Control of PI(3) Kinase in Treg Cells Maintains Homeostasis and Lineage Stability Researchers found that control of phosphatidylinositol-3-OH kinase (PI(3)K) in Foxp3+ regulatory T cells (Treg cells) was essential for lineage homeostasis and stability. Mice lacking Pten in Treg cells developed an autoimmune-lymphoproliferative disease characterized by excessive T helper type 1 responses and B cell activation. [Nat Immunol] Abstract Treg Cells Require the Phosphatase PTEN to Restrain TH1 and TFH Cell Responses Investigators found that the phosphatase PTEN links regulatory T cells (Treg cells) cell stability to repression of type 1 helper T cell (TH1 cell) and follicular helper T cell (TFH cell) responses. Depletion of PTEN in Treg cells resulted in excessive TFH cell and germinal center responses and spontaneous inflammatory disease. [Nat Immunol] Abstract Sterol Metabolism Controls TH17 Differentiation by Generating Endogenous ​RORγ Agonists Scientists report that during TH17 differentiation, ​cholesterol biosynthesis and uptake programs are induced, whereas their metabolism and efflux programs are suppressed. These changes result in the accumulation of the cholesterol precursor, ​desmosterol, which functions as a potent endogenous ​retinoic acid receptor-related orphan receptor γ (​RORγt) agonist. [Nat Chem Biol] Abstract | Press Release Proinflammatory TLR Signaling Is Regulated by a ​TRAF2-Dependent Proteolysis Mechanism in Macrophages Researchers show that myeloid cell-specific ablation of ​TRAF2 greatly promotes toll-like receptor (TLR)-stimulated proinflammatory cytokine expression in macrophages and exacerbates colitis in an animal model of inflammatory bowel disease. [Nat Commun] Abstract Intracellular Osteopontin Regulates Homeostasis and Function of Natural Killer Cells Scientists report that deficient expression of intracellular osteopontin by natural killer (NK) cells results in defective responses to IL-15 associated with a substantial increase in the NK cell contraction phase of homeostatic expansion, defective expression of the Eomes transcription factor, and diminished responses to metastatic tumors. [Proc Natl Acad Sci USA] Abstract miR-155 Augments CD8+ T-Cell Antitumor Activity in Lymphoreplete Hosts by Enhancing Responsiveness to Homeostatic γc Cytokines Researchers found that microRNA-155 (miR-155) enabled tumor-specific CD8+ T cells to mediate profound antitumor responses in lymphoreplete hosts that were not potentiated by immune-ablation. miR-155 enhanced T-cell responsiveness to limited amounts of homeostatic γc cytokines, resulting in delayed cellular contraction and sustained cytokine production. [Proc Natl Acad Sci USA] Abstract Syk Is Indispensable for CpG-Induced Activation and Differentiation of Human B Cells Investigators describe a so far unidentified spleen tyrosine kinase (Syk)-dependent pathway which is indispensable for CpG-induced human B cell activation. They show that triggering of B cells by CpG results in Syk and src kinase phosphorylation, proliferation, as well as cytokine and antibody production independent of the BCR. [Cell Mol Life Sci] Abstract Effector T Cells Boost Regulatory T Cell Expansion by IL-2, TNF, OX40, and Plasmacytoid Dendritic Cells Depending on the Immune Context Activated effector CD4+ T cells can boost regulatory T (Treg) cell expansion through TNF or IL-2. Researchers further characterized this effector T cell-dependent Treg cell boost in vivo in mice. [J Immunol] Abstract Subscribe to our sister publications: Human Immunology News and Immunology of Infectious Disease News! |