Dynamic Cardiolipin Synthesis Is Required for CD8+ T Cell Immunity.
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ABSTRACT:
SUBMITTER: Corrado M
PROVIDER: S-EPMC7721104 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Whether inflation of CD8+ memory T (mT) cells, which is often derived from repeated prime-boost vaccinations or chronic viral infections in the elderly, would affect late CD8+ T-cell immunity is a long-standing paradox. We have previously established an animal model with mT-cell inflation by transferring ConA-stimulated monoclonal CD8+ T cells derived from Ova-specific T-cell-receptor transgenic OTI mice into irradiation-induced lymphopenic B6 mice. In this study, we also established another two animal models with mT-cell inflation by transferring, 1) ConA-stimulated monoclonal CD8+ T cells derived from lymphocytic choriomeningitis virus glycoprotein-specific T-cell-receptor transgenic P14 mice, and 2) ConA-stimulated polyclonal CD8+ T cells derived from B6.1 mice into B6 mice with irradiation-induced lymphopenia. We vaccinated these mice with recombinant Ova-expressing Listeria monocytogenes and Ova-pulsed dendritic cells, which stimulated CD4+ T cell-independent and CD4+ T-cell-dependent CD8+ T-cell responses, respectively, and assessed Ova-specific CD8+ T-cell responses by flow cytometry. We found that Ova-specific CD8+ T-cell responses derived from the latter but not the former vaccination were significantly reduced in mice with CD8+ mT-cell inflation compared to wild-type B6 mice. We determined that naïve CD8+ T cells purified from splenocytes of mice with mT-cell inflation had defects in cell proliferation upon stimulation in vitro and in vivo and upregulated T-cell anergy-associated Itch and GRAIL molecules. Taken together, our data reveal that CD8+ mT-cell inflation renders compromised CD4+ T-cell-dependent CD8+ T-cell immunity via naïve T-cell anergy, and thus show promise for the design of efficient vaccines for elderly patients with CD8+ mT-cell inflation.
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Project description:CD160 promotes NK cell cytotoxicity and IFN-γ production, but the function of CD160 on CD8+ T cells remains unclear with some studies supporting a coinhibitory role and others a costimulatory role. In this study, we demonstrate that CD160 has a costimulatory role in promoting CD8+ T cell effector functions needed for optimal clearance of oral Listeria monocytogenes infection. CD160-/- mice did not clear oral L. monocytogenes as efficiently as wild type (WT) littermates. WT RAG-/- and CD160-/- RAG-/- mice similarly cleared L. monocytogenes, indicating that CD160 on NK cells does not contribute to impaired L. monocytogenes clearance. Defective L. monocytogenes clearance is due to compromised intraepithelial lymphocytes and CD8+ T cell functions. There was a reduction in the frequencies of granzyme B-expressing intraepithelial lymphocytes in L. monocytogenes-infected CD160-/- mice as compared with WT littermate controls. Similarly, the frequencies of granzyme B-expressing splenic CD8+ T cells and IFN-γ and TNF-α double-producer CD8+ T cells were significantly reduced in L. monocytogenes-infected CD160-/- mice compared with WT littermates. Adoptive transfer studies showed that RAG-/- recipients receiving CD160-/- CD8+ T cells had a higher mortality, exhibited more weight loss, and had a higher bacterial burden compared with RAG-/- recipients receiving WT CD8+ T cells. These findings demonstrate that CD160 provides costimulatory signals to CD8+ T cells needed for optimal CD8+ T cell responses and protective immunity during an acute mucosal bacterial infection.
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Project description:BackgroundIncreasing infiltration of CD8+ T cells within tumor tissue predicts a better prognosis and is essential for response to checkpoint blocking therapy. Furthermore, current clinical protocols use unfractioned T cell populations as the starting point for transduction of chimeric antigen receptors (CARs)-modified T cells, but the optimal T cell subtype of CAR-modified T cells remains unclear. Thus, accurately identifying a group of cytotoxic T lymphocytes with high antitumor efficacy is imperative. Inspired by the theory of yin and yang, we explored a subset of CD8+ T cell in cancer with the same phenotypic characteristics as highly activated inflammatory T cells in autoimmune diseases.MethodsCombination of single-cell RNA sequencing, general transcriptome sequencing data and multiparametric cytometric techniques allowed us to map CXCR6 expression on specific cell type and tissue. We applied Cxcr6-/- mice, immune checkpoint therapies and bone marrow chimeras to identify the function of CXCR6+CD8+ T cells. Transgenic Cxcr6-/- OT-I mice were employed to explore the functional role of CXCR6 in antigen-specific antitumor response.ResultsWe identified that CXCR6 was exclusively expressed on intratumoral CD8+ T cell. CXCR6+CD8+ T cells were more immunocompetent, and chimeras with specific deficiency on CD8+ T cells showed weaker antitumor activity. In addition, Cxcr6-/- mice could not respond to anti-PD-1 treatment effectively. High tumor expression of CXCR6 was not mainly caused by ligand-receptor chemotaxis of CXCL16/CXCR6 but induced by tumor tissue self. Induced CXCR6+CD8+ T cells possessed tumor antigen specificity and could enhance the effect of anti-PD-1 blockade to retard tumor progression.ConclusionsThis study may contribute to the rational design of combined immunotherapy. Alternatively, CXCR6 may be used as a biomarker for effective CD8+ T cell state before adoptive cell therapy, providing a basis for tumor immunotherapy.
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