IgA Production Requires B Cell Interaction with Subepithelial Dendritic Cells in Peyer’s Patches The authors showed that in mice, activated B cells use the chemokine receptor CCR6 to access the subepithelial dome (SED) of Peyer’s patches (PPs). There, B cells undergo prolonged interactions with SED dendritic cells (DCs). PP IgA class switching requires innate lymphoid cells, which promote lymphotoxin-β receptor-dependent maintenance of DCs. [Science] Abstract Maternal IgG and IgA Antibodies Dampen Mucosal T Helper Cell Responses in Early Life Scientists report the surprising observation that mice generate T cell-independent and largely Toll-like receptor (TLR)-dependent IgG2b and IgG3 antibody responses against their gut microbiota. They demonstrated that maternal acquisition of these antibodies dampens mucosal T follicular helper responses and subsequent germinal center B cell responses following birth. [Cell] Abstract | Graphical Abstract | Press Release BACH2 Regulates CD8+ T Cell Differentiation by Controlling Access of AP-1 Factors to Enhancers Researchers found that the transcription factor (TF) BACH2 restrains terminal differentiation to enable generation of long-lived memory cells and protective immunity after viral infection. BACH2 was recruited to enhancers, where it limited expression of TCR-driven genes by attenuating the availability of activator protein-1 (AP-1) sites to Jun family signal-dependent TFs. [Nat Immunol] Abstract Indoleamine 2,3-Dioxygenase-Expressing Aortic Plasmacytoid Dendritic Cells Protect against Atherosclerosis by Induction of Regulatory T Cells Scientists identified functional mouse and human plasmacytoid dendritic cells (pDCs) in the aortic intima and showed that selective, inducible pDC depletion in mice exacerbates atherosclerosis. Aortic pDCs expressed CCR9 and indoleamine 2,3-dioxygenase 1, an enzyme involved in driving the generation of regulatory T cells. [Cell Metab] Abstract | Graphical Abstract Combinatorial Targeting of TSLP, IL-25, and IL-33 in Type 2 Cytokine–Driven Inflammation and Fibrosis Using chronic models of helminth infection and allergic lung inflammation, researchers showed that collective disruption of thymic stromal lymphopoietin (TSLP), interleukin-25 (IL-25), and IL-33 signaling suppresses chronic and progressive type 2 cytokine-driven inflammation and fibrosis. [Sci Transl Med] Abstract CD4+ Th2 Cells Are Directly Regulated by IL-10 During Allergic Airway Inflammation Researchers demonstrated that interleukin-10 (IL-10) directly limits Th2 cell differentiation and survival in vitro and in vivo. Ablation of IL-10 signaling in Th2 cells led to enhanced Th2 cell survival and exacerbated pulmonary inflammation in a murine model of house dust mite allergy. [Mucosal Immunol] Full Article Oral CD103−CD11b+ Classical Dendritic Cells Present Sublingual Antigen and Induce Foxp3+ Regulatory T Cells in Draining Lymph Nodes A major subset of oral classical dendritic cells with the CD103−CD11b+ phenotype showed retinoic acid (RA)-producing activity and converted naive CD4+ T cells to Foxp3+ Treg cells in a transforming growth factor-β- and RA-dependent manner in vitro. [Mucosal Immunol] Abstract Intralesional Rose Bengal in Melanoma Elicits Tumor Immunity via Activation of Dendritic Cells by the Release of High Mobility Group Box 1 The authors showed a mechanism of tumor-specific immune response induced by intralesional (IL) Rose Bengal (RB). In melanoma-bearing mice, IL RB induced regression of injected tumor and inhibited the growth of bystander lesions mediated by CD8+ T cells. [Oncotarget] Full Article | Press Release LRRK1 Is Critical in the Regulation of B-Cell Responses and CARMA1-Dependent NF-κB Activation Scientists discovered a critical function of leucine-rich repeat kinase 1 (LRRK1) in B-cell receptor-mediated immune responses. Lrrk1−/− mice exhibited altered B1a-cell development and basal immunoglobulin production. [Sci Rep] Full Article Don’t forget to subscribe to Human Immunology News and Immunology of Infectious Disease News! |