Browsing by Author "Ince, M. Nedim"

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    STAT6 and Furin Are Successive Triggers for the Production of TGF-β by T Cells
    (The American Association of Immunologists, Inc., 2018-11) Li, Yue; Liu, Weiren; Guan, Xiaqun; Truscott, Jamie; Creemers, John W.; Chen, Hung-Lin; Pesu, Marko; El Abiad, Rami G.; Karacay, Bahri; Urban, Joseph F.; Elliott, David E.; Kaplan, Mark H.; Blazar, Bruce R.; Ince, M. Nedim; Pediatrics, School of Medicine
    Production of TGF-β by T cells is key to various aspects of immune homeostasis, with defects in this process causing or aggravating immune-mediated disorders. The molecular mechanisms that lead to TGF-β generation by T cells remain largely unknown. To address this issue, we take advantage of the fact that intestinal helminths stimulate Th2 cells besides triggering TGF-β generation by T lymphocytes and regulate immune-mediated disorders. We show that the Th2 cell-inducing transcription factor STAT6 is necessary and sufficient for the expression of TGF-β propeptide in T cells. STAT6 is also necessary for several helminth-triggered events in mice, such as TGF-β-dependent suppression of alloreactive inflammation in graft-versus-host disease. Besides STAT6, helminth-induced secretion of active TGF-β requires cleavage of propeptide by the endopeptidase furin. Thus, for the immune regulatory pathway necessary for TGF-β production by T cells, our results support a two-step model, composed of STAT6 and furin.
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    The Impact of Cell-Intrinsic STAT6 Protein on Donor T Cell-Mediated Graft-Versus-Tumor Effect
    (MDPI, 2024-12-31) Guan, Xiaoqun; Fury, Hope; Issuree, Priya D.; Atagozli, Tyler; McManimon, Emory E.; Shao, Peng; Li, Yue; Chimenti, Michael; Butler, Noah S.; Kaplan, Mark H.; Elliott, David E.; Blazar, Bruce R.; Ince, M. Nedim; Pediatrics, School of Medicine
    Bone marrow transplantation (BMT) is mainly performed to restore an anti-tumor immune response, called the graft-versus-tumor (GVT) effect, against leukemia, myeloma and lymphoma. This GVT reactivity is driven by donor T cells, and it can also cause lethal graft-versus-host disease (GVHD). We previously demonstrated that the colonization of mice with helminths preserves the GVT response while suppressing GVHD. As the T helper-2 (Th2) pathway is critical to helminthic immune regulation, we asked whether the genetic induction of Th2 signaling in donor T cells can restore helminthic immune regulation after BMT. Our studies utilized transgenic donor T lymphocytes that overexpress a constitutively active form of the Th2-associated transcription factor STAT6. Constitutively active STAT6 sustained the GVT response without causing severe acute GVHD, where transgenic T cells generated robust quantities of cytotoxic proteins important in GVT response, such as granzymes A and B, interferon-γ and Fas ligand, in addition to generating high quantities of Th2/regulatory cytokines. Bioinformatic analysis based on chromosome immune precipitation experiments indicated that STAT6 stimulates the expression of granzymes directly. Thus, in preserving the GVT response without causing GVHD mortality, our results indicate the therapeutic potential of restoring helminthic immune modulation by targeting STAT6 and STAT6-dependent T cell maturation.