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Nagaoka-Kamata, Y.

Publications and source records attributed to Nagaoka-Kamata, Y..

5 recordsLinked to original sources

IL-23 Licenses Pathogenic Th17 Transdifferentiation via STAT4-dependent Upregulation of IL-12Rβ2

Th17 cells exhibit substantial developmental plasticity, transdifferentiating into pathogenic, interferon-{gamma} (IFN-{gamma})-producing Th1-like effectors during chronic autoimmune inflammation. While both IL-23 and IL-12 are implicated in this process, how these structurally related cytokines coordinate to drive transdifferentiation remains unresolved. Here, we show that IL-23 acts as a developmental licensor rather than a terminal trigger, priming Th17 cells for transdifferentiation upon subsequent IL-12 encounter. IL-23 signals through STAT4 to upregulate the IL-12-specific receptor subunit IL-12R{beta}2, lowering the signalling threshold for IL-12. This licensing can be conferred at both early and late stages of Th17 development and produces a temporal logic in which IL-23-mediated STAT4 signaling functionally arms Th17 cells to terminally transdifferentiate in response to IL-12. Using Stat4 conditional knockouts and a structure-based IL-23 mutein that selectively abolishes IL-23-driven STAT4 signaling while preserving STAT3-dependent lineage maintenance, we genetically establish the IL-23-STAT4-IL-12R{beta}2 axis as a discrete licensing module. Furthermore, using the adoptive Th17 transfer colitis model, we show that host-derived IL-23 and IL-12 are required for Th17-driven colitis, and the inflamed colonic environment reconstitutes transdifferentiation capacity in classically "non-pathogenic" Th17 cells. These findings reframe the pathogenic dichotomy of Th17 cells as one of cumulative cytokine exposure rather than fixed cellular fate, and reveal a stepwise architecture of Th17 plasticity in which IL-23 licensing and IL-12 triggering operate as functionally distinct events. Significance StatementTh17 cells protect mucosal barriers but can convert into pathogenic, IFN-{gamma}-producing effectors that drive inflammatory bowel disease (IBD). Although IL-23 is essential for this conversion, the underlying molecular mechanism remains elusive. We show that IL-23 does not directly trigger transdifferentiation but instead licenses Th17 cells for this conversion, during both early and late stages of their development. By signaling through STAT4, IL-23 upregulates the IL-12-specific receptor subunit IL-12R{beta}2 on Th17 cells, rendering them responsive to subsequent IL-12 exposure. Our findings reframe the classical "pathogenic" versus "non-pathogenic" Th17 distinction and provide a mechanistic basis for the clinical efficacy of IL-23-targeted therapies in IBD.

immunology↗

Barrier Immune Memory is Promoted by Intestinal Epithelial Cell Presentation of Injected Bacterial Antigens

The contributions of antigen compartmentalization to recognition differences between CD4 and CD8 T cells have long been appreciated, but little is known of how subcellular localization of different antigens expressed by a single pathogen impacts T cell immunity. By tracking a clonal CD4 T cell response to its cognate epitope shuttled between different virulence proteins of the enteropathogenic bacterium, Citrobacter rodentium (Cr), we find a remarkable bias in the magnitude and quality of the response contingent on whether antigen remains bacterially associated or is introduced into intestinal epithelial cells colonized by the bacterium. Only proteins injected into the cytosol of colonocytes via the type 3 secretion system (T3SS) of Cr were found to recruit robust antigen-specific T cell responses to the infected mucosa and give rise to CD4 resident memory T (Trm) cells that populate the mucosal epithelium--and this required direct presentation of these antigens by infected epithelial cells. Single-cell transcriptomic analyses revealed that sustained, bidirectional epithelial-T cell communication was required both to elicit epithelial barrier-protective T cell help and to promote transcriptional networks that program a tissue-residency rather than central memory fate. These results establish a central role for antigen presentation by non-professional APCs in controlling memory fate decisions by CD4 T cells, with important implications for development of successful mucosal vaccines.

immunology↗

JNK knockdown enhances CAR-T cell cytotoxicity

BackgroundBoosting the performance of chimeric antigen receptor T (CAR-T) cell therapy in solid tumors may provide a substantial advantage for cancer patients. Recognizing the vital role of the nuclear factor of activated T cells (NFAT) in T cell function, we hypothesized that the strategic regulation of NFAT activity by targeting c-Jun N-terminal Kinases (JNK) can bolster the tumor-eradicating potential of CAR-T cells. MethodsWe developed a lentivirally encoded short-hairpin RNA (shRNA) for stable knockdown of JNK in CAR-T cells. CAR-T cells targeting human epidermal growth factor receptor 2 (HER2) were produced from human peripheral blood. Functionality was tested in vitro and in two xenograft models of human ovarian cancer. ResultsJNK knockdown in CAR-T cells suppressed antigen-induced stimulation and helper T cell cytokine production, while enhancing anti-tumor cytotoxicity in vitro and in ovarian cancer xenograft experiments. Mechanistically, JNK knockdown led to elevated levels of granzyme B expression which could be recapitulated through overexpression of NFATc1, suggesting an NFATc1 dependent mechanism of action. ConclusionsJNK signaling is a significant regulator of CAR-T cell cytotoxicity, offering a potential strategy to directly enhance CAR-T effectiveness in human cancer therapies.

immunology↗

Exploring the immune environment of glioblastoma through single-cell RNA sequencing in humanized mouse models

BackgroundGlioblastoma (GBM) is the deadliest primary brain tumor in adults, where current therapies fail to meaningfully extend survival. Available animal GBM tumor models, especially therapy-resistant and recurrent ones with unique immunological aspects, are restricted, impeding innovative treatment research. To confront this critical obstacle we established a unique GBM mouse model that utilizes patient-derived xenografts (PDXs) within humanized mice. MethodsWe selected two immune-deficient mouse models to facilitate the reconstitution of myeloid lineage cells. After undergoing myeloablation, mice received CD34+ hematopoietic stem progenitor cells derived from human umbilical cord blood for humanization. Upon confirming the reconstitution of human blood cells, mice were xenografted with PDXs resistant to radiation. Tumor profiles and immune cell infiltration were analyzed via flow cytometry, immunohistochemistry, and single-cell RNA sequencing (scRNA-seq). The findings were evaluated against scRNA-seq data from recurrent human GBM. ResultsA diverse range of human immune cells, including T, NK, and myeloid lineage cells, infiltrated PDX tumors in humanized mice. Notably, gene expression profiles in these immune cells resembled that of recurrent human GBM. Unlike conventional xenograft models, this model highlighted enhanced tumor diversity, particularly a high fraction of neural progenitor-like cells. ConclusionsOur humanized GBM mouse model displayed an immune cell signature similar to recurrent GBM. This model is a valuable resource for analyzing the tumor immune landscape and assessing new therapies, particularly immunotherapies. By enabling effective evaluation of novel treatments, our model has the potential to significantly advance GBM research. Key PointsO_LIA wide array of human immune cells infiltrates GBM-PDX tumors in humanized mice. C_LIO_LIThe tumor heterogeneity of GBM-PDX is more evident in humanized mouse xenografts. C_LI Importance of the studyCurrent GBM treatment development is primarily constrained by the absence of appropriate animal models that can enhance our understanding of human GBM biology and its immune dynamics. We created a specialized GBM mouse model using humanized mice with patient-derived xenografts resistant to radiation. Detailed immune cell analysis showed various human blood cells in the GBM-PDX derived from humanized mice. Single-cell RNA sequencing uncovered crucial T-cell subgroups, notably regulatory and exhausted T cells, which matched those observed in recurrent GBM patient tumors. Moreover, the model outperformed standard xenograft approaches in tumor heterogeneity, resembling the intricate diversity observed in recurrent GBM samples. Our humanized GBM mouse model provides a powerful platform to study the interactions between human tumors and immune cells. This tool will facilitate the discovery of immunosuppressive mechanisms and accelerate the assessment of immunotherapies applicable to various brain tumors.

immunology↗

A novel subset of colonocytes targeted by Citrobacter rodentium elicits epithelial MHCII-restricted help from CD4 T cells

Interleukin (IL)-22 plays a non-redundant role in immune defense of the intestinal barrier1-3. We recently discovered an indispensable role for T cells, but not ILCs, in sustaining IL-22 signaling required for protection of colonic crypts against invasion during infection by the enteropathogen, Citrobacter rodentium (C.r)4. However, identification of the intestinal epithelial cell (IEC) subsets targeted by T cell-derived IL-22 and how T cell-derived IL-22 sustains activation in IECs are undefined. Here, we identify a novel subset of absorptive IECs in the mid-distal colon that are differentially targeted by C.r and are differentially responsive to IL-22 signaling. Importantly, MHCII expression by these colonocytes was required to elicit T cell-activated IL-22 signaling necessary to resist C.r invasion. Our findings explain the basis for the regionalization of the host response to C.r and demonstrate that epithelial cells must elicit MHCII-dependent help from IL-22-producing T cells to orchestrate immune protection in the intestines.

immunology↗