The Transcription Factor T-bet Is Essential for the Development of NKp46+ Innate Lymphocytes via the Notch Pathway The authors report that the transcription factor T-bet (encoded by Tbx21) is essential for the development of NKp46+ innate lymphoid cells (ILCs) but not of lymphoid tissue-inducer cells or nuocytes. Deficiency in interleukin 22-producing NKp46+ ILCs resulted in greater susceptibility of Tbx21−/− mice to intestinal infection. [Nat Immunol] Abstract | Press Release Inadequate T Follicular Cell Help Impairs B Cell Immunity during HIV Infection Researchers report that even though there is an expansion of follicular helper T (TFH) cells in HIV-infected individuals, the cells are unable to provide adequate B cell help. They found a higher frequency of programmed cell death ligand 1 (PD-L1)+ germinal center B cells from lymph nodes of HIV-infected individuals suggesting a potential role for PD-1–PD-L1 interaction in regulating TFH cell function. [Nat Med] Abstract Persistent Antigen at Vaccination Sites Induces Tumor-Specific CD8+ T Cell Sequestration, Dysfunction and Deletion To understand why cancer vaccine-induced T cells often do not eradicate tumors, investigators studied immune responses in mice vaccinated with gp100 melanoma peptide in incomplete Freund’s adjuvant, which is commonly used in clinical cancer vaccine trials. [Nat Med] Abstract | Press Release | Video Signals via the Adaptor MyD88 in B Cells and Dendritic Cells Make Distinct and Synergistic Contributions to Immune Activation and Tissue Damage in Lupus Investigators demonstrated that formation of anti-nuclear antibodies in MRL.Faslpr mice entirely depends on the Toll-like receptor (TLR) signaling adaptor MyD88 in B cells. Further, MyD88 deficiency in B cells ameliorated nephritis, including antibody-independent interstitial T cell infiltrates, suggesting that nucleic acid-specific B cells activate nephrotoxic T cells. [Immunity] Abstract IL-1R1 Is Required for Dendritic Cell-Mediated T Cell Reactivation within the CNS during West Nile Virus Encephalitis Scientists found that IL-1R1 is critical for effector T cell reactivation and limits inflammation within the central nervous system (CNS) during murine West Nile virus (WNV) encephalitis. Ex vivo analysis of CD4+ T cells from WNV-infected CNS of IL-1R1−/− mice revealed impaired effector responses, whereas CD8+ T cells revealed no cell intrinsic defects in response to WNV antigen. [J Exp Med] Abstract Rapamycin-Treated Human Endothelial Cells Preferentially Activate Allogeneic Regulatory T Cells The authors report the effects of rapamycin on endothelial cell (EC) alloimmunogenicity. Compared with mock-treated cells, rapamycin-pretreated human ECs stimulated less proliferation and cytokine secretion from allogeneic CD4+ memory cells, an effect mimicked by shRNA knockdown of mTOR or raptor in ECs. [J Clin Invest] Full Article B Cells Promote Inflammation in Obesity and Type 2 Diabetes through Regulation of T-Cell Function and an Inflammatory Cytokine Profile Investigators demonstrated that B cells from type 2 diabetes (T2D) subjects support proinflammatory T-cell function in obesity/T2D through contact-dependent mechanisms. In contrast, human monocytes increase proinflammatory T-cell cytokines in both T2D and non-T2D analyses. [Proc Natl Acad Sci USA] Abstract | Press Release Targeting the Intracellular WT1 Oncogene Product with a Therapeutic Human Antibody Using phage display technology, the authors discovered a fully human “T cell receptor-like” monoclonal antibody, ESK1, specific for the Wilms tumor 1 (WT1) RMFPNAPYL peptide/human leukocyte antigen (HLA)-A0201 complex. ESK1 bound to several leukemia and solid tumor cell lines and primary leukemia cells, in a WT1- and HLA-A0201-restricted manner, with high avidity. ESK1 mediated antibody-dependent human effector cell cytotoxicity in vitro. [Sci Trans Med] Abstract | Press Release Dendritic Cell Immune Receptor (DCIR) Regulates Chikungunya Virus Pathogenesis in Mice Alphaviruses are known to interact with members of the C-type lectin receptor family of pattern recognition proteins, and given that the DCIR is known to act as a negative regulator of the host inflammatory response and has previously been associated with rheumatoid arthritis, the authors evaluated DCIR’s role in response to Chikungunya virus infection. [J Virol] Abstract |