Supplementary MaterialsSupplemental. cell expression of restricts autoimmune and virus-specific CD4+ T cell responses by attenuating T cell signaling and metabolic pathways in CD4+ T cells. INTRODUCTION Pattern-recognition receptors (PRRs) are indispensable for innate immune responses. PRRs are receptors or sensors that detect pathogen-associated molecular patterns (PAMPs) from microbes and damage-associated molecular patterns (DAMPs) from cellular sources either directly or indirectly. In most cases, these molecules function to initiate innate immune and inflammatory signaling cascades (Brubaker et al., 2015). The nucleotide-binding domain name and leucine-rich-repeat-containing (NLR) proteins are cytosolic PRRs and are known to sense or bind intracellular PAMPs and DAMPs. You will find VX-702 two groups of NLRs based on their functions: inflammasome-forming NLRs and non-inflammasome-forming NLRs (Allen, 2014; Guo et al., 2015). Some of the best-studied inflammasome-forming NLRs, including NLRP1, NLRP3, and NLRC4, regulate the activation of caspase-1, which is necessary for the processing of important pro-inflammatory cytokines that drive innate immune responses to PAMPs and DAMPs. Upon activation by PAMPs or cellular disturbances, inflammasome NLRs undergo a conformational switch that allows the recruitment and binding of the ASC (apoptotic-speck-containing protein with a CARD) adaptor and procaspase-1 to form a fibril-like macromolecular structure (Lechtenberg et al., 2014; Lu et al., 2014). This prospects to the catalytic cleavage and activation of caspase-1, which drives the subsequent catalytic cleavage and activation of IL-1 and IL-18. Non-inflammasome-forming NLRsfor example, CIITA, NLRC5, NOD1, and NOD2demonstrate enhanced major histocompatibility gene expression and immune signaling. By contrast, an increasingly large group of NLRs negatively regulate innate immunity and inflammatory responses in the myeloid lineage. These include NLRP2 (Bruey et al., 2004), NLRP4 (Lin et al., 2016; Cui et al., 2012), NLRP6 (Anand et al., 2012), NLRP12 (Allen et al., 2012; Zaki et al., 2011), NLRX1 (Allen et al., 2011; Xia et al., 2011), NLRC5 (Cui et al., 2010), and NLRC3 (Schneider et al., 2012; Zhang et VX-702 al., 2014; Karki et al., 2016), although some of these proteins have pleiotropic functions. Murine NLRC3 reduces toll-like-receptor (TLR)-induced nuclear factor kappa B (NF-B) activation through inhibition of the adaptor protein TNF-receptor-associated factor 6 (TRAF6) in peritoneal macrophages (Schneider et al., 2012). NLRC3 also reduces stimulator of interferon genes (STING)-dependent innate immune activation in response to cytosolic DNA and cyclic di-GMP by blocking STING and TANK-binding kinase 1 (TBK1) conversation required for type 1 interferon (IFN) production (Zhang et al., 2014). NLRC3 additionally plays a role in non-immune cells, where its association with VX-702 PI3K blocks activation of the PI3K-dependent Akt kinase and inhibits mTOR pathways in colon epithelial cells (Karki Rabbit polyclonal to ZNF564 et al., 2016). Although its function has been analyzed in myeloid and epithelial cells, expression in these cells is extremely low. Paradoxically, both mouse and human show the highest expression in T cells and secondary lymphoid organs (Conti et al., 2005); however, the biologic role of NLRC3 in main T cells remains to be elucidated. Although PRRs in general have been extensively analyzed in the innate immune system, there are few reports addressing their roles in adaptive immune cells. is unique among NLRs because of its high expression in lymphocytes. Herein, we used Is Down-regulated Upon T Cell Activation and Suppresses CD4+ T Cell Activation VX-702 To explore the role of in T cell function, we analyzed expression in splenic CD4+ T cells and CD8+ T cells from wild-type (WT) mice after stimulation with anti-CD3 and anti-CD28 monoclonal antibodies. expression in CD4+ T cells but not CD8+ T cells was decreased after stimulation (Figure 1A). CD4+ T cells differentiated under Th0, Th1 (IL-12), and Th17 (IL-6 and TGF-) cell conditions also showed decreased expression 24 VX-702 and 48 hr after anti-CD3 and anti-CD28 stimulation.