CCR6 is expressed on an IL-10-producing, autoreactive memory T cell population with context-dependent regulatory function

Interleukin (IL)-10 produced by regulatory T cell subsets is important for the prevention of autoimmunity and immunopathology, but little is known about the phenotype and function of IL-10–producing memory T cells. Human CD4+CCR6+ memory T cells contained comparable numbers of IL-17– and IL-10–producing cells, and CCR6 was induced under both Th17-promoting conditions and upon tolerogenic T cell priming with transforming growth factor (TGF)–. In normal human spleens, the majority of CCR6+ memory T cells were in the close vicinity of CCR6+ myeloid dendritic cells (mDCs), and strikingly, some of them were secreting IL-10 in situ. Furthermore, CCR6+ memory T cells produced suppressive IL-10 but not IL-2 upon stimulation with autologous immature mDCs ex vivo, and secreted IL-10 efficiently in response to suboptimal T cell receptor (TCR) stimulation with anti-CD3 antibodies. However, optimal TCR stimulation of CCR6+ T cells induced expression of IL-2, interferon-, CCL20, and CD40L, and autoreactive CCR6+ T cell lines responded to various recall antigens. Notably, we isolated autoreactive CCR6+ T cell clones with context-dependent behavior that produced IL-10 with autologous mDCs alone, but that secreted IL-2 and proliferated upon stimulation with tetanus toxoid. We propose the novel concept that a population of memory T cells, which is fully equipped to participate in secondary immune responses upon recognition of a relevant recall antigen, contributes to the maintenance of tolerance under steady-state conditions

CCR6 is expressed on an IL-10–producing, autoreactive memory T cell population with context-dependent regulatory function

Interleukin (IL)-10 produced by regulatory T cell subsets is important for the prevention of autoimmunity and immunopathology, but little is known about the phenotype and function of IL-10–producing memory T cells. Human CD4+CCR6+ memory T cells contained comparable numbers of IL-17– and IL-10–producing cells, and CCR6 was induced under both Th17-promoting conditions and upon tolerogenic T cell priming with transforming growth factor (TGF)–β. In normal human spleens, the majority of CCR6+ memory T cells were in the close vicinity of CCR6+ myeloid dendritic cells (mDCs), and strikingly, some of them were secreting IL-10 in situ. Furthermore, CCR6+ memory T cells produced suppressive IL-10 but not IL-2 upon stimulation with autologous immature mDCs ex vivo, and secreted IL-10 efficiently in response to suboptimal T cell receptor (TCR) stimulation with anti-CD3 antibodies. However, optimal TCR stimulation of CCR6+ T cells induced expression of IL-2, interferon-γ, CCL20, and CD40L, and autoreactive CCR6+ T cell lines responded to various recall antigens. Notably, we isolated autoreactive CCR6+ T cell clones with context-dependent behavior that produced IL-10 with autologous mDCs alone, but that secreted IL-2 and proliferated upon stimulation with tetanus toxoid. We propose the novel concept that a population of memory T cells, which is fully equipped to participate in secondary immune responses upon recognition of a relevant recall antigen, contributes to the maintenance of tolerance under steady-state conditions

An Efficient Strategy to Induce and Maintain In Vitro Human T Cells Specific for Autologous Non-Small Cell Lung Carcinoma

BACKGROUND: The efficient expansion in vitro of cytolytic CD8+ T cells (CTLs) specific for autologous tumors is crucial both for basic and translational aspects of tumor immunology. We investigated strategies to generate CTLs specific for autologous Non-Small Cell Lung Carcinoma (NSCLC), the most frequent tumor in mankind, using circulating lymphocytes. PRINCIPAL FINDINGS: Classic Mixed Lymphocyte Tumor Cultures with NSCLC cells consistently failed to induce tumor-specific CTLs. Cross-presentation in vitro of irradiated NSCLC cells by autologous dendritic cells, by contrast, induced specific CTL lines from which we obtained a high number of tumor-specific T cell clones (TCCs). The TCCs displayed a limited TCR diversity, suggesting an origin from few tumor-specific T cell precursors, while their TCR molecular fingerprints were detected in the patient's tumor infiltrating lymphocytes, implying a role in the spontaneous anti-tumor response. Grafting NSCLC-specific TCR into primary allogeneic T cells by lentiviral vectors expressing human V-mouse C chimeric TCRalpha/beta chains overcame the growth limits of these TCCs. The resulting, rapidly expanding CD4+ and CD8+ T cell lines stably expressed the grafted chimeric TCR and specifically recognized the original NSCLC. CONCLUSIONS: This study defines a strategy to efficiently induce and propagate in vitro T cells specific for NSCLC starting from autologous peripheral blood lymphocytes

Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)

The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer‐reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state‐of‐the‐art handbook for basic and clinical researchers.DFG, 389687267, Kompartimentalisierung, Aufrechterhaltung und Reaktivierung humaner Gedächtnis-T-Lymphozyten aus Knochenmark und peripherem BlutDFG, 80750187, SFB 841: Leberentzündungen: Infektion, Immunregulation und KonsequenzenEC/H2020/800924/EU/International Cancer Research Fellowships - 2/iCARE-2DFG, 252623821, Die Rolle von follikulären T-Helferzellen in T-Helferzell-Differenzierung, Funktion und PlastizitätDFG, 390873048, EXC 2151: ImmunoSensation2 - the immune sensory syste