VAMP7 Controls T Cell Activation by Regulating the Recruitment and Phosphorylation of Vesicular Lat at TCR-Activation Sites Investigators found, by silencing approaches and genetically modified mice, that the vesicular SNARE VAMP7 was required for the recruitment of Lat-containing vesicles to T cell antigen receptor (TCR)-activation sites. [Nat Immunol] Abstract Real-Time In Vivo Analysis of T Cell Activation in the Central Nervous System Using a Genetically Encoded Calcium Indicator To study T cell activation in vivo in real time, researchers introduced a newly developed fluorescence resonance energy transfer-based, genetically encoded calcium indicator into autoantigen-specific and non-autoantigen-specific CD4+ T cells. [Nat Med] Abstract EZH2 Is Required for Germinal Center Formation and Somatic EZH2 Mutations Promote Lymphoid Transformation Investigators found that EZH2 deletion or pharmacologic inhibition suppresses germinal cell (GC) formation and functions. EZH2 represses proliferation checkpoint genes and helps establish bivalent chromatin domains at key regulatory loci to transiently suppress GC B cell differentiation. [Cancer Cell] Abstract | Press Release Generation of Functional Thymic Epithelium from Human Embryonic Stem Cells that Supports Host T Cell Development Researchers describe a robust in vitro method to direct differentiation of human embryonic stem cells (hESCs) into thymic epithelial progenitors (TEPs) by precise regulation of TGFβ, BMP4, RA, Wnt, Shh, and FGF signaling. The hESC-derived TEPs further mature into functional thymic epithelial cells that support T cell development upon transplantation into thymus-deficient mice. [Cell Stem Cell] Abstract | Graphical Abstract | Press Release An Inherently Bifunctional Subset of Foxp3+ T Helper Cells Is Controlled by the Transcription Factor Eos At sites of inflammation, certain regulatory T cells can undergo rapid reprogramming into helper-like cells without loss of the transcription factor Foxp3. Scientists showed that reprogramming is controlled by downregulation of the transcription factor Eos, an obligate corepressor for Foxp3. [Immunity] Abstract | Graphical Abstract Cognate Antigen Directs CD8+ T Cell Migration to Vascularized Transplants The prevailing view is that key steps involved in T cell migration – integrin-mediated firm adhesion followed by transendothelial migration – are dependent on the activation of Gαi-coupled chemokine receptors on T cells. In contrast to this view, researchers demonstrated in vivo that cognate antigen was necessary for the firm adhesion and transendothelial migration of CD8+ effector T cells specific to graft antigens and that both steps occurred independent of Gαi signaling. [J Clin Invest] Full Article Primary Tumors Modulate Innate Immune Signaling to Create Pre-Metastatic Vascular Hyperpermeability Foci The authors showed that MD-2, a coreceptor for Toll-like receptor 4 that has a key role in the innate immune response, triggers the formation of regions of hyperpermeability in mice by upregulating C-C chemokine receptor type 2 expression. [Nat Commun] Full Article Identification of CD3+CD4–CD8–T Cells as Potential Regulatory Cells in an Experimental Murine Model of Graft vs. Host Skin Disease (GvHD) The authors developed K14-mOVA transgenic (Tg) mice that express membrane-associated ovalbumin (mOVA) under the control of a K14 promoter as well as double Tg mice by crossing them with OT-I mice that have a T cell receptor recognizing OVA peptide. When injected with CD8+ OT-I cells, K14-mOVATg mice develop GvHD, whereas double Tg mice are protected. [J Invest Dermatol] Abstract Markers of Nonselective and Specific NK Cell Activation NK cells undergo two distinct phases of activation during murine CMV infection: a nonselective phase mediated by proinflammatory cytokines and a specific phase driven by signaling through Ly49H, an NK cell activation receptor that recognizes infected cells. Investigators sought to delineate cell surface markers that could distinguish NK cells that had been activated nonselectively from those that had been specifically activated through NK cell receptors. [J Immunol] Abstract Don’t forget to subscribe to our sister publications: Human Immunology News and Immunology of Infectious Disease News! |