Matched t-cells and myeloid cells from cell culture

Abstract

The present invention relates to a combination of a) myeloid cells and b) T cells, wherein the myeloid cells and the T cells are isogenic human cells, and wherein the myeloid cells and the T cells are derived from a T- cell-derived iPSC. The present invention also relates to the use of a combination of a) myeloid cells and b) T cells, wherein the myeloid cells and the T cells are isogenic human cells, and wherein the myeloid cells and the T cells are derived from a T-cell-derived iPSC in cell therapy. The present invention also relates to the use of a combination of a) myeloid cells and b) T cells, wherein the myeloid cells and the T cells are isogenic human cells, and wherein the myeloid cells and the T cells are derived from a T-cell-derived iPSC for drug screening.

Description

[0001] MATCHED T-CELLS AND MYELOID CELLS FROM CELL CULTURE

[0002] BACKGROUND OF THE INVENTION

[0003] The interaction between myeloid cells, including dendritic cells (DCs), macrophages, and neutrophils, and T cells plays a critical role in regulating the immune response, particularly in the context of cancer. Myeloid cells, especially dendritic cells, are specialized antigen-presenting cells (APCs) that capture, process, and present antigens to T cells. This process is essential for initiating and directing adaptive immune responses against cancer cells. DCs present tumor antigens to T cells, which activates them and initiates the anti-tumor immune response. Along with antigen presentation, myeloid cells provide co-stimulatory signals to T cells, which are necessary for full T cell activation. Co-stimulation ensures that T cells respond appropriately to antigens and become activated to mount an effective immune response, for example against cancer cells.

[0004] Overall, the interaction between myeloid cells and T cells is essential for orchestrating effective immune responses, in particular anti-tumor immune responses. Dysregulation of this interaction can promote immune evasion and tumor progression, highlighting the significance of understanding the myeloid cell-T cell interactions. (Basak, Sarkar et al. 2023)

[0005] The interaction between myeloid cells and T-cells is particularly relevant in the tumor microenvironment (TME). Myeloid cells influence the composition and function of the TME. In solid tumor, the TME can be immunosuppressive, allowing tumors to evade immune surveillance. Myeloid cells, particularly tumor- associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs), can contribute to this immunosuppression by inhibiting T cell function and promoting tumor growth.

[0006] For example, myeloid cells can express immune checkpoint molecules, such as PD-L1, which interact with corresponding receptors on T cells (e.g., PD-1). This interaction can suppress T cell activation and function, leading to immune evasion by cancer cells. Strategies targeting immune checkpoints aim to block these inhibitory signals and restore T cell-mediated anti-tumor immunity. (Li, Wu et al. 2022)

[0007] Understanding the interaction between myeloid cells and T cells, for example in the tumor microenvironment, is therefore a crucial research goal and is particularly relevant for developing effective cancer immunotherapies. Therapeutic approaches targeting myeloid cells, such as DC-based vaccines, macrophage-targeted therapies, and strategies to modulate MDSC function, aim to enhance T cell activation and overcome immunosuppression in the TME. There is therefore a need to provide tools for studying the interaction between myeloid cells and T cells.

[0008] T-cells interact with myeloid cells via several pairs of cell surface complexes. Most importantly, T cells recognize antigens presented on major histocompatibility complex (MHC) molecules through a process known as MHC-restricted antigen recognition.

[0009] The principle of MHC-restriction refers to the fact that T cells recognize antigens only when they are presented in association with self-MHC molecules. This means that a CD8+ T cell recognizes antigenic peptides presented by self MHC class I molecules only, and a CD4+ T cell can only recognize antigenic peptides presented by self MHC class II molecules. The principle of positive and negative selection in the thymus is essential for the development of functional T cells and is the underlying reason for MHC- restriction.

[0010] Positive selection occurs in the cortex of the thymus and is a process by which developing T cells that express a T cell receptor capable of recognizing self-MHC molecules with low to moderate affinity are allowed to survive. Dining positive selection, thymocytes interact with cortical thymic epithelial cells (cTECs) expressing self-MHC molecules. If a thymocyte's TCR binds weakly or not at all to self-MHC molecules, it undergoes apoptosis (programmed cell death). Thymocytes with TCRs that bind self-MHC molecules with sufficient affinity receive survival signals and progress to the next stage of development. Negative selection, which mainly occurs in the medulla of the thymus, is a process by which developing T cells that recognize self-antigens presented on self-MHC molecules with high affinity are eliminated to prevent the development of autoreactive T cells. Dining negative selection, medullary thymic epithelial cells (mTECs) and dendritic cells (DCs) present a wide array of self-antigens derived from various tissues throughout the body. Thymocytes with TCRs that bind strongly to self-antigens undergo apoptosis, thereby eliminating potentially harmful autoreactive T cells.

[0011] The interplay between positive and negative selection ensures the development of a diverse repertoire of T cells capable of recognizing foreign antigens presented by self-MHC molecules while minimizing the risk of autoimmunity. Thymocytes that successfully undergo both positive and negative selection mature into functional T cells and migrate to the peripheral lymphoid organs, where they participate in immune responses.

[0012] The MHC-restriction of T cell responses arises from the requirement for T cells to interact with self-MHC molecules during positive selection. As a result, mature T cells are primed to recognize antigens presented by self-MHC molecules in the periphery, leading to MHC-restricted antigen recognition and ensuring specificity and efficacy of the adaptive immune response.

[0013] This restriction ensures that T cell responses are specific to foreign antigens while avoiding recognition of self-antigens. As already mentioned, there are two main classes of MHC molecules: MHC class I and MHC class II. MHC class I molecules are present on almost all cell types and present peptides derived from intracellular proteins to CD8+T cells (cytotoxic T cells), while MHC class II molecules are mainly expressed by antigen-presenting cells and present peptides derived from extracellular proteins to CD4+ T cells. MHC molecules are highly polymorphic cell surface proteins encoded by the human leukocyte antigen (HLA) genes in humans.

[0014] T cells express T cell receptors (TCRs) on their surface, which are responsible for recognizing the antigen- MHC complex. TCRs are highly specific and bind to the peptide-MHC complex with high affinity. The TCR interacts with both the peptide and the MHC molecule, forming a stable interaction.

[0015] Upon recognition of the antigen-MHC complex by the TCR, T cells become activated and initiate adaptive immune responses. CD8+ T cells recognize antigens presented on MHC class I molecules and differentiate into cytotoxic T lymphocytes (CTLs), which kill infected or abnormal cells. CD4+ T cells recognize antigens presented on MHC class II molecules and differentiate into various subsets of helper T cells, which provide help to B cells for antibody production, activate macrophages, or orchestrate other aspects of the immune response. (Kennedy and Celis 2008)

[0016] In summary, MHC-restricted antigen recognition ensures that T cells recognize antigens only when presented in association with self-MHC molecules, which is crucial for the specificity and regulation of T cell responses in the immune system. For a more in-depth explanation of MHC-restriction see, for example, textbooks like Janeway's Immunobiology, 10thedition.

[0017] The principle of MHC-restriction presents a problem for studying T-cell / myeloid-cell interaction ex vivo. The available T-cell-lines and myeloid cell lines are from different individuals and therefore the MHC- complexes of the myeloid cells and the TCRs of the T-cells are not matched. The T-cells which would react to a particular antigen presented on a matched MHC-complex do not recognize the same antigen presented on a non-self MHC-complex and are then not activated. Instead, so called alloreactive T-cells get activated which recognize non-self MHC-complexes, initiating an immune response against the non-self myeloid cells rather than against the cell type from which the peptide presented by the APC was derived. This is not the response that is of interest for studying the T-cell / myeloid cell interaction in the context of a tumor setting, where T-cells and myeloid cells are autologous, i.e. derived from the same individual. Consequently, the studies which have investigated the interaction between T-cells and myeloid cells ex vivo have done so by using primary cell cultures, i.e. by isolating and purifying T-cells and myeloid cells from the blood of an individual donor, culturing them and then using them for the co-culture experiments. This approach has problems, as myeloid cells are not easily expanded in cell culture and therefore the available cell numbers for the co-culture experiments are limited, making it hard to systematically investigate the T-cell / myeloid cell interaction, for example by way of screening experiments. Besides, the cell populations derived by purification from blood are often impure so that other cell types which were not completely purified away can lead to confounding results which do not reflect the true interaction between the two desired cell types, i.e. T-cells and myeloid cells. There is thus a need to provide T-cells and myeloid cells which are MHC- matched in quantities sufficient for cell culture experiments.

[0018] Moreover, T-cells and myeloid cells synergize in the tumor microenvironment. For example, EP4338745A1 describes that allogeneic myeloid cells for tumor cell therapy should be MHC-II matched with regard to the patient to be treated so that the allogeneic myeloid cells can activate the T-cells of the patient and produce a synergistic antitumor response. There is therefore also a need for MHC matched myeloid cells, for example for cell therapy. Jieming et al. “Derivation of mimetic gamma / delta T cells endowed with cancer recognition receptors from reprogrammed gamma / delta T cells” PLOS ONE, Vol.14, May 9, 2019, test the expression of CD25 on yb T cells after stimulation with syngeneic zolendronic acid iPSC-DCs.

[0019] SUMMARY OF THE INVENTION

[0020] This problem is solved by the present invention, in particular by the subject-matter of the claims.

[0021] The present invention relates to the use of a T-cell-derived induced pluripotent stem cell (T-iPSC) for producing a myeloid cell. The present invention also relates to a method of producing myeloid cells comprising the step of forming an embryoid body from T-iPS cells. The present invention also relates to a method of producing a myeloid cell, wherein T-iPSCs are differentiated into a myeloid cell. The present invention also relates to a myeloid cell wherein the T-cell receptor locus is at most 90% in length when compared to the T-cell receptor locus of the human reference genome. The present invention also relates to a kit of parts comprising a) myeloid cells comprising MHC-genes with a specific genotype, and b) T-cells comprising a T-cell receptor that is matched to the myeloid cells’ MHC-complexes.

[0022] By differentiating both myeloid cells and T-cells separately from the same T-iPSC it becomes possible to produce “matched” myeloid cells and T-cells in cell culture and thus in cell numbers which are sufficiently large for screening methods which investigate the interaction between the two cell types. The myeloid cells which are derived from the T-iPSCs have essentially the same genome as T-cells derived from the T-iPSCs. The T-iPSCs in turn were derived from donor T-cells which were selected in the thymus of the T-cell donor to selectively recognize the MHC-complexes which are encoded by the donor genome, i.e. self-MHC complexes (self MHC-I in the case of CD8+ T-cells and self MHC-II in the case of CD4+ T-cells). And since the T-iPSC-derived myeloid cells express the same MHC-complexes against which the donor T-cells were trained, the T-iPSC-derived myeloid cells express the self-MHC complexes which the T-iPSC-derived T-cells will recognize as self. Thus, myeloid cells derived from T-iPSCs can communicate and interact with the T-iPSC-derived T-cells in essentially the same manner as myeloid cells and T-cells directly taken from the same individual. Therefore, the physiological interaction between autologous myeloid cells and T-cells can now be studied with cell-culture derived cells.

[0023] Moreover, since T-cells and myeloid cells synergize in the anti-tumor response, combination cell therapies where T-cells are used together with a myeloid cell type are attractive future therapies, for example against solid tumors. However, cell therapies are expensive. This is to no small part due to the costs for the preparation, characterization and storage of an approved master cell bank of iPSCs, i.e. the single pool of iPS cells that has been prepared from the selected iPS cell clone under defined conditions, that has been rigorously characterized according to the requirements of a regulatory authority, such as the EMA, then dispensed into multiple containers, and stored under defined conditions. It is therefore a significant advantage if the same master cell bank of T-iPSCs can be used both for T-cell and for myeloid cell production. The invention therefore also relates to the use of a master cell bank of T-iPSCs in the production of a cell therapy comprising myeloid cells, such as dendritic cells, monocytes or macrophages. The invention also relates to the use of a master cell bank of T-iPSCs in the production of a cell therapy comprising both T-cells and myeloid cells.

[0024] REFERENCES

[0025] Basak, U., T. Sarkar, S. Mukherjee, S. Chakraborty, A. Dutta, S. Dutta, D. Nayak, S. Kaushik, T. Das and G. Sa (2023). "Tumor-associated macrophages: an effective player of the tumor microenvironment." Front Immunol 14: 1295257.

[0026] Bltimke, A., J. Simon, E. Leber, M. Scatena and C. M. Giachelli (2024). "Differentiation and Characterization of Osteoclasts from Human Induced Pluripotent Stem Cells." J Vis Exp(205).

[0027] Devito, L., A. Petrova, C. Miere, S. Codognotto, N. Blakely, A. Lovatt, C. Ogilvie, Y. Khalaf and D. Ilic (2014). "Cost-effective master cell bank validation of multiple clinical-grade human pluripotent stem cell lines from a single donor." Stem Cells Transl Med 3(10): 1116-1124.

[0028] Fong H, Mendel M, Jascur J, et al. A serum- and feeder-free system to generate CD4 and regulatory T cells from human iPSCs. Stem Cells. 2025;43(3):sxaf001.

[0029] Hu, G., Y. Su, B. H. Kang, Z. Fan, T. Dong, D. R. Brown, J. Cheah, K. D. Wittrup and J. Chen (2021). "High-throughput phenotypic screen and transcriptional analysis identify new compounds and targets for macrophage reprogramming." Nat Commun 12(1): 773.

[0030] Jieming et al. “Derivation of mimetic gamma / delta T cells endowed with cancer recognition receptors from reprogrammed gamma / delta T cells” PLOS ONE, Vol.14, May 9, 2019

[0031] Joyce, D., M. Fujino, M. Morita, R. Araki, J. Fung, S. Qian, L. Lu and X. K. Li (2018). "Induced pluripotent stem cells-derived myeloid-derived suppressor cells regulate the CD8(+) T cell response." Stem Cell Res 29: 32-41.

[0032] Kawamoto, H., K. Masuda and S. Nagano (2021). "Regeneration of antigen-specific T cells by using induced pluripotent stem cell (iPSC) technology." Int Immunol 33(12): 827-833.

[0033] Kennedy, R. and E. Celis (2008). "Multiple roles for CD4+ T cells in anti-tumor immune responses." Immunol Rev 222: 129-144.

[0034] Kuen, J., D. Darowski, T. Kluge and M. Majety (2017). "Pancreatic cancer cell / fibroblast co-culture induces M2 like macrophages that influence therapeutic response in a 3D model." PLoS One 12(7): e0182039.

[0035] Kumar S, Tailor D, Dheeraj A, et al. Uncovering therapeutic targets for macrophage-mediated T cell suppression and PD-L1 therapy sensitization. Cell Rep Med. 2024;5(9):101698.

[0036] Li, W., F. Wu, S. Zhao, P. Shi, S. Wang and D. Cui (2022). "Correlation between PD-1 / PD-L1 expression and polarization in tumor-associated macrophages: A key player in tumor immunotherapy." Cytokine Growth Factor Rev 67: 49-57.

[0037] Nagano, S., T. Maeda, H. Ichise, S. Kashima, M. Ohtaka, M. Nakanishi, T. Kitawaki, N. Kadowaki, A. Takaori-Kondo, K. Masuda and H. Kawamoto (2020). "High Frequency Production of T Cell-Derived iPSC Clones Capable of Generating Potent Cytotoxic T Cells." Mol Ther Methods Clin Dev 16: 126- 135.

[0038] Nishimura, T., Y. Murmann and H. Nakauchi (2019). "Human iPSC Generation from Antigen-Specific T Cells." Methods Mol Biol 2048: 53-57.

[0039] Oliveira, N. A. J. and H. Sevim (2022). "Dendritic Cell Differentiation from Human Induced Pluripotent Stem Cells: Challenges and Progress." Stem Cells Dev 31(9-10): 207-220.

[0040] Olivo Pimentel, V., A. Yaromina, D. Marcus, L. J. Dubois and P. Lambin (2020). "A novel co-culture assay to assess anti-tumor CD8(+) T cell cytotoxicity via luminescence and multicolor flow cytometry." J Immunol Methods 487: 112899. Teo, F., C. Y. L. Kok, M. J. Tan and H. S. Je (2024). "Human pluripotent stem cell (hPSC)-derived microglia for the study of brain disorders. A comprehensive review of existing protocols." IBRO Neurosci Rep 16: 497-508.

[0041] Umiker, B., Y. Hashambhoy-Ramsay, J. Smith, T. Rahman, A. Mueller, R. Davidson, C. Meyer, G. Patankar, M. M. Alam, S. Jaffe, K. Krukenberg, A. Goodman, V. Spaulding, M. Priess, A. Dhaneshwar, M. Wong, A. Diiorio, K. O'Malley, L. McGrath, M. Wilier, L. Pepper, M. Gostissa, K. Kis-Toth, D. Wiederschain, H. Cohen and D. R. Shaffer (2023). "Inhibition of LILRB2 by a Novel Blocking Antibody Designed to Reprogram Immunosuppressive Macrophages to Drive T-Cell Activation in Tumors." Mol Cancer Ther 22(4): 471-484.

[0042] Watanabe, D., M. Koyanagi-Aoi, M. Taniguchi-Ikeda, Y. Yoshida, T. Azuma and T. Aoi (2018). "The Generation of Human y5T Cell-Derived Induced Pluripotent Stem Cells from Whole Peripheral Blood Mononuclear Cell Culture." Stem Cells Transl Med 7(1): 34-44.

[0043] Nishimura T, Nakauchi H. Generation of Antigen-Specific T Cells from Human Induced Pluripotent Stem Cells. Methods Mol Biol. 2019;1899:25-40. doi: 10.1007 / 978-l-4939-8938-6_3. PMID: 30649763.

[0044] DETAILED DESCRIPTION OF THE INVENTION

[0045] The present invention relates to the use of T-iPS cells for the production of myeloid cells. T-iPSCs are induced pluripotent stem cells which were derived from human T cells. They are described, for example, in WO20II096482AI, WO2014165707A1, W02017100403A1 and WO2022216624A1, which are herein incorporated by reference

[0046] In other words, T-iPSCs are T cell-derived induced pluripotent stem cells. They are a type of pluripotent stem cell generated by reprogramming mature T cells into a pluripotent state. The process for generating T- iPSCs is described in detail in the references cited above and typically includes the steps of isolating mature T cells from peripheral blood or other sources, such as lymphoid tissues, reprogramming the isolated T cells using specific transcription factors, commonly Oct4, Sox2, Klf4, and c-Myc, to induce pluripotency, culturing and expanding clones of the reprogrammed cells, now T-iPSCs, in vitro under conditions that support their growth as pluripotent stem cells. During this process, the T-iPSCs acquire the ability to differentiate into cells of all three germ layers: ectoderm, endoderm, and mesoderm.

[0047] Since T-iPSCs are derived from mature T-cells which had undergone positive and negative selection in the thymus of an individual, their T-cell receptor locus is different from that of iPSCs which were derived from non-immune cells, such as epithelial cells. This is because of RAG1 / 2 dependent recombination during T- cell development, where sequences are removed between various segments of the genes coding for TCRoc, TCRp, TCRy or TCR8 and excised as circular T-cell receptor excision circles. The genomic loci of the genes coding for TCRoc, TCRp, TCRy and / or TCR8 are therefore smaller in T-iPSCs and the skilled person can therefore identify any cell, such as a myeloid cell, which is derived from a T-iPSC by analyzing the sequence of the genes coding for TCRoc, TCRp, TCRy or TCR8.

[0048] The present invention also relates to a method of manufacturing a myeloid cell comprising differentiating a T-iPSC under conditions for cell differentiation which generate a myeloid cell. Typically, in such a method embryoid bodies are formed first from the T-iPSC and then cultivated in the presence of cytokines that enable second the generation of hematopoietic precursor cells, such as cultivation in IL-3, and then third the generation of myeloid cells. To that end, at least one additional cytokine is added and the embryoid bodies are then cultivated for a period of time sufficient to produce myeloid cells, such as for at least one week, and myeloid cells are then isolated. WO2018 / 202881A1, which is herein incorporated by reference, describes in detail, how the various myeloid cells are generated from iPSCs, and these cultivation processes can be applied to T-iPSCs in the context of the present invention. The additional cytokine may be M-CSF for the production of macrophages; or G-CSF for the production of granulocytes; or GM-CSF for the production of macrophages and granulocytes; or SCF and EPO for the production of erythroid cells; or SCF and TPO for the production of megakaryocytes and / or thrombocytes; or GM-CSF and IL-4 for the production of dendritic cells. There may also be no additional cytokine to IL-3, and the produced myeloid cells are then immature cells capable of further differentiation which may be harvested and further differentiated, for example by cultivating said immature cells in the presence of M-CSF until macrophages are obtained; or by cultivating said immature cells in the presence of G-CSF until granulocytes are obtained; or by cultivating said immature cells in the presence of GM-CSF until granulocytes and macrophages are obtained; or by cultivating said immature cells in the presence of SCF and EPO until erythroid cells are obtained; or by cultivating said immature cells in the presence of SCF and TPO until megakaryocytes and / or thrombocytes are obtained.

[0049] On page 35 under the heading “Derivation of multiple human iPSC-derived myeloid lineages in dynamic suspension culture” WO2018 / 202881A1 describes the experimental conditions which may be used for obtaining the various different myeloid cells from iPSCs. This passage is incorporated by reference. Also the whole passage of WO2018 / 202881 Al starting on page 2 with “The present invention provides a method of producing hematopoietic ...” and ending on page 10 with “...and may be used in pharmaceutical compositions.” is incorporated by reference and describes in detail the conditions which may be used for the preparation of myeloid cells from T-iPSCs. Further references relating to the production of myeloid cells from iPSCs are (Teo, Kok et al. 2024) (relating to microglia), (Blumke, Simon et al. 2024) (relating to osteoclasts), (Oliveira and Sevim 2022) (relating to dendritic cells), (Joyce, Fujino et al. 2018) (relating to MDSCs), and WO2012127206A1 (relating to dendritic cells) to name but a few. Each of these references is herein incorporated by reference.

[0050] The myeloid cell which are thus produced from T-iPSCs and to which this invention relates are different from myeloid cells obtained from regular iPSCs because they derive from cells wherein at least one, such as two or more of the genomic loci TRA, TRB, TRD and TRG have been changed by genomic rearrangement. The remaining genetic loci are shortened when compared to the human reference genome, and have a length of most 90% the length, such as at most 80% the length, for example at most 70% the length, of the corresponding genetic locus in the human reference genome. In the human reference genome TRA, TRB, TRD and TRG are defined by gene ID 6955, gene ID 6957, gene ID 6964 and gene ID 6965, respectively.

[0051] The at least two shortened genomic loci may be the pair TRA and TRB and / or the pair TRD and TRG.

[0052] The present invention also relates to such myeloid cells which are derived from a T-iPSC, for example to myeloid cells, wherein at least two of the genomic loci TRA, TRB, TRD and TRG have undergone a genomic rearrangement, for example wherein the at least two genomic loci are the pair TRA and TRB and / or the pair TRD and TRG. The genomic recombination at said genomic loci leads, for example, to a J-segment of the genomic loci TRA, TRB, TRD or TRG to be joined with a C-segment of the same genomic locus. The skilled person can determine, whether such changes have occurred, by simply sequencing said loci in myeloid cells which are suspected to be derived from T-iPSCs.

[0053] As already mentioned above, it is an advantage of the present invention that it can provide T-cells and myeloid cells which are “matched”. The present invention therefore also relates to a kit of parts comprising a) myeloid cells comprising MHC-genes with a specific genotype, and b) T-cells comprising a T-cell receptor that is matched to the myeloid cells MHC-complexes, and wherein the myeloid cells are preferably myeloid cells as described above. For example, the myeloid cells and the T-cells may both be derived from the same T-iPSC.

[0054] The skilled person will easily be able to determine, if the the myeloid cells and the T-cells are both derived from the same T-iPSC. For example, the highly polymorphic genes encoding HLA-A and HLA-B are identical between the a) myeloid cells and the b) T-cells, and / or other highly polymorphic genes, like the genes encoding HLA-DRA and HLA-DRB1 are identical between the a) myeloid cells and the b) T-cells. Alternatively, the skilled person may determine, whether the a) myeloid cells and the b) T-cells have identical chromosomes 7 and 14 as evaluated by G-banding. This is because the T-iPSCs have the abovediscussed gene rearrangements on these chromosomes.

[0055] Alternatively, the skilled person may determine, whether the a) myeloid cells and the b) T-cells have essentially identical sequences for the genomic loci at the pair TRA and TRB and / or at the pair TRD and TRG. All this is because the a) myeloid cells and the b) T-cells may have essentially the same genome when derived from the same T-iPSC.

[0056] A preferred myeloid cell in the kit of parts of the present invention may be selected from the group consisting of a dendritic cell, a monocyte, a macrophage, a neutrophil, a myeloid derived suppressor cell and an eosinophile. In one embodiment the myeloid cell is not a dendritic cell. In one embodiment the myeloid cell is a macrophage, a neutrophile or a myeloid-derived suppressor cell.

[0057] A preferred T cell in the kit of parts of the present invention may be selected from the group consisting of a y / S T cell, a oc / p T cell, a memory T cell, a CD8+ T cell and a CD4+ T cell.

[0058] A CD4+ T cell may, for example, be selected from the group consisting of a Th 1 cell, a Th2 cell, a Th 17 cell and a regulatory T cell.

[0059] The preparation of various types of T-cells from T-iPSCs is reviewed in (Kawamoto, Masuda et al. 2021) and (Nishimura, Murmann et al. 2019), and also described in detail in the patent literature, for example in WO2011096482A1, WO2014165707A1, W02017100403A1 and WO2022216624A1, already mentioned above. WO2022216624A1 describes the preparation of oc T cells from oc TiPSCs, which TiPSCs may or may not be further modified to express a chimeric antigen receptor. Examples 1 to 3 on pages 81 to 86 explain the preparation of the oc TiPSCs and the oc T-cells derived therefrom and are herein incorporated by reference. W02017100403A1 describes the preparation of various types of T cells from T iPSCs, for example mature T cells and T stem cell memory cells. Example 1 to example 9 from page 39 to page 54 are herein incorporated by reference. (Nagano, Maeda et al. 2020) describe the preparation of antigen-specific cytotoxic CD8 T cells from T iPSCs. This reference, and in particular the Materials and Methods section on pages 132 and 133 and in the supplement https: / / doi.Org / 10.1016 / j.omtm.2019.12.006 is herein incorporated by reference. (Watanabe, Koyanagi-Aoi et al. 2018) describe the preparation of yb T cells from yb T iPSCs and is herein incorporated by reference. In some embodiments the RAG2 gene is deleted in the T-iPSC. A further reference describing the preparation of CD4+ T-cells from iPSCs is PMID: 39878584, Fong et al. 2025, which is herein incorporated by reference. The process described by Wong et al. for the generation of CD4+ T-cells from iPSCs can be applied to the generation of CD4+ T-cells from T-iPSCs as well, preferably wherein the T-iPSC is derived from a CD4+ T-cell and more preferably wherein Rag2-activity is either suppressed dining the differentiation process of CD4+ T-cells from the T-iPSC or wherein the T-iPSC is a T-iPSC wherein Rag2 has been deleted. As explained in the introduction, CD8+ T cells recognize antigens presented on MHC class I molecules while CD4+ T cells recognize antigens presented on MHC class II. Also as explained above, the rearranged TCR-locus is preferably preserved during the steps of generating the T-iPSC from the original, preferably antigen-specific, T-cell and then producing the T-iPSC-derived T- cells from the T-iPSC. The skilled person will therefore appreciate that a T-iPSC derived from one type of T-cell is to be used for the production of the corresponding type of T-cell, for example a CD 8+ T-cell derived T-iPSC is to be used for the production of CD8+ T-cells, a T-iPSC derived from a CD4+ T-cell is to be used for the production of CD4+ T-cells and a T-iPSC derived from a gammadelta T-cell is to be used for the production of gammadelta T-cells.

[0060] A preferred combination of myeloid cells and T cells may be a combination wherein the a) myeloid cell is a dendritic cell and the b) T cell is a CD4+ T cell or wherein the a) myeloid cell is a macrophage and the b) T cell is a CD4+ T cell or wherein the a) myeloid cell is a myeloid derived suppressor cell and the b) T cell is a CD8+ T cell or wherein the a) myeloid cell is a macrophage and the b) T cell is a CD8+ T cell or wherein the a) myeloid cell is a neutrophil and the b) T cell is a CD8+ T cell or wherein the a) myeloid cell is a neutrophil and the b) T cell is a CD4+ T cell.

[0061] As explained above, the preparation of a master cell bank of iPSCs is extremely expensive. (Devito, Petrova et al. 2014) Being able to use one and the same master cell bank for the preparation of both, myeloid cells and T-cells, is therefore a significant economic advantage. The present invention therefore also relates to the use of a master cell bank of T-iPSCs in the production of myeloid cells, for example wherein the myeloid cells are dendritic cells, monocytes or macrophages, in particular in the production of a cell therapy comprising myeloid cells, for example wherein the myeloid cells are dendritic cells, monocytes or macrophages. A preferred use of the master cell bank of T-iPSCs is in the production of a cell therapy comprising a) myeloid cells and b) T-cells, for example wherein the a) myeloid cells and b) T cells are the combinations of myeloid cells and T cells as described above, for example the myeloid cell may be selected from the group consisting of a dendritic cell, a monocyte, a macrophage, a neutrophil, a myeloid derived suppressor cell and an eosinophile and / or the T-cell may be selected from the group consisting of a y / S T cell, a a / p T cell, a memory T cell, a CD8+ T cell and a CD4+ T cell.

[0062] The combinations of a) myeloid cells and b) T cells may be for use in cell therapy, such as wherein the cell therapy is a method of treating cancer, in particular a method of treating solid tumor.

[0063] The combinations of a) myeloid cells and b) T cells and, optionally, further cell types, such as cancer cells, may also be used in a method of screening substances which can modify the interaction between the myeloid cells and the T cells. For example, M2-polarized macrophages are known to inhibit T-cell activation and proliferation in Co-culture assays, for example as described in (Kuen, Darowski et al. 2017) and (Umiker, Hashambhoy-Ramsay et al. 2023). Screening methods based on cell culture systems are well known in the art, for example macrophage cell cultures have been used by (Hu, Su et al. 2021) for high-throughput screening and T-cells have been used by (Olivo Pimentel, Yaromina et al. 2020) for high throughput screening, and co-cultures of macrophages and T-cells have been used by Kumar et al. PMID 39181134. For example a co-culture and may be carried out as follows: The matching myeloid cells and T cells of the present invention, optionally in the presence of further cell types, such as cancer cells, may be co-cultured, for example in multi-well plates, in the presence or absence of a compound or collection of compounds to be screened, and the T cell activation and / or proliferation may be quantified after a sufficiently long incubation period so that compounds which lead to T-cell activation and / or proliferation even in the presence of myeloid cells, such as macrophages, for example M2-polarized macrophages, may be identified. Preferably, the T-cell which is used in the co-culture is capable of recognizing a cancer-cell specific antigen presented by a matched MHC-complex, such as an MHC-I complex, for example an MHC-I complex of the cancer cell, or an MHC-II complex, for example an MHC-II complex of an antigen-presenting myeloid cell such as a macrophage.

[0064] T-iPSCs can be generated from antigen-specific T-cells, and can then be used for producing T-iPSC-derived T-cells with the same binding specificity. Nishimura T, Nakauchi H. Generation of Antigen- Specific T Cells from Human Induced Pluripotent Stem Cells. PMID: 30649763. Briefly, a desired T-cell type, such as CD8+ T-cells, CD4+ T-cells or gammadelta T-cells, is isolated from a donor source, such as peripheral blood mononuclear cells. T-cells with a desired antigen-specificity can then be isolated based on their binding to MHC-tetramers loaded with the desired antigen, for example by fluorescence-activated cell sorting, if a dye- conjugated antigen-loaded MHC-tetramer is used. Antigen-specific T-cell clones can then be generated by single cell sorting and expansion of the clones with the right antigen-specificity with HLA-matched feeder cells and the antigenic peptide. The antigen-specific T-cell clones can then be used for the reprogramming step into T-iPSCs from which then T-cells with the same antigen-specificity can be produced, as well as the MHC-matched macrophages, neutrophils and myeloid suppressor cells of the present invention.

[0065] The process for producing an antigen-specific T-cell clone is described in detail by Matthis J, and Reijonen H. Production of primary human CD4+T cell lines and clones. Methods Mol Biol. 2013;960:545-555. PMID 23329513 for the case of CD4+ T-cells. The skilled person will appreciate that for the generation of CD8+ T-cell clones with a desired antigen-specificity antigen-loaded MHC-I tetramers would be used. The database “Immune epitope database and tools” https: / / www.iedb.org provides access to known T-cell epitopes, for example linear peptides of pathogens or cancer cells that were found to be presented by an MHC-I or MHC-II complex and to trigger a T-cell response by a CD8+ or CD4+ T-cell, respectively. For example, a search with Leishmania as the epitope source and Homo sapiens as the host for known MHC-II restricted linear peptides allows the identification (April 17, 2025) of 83 epitopes from 32 antigens, and leishmanolysin (Uni Prot Q4QHH2) as a well known antigen that can trigger T-cell-responses. This database can aid in identifying suitable peptides for presentation on a MHC-tetramer (and thus for selection of an antigen-specific T-cell clone from which a T-iPSC may be generated), but, of course, the wide literature on known T-cell antigens, be it from cancer cells, pathogens or autoimmune antigens, is also a useful starting point for selecting an antigen for MHC-tetramer loading.

[0066] Moreover, many T-cell receptors with known antigen-specificity are known, such as TCRs targeting, for example, an epitope derived from melanoma-associated antigen 3 (MAGE-A3); melanoma antigen recognized by T cells 1 (MART-1); New York esophageal squamous cell carcinoma-1 (NY-ESO-1); melanoma-associated antigen 1 (MAGE-A1); tumor protein p53 (P53); cytotoxic T cell (CTL)-recognized antigen on melanoma (CAMEL), Wilms’ tumor 1 (WT1) and a renal cell carcinoma (RCC) tumor antigen. The invention therefore also relates to the use of T-cells derived from iPSCs and expressing these TCRs with known binding specificity in combination with myeloid cells derived from the same iPSCs, in screening assays, for example for drugs affecting the tumor microenvironment. Compounds identified by such screening assays are useful as drug candidates for the treatment of solid tumors. In solid tumors tumor- associated macrophages are known to have a strong immune suppressive effect, which might be alleviated by the identified drug candidates. The skilled person will appreciate that in the context of such a combination of three cell types - the T-iPSC-derived T cell having a T cell receptor with known antigen-specificity against an epitope derived from a cancer cell, a matched myeloid cell, such as a myeloid cell derived from the same T iPSC as the T cell, and a cancer cell - the cancer cell is a cancer cell which expresses the target antigen of the TCR. For example, if a T cell having a TCR which targets MAGE-A3 is used, then the cancer cell line which is used together with the T-iPSC-derived T cell and the matched myeloid cell, such as the macrophage, neutrophil, myeloid derived suppressor cell derived from the same T-iPSC, is a cancer cell line expressing MAGE-A3. For example, if a T cell having a TCR which targets NY-ESO-1 is used, then the cancer cell line which is used together with the T-iPSC-derived T cell and the matched myeloid cell, such as the macrophage, neutrophil, myeloid derived suppressor cell derived from the same T-iPSC, is a cancer cell line expressing NY-ESO-1. For example, if a T cell having a TCR which targets WT1 is used, then the cancer cell line which is used together with the T-iPSC-derived T cell and the matched myeloid cell, such as the macrophage, neutrophil, myeloid derived suppressor cell derived from the same T-iPSC, is a cancer cell line expressing WT1. For example, if a T cell having a TCR which targets CAMEL is used, then the cancer cell line which is used together with the T-iPSC-derived T cell and the matched myeloid cell, such as the macrophage, neutrophil, myeloid derived suppressor cell derived from the same T-iPSC, is a cancer cell line expressing CAMEL.

[0067] Another example where the combination of a) myeloid cells and b) T cells and further organisms, such as pathogens, may be useful, is a method of screening for substances which can help to control, weaken, limit or destroy the pathogen. There are numerous examples of pathogens, such as human pathogens, where the pathogen infects either T-cells or myeloid cells or both. An example for a pathogen infecting T-cells is the human immunodeficiency virus (HIV). Examples of pathogens infecting myeloid cells, such as macrophages, are bacteria, for example mycobacteria, salmonellae, listeria, brucellae, francilscellae, yersiniae and rodococci, viruses, for example HIV, CMV, Dengue virus, Ebola virus, Zika virus and Marburg virus, eucaryotic parasites, for example leishmania spp., plasmodium spp., Toxoplasma and trypanosoma, and fungal pathogens, for example histoplasma capsulatum and cryptococcus neoformans. These pathogens can form latent and persistent infections using myeloid cells, such as macrophages, as a reservoir, often subverting the immune-monitoring mechanisms by which T-cells, such as CD8+ T cells and / or CD4+ T cells, would normally identify an infected macrophage, and where the T-cells would then normally proceed to either kill the infected macrophage, for example in the case of a CD8+ T cell identifying the presence of a pathogen-epitope presented on a MHC-I complex, or activate the infected myeloid cell itself, for example a macrophage, so as to clear pathogens hiding within its phagosomes, for example in the case of a CD4+ T cell identifying a pathogen-epitope presented on an MHC-II complex.

[0068] Preferably, the T-cell which is used in the co-culture is capable of recognizing a pathogen-cell specific antigen presented by a matched MHC-complex, such as an MHC-I complex, for example an MHC-I complex of the myeloid cell, such as a macrophage, or an MHC-II complex, for example an MHC-II complex of an antigen-presenting myeloid cell such as a macrophage. As explained above, T-iPSCs can be generated from antigen-specific T-cells, and can then be used for producing T-iPSC-derived T-cells with the same binding specificity.

[0069] For example, a T cell receptor (TCR) that specifically recognizes a pathogen-derived peptide presented by major histocompatibility complex (MHC) molecules, can be identified by employing a multi-step workflow integrating immunopeptidomics, T cell screening, TCR sequencing, and functional validation. In a first step, MHC-presented pathogen peptides are identified. To determine the peptides derived from the pathogen that are naturally presented on MHC molecules, antigen-presenting cells (APCs) can be infected with the pathogen of interest. MHC-bound peptides are then subsequently isolated via immunoprecipitation and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS / MS). Additionally, bioinformatics tools such as NetMHCpan and IEDB can be employed to predict high-affinity peptide-MHC interactions. Following peptide identification, antigen-specific T cells can be identified in a second step. For example, the presence of antigen-specific T cells can be assessed using MHC-tetramer staining and flow cytometry. For unknown TCRs, peripheral blood mononuclear cells (PBMCs) can be stimulated with peptide-pulsed dendritic cells, and T cell activation can be measured via IFN-y ELISPOT assays, intracellular cytokine staining (ICS), and proliferation assays. The TCRs can then be cloned and sequenced, for example by sorting the antigen-specific T cells identified in the previous step using fluorescence- activated cell sorting (FACS), followed by single-cell RNA sequencing (scRNA-seq) to obtain paired TCRa and TCRP sequences. The binding specificity of the so identified TCRs can then be validated, for example by cloning its coding sequence into a TCR-deficient Jurkat cell line or primary T cells via lentiviral transduction. Engineered T cells can then be co-cultured with peptide-pulsed APCs, and TCR activation can be assessed by measuring CD69 upregulation, IL-2 secretion, and phosphorylation of key signaling molecules (e.g., ZAP-70, ERK1 / 2). Additionally, surface plasmon resonance (SPR) or biolayer interferometry (BLI) can be used to quantify direct TCR-MHC binding kinetics. Finally, the so identified TCRs can be functionally characterized. For example, in order to determine whether the identified TCR is capable of eliciting an effector response, TCR-transduced CD8+T cells can be assessed for cytotoxic activity using target cell killing assays (e.g., Cr51release assay or live-cell imaging). Cytokine production (IFN-y, TNF-a, IL-2) can be measured via multiplex cytokine assays or ELISA. The following reviews provide further guidance on how antigen-specific TCRs can be identified, for example Tippalagama et al. (2023) PMID: 37122719, which is herein incorporated by reference, and Smith et al (2021), PMID: 34032640, which is herein incorporated by reference. The skilled person will understand that these review articles provide access to the primary literature, where the individual procedures are described in detail. Methods for identifying antigen-specific T-cell receptors are also described in the patent literature, for example in WO2023 / 019583A1 and JP2015133938A.

[0070] This integrated approach enables the identification and characterization of pathogen-specific TCRs, facilitating their potential application in immunotherapeutic strategies and vaccine development. Moreover, many T-cell receptors with known antigen-specificity are known, such as TCRs targeting, for example, an epitope derived from M. tuberculosis (see CN102875666A), human immunodeficiency virus (HIV) Gag and Pol antigens; hepatitis C virus (HCV) non-structure protein 3 (NS3); Epstein-Barr virus (EBV) and human papillomavirus (HPV). The invention therefore also relates to the use of T-cells derived from iPSCs and expressing TCRs with known binding specificity, for example against the epitopes mentioned above, in combination with myeloid cells derived from the same iPSCs, in screening assays, for example for drugs affecting pathogen survival and / or clearance. Compounds identified by such screening assays are useful as drug candidates for the treatment of infections, for example bacterial, viral, fungal or protozoic infections. In several infectious diseases, where macrophages are known to be infected by a pathogen, the pathogen has developed strategies for evading detection of the infected macrophage by patrolling T-cells. The screening assays may identify drugs that counteract the pathogen-induced immune evasion strategies, thus re-enabling T-cell induced pathogen clearance within the macrophage or T-cell induced killing of an infected macrophage.

[0071] The skilled person will appreciate that in the context of such a combination of three cell types - the T-iPSC- derived T cell having a T cell receptor with known antigen-specificity against an epitope derived from a pathogen, a matched myeloid cell, such as a myeloid cell derived from the same T iPSC as the T cell, and a pathogen - the pathogen is a pathogen which expresses the target antigen of the TCR. For example, if a T cell having a TCR which targets an epitope derived from HIV is used, then the pathogen which is used together with the T-iPSC-derived T cell and the matched myeloid cell, such as the macrophage, neutrophil, myeloid derived suppressor cell derived from the same T-iPSC, is HIV. For example, if a T cell having a TCR which targets an epitope derived from HPV is used, then the pathogen which is used together with the T-iPSC-derived T cell and the matched myeloid cell, such as the macrophage, neutrophil, myeloid derived suppressor cell derived from the same T-iPSC, is HPV. For example, if a T cell having a TCR which targets an epitope derived from a bacterium is used, then the pathogen which is used together with the T-iPSC- derived T cell and the matched myeloid cell, such as the macrophage, neutrophil, myeloid derived suppressor cell derived from the same T-iPSC, is the corresponding bacterium. For example, if a T cell having a TCR which targets an epitope derived from a virus is used, then the pathogen which is used together with the T- iPSC-derived T cell and the matched myeloid cell, such as the macrophage, neutrophil, myeloid derived suppressor cell derived from the same T-iPSC, is the corresponding virus. For example, if a T cell having a TCR which targets an epitope derived from a fungus is used, then the pathogen which is used together with the T-iPSC-derived T cell and the matched myeloid cell, such as the macrophage, neutrophil, myeloid derived suppressor cell derived from the same T-iPSC, is the corresponding fungus. For example, if a T cell having a TCR which targets an epitope derived from a protist is used, then the pathogen which is used together with the T-iPSC-derived T cell and the matched myeloid cell, such as the macrophage, neutrophil, myeloid derived suppressor cell derived from the same T-iPSC, is the corresponding protist.

[0072] A co-culture of T-cells with pathogen-infected macrophages is, for example, described in Kelvinson et al. PMID: 27136900, and the skilled person will be able to adapt the co-culture conditions to human cells, for example by taking the co-culture conditions of Kumar et al. PMID 39181134 as a guidance.

[0073] The present invention also relates to the combination of a) myeloid cells and b) T cells and a source of an autoantigen that is recognized by the T-cell. This combination may be useful in a method of screening for substances which can treat autoimmune diseases. There are numerous examples of autoimmune diseases where T-cells recognize epitopes from self-antigens presented by a myeloid antigen-presenting cell, such as a dendritic cell or a macrophage, and then attack self-tissue. For example, in type 1 diabetes insulin, glutamic acid decarboxylase and / or islet antigen-2 are known to be recognized by CD4+ and / or CD8+ T-cells, which then attack beta-cells in the pancreas. A drug screen can now be performed in a coculture of a T-cell which is capable of recognizing a self-antigen presented by a matched MHC-complex, together with an antigen- presenting myeloid cell, such as a macrophage or dendritic cell, and a source of the self-antigen, which may be the self-antigen itself or another source of the self-antigen, such as an additional cell type expressing the self-antigen. As explained above, T-iPSCs can be generated from antigen-specific T-cells, and can then be used for producing T-iPSC-derived T-cells with the same binding specificity. The skilled person will appreciate that iPSCs, which comprise an expression construct coding for a functional T cell receptor, such as an expression construct comprising pairs of rearranged TCRA and TCRB genes or pairs of rearranged TCRD and TCRG genes, which are capable of generating functional T cells under the appropriate differentiation conditions, will also generate matched T cells and myeloid cells. Such iPSCs may have the rearranged TCRA and TCRB genes or the rearranged TCRD and TCRG genes at a genomic site that is different from the TCR-loci on chromosomes 7 and 14. Such iPSCs may further comprise a deletion of the genes TCRA, TCRB, TCRD and / or TCRG at the original loci so that only the TCR genes which were introduced by genetic engineering are expressed in a T cell derived from such an iPSC. The present invention also relates to matched isogenic pairs of T-cells and myeloid cells, in particular macrophages, monocytes, neutrophiles and myeloid-derived suppressor cells, which are derived from such genetically engineered iPSCs which comprise an expression construct encoding for a functional T cell receptor.

[0074] Moreover, T-cell receptors with known antigen-specificity are known, such as TCRs targeting, for example, an epitope derived from insulin (for example from Tran et al. Nature Communications, PMID 34433824). The invention therefore also relates to the use of T-cells derived from iPSCs and expressing TCRs with known binding specificity against an epitope of a self-antigen, in combination with myeloid cells derived from the same iPSCs in screening assays, for example for drugs for the treatment of autoimmune disease. Compounds identified by such screening assays are useful as drug candidates for the treatment of autoimmune diseases, such as rheumatoid arthritis, type 1 diabetes, multiple sclerosis, systemic lupus erythematosus, celiac disease, hashimoto’s thyroiditis or autoimmune hepatitis. The screening assays may identify drugs that counteract the self-antigen triggered T-cell-induced immune activation. The skilled person may take the co-culture conditions described by Kumar et al. PMID 39181134 as a guidance, adding the source of the self-antigen either as the epitope itself, as the self-antigenic protein or as a separate cell type expressing the self-antigen.

[0075] Definitions

[0076] The term "gene" means a DNA sequence that codes for an RNA or a particular sequence of amino acids which comprise all or part of one or more proteins or enzymes, and may or may not include regulatory DNA sequences, such as promoter sequences, which determine for example the conditions under which the gene is expressed. Herein genes are identified by their human gene symbol as defined by the HUGO Gene nomenclature committee. The relevant date is April 21, 2024.

[0077] A "promoter" or "promoter sequence" is a DNA regulatory region capable of binding RNA polymerase in a cell and initiating transcription of a downstream (3' direction) coding sequence. Some genes, which are not structural genes, may be transcribed from DNA to RNA, but are not translated into an amino acid sequence. Other genes may function as regulators of structural genes or as regulators of DNA transcription. In particular, the term gene may be intended for the genomic sequence encoding a protein, i.e. a sequence comprising regulator, promoter, intron and exon sequences.

[0078] Within the context of the present invention the terms "mutant" and "mutation" mean a detectable change in genetic material, i.e. genomic DNA. Mutations include deletion, insertion or substitution of one or more nucleotides. The mutation may occur in the coding region of a gene (i.e. in exons), in introns, or in the regulatory regions (e.g. enhancers, response elements, suppressors, signal sequences, polyadenylation sequences, promoters) of the gene. Generally, a mutation is identified in a subject by comparing the sequence of a nucleic acid or polypeptide expressed by said subject with the corresponding nucleic acid or polypeptide expressed in a control population. Where the mutation is within the gene coding sequence, the mutation may be a "missense" mutation, where it replaces one amino acid with another in the gene product, or a "nonsense" mutation, where it replaces an amino acid codon with a stop codon. A mutation may also occur in a splicing site where it creates or destroys signals for exon-intron splicing and thereby lead to a gene product of altered structure. Within the context of the present invention a mutation is not silent, i.e. it results at least in an alteration of the amino acid sequence (where the gene product is a protein). As used herein the term “deletion” means that at least 10 nucleotides of a genomic-sequence are missing compared to a reference sequence for said genomic region.

[0079] As used herein the term "expression" refers to gene expression of a polypeptide or protein.

[0080] As used herein the “expression of an mRNA” relates to the transcriptional level of gene expression.

[0081] As used herein an “exon” is any part of a gene that will encode a part of the final mature RNA produced by that gene after introns have been removed by RNA splicing. The term exon refers to both the DNA sequence within a gene and to the corresponding sequence in RNA transcripts. In RNA splicing, introns are removed and exons are covalently joined to one another as part of generating the mature messenger RNA.

[0082] In accordance with the invention, the engineered iPSC’s hereof are capable of being differentiated into myeloid cells, such as mononuclear cells (e.g. conventional dendritic cells, macrophages and monocytes) and granulocytes (e.g. eosinophiles, basophiles and neutrophiles). As used herein, the term "differentiation" is the process by which an unspecialized ("uncommitted") or less specialized cell acquires the features of a specialized cell. Specialized cells include, for example, a conventional dendritic cell, a macrophage, a monocyte, an eosinophile, a basophile and a neutrophile. A differentiated or differentiation- induced cell is one that has taken on a more specialized ("committed") position within the lineage of a cell. The term "committed", when applied to the process of differentiation, refers to a cell that has proceeded in the differentiation pathway to a point where, under normal circumstances, it will continue to differentiate into a specific cell type or subset of cell types, and cannot, under normal circumstances, differentiate into a different cell type or revert to a less differentiated cell type.

[0083] As used herein, "induced pluripotent stem cells" or, iPSCs, refers to stem cells which are produced from differentiated adult, neonatal or fetal cells that have been induced or changed or reprogrammed into cells capable of differentiating into tissues of all three germ or dermal layers: mesoderm, endoderm, and ectoderm. Induced pluripotent stem cells are cells that are not found in nature.

[0084] As used herein “T cell” refers to a type of white blood cell that has completed maturation in the thymus. A T cell can, for example, identify specific foreign antigens presented by a self-MHC complex and lead to the activation and deactivation of other immune cells. The T cell can be CD3+ cells. The T cell can be a CD4+ helper T cell (e.g., Thl and Th2 cells), a CD8+ T cells (e.g., cytotoxic T cells), a T-cell derived from peripheral blood mononuclear cells (PBMCs), peripheral blood leukocytes (PBLs), tumor infiltrating lymphocytes (TILs), memory T cells, naive T cells, regulator T cells, gamma delta T cells (gd T cells), and the like. CD4+ T cells include for example Th3 (Treg), Thl7, Th9, or Tfh cells. Additional types of memory T cells include cells such as central memory T cells (Tcm cells), effector memory T cells (Tern cells and TEMRA cells).

[0085] The T cell receptor (TCR) is a membrane complex located on T cells' surface and is able to specifically recognize antigens. Comprising either alpha (a) and beta (b) chains or gamma (g) and delta (d) chains, it is a heterodimer. Each chain, whether alpha, beta, gamma, or delta, can be glycosylated. The diversity of TCRs is generated akin to antibodies, primarily through genetic recombination via somatic V(D)J recombination in individual somatic T cells. Within a single cell, the T cell receptor loci undergo stochastic rearrangement and expression. If both delta and gamma rearrangements yield functional polypeptides, the cell co-expresses delta and gamma. Otherwise, it proceeds to rearrange the beta and alpha loci. Unlike antibodies, TCR genes do not undergo somatic hypermutation.

[0086] In this context, a "rearranged TCR" denotes a TCR encoded by a rearranged TCR gene that has undergone a physical rearrangement, fusing distant gene segments together. The human genome possesses four TCR gene clusters: alpha (a), beta (b), gamma (g), and delta (d), encoding the TCR alpha, beta, gamma, and delta chains, respectively, through rearranged TCR genes in T cells. "MHC-restricted antigen recognition," or "MHC restriction," denotes a T cell's ability to recognize a foreign peptide bound to a self-major histocompatibility complex molecule, only responding when the antigen binds to a specific self MHC molecule (e.g., HLA-A*0201). During T cell development, thymic selection ensures that the TCR does not recognize MHC molecules presenting self-antigens, resulting in T cells with TCRs responsive to certain MHC molecules but not others (e.g., non-restricted MHC molecules). In humans the MHC genes are called HLA.

[0087] The T cell receptor Alpha locus is described in detail as gene TRA with gene ID 6955 in the NCBI Gene database. It is located on chromosome 14 at the location 14ql 1.2. It spans the region (Assembly GRCh38.pl4 in Annotation release RS 2023 10) between nucleotide 21621904 and nucleotide 22552132. It is a complex locus and contains more than 50 variable (V) segments, also more than 50 joining (J) segments and one constant (C) segment. A gene coding for a functional TCR alpha chain is generated dining T cell development by joining V, J and C segments. The T cell receptor Alpha locus in T-iPSCs is thus significantly smaller than the about 9300000 nucleotides it has in somatic cells.

[0088] The T cell receptor alpha locus also contains the gene segments coding for the TCR delta chain. The T cell receptor delta locus is described as gene TRD with gene ID 6964 in the NCBI database. As mentioned above, it is located within the T cell receptor Alpha locus and spans the region (Assembly GRCh38.pl 4 in Annotation release RS 2023 10) between nucleotide 22422546 and nucleotide 22466577. It is itself a complex locus and shares several variable (V) segments with the TRA locus, contains at least one diversity (D) segment, at least four J segments and one TRD-specific constant (C) segment. A gene coding for a functional TCR delta chain is generated during T cell development by joining V, D, J and C segments.

[0089] The T cell receptor Beta locus is described in detail as gene TRB with gene ID 6957 in the NCBI Gene database. It is located on chromosome 7 at the location 7pl4.1. It spans the region (Assembly GRCh38.pl4 in Annotation release RS 2023 10) between nucleotide 38240024 and nucleotide 38368055. It is a complex locus and contains a cluster of more than 50 variable (V) segments, upstream of two D-J-C clusters, each composed of one D segment, at least six J segments and one C segment. A gene coding for a functional TCR beta chain is generated during T cell development by joining V, D, J and C segments. The T cell receptor Beta locus in T-iPSCs derived from alpha / beta T-cells is thus significantly smaller than the about 514000 nucleotides it has in somatic cells.

[0090] The T cell receptor Gamma locus is described in detail as gene TRG with gene ID 6965 in the NCBI Gene database. It is located on chromosome 7 at the location 7pl4.1. It spans the region (Assembly GRCh38.pl4 in Annotation release RS 2023 10) between nucleotide 38240024 and nucleotide 38368055. It is again a complex locus and contains at least 14 variable (V) segments, also at least 5 joining (J) segments and two constant (C) segment. A gene coding for a functional TCR gamma chain is generated during T cell development by joining V, J and C segments. The T cell receptor Gamma locus in T-iPSCs derived from gamma / delta T-cells is thus significantly smaller than the about 128000 nucleotides it has in somatic cells.

[0091] Each T cell receptor is a dimer consisting of one alpha and one beta chain or one delta and one gamma chain. In a single cell, the T cell receptor loci are rearranged and expressed in the order delta, gamma, beta, and alpha. If both delta and gamma rearrangements produce functional chains, the cell expresses delta and gamma. If not, the cell proceeds to rearrange the beta and alpha loci.

[0092] Myeloid cells are “matched” with T-cells if the myeloid cells express MHC-complexes which the T-cells have been trained to selectively recognize as self.

[0093] A “unit dose” as used herein is the amount of a medication administered to a patient in a single dose.

[0094] Medical or physiological terms, like “erythema”, as used herein have the meaning as known to the experienced general practitioner or medical doctor; unless specified otherwise. In cases of doubt, the English language version of the book “Pschyrembel” can be used to define medical or physiological terms. As used herein, the term "subject" or “individual” as used herein denotes a human being.

[0095] In the context of the invention, the term "treating" or "treatment", as used herein, means reversing, alleviating, inhibiting the progress of, or preventing the disorder, disease or condition to which such term applies, or one or more symptoms of such disease or condition. Preferably it means reversing, alleviating, inhibiting the progress of, or preventing the disease or condition.

[0096] All numerical designations, e.g., pH, temperature, time, concentration, and molecular weight, including ranges, are approximations which are varied (+) or (-) by increments of 0.1. It is to be understood, although not always explicitly stated that all numerical designations are preceded by the term “about.” It also is to be understood, although not always explicitly stated, that the reagents described herein are merely examples and that equivalents of such are known in the art.

[0097] It is to be understood that this invention is not limited to the particular materials and methods described herein. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments and is not intended to limit the scope of the present invention, which will be limited only by the appended claims. As used herein, the singular forms "a", "an", and "the" include plural reference unless the context clearly indicates otherwise.

[0098] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. The following references provide one of skill with a general definition of many of the terms used in this invention - unless defined otherwise herein - and ranked in increasing order of priority: Singleton et al., Dictionary of Microbiology and Molecular Biology (3rd ed. 2006); The Glossary of Genomics Terms (JAMA. 2013; 309(14): 1533-1535), Janeway’s Immunobiology, 9th edition and “Practical Flow Cytometry”, 4th edition by H.M. Shapiro.

[0099] All publications mentioned herein are cited for the purpose of describing and disclosing the cell lines, protocols, reagents and vectors which are reported in the publications and which might be used in connection with the invention. Nothing herein is to be construed as an admission that the invention is not entitled to antedate such disclosure by virtue of prior invention.

[0100] The invention further relates to the following embodiments

[0101] 1. Use of a T-iPSC in a method of producing myeloid cells.

[0102] 2. The use according to item 1, wherein the T-iPSC is derived from an a / 0 T-cell or from an y / S T- cell.

[0103] 3. A method of manufacturing a myeloid cell comprising differentiating a T-iPSC under conditions for cell differentiation which generate a myeloid cell.

[0104] 4. The method of item 3, comprising the step a) of forming an embryoid body from the T-iPSC.

[0105] 5. The method according to any one of items 3 to 4 further comprising the steps b) of cultivating embryoid bodies in the presence of IL-3 and, optionally, at least one additional cytokine, for a period of time sufficient to produce myeloid cells and c) isolating the myeloid cells.

[0106] 6. The method according to any one of items 3 to 5, wherein in step b) bl) the additional cytokine is M-CSF and the produced myeloid cells are macrophages; or b2) the additional cytokine is G-CSF and the produced myeloid cells are granulocytes; or b3) the additional cytokine is GM-CSF and the produced myeloid cells are macrophages and granulocytes; or b4) the additional cytokines are SCF and EPO and the produced myeloid cells are erythroid cells; or b5) the additional cytokines are SCF and TPO and the produced myeloid cells are megakaryocytes and / or thrombocytes; or b6) the additional cytokine is GM-CSF and IL-4 and the produced myeloid cells are dendritic cells; or b7) there is no additional cytokine to IL-3, and the produced myeloid cells are immature cells capable of further differentiation, wherein, optionally, said method further comprises i) cultivating said immature cells in the presence of M-CSF until macrophages are obtained; or ii) cultivating said immature cells in the presence of G-CSF until granulocytes are obtained; iii) cultivating said immature cells in the presence of GM-CSF until granulocytes and macrophages are obtained; iv) cultivating said immature cells in the presence of SCF and EPO until erythroid cells are obtained; v) cultivating said immature cells in the presence of SCF and TPO until megakaryocytes and / or thrombocytes are obtained. A myeloid cell wherein at least one of the genomic loci TRA, TRB, TRD and TRG is at most 90% the length of the corresponding genetic locus as defined by gene ID 6955, gene ID 6957, gene ID 6964 and gene ID 6965, respectively. The myeloid cell according to item 7, wherein at least two of said genomic loci are at most 90% the length of the corresponding genetic locus. The myeloid cell according to item 7, wherein at least two of said genomic loci are at most 70% the length of the corresponding genetic locus. The myeloid cell according to any one of items 7 to 9, wherein the at least two genomic loci are the pair TRA and TRB and / or the pair TRD and TRG. A myeloid cell derived from a T-iPSC. The myeloid cell according to item 11, wherein at least two of the genomic loci TRA, TRB, TRD and TRG have undergone a genomic rearrangement. The myeloid cell according to item 12, wherein the at least two genomic loci are the pair TRA and TRB and / or the pair TRD and TRG. The myeloid cell according to any one of items 12 to 13, wherein a J-segment of the genomic loci TRA, TRB, TRD or TRG is joined with a C-segment of the same genomic locus. A kit of parts comprising a) myeloid cells comprising MHC-genes with a specific genotype, and b) T-cells comprising a T-cell receptor that is matched to the myeloid cells MHC-complexes, wherein the myeloid cells are myeloid cells according to any one of items 7 to 14. The kit of parts according to item 15, wherein the myeloid cells and the T-cells are derived from the same T-iPSC. The kit of parts according to any one of items 15 to 16, wherein the genes encoding HLA-A and HLA-B are identical between the a) myeloid cells and the b) T-cells. The kit of parts according to any one of items 15 to 16, wherein the genes encoding HLA-DRA and HLA-DRB1 are identical between the a) myeloid cells and the b) T-cells. The kit of parts according to any one of items 15 to 16, wherein the a) myeloid cells and the b) T- cells have identical chromosomes 7 and 14 as evaluated by G-banding. The kit of parts according to any one of items 15 to 16, wherein the a) myeloid cells and the b) T- cells have essentially identical sequence for the genomic loci at the pair TRA and TRAB and / or at the pair TRD and TRG. The kit of parts according to any one of items 15 to 16, wherein the a) myeloid cells and the b) T- cells have essentially the same genome. The kit of parts according to any one of items 15 to 21, wherein the a) myeloid cell is a dendritic cell. The kit of parts according to any one of items 15 to 21, wherein the a) myeloid cell is a monocyte. The kit of parts according to any one of items 15 to 21, wherein the a) myeloid cell is a macrophage. The kit of parts according to any one of items 15 to 21, wherein the a) myeloid cell is a neutrophil. The kit of parts according to any one of items 15 to 21, wherein the a) myeloid cell is a myeloid derived suppressor cell. The kit of parts according to any one of items 15 to 21, wherein the a) myeloid cell is an eosinophile. The kit of parts according to any one of items 15 to 21, wherein the b) T cell is a y / S T cell. The kit of parts according to any one of items 15 to 21, wherein the b) T cell is a a / 0 T cell. The kit of parts according to any one of items 15 to 21, wherein the b) T cell is a CD8+ T cell. The kit of parts according to any one of items 15 to 21 , wherein the b) T cell is a CD4+ T cell. The kit of parts according to item 31, wherein the CD4+ T cell is selected from the group consisting or a Thl cell, a Th2 cell, a Thl7 cell and a regulatory Tcell. The kit of parts according to any one of items 15 to 21, wherein the b) T cell is a memory T cell. The kit of parts according to any one of items 15 to 21, wherein the a) myeloid cell is a dendritic cell and the b) T cell is a CD4+ T cell. The kit of parts according to any one of items 15 to 21, wherein the a) myeloid cell is a macrophage and the b) T cell is a CD4+ T cell. The kit of parts according to item 35, wherein the T-cell is a regulatory T cell. The kit of parts according to any one of items 15 to 21, wherein the a) myeloid cell is a myeloid derived suppressor cell and the b) T cell is a CD8+ T cell. The use of a master cell bank of T-iPSCs in the production of a cell therapy comprising myeloid cells. The use of item 38, wherein the myeloid cells are dendritic cells, monocytes or macrophages. The use of a master cell bank of T-iPSCs in the production of a cell therapy comprising a) myeloid cells and b) T-cells. The use according to item 40, wherein the a) myeloid cells and b) T cells are the combinations of myeloid cells and T cells as defined in items 15 to 37. The use according to item 40, wherein the a) myeloid cells and b) T cells are the combinations of myeloid cells and T cells according to items 34 or 35. A combination of a) myeloid cells and b) T cells for use in cell therapy, wherein the myeloid cell is a myeloid cell according to any one of items 7 to 11. A combination of a) myeloid cells and b) T cells for use in cell therapy, wherein the a) myeloid cells and b) T cells are the combinations of myeloid cells and T cells as defined in items 15 to 37. A combination of a) myeloid cells and b) T cells for use in cell therapy, wherein the a) myeloid cells and b) T cells are the combinations of myeloid cells and T cells according to items 34 or 35. The combinations of A) myeloid cells and b) T cells for use in cell therapy according to items 44 to 45, wherein the cell therapy is a method of treating cancer, in particular a method of treating s solid tumor. A combination of a) myeloid cells and b) T cells for use in a method of screening for drugs which can modify a myeloid cell / T cell interaction. The combination for the use according to item 47, wherein the drug is a drug having an antitumor activity. A method of screening for a drug which can modify a myeloid cell / T-cell interaction, comprising the steps of:

[0107] (1) contacting a test substance with a combination of myeloid cells and T cells according to any one of items 15 to 35;

[0108] (2) measuring T cell activation and or T cell proliferation; and

[0109] (3) selecting the test substance as a drug candidate for modifying myeloid cell / T cell interaction when the extent of T cell activation and / or T cell proliferation measured in step (2) is higher than the extent of T cell activation and / or proliferation derived from the same combination of myeloid cell and T cells but not contacted with the test substance. The method of screening according to item 49, wherein the myeloid cells and T cells are co-cultured, optionally co-cultmed in the presence of at least one additional cell type. The method of screening according to any one of items 49 to 50, wherein the myeloid cells are macrophages. The method according to item 51, wherein the macrophages are M2 -polarized macrophages. The method according to any one of items 51 to 52, wherein the macrophages are positive for CD206, CD14 and CD163 when analyzed by FACS. The combination of cells according to item 47, wherein the combination of myeloid cells and T- cells is any one combination of cells according to items 15 to 37. The combination of cells according to item 54, wherein the T-cells express a T-cell receptor capable of binding a tumor-cell derived epitope presented by MHC-I or MHC-II. The combination of cells according to item 55, wherein the tumor-cell derived epitope is an epitope derived from melanoma-associated antigen 3 (MAGE-A3), an epitope derived from melanoma antigen recognized by T cells 1 (MART-1), an epitope derived from New York esophageal squamous cell carcinoma- 1 (NY-ESO-1), an epitope derived from melanoma-associated antigen 1 (MAGE-A1), an epitope derived from tumor protein p53 (P53), an epitope derived from cytotoxic T cell (CTL)-recognized antigen on melanoma (CAMEL), an epitope derived from Wilms’ tumor 1 (WT1) or an epitope derived from a renal cell carcinoma (RCC) tumor antigen. The combination of cells according to any one of items 54 to 56, further comprising a tumor cell as a source of the tumor-cell derived epitope which is the target of the T-cell’s T-cell receptor. Use of the combination of cells according to any one of items 55 to 57 in a method of screening for a drug, in particular wherein the drug can modify a myeloid cell / T-cell interaction, such as in a method according to any one of items 49 to 53. The combination of cells according to item 54, wherein the T-cells express a T-cell receptor capable of binding a pathogen-derived epitope presented by MHC-I or MHC-II. The combination of cells according to item 60, wherein the pathogen is a bacterial pathogen, a viral pathogen, a fungal pathogen or a protozoic pathogen. The combination of cells according to item 61, wherein the bacterial pathogen is selected from the genus Mycobacterium, such as Mycobacterium tuberculosis, from the genus Salmonella, such as Salmonella enterica, from the genus Listeria, such as Listeria monocytogenes, from the genus Brucella, such as Brucella melitensis or Brucella abortus, from the genus Francisella, such as Francisella tularensis, from the genus Legionella, such as Legionella pneumophile, from the genus Yersinia, such as Yersinia pestis and from the genus Rhodococcus, such as Rhodococcus equi. The combination of cells according to item 60, wherein the viral pathogen is selected from human immunodeficiency virus, cytomegalovirus, dengue virus, ebola virus, zika virus and Marburg virus. The combination of cells according to item 60, wherein the protozoan pathogen is selected from the genus Leishmania, from the genus Plasmodium, from the genus Toxoplasma and from the genus Trypanosoma, such as Trypanosoma cruzi. The combination of cells according to item 60, wherein the fungal pathogen is selected from the genus Histoplasma, such as Histoplasma capsulatum and from the genus Cryptococcus, such as Cryptococcus neoformans. Use of the combination of cells according to any one of items 59 to 64 in a method of screening for a drug, in particular wherein the drug can modify a myeloid cell / T-cell interaction. Use of the combination of cells according to any one of items 59 to 64 in a method of screening for a drug for the treatment of an infection with a pathogen, in particular with the corresponding pathogen. The combination of cells according to item 54, wherein the T-cells express a T-cell receptor capable of binding a self- epitope presented by MHC-I or MHC-II. The combination of cells according to item 67, further comprising a source of the self-epitope which is the target of the T cell’s T-cell receptor. The combination of cells according to item 68, wherein the self-epitope is selected from selfantigens involved in autoimmune diseases. The combination of cells according to item 69, wherein the autoimmune disease is type I diabetes and wherein the self-antigen is selected from Insulin, GAD2, PTPRN and SLC30A8. The combination of cells according to item 69, wherein the autoimmune disease is rheumatoid arthritis and wherein the self-antigen is selected from citrullinated proteins, Type II collagen and Glucose-6-phosphate isomerase. The combination of cells according to item 69, wherein the autoimmune disease is multiple sclerosis and wherein the self-antigen is selected from myelin basic protein, myelin oligodendrocyte glycoprotein and proteolipid protein. Use of the combination of cells according to any one of items 68 to 72 in a method of screening for a drug for the treatment of an autoimmune disease. The use according to item 1, wherein the T-iPSC is derived from a CD8+ T-cell. The use according to item 74, wherein the T-iPSC is derived from an antigen-specific CD8+ T-cell clone. The use according to item 1, wherein the T-iPSC is derived from a CD4+ T-cell. The use according to item 76, wherein the T-iPSC is derived from an antigen-specific CD4+ T-cell clone. The kit of parts according to item 15, wherein the myeloid cells and the T-cells are derived from the same CD4+ -derived T-iPSC and wherein the T-cells are CD4+ T-cells. The kit of parts according to item 78, wherein the T-cells are monocloncal CD4+ T-cells. The kit of parts according to any one of items 78 to 79, wherein the a) myeloid cell is a macrophage. The kit of parts according to item 80, wherein the b) CD4+ T cells are capable of binding a human MHC-II tetramer loaded with a peptide. The kit of parts according to item 81, wherein the peptide is derived from a human pathogen. The kit of parts according to item 82, wherein the human pathogen is an intracellular pathogen of myeloid cells. The kit of parts according to any one of items 82 to 83, wherein the human pathogen is selected from the group consisting of Mycobacterium tuberculosis, Plasmodium spp., Leishmania spp., Toxoplasma gondii, Cryptococcus neoformans, Histoplasma capsulatum, Trypanosoma cruzei, Francisella tularensis and Brucella spp. The kit of parts according to item 81, wherein the peptide is derived from a human protein. The kit of parts according to item 82, wherein the human protein is encoded by a gene selected from the group consisting of INS, GAD2, MBP, COL2A1 and TG. The kit of parts according to item 15, wherein the myeloid cells and the T-cells are derived from the same CD8+ -derived T-iPSC and wherein the T-cells are CD8+ T-cells. The kit of parts according to item 87, wherein the T-cells are monoclonal CD8+ T-cells. The kit of parts according to any one of items 87 to 88, wherein the a) myeloid cell is a macrophage. The kit of parts according to item 89, wherein the b) CD8+ T cells are capable of binding a human MHC-I tetramer loaded with a peptide. The kit of parts according to item 90, wherein the peptide is wherein the peptide is derived from a human protein The kit of parts according to any one of items 90 to 91, wherein the human protein is an oncoprotein. The kit of parts according to any one of items 90 to 92, wherein the peptide is a tumor-associated antigen or a tumor-specific antigen. . The kit of parts according to any one of items 90 to 93, wherein the peptide is selected from the group consisting of NY-ESO-1, MAGE- A3, MART-1, gplOO, WT1, BIRC5, PRAME, KRAS G12D and HPV E6 / E7. 95. A cell culture comprising myeloid cells and T-cells, wherein the myeloid cells and the T-cells are derived from the same CD4+ -derived T-iPSC and wherein the T-cells are CD4+ T-cells.

[0110] 96. The cell culture according to item 95, wherein the T-cells are monocloncal CD4+ T-cells.

[0111] 97. The cell culture according to any one of items 95 to 96, wherein the a) myeloid cell is a macrophage.

[0112] 98. The cell culture according to item 97, wherein the b) CD4+ T cells are capable of binding a human MHC-II tetramer loaded with a peptide.

[0113] 99. The cell culture according to item 98, wherein the peptide is derived from a human pathogen.

[0114] 100. The cell culture according to item 99, wherein the human pathogen is an intracellular pathogen of myeloid cells.

[0115] 101. The cell culture according to any one of items 99 to 100, wherein the human pathogen is selected from the group consisting of Mycobacterium tuberculosis, Plasmodium spp., Leishmania spp., Toxoplasma gondii, Cryptococcus neoformans, Histoplasma capsulatum, Trypanosoma cruzei, Francisella tularensis and Brucella spp.

[0116] 102. The cell culture according to item 98, wherein the peptide is derived from a human protein.

[0117] 103. The cell culture according to item 102, wherein the human protein is encoded by a gene selected from the group consisting of INS, GAD2, MBP, COL2A1 and TG.

[0118] 104. The cell culture comprising myeloid cells and T-cells, wherein the myeloid cells and the T- cells are derived from the same CD8+ -derived T-iPSC and wherein the T-cells are CD8+ T-cells.

[0119] 105. The cell culture according to item 104, wherein the T-cells are monoclonal CD8+ T-cells.

[0120] 106. The cell culture according to any one of items 104 to 105, wherein the a) myeloid cell is a macrophage.

[0121] 107. The cell culture according to item 106, wherein the b) CD8+ T cells are capable of binding a human MHC-I tetramer loaded with a peptide.

[0122] 108. The cell culture according to item 107, wherein the peptide is derived from a human protein

[0123] 109. The cell culture according to item 108, wherein the human protein is an oncoprotein.

[0124] 110. The cell culture according to any one of items 107 to 109, wherein the peptide is a tumor- associated antigen or a tumor-specific antigen.

[0125] 111. The cell culture according to any one of items 107 to 110, wherein the peptide is selected from the group consisting of NY-ESO-1, MAGE-A3, MART-1, gplOO, WT1, BIRC5, PRAME, KRAS G12D and HPV E6 / E7.

[0126] 112. The cell culture according to any one of items 99 to 101 for use in a method of screening for a drug for the treatment of an infection with a pathogen.

[0127] 113. The cell culture according to any one of items 102 to 103 for use in a method of screening for a drug for the treatment of an autoimmune disease.

[0128] 114. The cell culture according to any one of items 109 to 111 for use in a method of screening for a drug for the treatment of cancer.

[0129] The practice of the present invention employs, unless otherwise indicated, conventional techniques of molecular biology (including recombinant techniques), microbiology, cell biology, biochemistry and immunology, which are well within the purview of the skilled artisan. Such techniques are explained fully in the literature, such as, "Molecular Cloning: A Laboratory Manual", fourth edition (Sambrook, 2012); "Handbook of Experimental Immunology" (Weir, 1997); "Short Protocols in Molecular Biology" (Ausubel, 2002); "Polymerase Chain Reaction: Principles, Applications and Troubleshooting", (Babar, 2011); "Current Protocols in Immunology" (Coligan, 2002). These techniques may be considered in making and practicing the invention.

[0130] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications without departing from the spirit or essential characteristics thereof. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations or any two or more of said steps or features. The present disclosure is therefore to be considered as in all aspects illustrated and not restrictive, the scope of the invention being indicated by the appended Claims, and all changes which come within the meaning and range of equivalency are intended to be embraced therein.

[0131] Various references are cited throughout this specification, each of which is incorporated herein by reference in its entirety.

Claims

CLAIMS1. A combination of a) myeloid cells and b) T cells, wherein the myeloid cells and the T cells are isogenic human cells, wherein the myeloid cells are not dendritic cells, and wherein the T cells are derived from an induced pluripotent stem cell, in particular from a T-cell-derived iPSC, and express a functional T cell receptor.

2. The combination of myeloid cells and T cells according to claim 1, wherein the combination of isogenic myeloid cells and T cells is in the form of a cell co-culture.

3. The combination of myeloid cells and T cells according to any one of claims 1 or 2, wherein the myeloid cells are derived from a T-iPSC.

4. The combination of myeloid cells and T cells according to any one of claims 1 to 3, wherein the myeloid cell is a macrophage.

5. The combination of myeloid cells and T cells according to any one of claims 1 to 4, wherein the T cell is a CD4+ T cell or a CD8+ T cell.

6. The combination of myeloid cells and T cells according to claim 5 in combination with claim 4, wherein the combination of isogenic macrophages and T cells is a co-culture and wherein the co culture further comprises non-immune cells, for example cancer cells.

7. The combination of myeloid cells and T cells according to claim 5, wherein the combination of isogenic myeloid cells and T cells is a co-culture and wherein the co culture further comprises a pathogen.

8. The combination of myeloid cells and T cells according to claim 7, wherein the T cells and / or the myeloid cells are infected by the pathogen.

9. The combination of myeloid cells and T cells according to claim 8, wherein the myeloid cell is a macrophage.

10. The combination of myeloid cells and T cells according to claim 9, wherein macrophages are infected by the pathogen.

11. The combination of myeloid cells and T cells according to claim 10, wherein the pathogen is a bacterial pathogen, a viral pathogen, a fungal pathogen or a protozoan pathogen.

12. Use of the combination of a) myeloid cells and b) T cells according to any one of claims 1 to 11 in a method of screening for drugs which can modify a myeloid cell / T cell interaction.

13. A method of screening for a drug which can modify the interaction between a myeloid cell and a T- cell, comprising the steps of:(1) contacting a test substance with a combination of myeloid cells and T cells according to any one of claims 1 to 11 ;(2) detecting an effect of the test substance on the T-cells, myeloid cells, the non-immune cells, if present and / or the pathogen, if present; and(3) selecting the test substance as a drug candidate for modifying myeloid cell / T cell interaction when an effect observed in step (2) is different from the effect observed in the same combination of myeloid cell and T cells and non-immune cells, if present, and pathogen, if present, but not contacted with the test substance.

14. The method of screening for a drug according to claim 13, wherein in step 1) non-immune cells are present, in particular cancer cells, and wherein step 2) comprises measuring T cell activation and / or measuring T cell proliferation and / or measuring non-immune cell proliferation of survival.

15. The method of screening for a drug according to claim 13, wherein in step 1) a pathogen is present, in particular wherein a pathogen is present within the myeloid cell, and wherein step 2) comprises measuring T cell activation and / or measuring T cell proliferation and / or measuring pathogen proliferation and / or survival.