-55, 59-61, or 65-67, respectively, provides a pro-stimulatory immune effect in a subject in need thereof, as opposed to an anti-stimulatory or pro-regulatory effect. In some embodiments, the use of an anti-IL-2 antibody comprising a heavy chain variable region (VH) comprising the complementarity determining regions (CDR1, CDR2, and CDR3) set forth in the amino acid sequences of SEQ ID NOs: 38-40, 44-46, 50-52, 56-58, or 62-64, respectively, and a light chain variable region (VL) comprising the complementarity determining regions (CDR1, CDR2, and CDR3) set forth in the amino acid sequences of SEQ ID NOs: 41-43, 47-49, 53-55, 59-61, or 65-67, respectively, provides a pro-stimulatory immune effect, as opposed to an anti-stimulatory or pro-regulatory effect, in a subject in need thereof. In some embodiments, the use comprises the use of an anti-IL-2 antibody. In some embodiments, the use comprises the use of an anti-IL-2 antibody and IL-2. In some embodiments, the use comprises the use of a conjugate of an anti-IL-2 antibody and IL-2.

[0180] Thus, the engineered anti-IL-2 antibodies disclosed herein are believed to be useful in modulating immune cell populations and inducing the differentiation and proliferation of specific immune effector cells in methods for treating diseases such as viral infections, bacterial infections, or cancer, or conditions such as IL-2-induced pulmonary edema or IL-2-induced vascular leakage.

[0181] Disclosed herein, in some embodiments, are methods of immunizing a subject, wherein immunization comprises administering a vaccine comprising an adjuvant, and the adjuvant comprises an IL-2 antibody adjuvant. In some embodiments, the IL-2 antibody adjuvant comprises an anti-IL-2 antibody and IL-2, or an anti-IL-2 antibody complexed with IL-2. In some embodiments, the IL-2 antibody adjuvant comprises an anti-IL-2 antibody and IL-2. In some embodiments, the IL-2 antibody adjuvant comprises an anti-IL-2 antibody complexed with IL-2. In some embodiments, the IL-2 antibody adjuvant comprises an anti-IL-2 antibody.

[0182] In some embodiments, the subject to be immunized is a mammalian subject. In some embodiments, the subject to be immunized is a human. In some embodiments, the subject to be immunized has a weakened immune system.

[0183] In some embodiments of the methods of immunizing, the anti-IL-2 antibody comprises a heavy chain variable region (VH) having the sequence of one of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36. In some embodiments of the methods of immunizing, the anti-IL-2 antibody comprises a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37. In some embodiments of the methods of immunizing, the anti-IL-2 antibody comprises an anti-IL-2 antibody comprising a heavy chain variable region (VH) and a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 10 and 11, SEQ ID NOs: 12 and 13, SEQ ID NOs: 14 and 15, SEQ ID NOs: 16 and 17, SEQ ID NOs: 18 and 19, SEQ ID NOs: 20 and 21, SEQ ID NOs: 22 and 23, SEQ ID NOs: 24 and 25, SEQ ID NOs: 26 and 27, or SEQ ID NOs: 36 and 37.

[0184] In some embodiments of the methods of immunizing, the anti-IL-2 antibody comprises an anti-IL-2 antibody comprising a heavy chain variable region (VH) comprising complementarity determining regions (CDR1, CDR2, and CDR3, CDR1, CDR2, and CDR3) comprising the amino acid sequences of SEQ ID NOs: 38-40, respectively, SEQ ID NOs: 44-46, respectively, SEQ ID NOs: 50-52, respectively, SEQ ID NOs: 56-58, respectively, or SEQ ID NOs: 62-64, respectively. In some embodiments of the methods of immunizing, the anti-IL-2 antibody comprises an anti-IL-2 antibody comprising a light chain variable region (VL) comprising complementarity determining regions (CDR1, CDR2, and CDR3, CDR1, CDR2, and CDR3) comprising the amino acid sequences of SEQ ID NOs: 41-43, respectively, SEQ ID NOs: 47-49, respectively, SEQ ID NOs: 53-55, respectively, SEQ ID NOs: 59-61, respectively, or SEQ ID NOs: 65-67, respectively. In some embodiments of the immunization method, the anti-IL-2 antibody comprises an anti-IL-2 antibody comprising a heavy chain variable region (VH) and a light chain variable region (VL), wherein the heavy chain variable region (VH) and the light chain variable region (VL) comprise complementarity determining regions (CDR1, CDR2, and CDR3), and the complementarity determining regions (CDR1, CDR2, and CDR3) of the heavy chain variable region (VH) comprise the amino acid sequences of SEQ ID NOs: 38-40, 44-46, 50-52, 56-58, or 62-64, respectively, and the complementarity determining regions (CDR1, CDR2, and CDR3) of the light chain variable region (VL) comprise the amino acid sequences of SEQ ID NOs: 41-43, 47-49, 53-55, 59-61, or 65-67, respectively.

[0185] In some embodiments of the methods of immunizing a subject, immunization comprises administering a vaccine comprising an adjuvant, wherein the adjuvant comprises an IL-2 antibody adjuvant, and the anti-IL-2 antibody comprises an anti-IL-2 antibody disclosed herein. In some embodiments, the IL-2 antibody adjuvant comprises an anti-IL-2 antibody and IL-2, or an anti-IL-2 antibody complexed with IL-2. In some embodiments of the methods of immunizing a subject, the subject has a weakened immune system.

[0186] In some embodiments, subjects for immunization with a vaccine comprising an IL-2 antibody adjuvant include subjects with a condition comprising a genetic predisposition that increases the likelihood of cancer in the subject. In some embodiments, the genetic predisposition comprises an alteration in the expression or activity of a gene product. In some embodiments, the genetic predisposition that increases the likelihood of cancer comprises a mutation in a tumor suppressor gene, a mismatch repair (MMR) gene, or a combination thereof. As non-limiting examples, many hereditary cancers are known in the art, such as, but not limited to, hereditary breast and ovarian cancer (HBOC) syndrome, Lynch syndrome (hereditary nonpolyposis colorectal cancer), and Li-Fraumeni syndrome.

[0187] In some embodiments, a subject being treated by the methods disclosed herein for treating a disease or condition is further treated with one or more immune checkpoint inhibitors that target one or more immune checkpoints. In some embodiments, the subject is treated with the immune checkpoint inhibitor simultaneously with treatment with an anti-IL-2 antibody, prior to treatment with an anti-IL-2 antibody, or after treatment with an anti-IL-2 antibody. In some embodiments of the methods of treatment disclosed herein, the immune checkpoints include PD-1, PDL-1, CTLA-4, TIGIT, TIM-3, B7-H3, CD73, LAG3, CD27, CD70, 4-1BB, GITR, OX40, SIRP-α (CD47), CD39, ILDR2, VISTA, BTLA, VTCN-1, or any combination thereof.

[0188] In some embodiments, as described above, the therapeutic methods of treatment disclosed herein further comprise an additional active agent, including an immune checkpoint inhibitor. One skilled in the art will appreciate that combination therapies comprising anti-IL-2 antibody therapy, with or without IL-2, and further a checkpoint inhibitor may utilize any of the therapeutic compositions or formulations comprising an anti-IL-2 antibody + / - IL-2 and a checkpoint inhibitor provided herein. In some embodiments, at least two checkpoint inhibitors are used in the combination therapy.

[0189] Embodiments of the present application include the following.

[0190] An isolated anti-IL-2 antibody comprising a heavy chain variable region (VH) having the sequence of one of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36.

[0191] An antibody, including an IgG, IgA, IgM, IgE, IgD, Fv, scFv, Fab, F(ab´)2, minibody, diabody, triabody, nanobody, or single domain antibody.

[0192] An IgG comprising: (a) an IgG1, IgG2, IgG3, or IgG4; (b) a heavy chain comprising a mutation that reduces binding to Fcγ receptors (FcγRs); (c) a lambda or kappa light chain; or (d) any combination of (a)-(c).

[0193] A composition comprising an isolated anti-IL-2 antibody and a pharmaceutically acceptable carrier.

[0194] An isolated anti-IL-2 antibody comprising a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37.

[0195] An isolated anti-IL-2 antibody comprising a heavy chain variable region (VH) and a light chain variable region (VL) having one of the sequences set forth in SEQ ID NOs: 10 and 11, 12 and 13, 14 and 15, 16 and 17, 18 and 19, 20 and 21, 22 and 23, 24 and 25, 26 and 27, or 36 and 37.

[0196] Heavy chain variable region (VH) with complementarity determining regions (CDR1, CDR2, and CDR3) wherein the complementarity determining regions (CDR1, CDR2, and CDR3) comprise the amino acid sequences of SEQ ID NOs: 38-40, 44-46, 50-52, 56-58, or 62-64, respectively.

[0197] An isolated anti-IL-2 antibody comprising a light chain variable region (VL) having complementarity determining regions (CDR1, CDR2, and CDR3), wherein the complementarity determining regions (CDR1, CDR2, and CDR3) comprise the amino acid sequences of SEQ ID NOs: 41-43, 47-49, 53-55, 59-61, or 65-67, respectively.

[0198] An isolated anti-IL-2 antibody comprising a heavy chain variable region (VH) comprising complementarity determining regions (CDR1, CDR2, and CDR3) comprising the amino acid sequences of SEQ ID NOs: 38-40, 44-46, 50-52, 56-58, or 62-64, respectively, and a light chain variable region (VL) comprising complementarity determining regions (CDR1, CDR2, and CDR3) comprising the amino acid sequences of SEQ ID NOs: 41-43, 47-49, 53-55, 59-61, or 65-67, respectively.

[0199] An isolated polynucleotide sequence encoding the heavy chain variable region (VH) of an anti-IL-2 antibody, wherein the heavy chain variable region (VH) comprises one of the amino acid sequences of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36.

[0200] A vector comprising a polynucleotide sequence described herein. A host cell comprising a vector described herein.

[0201] An isolated polynucleotide sequence encoding the light chain variable region (VL) of an anti-IL-2 antibody, wherein the light chain variable region (VL) comprises one of the amino acid sequences set forth in SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37.

[0202] An isolated polynucleotide sequence encoding the heavy chain variable region (VH) and light chain variable region (VL) of an anti-IL-2 antibody, wherein the heavy chain variable region (VH) comprises one of the amino acid sequences of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36, and the light chain variable region (VL) comprises one of the amino acid sequences of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37.

[0203] An isolated polynucleotide sequence comprising one of SEQ ID NOs: 1, 2, 3, 4, 5, 31, 32, 33, 34, or 35, and encoding an scFv.

[0204] A method for producing a heavy chain variable region (VH) of an anti-IL-2 antibody, the method comprising the step of culturing a host cell containing a vector disclosed herein under conditions that promote expression of the vector in the host cell, thereby producing the heavy chain variable region (VH) of the anti-IL-2 antibody.

[0205] A method for producing a light chain variable region (VL) of an anti-IL-2 antibody, comprising culturing a host cell under conditions that promote expression of a vector in the host cell, thereby producing the light chain variable region (VL) of the anti-IL-2 antibody.

[0206] A method for producing an anti-IL-2 antibody comprising a heavy chain variable region (VH) and a light chain variable region (VL) of the anti-IL-2 antibody, the method comprising the step of culturing a host cell under conditions that promote expression of a vector in the host cell, thereby producing the light chain variable region (VL) of the anti-IL-2 antibody.

[0207] A method for promoting the differentiation and growth of immune cells in a subject, the method comprising the step of administering a composition comprising an anti-IL-2 antibody, thereby promoting the differentiation and growth of immune cells in the subject.

[0208] A method for treating a subject with cancer by inducing the differentiation and growth of immune cells, the method comprising the step of administering a composition comprising an anti-IL-2 antibody, thereby treating the subject with cancer.

[0209] A method for treating a disease or condition in a subject, comprising administering to the subject a composition comprising an anti-IL-2 antibody, wherein the anti-IL-2 antibody promotes the proliferation of a subset of immune cells and reduces undesirable effects caused by IL-2, thereby treating the disease or condition in the subject.

[0210] In some embodiments, the disease comprises a viral infection, a bacterial infection, or cancer. In some embodiments, the viral infection is caused by SARS-CoV-2, norovirus, rotavirus, hepatitis A, B, C, D, or E virus, rabies virus, West Nile virus, enterovirus, echovirus, coxsackievirus, herpes simplex virus (HSV), HSV-2, varicella-zoster virus, mosquito-borne virus, arbovirus, St. Louis encephalitis virus, California encephalitis virus, lymphocytic choriomeningitis virus, human immunodeficiency virus (HIV), poliovirus, Zika virus, rubella virus, cytomegalovirus, human papillomavirus (HPV), enterovirus D68, severe acute respiratory syndrome (SARS) coronavirus, Middle East respiratory syndrome coronavirus, Epstein-Barr virus, influenza virus, respiratory syncytial virus, polyomavirus including JC virus, BK virus, Ebola virus, dengue virus, or any combination thereof. In some embodiments, the condition comprises a weakened immune system and the treatment prophylactically boosts the immune system.

[0211] In some embodiments, the condition comprises IL-2 induced pneumonia.

[0212] In some embodiments of the methods disclosed herein, the immune cells include naive T cells, memory T cells, CD8 + The cells include one or more of T cells, NK cells, or natural killer T cells.

[0213] In some embodiments, the undesirable effects caused by IL-2 include the activation of regulatory T cells, CD25 + These include one or more of T effector cell apoptosis, IL-2-induced pulmonary edema, IL-2-induced pneumonia, or IL-2-induced vascular leakage.

[0214] In some embodiments, the anti-IL-2 antibodies disclosed herein inhibit the binding of IL-2 to CD25.

[0215] A method of immunizing a subject, wherein immunizing comprises administering a vaccine comprising an adjuvant, wherein the adjuvant comprises an IL-2 antibody adjuvant.

[0216] In some embodiments, the IL-2 antibody adjuvant comprises an anti-IL-2 antibody and IL-2, or an anti-IL-2 antibody complexed with IL-2.

[0217] In some embodiments, the subject is an animal or a human, hi some embodiments, the subject has a weakened immune system.

[0218] In some embodiments of the methods disclosed herein, the immune cells are CD8 + They are T cells or NK cells.

[0219] In some embodiments of the methods disclosed herein, the anti-IL-2 antibody comprises a heavy chain variable region (VH) having the sequence of one of SEQ ID NOs: 10, 12, 14, 16, 18, 20, 22, 24, 26, or 36.

[0220] In some embodiments of the methods disclosed herein, the anti-IL-2 antibody comprises a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 11, 13, 15, 17, 19, 21, 23, 25, 27, or 37.

[0221] In some embodiments of the methods disclosed herein, the anti-IL-2 antibody comprises a heavy chain variable region (VH) and a light chain variable region (VL) having the sequence of one of SEQ ID NOs: 10 and 11, SEQ ID NOs: 10 and 11, SEQ ID NOs: 10 and 11, SEQ ID NOs: 12 and 13, SEQ ID NOs: 14 and 15, SEQ ID NOs: 16 and 17, SEQ ID NOs: 18 and 19, SEQ ID NOs: 20 and 21, SEQ ID NOs: 22 and 23, SEQ ID NOs: 24 and 25, SEQ ID NOs: 26 and 27, or SEQ ID NOs: 36 and 37.

[0222] In some embodiments of the methods disclosed herein, the anti-IL-2 antibody comprises a heavy chain variable region (VH) comprising complementarity determining regions (CDR1, CDR2, and CDR3, CDR1, CDR2, and CDR3) comprising the amino acid sequences of SEQ ID NOs: 38-40, respectively, SEQ ID NOs: 44-46, respectively, SEQ ID NOs: 50-52, respectively, SEQ ID NOs: 56-58, respectively, or SEQ ID NOs: 62-64, respectively.

[0223] In some embodiments of the methods disclosed herein, the anti-IL-2 antibody comprises a light chain variable region (VL) comprising complementarity determining regions (CDR1, CDR2, and CDR3, CDR1, CDR2, and CDR3) comprising the amino acid sequences of SEQ ID NOs: 41-43, respectively, SEQ ID NOs: 47-49, respectively, SEQ ID NOs: 53-55, respectively, SEQ ID NOs: 59-61, respectively, or SEQ ID NOs: 65-67, respectively.

[0224] In some embodiments of the methods disclosed herein, the anti-IL-2 antibody comprises a heavy chain variable region (VH) and a light chain variable region (VL), each of which comprises a complementarity determining region (CDR1, CDR2, and CDR3), wherein the heavy chain complementarity determining regions (CDR1, CDR2, and CDR3) comprise the amino acid sequences of SEQ ID NOs: 38-40, 44-46, 50-52, 56-58, or 62-64, respectively, and the light chain complementarity determining regions (CDR1, CDR2, and CDR3) comprise the amino acid sequences of SEQ ID NOs: 41-43, 47-49, 53-55, 59-61, or 65-67, respectively.

[0225] As used herein, the singular forms "a," "an," and "the" include the plural of their referents unless the context clearly dictates otherwise. For example, the terms "one compound" or "at least one compound" can include a plurality of compounds, including combinations thereof.

[0226] Throughout this application, various embodiments of the invention may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Thus, descriptions in range format should be considered to specifically disclose not only each individual numerical value subsumed within that range, but also all the possible subranges subsumed within that range. For example, a description of a range of 1 to 6 should be considered to specifically disclose the subranges of 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, ..., as well as each individual numerical value subsumed within that range (e.g., 1, 2, 3, 4, 5, and 6). This applies regardless of the breadth of the range.

[0227] Whenever a range of values ​​is specified herein, it is meant to include all numbers (fractional or integer) subsumed within the specified range of values. The phrases "ranging between" a first specified number and a second specified number, and "ranging from" a first specified number to a second specified number, are used interchangeably herein and are meant to include the first specified number and the second specified number, and all fractional and integer numbers therebetween.

[0228] Those of ordinary skill in the art will understand that the term "about" can encompass deviations of 0.0001 to 5% from a stated numerical value or range of values. In some cases, the term "about" can encompass deviations of 1 to 10% from a stated numerical value or range of values. In some cases, the term "about" can encompass deviations of up to 25% from a stated numerical value or range of values.

[0229] Example

[0230] Example 1

[0231] This example describes the generation of modified anti-IL-2 antibodies based on embodiments of the antibodies generated. The illustration of the generation of modified anti-IL-2 antibodies is based on a subset of the antibodies disclosed herein. The description and results presented in Example 1 are exemplary and are not intended to limit the generation of modified anti-IL-2 antibodies disclosed throughout this application.

[0232] Library Design

[0233] A library was designed to introduce mutations into the JES6.1 sequence. The amino acid sequences of the heavy and light chain variable regions of JES6.1 are shown in SEQ ID NOs: 6 and 7, respectively. Briefly, three positions were varied in all amino acid-encoding codons (codons NNS). The library design allowed for one mutation in both CDRL3 and H3, and one mutation in any of the CDRs: H1, H2, or L2. CDRs were defined by meeting the definitions of either IMGT or ABR (Kunik et al., 2012). Conserved CDR residues (based on a Blast search against the PDB database) or CDR residues that do not form specific interactions with mouse IL-2 (mIL-2) in the crystal structure of the mIL2-JES6.1 complex (PDB4YQX) were excluded from mutation. The theoretical size of the library was 1.38E+7 mutants.

[0234] Library Selection

[0235] Screening and selection using yeast surface display

[0236] The yeast display scFv library was grown in SDCAA selective medium and induced with 2% w / v galactose overnight at 30°C according to established protocols. The library was incubated with 100 nM recombinant human IL-2 with a 6xHis tag (hIL-2-His) (Reprokine, Israel) in PBS 0.1% BSA for 1 hour. The library was then washed three times with PBS 0.1% BSA and labeled with fluorescently labeled mouse anti-Myc-FITC (Santa Cruze, USA) and mouse monoclonal anti-HisAPC (Miltenyi Biotec, Germany, cat: 0020130-119-782). After labeling, the library was sorted for high-affinity binders to recombinant human IL-2 on a BioRad S3e fluorescence-activated cell sorter. Clones isolated from the final sort were sequenced by extracting plasmid DNA from the yeast clones using a Zymoprep kit (Zymo Research, USA), which allowed DNA sequencing.

[0237] Koff's Choice

[0238] To select binders with improved off-rates, clones from the second round of selection were incubated with 10 nM 6xHis tag (hIL-2) for 15 min. Yeast were then washed three times with 1 ml of PBS 0.1% BSA and incubated with 100 nM unlabeled IL-2 for 5 min, 4 h, 6 h, and 24 h. At the indicated time points, yeast were washed, labeled with Myc-FITC (Santa Cruz, USA) and monoclonal anti-HisAPC (Miltenyi Biotec, Germany, cat: 002030-119-782), and sorted with Se3 as described above.

[0239] IgG production

[0240] JES6.1 w.t. was purchased from Thermo Fisher (cat: 16-7022-81). JES6.1.RMC was cloned as a rat Fv with a mouse IgG2a constant region and produced by GeneScript Antibody Production Services (Genscript, New Jersey, USA). BDG17.0014 was cloned into a human IgG1 constant region and produced by GeneScript Antibody Production Services. The amino acid sequences of the heavy and light chain variable regions of JES6.1.RMC are shown in SEQ ID NO:8 and SEQ ID NO:9, respectively. All other antibodies were produced as described below.

[0241] Reformat

[0242] Selected scFv clones were reformatted to a human IgG1 format. The sequences of the light chain (LC) and heavy chain (HC) variable regions were optimized for mammalian codon usage and ordered as GenBlocks (GB) from IDT (Integrated DNA Technologies, Coralville, IA, USA). The GBs were cloned into pSF-CMV-HuIgG1_HC (HC plasmid) and pSF-CMV-HuLambda_LC (LC plasmid) (Oxford Genetics, Oxford, UK) using standard cloning techniques. Where indicated, the variable heavy chain was cloned into pSF-CMV-HuIgG1_HC_LALA (HC plasmid), in which the DNA encoding L234 and L235 of the heavy chain had been mutated to alanine codons (L234A, L235A).

[0243] IgG expression

[0244] Expi-CHO cells (Thermo Fisher Scientific, USA) were transfected with the LC and HC plasmids at a 2:1 ratio and expressed according to the manufacturer's instructions. Briefly, 50 ml of Expi-CHO cells were cultured at 37°C, 120 rpm, and 8% CO2 at 6 × 10 6 The cells were cultured to a density of 1000 cells / ml. CHO cells were then transfected with 50 μg of heavy and light chain expression plasmids at a 1:2 ratio. After transfection, booster enhancers and feed were added to the culture, and growth conditions were changed to 32°C, 120 rpm, and 5% CO2. Cells were harvested 10 days after transfection. IgG was purified from the supernatant using protein A beads (Tosoh Bioscience GmbH, Germany), followed by size-exclusion chromatography (SEC) purification on a Superdex 200 10 / 300 increasing column using PBS as the mobile phase (GE Healthcare, USA).

[0245] array

[0246] The DNA sequence encoding the scFv of clone 1 (17.021) is shown in SEQ ID NO: 1. The DNA sequence encoding the scFv of clone 2 (17.022) is shown in SEQ ID NO: 2. The DNA sequence encoding the scFv of clone 4 (17.023) is shown in SEQ ID NO: 3. The DNA sequence encoding the scFv of clone 5 (17.030) is shown in SEQ ID NO: 4. The DNA sequence encoding the scFv of clone 6 (17.035) is shown in SEQ ID NO: 5.

[0247] The amino acid sequences of the heavy and light chain variable regions of the original JES6_1 starting sequence and various anti-IL-2 clones are shown in Table 2 below and in Figures 11 and 12.

[0248] [Table 2]

[0249] Measurement of IgG binding to human IL-2

[0250] SPR analysis was performed on a Biacore 200 (GE Healthcare, USA) on a CM5 chip (GE Healthcare, USA, cat: br10005-30). The CM5 chip was crosslinked to 8000 RU of target with a primary capture antibody against human IgG (GE Healthcare, USA, cat: br-1008-39) or a primary capture antibody against mouse IgG (GE Healthcare, USA, cat: BR-1008-38). After crosslinking of the primary capture antibody, mouse and human test antibodies were immobilized on the primary capture antibody at approximately 500 RU of additional target. JES6.1 was crosslinked directly onto the CM5 chip. Human IL-2 (Reprokin, Israel, cat: 60568) analyte was streamed in a series of 2- or 3-fold dilutions, one concentration per cycle, at concentrations ranging from 128 to 0.03 nM in HEB-EP or PBS 0.05% Tween-20 (PBS-T) buffer. Murine IL-2 (Reprokin, Israel, cat:RKP04351) was streamed into HEB-EP or PBS-T buffer at concentrations ranging from 0.5 to 40 nM. At the end of each cycle, the analyte and tested antibody were stripped from the chip using 3 M MgCl2, and a new antibody was loaded onto the chip as described above. Where indicated, instead of stripping the antibody, kinetics were determined by injecting a range of analyte concentrations in one cycle using the single-cycle kinetics method. Binding kinetics were determined using a 1:1 binding model using Biacore T200 evaluation software.

[0251] IgG binding to cynomolgus monkey IL-2

[0252] SPR analysis was performed on a Biacore 200 (GE Healthcare, USA) on a CM5 chip (GE Healthcare, USA, cat: br10005-30). The CM5 chip was crosslinked to 5000 RU of target with a primary capture antibody against human IgG (GE Healthcare, USA, cat: br-1008-39), and cynomolgus IL-2 (cIL-2) was tested using the multi-cycle method under the same conditions as above.

[0253] SEC analysis

[0254] To analyze IgG, 100 μg of sample was loaded onto a Superdex 200 10 / 300 gain column (GE Healthcare, USA) on a GE AKTA Explorer chromatography system (GE Healthcare, USA) at a flow rate of 0.8 ml / min. Antibody retention time was monitored at 280 nm.

[0255] Testing specific binding to CD25 and CD122

[0256] To test for specific binding to CD25, BDG17.023 was immobilized on a CM5 chip with a target RU of approximately 300, as described above. Subsequently, 50 nM IL-2 was injected until BDG17.023 or a control antibody was saturated with IL-2. The Ab-IL-2 complex was then washed with PBS-T buffer for 10 seconds, and 1000 nM CD25 was injected to observe the response.

[0257] To test specific binding to CD122, BDG17.023 was immobilized on a CM5 chip with a target RU of approximately 300-500 RU as described above. Subsequently, 50 nM hIL-2 was injected until the BDG17.023 antibody was saturated with hIL-2. The Ab-hIL-2 complex was then washed with PBS-T buffer for 10 seconds, and 1000 nM CD122 was injected and the reaction observed.

[0258] To test the specific binding of humanized antibody-IL-2 conjugates to CD122 and CD25, antibodies BDG17.038, BDG17.043, BDG17.053, BDG17.054, BDG17.067, and BDG17.069 (see Tables 6 and 7 in Example 2 for sequence information for these clones) were immobilized on capture antibodies attached to a CM5 chip channel with a target RU of approximately 300, as described above. Subsequently, 50 nM IL-2 was injected until each antibody was saturated with hIL-2. The Ab-IL-2 conjugates were then washed with PBS-T buffer for 60 seconds, and 1000 nM CD25 was injected and the response was observed. Running buffer was then injected for 60 seconds until a steady baseline was reached, followed by 30 seconds of 1000 nM CD122 at a flow rate of 30 μl / min. To test for CD122 binding, the same experiment was repeated in the reverse order: CD25 was injected first, followed by CD122.

[0259] DSF analysis of IgG Tm

[0260] To determine the T-onset and Tm of the humanized anti-hIL-2 antibody, the antibody was diluted to 0.5 mg / ml in PBS and analyzed using a NanoDSF Prometheus NT.48 (Nanotemper, Germany) at a temperature ramp rate of 1°C / min.

[0261] In vivo experiments

[0262] Treatment of mice with IL-2 / Ab complexes

[0263] Groups of six male C57BL / 6 mice, 7-8 weeks of age, were intraperitoneally (ip) administered BDG17.023 / hIL-2 or JES6.1 / mIL-2 immunoconjugates daily for four consecutive days. PBS and free hIL-2 or mIL-2 served as controls. At the end of the fourth day, mice were sacrificed, and spleens were harvested and homogenized to a single-cell suspension. Cells were filtered, centrifuged (400 g for 5 min), resuspended in 5 ml of PBS, and collected at 5 × 10 6The final concentration was 100 lymphocytes / ml. Experiments were performed in accordance with the guidelines of the Israeli Animal Care and Use Committee (IACUC).

[0264] Groups of six male C57BL / 6 mice, 7–8 weeks of age, were intraperitoneally (ip) injected daily for four consecutive days with BDG17.038 / hIL-2, BDG17.043 / hIL-2, BDG17.054 / hIL-2, BDG17.038 / hIL-2, or isotype control / hIL-2 immunoconjugates. To form the complexes, 10 μg of antibody was preincubated with 0.5 μg of hIL-2 at 37°C for 30 minutes prior to administration. At the end of the fourth day, mice were sacrificed, and spleens were harvested and homogenized to a single-cell suspension. Cells were filtered, centrifuged (400 g for 5 minutes), resuspended in 5 ml of PBS, and diluted to 5 × 10 6 The final concentration was 100 lymphocytes / ml. Experiments were performed in accordance with the guidelines of the Israeli Animal Care and Use Committee (IACUC).

[0265] B16F10 mouse melanoma tumor xenograft model

[0266] Female C57BL / 6 mice were inoculated with 2 × 10 5 B16-F10 tumor cells were inoculated subcutaneously. The tumor volume was approximately 30-50 mm. 3 Five days after inoculation, mice were randomized into experimental groups (n = 10 per group) and received a single dose of 10 μg of the indicated anti-IL-2 antibody / 1 μg of hIL-2 complex or PBS control intraperitoneally daily for four consecutive days. Mice were monitored for tumor volume growth, weight loss, and nonspecific clinical signs throughout the experiment.

[0267] Determination of immune cell populations by FACS

[0268] To identify immune cell populations, splenic lymphocytes were labeled with the following antibodies according to the manufacturer's instructions: Regulatory T cells (Treg): CD45 + / CD3 + / CD4 + / CD25+ / FoxP3 + Memory phenotype effector T cells (MPCD8+): CD45 + / CD3 + / CD8 + / CD44 + / IL-2RB(CD122) + Natural killer cells (NK): CD45 + / CD3 + / CD49b + / NK1.1 (CD161). Natural killer T cells (NKT): CD45 + / CD3 + / CD49b + / NK1.1 (CD161). The frequency and number of positive cells were calculated from the raw data acquired by the flow cytometer.

[0269] [Table 3]

[0270] result

[0271] JES6.1 bound strongly to mouse IL-2 but not to human IL-2.

[0272] JES6.1 has been reported to bind to mouse IL-2 (mIL-2) with a KD of 5.6 nM. To test whether JES6.1 can bind to human IL-2 (hIL-2), the JES6.1 antibody was tested by SPR on a Biacore T200. JES6.1 was directly crosslinked to a CM5 chip, and then human IL-2 or mouse IL-2 analytes were streamed at concentrations ranging from 0.5 to 128 nM or 0.5 to 16 nM, respectively. As shown in Figure 4A, when tested with human IL-2, JES6.1 showed no significant change in response units (RU). On the other hand, when tested with mouse IL-2, a strong response was observed (Figure 4B). This indicates that JES6.1 binds tightly to mouse IL-2 but not to human IL-2. This experiment was repeated using the JES6.1RMC antibody chimera expressed as a JES6.1 rat FV with a mouse constant region as described herein. JES6.1RMC was immobilized on a CM5 chip using a GE antibody capture kit. Streaming hIL-2 at concentrations up to 100 nM did not change the RU, indicating no binding to human IL-2 (Figure 4C). To test whether the JES6.1RMC chimera retained its mIL-2 binding properties like JES6.1, binding to mouse IL-2 was tested. Streaming mIL-2 at concentrations from 0.5 to 320 nM resulted in a large change in RU, indicating strong binding (Figure 4D). These results indicate that JES6.1 and JES6.1RMC bind strongly to mouse IL-2 but show no significant binding to human IL-2. Analysis of the binding kinetics of JES6.1RMC to both hIL-2 and mIL-2 is shown below.

[0273] [Table 4]

[0274] Change in binding specificity from mouse IL-2 to human IL-2

[0275] To change the binding specificity from mouse IL-2 to human IL-2, JES6.1 was cloned as an scFv into a yeast display vector. The scFv format of JES6.1 was well expressed on the yeast surface, as indicated by the carboxy-terminal myc tag (Figures 5A-C). When 100 nM of JES6.1 in IgG format was incubated with a YSD clone expressing mouse IL-2, strong binding occurred (Figures 5A-C). However, in correlation with the SPR results above, incubation of the JES6.1YSD clone with labeled human IL-2 at concentrations up to 1 μM did not result in an increase in fluorescence, indicating that JES6.1scFv does not bind to human IL-2.

[0276] A mutagenesis library was generated based on the JES6.1scFv as described above. Briefly, the YSD library was selected against recombinant human IL-2 as described above. The mutant library underwent one round of MACS selection against 1 μM human IL-2 and an additional round of FACS selection against 1 μM human IL-2. The top 0.2% of clones were selected. This mutant library was then subjected to two additional rounds of selection specifically aimed at improving the koff characteristics of the clones selected above. In the third round, yeast were incubated with 10 nM His-tagged hIL-2 at room temperature for 15 minutes, then washed with hIL-2 and incubated with 100 nM unlabeled IL-2 at room temperature for 5 minutes. The fourth round was performed in a similar manner, except that the yeast were labeled and washed and then incubated in 20 times the initial volume of PBS for 24 hours. In the fifth round, yeast were labeled and washed and then incubated with 100 nM unlabeled IL-2 at room temperature for 6 hours. After the fifth round, clones were isolated. Five YSD clones that acquired binding to hIL-2 (Figures 6A and 6B) were sequenced. Additionally, these clones were tested for specificity by labeling with a mixture of 500 nM soluble TNFR2, 500 nM OX40, and 500 nM PD1. As seen in Figures 6A and 6B, these clones were specific for hIL-2 and did not bind to other proteins.

[0277] Expression of BDG17.023

[0278] After characterization of the YSD, clone #4, which showed significant binding to hIL-2, was reformatted into a human chimeric IgG1 (BDG17.023) with rat FV and human Fc chimeras. The rat variable regions were subcloned into two separate expression vectors, pSF-CMV-HuIgG1_HC and pSF-CMV-HuLambda_LC, as described above. The IgG was expressed in ExpiCHO cells as described above. The purified IgG was >95% pure, as evidenced by SDS-PAGE analysis. Size-exclusion chromatography of BDG17.023 on a Superdex 200 10 / 300 column showed two major peaks. The first peak had a retention time of approximately 9.2 ml (0.36 CV), which was characteristic of large aggregates. The second peak had a retention time of approximately 12.6 ml (0.528 CV), which was characteristic of normal human hIgG1. The peak integrations for these SEC runs were 11% and 89%, respectively (Figure 7).

[0279] Binding kinetics of BDG17.023

[0280] To determine the binding kinetics and affinity of BDG17.023 to mIL-2 or hIL-2, the IgG was analyzed by SPR on a BIAcore T200 using the GE Capture Antibody Kit as described above. As shown in Figures 8A and 8B, BDG17.023 bound to hIL-2 at approximately 8 x 10 -11 It binds with an affinity of 1.3 × 10 and an on-rate of 1.3 × 10 7 , the off rate is 1×10 -3 In addition, BDG17.023 inhibited mIL-2 by approximately 2.5 × 10 -6 showed that it binds with much lower affinity than

[0281] [Table 5]

[0282] Receptor identification of BDG17.023-hIL-2 complex

[0283] The JES61-mIL-2 complex has been reported to specifically bind to CD25 but not to CD122. The JES6.1-mIL-2 complex bound to an SPR chip bound to CD25 but not to CD122. To test whether the BDG17.023-hIL-2 complex could discriminate between binding to CD25 or CD122, we performed a similar experiment. As shown in Figure 9, a control antibody complexed with hIL-2 bound to human CD25 but not to CD122. In contrast, the BDG17.023-hIL-2 complex was found to bind to CD122 but not to CD25. These results suggest that although BDG17.023 is derived from JES6.1, the JES6.1-mIL-2 complex and the BDG17.023-hIL-2 complex have very different IL-2 receptor selectivity, likely due to binding to different epitopes on mIL-2 and hIL-2, respectively. Alternatively, different allosteric effects may be induced on mIL-2 and hIL-2 that affect their binding preference for the IL-2 receptor.

[0284] In vivo characterization of BDG17.023

[0285] In vivo administration of JES6.1 complexed with mIL-2 resulted in robust proliferation of regulatory T cells and much less proliferation of effector T cells, thereby inhibiting MPCD8 + In SPR biochemical assays, the BDG17.023-hIL-2 complex showed a preference for binding to CD122 and excluded binding to CD25, suggesting that the BDG17.023-hIL-2 complex inhibited CD8+ / Treg ratios in vivo. +This is predicted to enhance the proliferation of effector and NK cells. Because human IL-2 can cross-react with the mouse IL-2 receptor, the BDG17.023-hIL-2 conjugate was administered to C57BL / 6 mice and its efficacy was tested in vivo as described above. Briefly, the 17.023 antibody-hIL-2 conjugate was incubated with hIL-2 at a 1:1 molar ratio and administered intraperitoneally to C57BL / 6 mice daily for four consecutive days. As controls, the JES6.1-mIL-2 conjugate, hIL-2 alone, or mIL-2 alone was also administered. On day 5, mouse spleens were harvested, and cells were labeled and analyzed by FACS as described above.

[0286] As can be seen in Figures 10A to 10D, BDG17.023 is a + showed a significant effect on the induction of proliferation of CD4 + The effect on Tregs was very small. JES6.1, on the other hand, showed a very different effect, consistent with its reported anti-inflammatory effect. These results demonstrate that, consistent with the binding data and in contrast to JES6.1, the BDG17.023-IL-2 complex has a strong stimulatory effect on the immune system in vivo, as opposed to an anti-stimulatory or pro-regulatory effect.

[0287] Example 2

[0288] This example presents results regarding further selection of human IL-2 binding agents and generation of humanized antibodies.

[0289] A different selection strategy was used to select human IL-2 binders under different selection pressures. Briefly, the library underwent one round of MACS selection against 1 μM human IL-2 and four additional rounds of FACS selection against 100 nM human IL-2. After one round of FACS selection, all binders were selected, and then the top 0.5%, top 0.5%, and top 0.1% of binders were selected. After five rounds of selection, clone C#7 (173R5C1-17.002) (SEQ ID NO: 28) was isolated, binding confirmed, and sequenced.

[0290] Antibody Humanization

[0291] Clone C#7 (173R5C1-17.002) was selected as the template for humanization. The human template was selected using the Schrodinger BioLuminate 'Antibody Humanization: CDR Grafting' CDR tool (Kai Zhu, Tyler Day et al., Antibody structure determination using a combination of homology modeling, energy-based refinement, and loop prediction. Proteins: Structure, Function and Bioinformatics, 82, 8, 8 2014), and the PDB entry of JES6-1 was used as a query (4YQX; Jamie B. Spangler, Jakub Tomala et al., Antibodies to Interleukin-2 Elicit Selective T Cell Subset Potentiation through Distinct Conformational Mechanisms. Immunity, 42, 5, 5 2015). The PDB entry 5I18 was selected because it had the best score for the combination of light and heavy chain framework identity and stem geometry (Alexey Teplyakov, Galina Obmolova et al., Structural diversity in a human antibody germline library. mAbs, 8, 6, 8, 2016). Mutations were introduced either in the CDR regions (according to the IMGT numbering scheme) or in antigen-interacting positions in 4YQX (within a 5A radius). The diversity at these positions was selected to include amino acids from both the human template (5I18) and the mouse query (4YQX). Additionally, due to the large structural changes between the H1 of the query and the template, the option of a complete transition between the H1 of 4YQX and 5I18 was introduced.This library contained approximately 1,300 variants.

[0292] This library underwent two rounds of selection by FACS. In the first round, the library was labeled with 5 nM hIL-2 and the top 5% of binding clones were selected. In the second round, the library was labeled with 1 nM hIL-2 and the top 5% of binding clones were selected. After clone selection, clones were sequenced and clone C#8 (173.2A.C6-17.014) (SEQ ID NO: 31) was used as a template for affinity maturation.

[0293] Humanized Antibody Affinity Maturation

[0294] CDR positions predicted to have a high incidence of somatic hypermutation (IMGT / ABR definition) were selected as mutation targets. Additional positions in L3 predicted to interact with antigen based on JES6-1, and the entire H3 were also selected as mutation targets. Mutations were based on sequence conservation at all positions except H3, which is the DHY codon. The theoretical diversity of this library was 3.21 x 10 12 It was.

[0295] Another library was constructed based on clone C#8 (173.2A.C6-17.014), where all CDR positions were probed using NNS degenerate codons encoding all amino acids. Variants with 2-3 mutations, up to one per CDR, were screened. The theoretical size of such a library is 2 x 10 6 double mutants, and 1 x 10 9 It is a triple mutant.

[0296] The humanized affinity-matured libraries generated above were pooled together for selection. Briefly, in the first selection round, the pooled YSD library was labeled with 10 nM hIL-2 and selected by MACS. In the second selection round, yeast was labeled with 0.1 nM hIL-2 and selected by MACS. In the third selection round, yeast was labeled with 0.1 nM hIL-2, and all binders were selected by FACS. In the fourth and fifth selection rounds, yeast was labeled with 10 nM hIL-2 and competed with 100 nM unlabeled hIL-2 for 24 and 48 hours, respectively. Yeast were then sorted by FACS, and all binders were selected. The final selection round was performed in the same manner as the fourth and fifth rounds, except that after labeling and washing, yeast was incubated in 1000 times its initial volume of PBS at room temperature for 1 week.

[0297] After selection, clones were isolated, binding confirmed, and sequenced. The amino acid sequences of several clones are shown below. Alignments of the heavy and light chain variable regions and CDR regions of a subset of clones are shown in Figures 13A and 13B.

[0298] [Table 6]

[0299] Note that clones 17.066, 17.067, and 17.069 contain LALA mutations (L234A mutation, L235A mutation).

[0300] The CDR sequences of specific clones are shown below.

[0301] [Table 7]

[0302] [Table 8]

[0303] Binding kinetics of humanized antibodies

[0304] To determine the binding kinetics and affinity of BDG17.038, BDG17.043, BDG17.053, BDG17.054, BDG17.067, BDG17.066, and BDG17.069 to hIL-2 and cynomolgus IL-2 (cIL-2), the clones were reformatted into IgG, expressed, and purified. The antibodies were then analyzed by SPR on a BIAcore T200 using the GE Capture Antibody Kit as described herein. As shown in Table 9, Figures 14A-14G, and 15A-15B, the antibodies bind tightly to both human IL-2 and cynomolgus IL-2 in the low double-digit pM range.

[0305] Size exclusion chromatography profile and thermal stability of humanized antibodies

[0306] To determine whether the humanized IgGs BDG17.038, BDG17.043, BDG17.053, BDG17.054, BDG17.066, BDG17.067, and BDG17.069 were correctly folded and stable, the antibodies were subjected to size exclusion chromatography and differential scanning fluorimetry (DSF) analysis as described above. The results are summarized in Figures 16A-16G and Table 8. Figures 16A-16G and Table 8 suggest that these IgGs were produced as >95% non-aggregated species, had SEC retention profiles typical of human IgG1, and thermal denaturation profiles with Tonset >54.4°C and Tm1 >69°C. A description of the receptor discrimination assay is shown in Figure 17A, and SPR results for different clones are shown in Figures 17B-17G. In conclusion, SPR, SEC, and DSF experiments demonstrated that the humanized antibodies bind tightly to human and cynomolgus IL-2, fold correctly, and are highly stable.

[0307] [Table 9]

[0308] Example 3

[0309] This example provides a disclosure of anti-IL-2 antibodies that specifically block the binding of human IL-2 to the IL-2 receptor CD25 and modulate the immune system in vivo.

[0310] Anti-IL-2 antibodies that bind to human IL-2 at an epitope that specifically blocks the interaction between IL-2 and human CD25 have several implications. This allows binding of the IL-2-antibody complex to effector T cells and NK cells, but inhibits binding of human IL-2 to non-immune cells expressing high levels of CD25 (e.g., pulmonary endothelium, vascular endothelium) or immune cells expressing high-affinity trimeric complexes (e.g., Treg cells, short-lived CD25+ cytotoxic effector T cells). As a result, these anti-IL-2 antibodies can increase effector T cells and NK cells without significantly increasing regulatory T cells (see Figures 1 and 2). In addition, it has previously been shown that pulmonary endothelial cells express CD25, and high levels of IL-2 in its presence can induce pulmonary edema. A similar effect was observed in IL-2-induced vascular leakage through the interaction of IL-2 with CD25 expressed on vascular endothelial cells. Therefore, by targeting IL-2 away from CD25, the anti-IL-2 antibodies disclosed herein are expected to reduce IL-2-associated pulmonary and vascular toxicity (Figures 3A and 3B).

[0311] Receptor identification of humanized IgG-hIL-2 complexes

[0312] The BDG17.023-hIL-2 complex (a complex of an anti-IL-2 antibody and human IL-2) was found to be capable of receptor binding discrimination, binding to CD122 but not CD25, resulting in specific immune system modulation. To test whether humanized antibodies have a similar effect, the humanized antibodies were conjugated to hIL-2 and analyzed for binding to CD122 and CD25 by SPR. This analysis was performed in a similar manner to that described for BDG17.023. As can be seen in the SPR traces in Figures 17B-17G, when humanized antibodies BDG17.038, BDG17.043, BDG17.053, BDG17.054, BDG17.066, BDG17.0067, or BDG17.069 were complexed with hIL-2, the complex bound to CD122 but not to CD25. This indicates that these antibodies retain the binding discrimination properties of the human-rat chimeric BDG17.023.

[0313] In vivo characterization of humanized antibodies

[0314] We hypothesized that blocking the CD25-binding epitope on IL-2 with a high-affinity antibody would allow human IL-2 to bind to effector T cells and NK cells but inhibit its binding to non-immune cells expressing CD25 (e.g., pulmonary endothelium, vascular endothelium) or cells expressing trimeric complexes (e.g., Treg cells, CD25+ effector T cells). To test this hypothesis in vivo, anti-IL-2 antibodies were pre-complexed with human IL-2 and administered to healthy C57BL / 6 male mice (Figures 18A and 18B). As seen in Figures 18A and 18B, the anti-IL-2 antibodies BDG17.043 and BDG17.054 were able to increase effector T cell, NKT cell, and NK cell populations without significantly increasing regulatory T cells (Figures 18A-18B), likely due to their epitope-specific properties. Additionally, proliferation of MP CD8+ T cells and NKT cells was dose-dependent with IgG-hIL-2 complexes and was much more robust than isotype controls treated with hIL-2, suggesting that BDG17.043 / IL-2 and BDG17.054 / IL-2 actively promote the CD122 / CD132 dimer activation pathway while avoiding the CD25 / CD122 / CD132 trimer pathway (Figures 19A and 19B).

[0315] BDG17.043 and BDG17.054 conjugated to IL-2 induced proliferation of MP CD8 effector T cells and NK cells but did not significantly promote proliferation of regulatory T cells, suggesting that these antibody-IL-2 conjugates, like JES6.1-IL-2 (Spangler JB, Tomala J, Luca VC, Jude KM, Dong S, Ring AM, Votavova P, Pepper M, Kovar M, Garcia KC. Antibodies to Interleukin-2 Elicit Selective T Cell Subset Potentiation through Distinct Conformational Mechanisms. Immunity. 2015 May 19;42(5):815-25.) and Pfizer's F5111.2-IL-2 (Trotta E, Bessette PH, Silveria SL, et al. A human anti-IL-2 antibody that potentiates regulatory T cells by promoting Treg proliferation and inducing counter-stimulatory effects of the immune system. These results suggest that the antibody-IL2 complex has a stronger stimulatory effect on the immune system than other antibody-IL2 complexes, such as those described in "A structure-based mechanism. Nat Med. 2018;24(7):1005-1014."

[0316] In the mouse study described above, mice were observed daily for weight loss and nonspecific clinical symptoms. When evaluating drug compounds in mice, a 20% weight loss is considered an action item requiring ethical intervention. As shown in Figures 20A and 20B, mice administered the 17.043 / IL-2 complex or the 17.054 / IL-2 complex experienced less than 10% weight loss at the end of the experiment. This result was observed in all dose cohorts, including mice administered the highest dose of 25 μg IgG / 1.25 μg IL-2 complex, indicating that the administered complexes were well tolerated.

[0317] Activity of humanized antibodies in the B16F10 syngeneic cancer model

[0318] Both viral clearance and cancer therapy share the common requirement of expanding adaptive T cell immune responses for efficacy. The ability of anti-IL-2 antibodies to effectively activate immune responses was tested in a B16F10 syngeneic melanoma model. C57BL / 6 mice were inoculated with B16F10 melanoma and administered 10 μg of anti-IL-2 antibody complexed with 1 μg of hIL-2, as described herein, or a PBS control. As shown in Figure 21A, all mice administered BDG17.043 or BDR17.054 complexed with IL-2 showed significant tumor growth inhibition 8 days after administration. This was significantly greater than when mice were administered the isotype control and hIL-2 (day 17 of the study), likely due to potent and specific immune stimulation. In addition, as seen in Figure 21B, the mean transient weight loss in mice administered the two anti-IL-2 antibodies was 6.84% ± 3.9% and 3.6% ± 5.2%. This indicates that the administered antibody / IL-2 complexes were well tolerated in the setting of the syngeneic B16F10 tumor model.

[0319] In summary, these studies demonstrated that the anti-IL-2 antibodies (17.043 and 17.054) bind with high affinity to human IL-2 at a predefined epitope, thereby completely blocking the interaction of IL-2 with its receptor CD25. Consequently, the antibody / IL-2 complex binds to and activates the IL-2R dimer (CD122 / CD132).

[0320] The dimeric receptor complex is present on effector cells. Analysis of the immunostimulatory effects in vivo demonstrated that IL-2 in the presence of anti-IL-2 clones 17.043 and 17.054 increased T-effector cell populations (IL-2Rβγ binding and signaling), but had no effect on regulatory T cells (IL-2Rαβγ binding and signaling). This demonstrates that the interaction of IL-2 with the dimeric IL-2 receptor results in nontoxic immune stimulation. Taken together, these data support the hypothesis that anti-human IL-2 antibodies that inhibit the cytokine's ability to bind to CD25-positive cells could be used in the treatment of cancer patients to enhance the immune response against cancer or, in the case of COVID-19 infection, increase viral load clearance. Additionally, these antibody properties could prevent IL-2-induced pulmonary edema and lung tissue damage in SARS-CoV-2-infected lungs.

[0321] Example 4

[0322] This example provides a description of studies that were performed to examine formulations of anti-IL-2 antibodies.

[0323] Methods: Formulation analysis was performed by incubating 30 mg / ml of anti-IL-2 clone BDG17.069 with the four formulations. (F1) 20 mM histidine, 8% sucrose, 0.04% PS80, pH 5.5; (F2) 20 mM histidine, 8% sucrose, 0.04% PS80, pH 6.0; (F3) 20 mM citric acid, 8% sucrose, 0.04% PS80, pH 5.5; and (F4) 20 mM histidine, 8% sucrose, 10 mM methionine, 0.04% PS80, pH 5.5.

[0324] The antibodies were subjected to (1) 1-week and 2-week incubations at 40°C, (2) 3 days at 25°C with 300 rpm agitation, and (3) 3-5 cycles of freeze / thaw (F / T). At T=0 and after treatments, the antibodies were analyzed for appearance, size-exclusion chromatography-ultra-performance liquid chromatography (SEC-UPLC), pH, protein concentration, PI (capillary isoelectric focusing: cIEF), subvisible particles (microflow imaging: MFI), and Tm (DSC).

[0325] Results: The tables shown in Figures 22A-22G show the results of the analysis of various antibody formulations.

[0326] As can be seen from the tables shown in Figures 22A-22G, BDG17.069 formulated as F2, F3, and F4 showed no apparent change in concentration or detectable change in appearance after 1 and 2 weeks of incubation at 40°C. Analysis of subvisible particles by MFI demonstrates that BDG17.069 formulated as F1, F2, or F4 did not form particles larger than 25 μM, with only slight changes in the formation of particles larger than 10 μM (Figure 22B). SEC-UPLC analysis revealed only a slight increase in low molecular weight species in all four formulation conditions. Additionally, caliper SDS analysis showed only slight changes in BDG17.069 formulated as F2 and F4, while analysis by cIEF showed relatively little change in BDG17.069 formulated as F4. However, BDG17.069 formulated as F3 showed a significant increase in acidity at 40°C after 2 weeks of incubation (Figure 22C).

[0327] BDG17.069 formulated as F2 and F3 showed little particle formation after agitation (Figure 22D), and BDG17.069 formulated as F4 and F1 showed no significant changes in appearance, pH, concentration, or formation of subvisible particles >5 μM after five freeze / thaw cycles (Figure 22F).

[0328] Taken together, these test results demonstrate that BDG17.069 in formulations F1, F2, F3, and F4 has good stability after agitation, freeze-thaw stress, and negligible aggregation after 2 weeks of incubation at 40°C. Considering all stress conditions, it is clear that BDG17.069 is most stable when formulated in 20 mM histidine, 8% sucrose, 10 mM methionine, 0.04% PS80, pH 5.5 (F4).

[0329] Example 5

[0330] This example provides a description of studies demonstrating the safety and efficacy of epitope-specific anti-hIL-2 antibodies designed to enhance immune responses to infectious agents such as SARS-CoV-2 by specifically activating effector T cells and NK cells, while inhibiting IL-2 binding to regulatory T cells and pulmonary endothelium.

[0331] Preclinical trials

[0332] The following non-clinical studies will be conducted in two phases: Phase 1, which will demonstrate the safety of a single intravenous dose of the compound in healthy subjects, and Phase 2, which will demonstrate the safety of multiple doses of the compound in animal models of viral infection.

[0333] As disclosed herein, anti-IL-2 antibodies specifically bind to human IL-2 but not to mouse IL-2. Because the mouse IL-2 receptor can bind to human IL-2, it is possible to load hIL-2 into the complex and use a mouse model; however, this is undesirable because normal mice subsequently begin producing high levels of mouse IL-2. Secreted mIL-2 binds to receptors in the lungs and induces edema, confounding safety interpretation. Therefore, animal models that allow the use of human IL-2 or that exhibit antibody cross-reactivity with endogenous IL-2 are preferred. For mouse models, several options are available. The first option is to use IL-2 knockout mice to examine whether antibodies or Ab / IL-2 complexes have a direct deleterious effect on CD25-expressing lung tissue. The main limitation of this model is the lack of subsequent amplification of the immune response or additional immune-inducing cytokines. The second option is to use healthy C57BL / 6 or BalbC mice depleted of mouse IL-2 using a neutralizing antibody. However, optimization of this model is still required. A third option is to generate mice that express a human immune system using CD34+ human umbilical cord blood cells transplanted into NOD-EXL mice. The advantage of this model is that (although there are some limitations) a nearly complete human immune system is expressed, particularly all T cell and NK cell populations. This model is also suitable for use as a model system in acute viral infection models and oncology research.

[0334] Based on the data presented here, 17.067 and 17.069 exhibit strong affinity for cynomolgus IL-2 and, based on their high homology to hIL-2 and cIL-2, are believed to exhibit Ab-IL-2 complex receptor recognition for both. Therefore, a primate safety model could be completed. Healthy cynomolgus monkeys were subjected to a single, ascending dose study. Cynomolgus monkeys are known to be susceptible to infection with SARS-CoV-1, and rhesus monkeys to SARS-CoV-2. In both situations, mild pulmonary edema was observed, similar to that observed in mild human infections. Therefore, these monkey models allow for testing both the safety and efficacy of anti-IL-2 antibody / IL-2 complexes.

[0335] Dose escalation experiments can be performed as follows using healthy animals (e.g., humanized mice, cynomolgus monkeys, etc.).

[0336] First-in-Man (FIM) wellness support. (a) dose escalation in IL-2 KO mice; and / or (b) mIL2 antibody-deficient hIL2+ antibody; and / or (c) CD34+SCT humanized mice (+ / -IL2); (d) single escalating dose administration to healthy cynomolgus or rhesus monkeys; (e) Multiple doses administered to healthy cynomolgus or rhesus monkeys (concurrent with single ascending doses of FIM).

[0337] Assistance with patient administration (Phase 1b or Phase 2) (a) Mice ((b) or (c) above, and / or hACE2 transgenic) viral load (acute influenza infection model or coronavirus, respectively). (b) Where available, acute coronavirus infection models in cynomolgus macaques (SARS-CoV) or rhesus macaques (SARS-CoV-2).

[0338] Clinical trials

[0339] Part (1): A dose-escalation study in healthy subjects was conducted to identify the maximum tolerated dose, with up to eight cohorts of 10 subjects (8 test, 2 placebo) with appropriate dosing intervals for all subjects to determine safety.

[0340] Part (2): Patients with mild, recent, symptomatic SARS-CoV-2 infection were treated with the dose determined in Part (1) to observe safety and efficacy. Efficacy was measured by shortening the time to viral clearance and reducing the signs and symptoms of respiratory infection. Exploratory endpoints included changes in peripheral blood immune cell populations and activation status.

[0341] Chemistry, Manufacturing, and Control

[0342] Cell lines, drug substances (DS), and drug products (DP) can be manufactured by GMP-certified manufacturers under GMP guidance (e.g., Wuxi Biologics). Accelerated production of materials can be performed to prepare materials for IND in 6 months. All bioburden, viral clearance, viral load, and host cell protein content can be tested and reduced to specifications specified in current manufacturing guidelines to ensure product safety. P can be formulated for intravenous administration. Stability testing can also be performed simultaneously to ensure product quality over the long term.

Claims

1. 1. An isolated anti-IL-2 antibody comprising a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprises heavy chain complementarity determining regions (HCDRs) HCDR1, HCDR2, and HCDR3; the light chain variable region (VL) comprises light chain complementarity determining regions (LCDRs) LCDR1, LCDR2, and LCDR3; The amino acid sequences of the heavy chain complementarity determining region (HCDR) and the light chain complementarity determining region (LCDR) are (a) the HCDR1 comprises the amino acid sequence of SEQ ID NO: 38, the HCDR2 comprises the amino acid sequence of SEQ ID NO: 39, the HCDR3 comprises the amino acid sequence of SEQ ID NO: 40, the LCDR1 comprises the amino acid sequence of SEQ ID NO: 41, the LCDR2 comprises the amino acid sequence of SEQ ID NO: 42, and the LCDR3 comprises the amino acid sequence of SEQ ID NO: 43; or (b) the HCDR1 comprises the amino acid sequence of SEQ ID NO: 44, the HCDR2 comprises the amino acid sequence of SEQ ID NO: 45, the HCDR3 comprises the amino acid sequence of SEQ ID NO: 46, the LCDR1 comprises the amino acid sequence of SEQ ID NO: 47, the LCDR2 comprises the amino acid sequence of SEQ ID NO: 48, and the LCDR3 comprises the amino acid sequence of SEQ ID NO: 49; or (c) the HCDR1 comprises the amino acid sequence of SEQ ID NO: 50, the HCDR2 comprises the amino acid sequence of SEQ ID NO: 51, the HCDR3 comprises the amino acid sequence of SEQ ID NO: 52, the LCDR1 comprises the amino acid sequence of SEQ ID NO: 53, the LCDR2 comprises the amino acid sequence of SEQ ID NO: 54, and the LCDR3 comprises the amino acid sequence of SEQ ID NO: 55; or (d) the HCDR1 comprises the amino acid sequence of SEQ ID NO: 56, the HCDR2 comprises the amino acid sequence of SEQ ID NO: 57, the HCDR3 comprises the amino acid sequence of SEQ ID NO: 58, the LCDR1 comprises the amino acid sequence of SEQ ID NO: 59, the LCDR2 comprises the amino acid sequence of SEQ ID NO: 60, and the LCDR3 comprises the amino acid sequence of SEQ ID NO: 61; or (e) the HCDR1 comprises the amino acids 26 to 33 of SEQ ID NO: 10, the HCDR2 comprises the amino acids 51 to 58 of SEQ ID NO: 10, the HCDR3 comprises the amino acids 97 to 110 of SEQ ID NO: 10, the LCDR1 comprises the amino acids 27 to 38 of SEQ ID NO: 11, the LCDR2 comprises the amino acids 56 to 58 of SEQ ID NO: 11, and the LCDR3 comprises the amino acids 95 to 103 of SEQ ID NO: 11; or (f) the HCDR1 comprises the amino acids 26 to 33 of SEQ ID NO: 12, the HCDR2 comprises the amino acids 51 to 58 of SEQ ID NO: 12, the HCDR3 comprises the amino acids 97 to 110 of SEQ ID NO: 12, the LCDR1 comprises the amino acids 27 to 38 of SEQ ID NO: 13, the LCDR2 comprises the amino acids 56 to 58 of SEQ ID NO: 13, and the LCDR3 comprises the amino acids 95 to 103 of SEQ ID NO: 13; or (g) the HCDR1 comprises the amino acids 26 to 33 of SEQ ID NO: 14, the HCDR2 comprises the amino acids 51 to 58 of SEQ ID NO: 14, the HCDR3 comprises the amino acids 97 to 110 of SEQ ID NO: 14, the LCDR1 comprises the amino acids 27 to 38 of SEQ ID NO: 15, the LCDR2 comprises the amino acids 56 to 58 of SEQ ID NO: 15, and the LCDR3 comprises the amino acids 95 to 103 of SEQ ID NO: 15; or (h) the HCDR1 comprises amino acids 26 to 33 of SEQ ID NO: 16, the HCDR2 comprises amino acids 51 to 58 of SEQ ID NO: 16, the HCDR3 comprises amino acids 97 to 110 of SEQ ID NO: 16, the LCDR1 comprises amino acids 27 to 38 of SEQ ID NO: 17, the LCDR2 comprises amino acids 56 to 58 of SEQ ID NO: 17, and the LCDR3 comprises amino acids 95 to 103 of SEQ ID NO: 17; or (i) An antibody wherein the HCDR1 comprises the amino acids at positions 26 to 33 of SEQ ID NO: 18, the HCDR2 comprises the amino acids at positions 51 to 58 of SEQ ID NO: 18, the HCDR3 comprises the amino acids at positions 97 to 110 of SEQ ID NO: 18, the LCDR1 comprises the amino acids at positions 27 to 38 of SEQ ID NO: 19, the LCDR2 comprises the amino acids at positions 56 to 58 of SEQ ID NO: 19, and the LCDR3 comprises the amino acids at positions 95 to 103 of SEQ ID NO:

19.

2. 2. The antibody of claim 1, The amino acid sequences of the heavy chain variable region (VH) and the light chain variable region (VL) are (a) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 36, and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 37; or (b) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 20, and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 21; or (c) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 22, and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 23; or (d) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 24, and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 25; or (e) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 10, and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 11; or (f) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 12, and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 13; or (g) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 14, and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 15; or (h) the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 16, and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO: 17; or (i) An antibody in which the heavy chain variable region (VH) comprises the amino acid sequence of SEQ ID NO: 18 and the light chain variable region (VL) comprises the amino acid sequence of SEQ ID NO:

19.

3. 3. The antibody of claim 1 or 2, The antibody includes an IgG, IgA, IgM, IgE, IgD, Fv, scFv, Fab, F(ab')2, minibody, diabody, or triabody.

4. The antibody according to any one of claims 1 to 3, The antibody comprises a heavy chain having a mutation that reduces binding to an Fcγ receptor.

5. 5. The antibody of claim 4, the antibody comprises a heavy chain sequence and a light chain sequence; The heavy chain sequence and the light chain sequence (a) a heavy chain sequence set forth in SEQ ID NO: 68 and a light chain sequence set forth in SEQ ID NO: 69; or (b) an antibody comprising the heavy chain sequence set forth in SEQ ID NO: 70 and the light chain sequence set forth in SEQ ID NO:

71.

6. A composition comprising the antibody of any one of claims 1 to 5 and a pharmaceutically acceptable carrier.

7. 7. The composition of claim 6, It is formulated to have a pH value of 5.0 to 6.0, A composition comprising a buffer selected from a histidine buffer and a citrate buffer.

8. 8. The composition of claim 7, The composition, further comprising at least one of sucrose, methionine, or PS80, or any combination thereof.

9. The composition according to any one of claims 6 to 8, The composition further comprising IL-2.

10. An isolated polynucleotide comprising a sequence encoding the heavy chain variable region (VH) and light chain variable region (VL) of an anti-IL-2 antibody, (a) the amino acid sequence of the heavy chain variable region (VH) is the amino acid sequence set forth in SEQ ID NO: 36, and the amino acid sequence of the light chain variable region (VL) is the amino acid sequence set forth in SEQ ID NO: 37; or (b) the amino acid sequence of the heavy chain variable region (VH) is the amino acid sequence set forth in SEQ ID NO: 20, and the amino acid sequence of the light chain variable region (VL) is the amino acid sequence set forth in SEQ ID NO: 21; or (c) the amino acid sequence of the heavy chain variable region (VH) is the amino acid sequence set forth in SEQ ID NO: 22, and the amino acid sequence of the light chain variable region (VL) is the amino acid sequence set forth in SEQ ID NO: 23, or (d) An isolated polynucleotide, wherein the amino acid sequence of the heavy chain variable region (VH) is the amino acid sequence set forth in SEQ ID NO: 24, and the amino acid sequence of the light chain variable region (VL) is the amino acid sequence set forth in SEQ ID NO:

25.

11. An isolated polynucleotide comprising a sequence encoding an anti-IL-2 antibody scFv, An isolated polynucleotide, wherein the sequence encoding the anti-IL-2 antibody scFv is the polynucleotide sequence set forth in SEQ ID NO: 31, 32, 33, or 34.

12. An isolated polynucleotide comprising a sequence encoding an anti-IL-2 antibody scFv comprising a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprises heavy chain complementarity determining regions (HCDRs) HCDR1, HCDR2, and HCDR3; the light chain variable region (VL) comprises light chain complementarity determining regions (LCDRs) LCDR1, LCDR2, and LCDR3; the HCDR1 comprises the amino acid sequence of SEQ ID NO: 62, the HCDR2 comprises the amino acid sequence of SEQ ID NO: 63, and the HCDR3 comprises the amino acid sequence of SEQ ID NO: 64; An isolated polynucleotide, wherein said LCDR1 comprises the amino acid sequence of SEQ ID NO:65, said LCDR2 comprises the amino acid sequence of SEQ ID NO:66, and said LCDR3 comprises the amino acid sequence of SEQ ID NO:

67.

13. An isolated polynucleotide comprising a sequence encoding an anti-IL-2 antibody comprising a heavy chain variable region (VH) and a light chain variable region (VL), the heavy chain variable region (VH) comprises heavy chain complementarity determining regions (HCDRs) HCDR1, HCDR2, and HCDR3; the light chain variable region (VL) comprises light chain complementarity determining regions (LCDRs) LCDR1, LCDR2, and LCDR3; the HCDR1 comprises the amino acid sequence of SEQ ID NO: 62, the HCDR2 comprises the amino acid sequence of SEQ ID NO: 63, and the HCDR3 comprises the amino acid sequence of SEQ ID NO: 64; An isolated polynucleotide, wherein said LCDR1 comprises the amino acid sequence of SEQ ID NO:65, said LCDR2 comprises the amino acid sequence of SEQ ID NO:66, and said LCDR3 comprises the amino acid sequence of SEQ ID NO:

67.

14. A vector comprising the isolated polynucleotide of any one of claims 10 to 13.

15. A host cell comprising the vector of claim 14.

16. 1. A composition for use in treating a disease or condition in a subject, comprising: The anti-IL-2 antibody of any one of claims 1 to 5 is included. The composition, wherein the antibody promotes the differentiation and growth of a subset of immune cells and reduces the undesirable effects caused by IL-2.

17. 17. The composition of claim 16, The composition comprises an anti-IL-2 antibody and IL-2, or an anti-IL-2 antibody complexed with IL-2.

18. 18. The composition of claim 16 or 17, The disease comprises a viral infection, a bacterial infection, or cancer.

19. The composition according to any one of claims 16 to 18, The condition comprises a genetic predisposition that increases the likelihood of cancer in the subject.

20. 20. The composition of claim 19, the genetic predisposition comprises an alteration in the expression or activity of a gene product; The composition, wherein the gene comprises a tumor suppressor gene, a mismatch repair (MMR) gene, or a combination thereof.

21. 20. The composition of claim 19, the genetic predisposition comprises an alteration in the expression or activity of a gene product; The composition, wherein the gene comprises BRCA1, BRAC2, MLH1, MSH2, MSH6, PMS1, PMS2, TP53, CHEK2, or any combination thereof.

22. The composition according to any one of claims 16 to 21, The composition, wherein the immune cells comprise one or more of naive T cells, memory T cells, CD8+ T cells, NK cells, or natural killer T cells.

23. The composition according to any one of claims 16 to 22, The undesirable effects caused by IL-2 include one or more of activation of regulatory T cells, apoptosis of CD25+ T effector cells, IL-2-induced pulmonary edema, IL-2-induced pneumonia, or IL-2-induced vascular leakage.

24. The composition according to any one of claims 16 to 23, The composition, wherein the anti-IL-2 antibody inhibits the binding of IL-2 to CD25.

25. The composition according to any one of claims 16 to 24, The composition is used in combination with one or more immune checkpoint inhibitors that target one or more immune checkpoints.

26. 26. The composition of claim 25, The composition is used with the one or more immune checkpoint inhibitors concurrently with treatment with the anti-IL-2 antibody, prior to treatment with the anti-IL-2 antibody, or after treatment with the anti-IL-2 antibody.

27. 27. The composition of claim 25 or 26, The composition, wherein the immune checkpoint comprises PD-1, PD-L1, CTLA-4, TIGIT, TIM-3, B7-H3, CD73, LAG3, CD27, CD70, 4-1BB, GITR, OX40, SIRP-α (CD47), CD39, ILDR2, VISTA, BTLA, VTCN-1, or any combination thereof.

28. 1. A vaccine for use in immunizing a subject, comprising: an IL-2 antibody adjuvant; A vaccine, wherein the IL-2 antibody adjuvant comprises an anti-IL-2 antibody according to any one of claims 1 to 5.

29. 29. The vaccine of claim 28, The IL-2 antibody adjuvant comprises an anti-IL-2 antibody and IL-2, or an anti-IL-2 antibody complexed with IL-2.

30. 30. The vaccine of claim 28 or 29, The subject has a weakened immune system.

31. The vaccine according to any one of claims 28 to 30, The subject has a genetic predisposition that increases the likelihood of cancer in the subject.

32. 32. The vaccine of claim 31 , the genetic predisposition comprises an alteration in the expression or activity of a gene product; The gene comprises a tumor suppressor gene, a mismatch repair (MMR) gene, or a combination thereof.

33. 32. The vaccine of claim 31 , the genetic predisposition comprises an alteration in the expression or activity of a gene product; The gene comprises BRCA1, BRAC2, MLH1, MSH2, MSH6, PMS1, PMS2, TP53, CHEK2, or any combination thereof.

Images