Robust Anti-Viral Immunity Requires Multiple Distinct T Cell-Dendritic Cell Interactions Scientists addressed the role of dendritic cell (DC) subsets in initial activation of the two T cell types and their co-operation. Surprisingly, initial priming of CD4+ and CD8+ T cells was spatially segregated within the lymph node and occurred on different DCs with temporally distinct patterns of antigen presentation via MHCI versus MHCII molecules. [Cell] Abstract | Graphical Abstract | Press Release TCR Affinity for Thymoproteasome-Dependent Positively Selecting Peptides Conditions Antigen Responsiveness in CD8+ T Cells The authors report that T cell antigen receptor (TCR) responsiveness of mature CD8+ T cells is fine-tuned by their affinity for positively selecting peptides in the thymus and that optimal TCR responsiveness requires positive selection on major histocompatibility complex class I–associated peptides produced by the thymoproteasome, which is specifically expressed in the thymic cortical epithelium. [Nat Immunol] Abstract Role of Tumor Pericytes in the Recruitment of Myeloid-Derived Suppressor Cells Silencing IL-6 expression in tumor cells attenuated the observed differences in myeloid-derived suppressor cells (MDSC) transmigration. Restoring the pericyte coverage in tumors abrogated the increased MDSC trafficking to pericyte-deficient tumors. [J Natl Cancer Inst] Abstract | Press Release Suppression of Th2 and Tfh Immune Reactions by Nr4a Receptors in Mature T Reg Cells Researchers showed that deletion of Nr4a genes specifically in regulatory T (T reg) cells caused fatal systemic immunopathology. Furthermore, Nr4a deficiency abrogated T reg cell suppressive activities and accelerated conversion to cells with Th2 and follicular helper T (Tfh) effector-like characteristics, with heightened expression of Th2 and Tfh cytokine genes. [J Exp Med] Abstract Adaptive Immune Regulation of Mammary Postnatal Organogenesis Investigators showed that adaptive immune responses participate in the normal postnatal development of a non-lymphoid epithelial tissue. They found that antigen-mediated interactions between mammary antigen-presenting cells and interferon-γ-producing CD4+ T helper 1 cells participate in mammary gland postnatal organogenesis as negative regulators, locally orchestrating epithelial rearrangement. [Dev Cell] Abstract | Graphical Abstract | Press Release NLRP3 Deficiency Protects from Type 1 Diabetes through the Regulation of Chemotaxis into the Pancreatic Islets The authors report that nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing protein (NLRP) 3 plays an important role in the development of type 1 diabetes in the nonobese diabetic mouse model. NLRP3 deficiency not only affected T-cell activation and Th1 differentiation, but also modulated pathogenic T-cell migration to the pancreatic islet. [Proc Natl Acad Sci USA] Abstract T Lymphocyte–Specific Activation of Nrf2 Protects from AKI Investigators generated mice with genetically amplified levels of Nrf2 specifically in T cells and examined the effect on antioxidant gene expression, T cell activation, cytokine production, and ischemia reperfusion-induced AKI. [J Am Soc Nephrol] Abstract Foxp3+ T Cells Expressing RORγt Represent a Stable Regulatory T-Cell Effector Lineage with Enhanced Suppressive Capacity during Intestinal Inflammation Scientists report that Foxp3+CD4+ T cells coexpressing retinoic acid-related orphan receptor-γt (RORγt), the master transcription factor for T helper type 17 cells, represent a stable effector regulatory T cell lineage. [Mucosal Immunol] Abstract LXR-Mediated ABCA1 Expression and Function Are Modulated by High Glucose and PRMT2 Using a mouse macrophage cell line and primary bone marrow derived macrophages cultured in normal or diabetes relevant high glucose conditions researchers found that high glucose inhibits the liver X receptor (LXR)-dependent expression of ATP-binding cassette transporter A1 (ABCA1), but not ABCG1. [PLoS One] Full Article Don’t forget to subscribe to Human Immunology News and Immunology of Infectious Disease News! |