Most Microbe-Specific Naïve CD4+ T Cells Produce Memory Cells during Infection Investigators found that in mice, essentially all microbe-specific naïve cells produced memory cells during infection. Different clonal memory cell populations had different B cell or macrophage helper compositions that matched effector cell populations generated much earlier in the response. [Science] Abstract Glutamylation of the DNA Sensor cGAS Regulates Its Binding and Synthase Activity in Antiviral Immunity Investigators found that deficiency in the carboxypeptidase CCP5 or CCP6 led to susceptibility to DNA viruses. CCP5 and CCP6 were required for activation of the transcription factor IRF3 and interferons. [Nat Immunol] Abstract Dysbiosis-Induced IL-33 Contributes to Impaired Antiviral Immunity in the Genital Mucosa Researchers demonstrated that dysbiosis caused by oral antibiotic treatment directly impairs antiviral immunity following viral infection of the vaginal mucosa. Antibiotic-treated mice succumbed to mucosal herpes simplex virus type 2 infection more rapidly than water-fed mice, and also showed delayed viral clearance at the site of infection. [Proc Natl Acad Sci USA] Abstract The Adhesion GPCR BAI1 Mediates Macrophage ROS Production and Microbicidal Activity against Gram-Negative Bacteria Scientists found that brain-specific angiogenesis inhibitor 1 (BAI1) triggered the killing of the internalized bacteria by stimulating the production of reactive oxygen species. When engaged by bacteria, BAI1 activated Rac1 to stimulate the activity of the NADPH oxidase complex Nox2 in macrophages. [Sci Signal] Abstract Combined Local and Systemic Immunization Is Essential for Durable T-Cell Mediated Heterosubtypic Immunity against Influenza A Virus Adenoviral vectors expressing flu nucleoprotein have previously been found to induce short-term protection in mice. Researchers confirm that systemic immunization rapidly induced heterosubtypic protection predominantly mediated by CD8 T cells, but within three months clinical protection completely disappeared. [Sci Rep] Full Article HIV Actin Dynamics Regulates Dendritic Cell-Mediated Transfer of HIV-1 to T Cells Scientists performed a shRNA screen of several hundred genes involved in organelle and membrane trafficking in immature human monocyte-derived dendritic cells. They identified TSPAN7 and DNM2, which control actin nucleation and stabilization, as having important and distinct roles in limiting HIV-1 endocytosis and in maintaining virus particles on dendrites, which is required for efficient transfer to T lymphocytes. [Cell] Abstract | Graphical Abstract Innate Lymphoid Cells Are Depleted Irreversibly during Acute HIV-1 Infection in the Absence of Viral Suppression Researchers found that human blood innate lymphoid cells (ILCs) were severely depleted during acute viremic HIV-1 infection and that ILC numbers did not recover after resolution of peak viremia. ILC numbers were preserved by antiretroviral therapy, but only if initiated during acute infection. [Immunity] Abstract | Graphical Abstract | Press Release Loss of Function of Intestinal IL-17 and IL-22 Producing Cells Contributes to Inflammation and Viral Persistence in SIV-Infected Rhesus Macaques Investigators longitudinally determined the levels and functions of IL-17, IL-22 and IL-17/IL-22 producing CD4+ T-cells in blood, lymph node and colorectum of SIV-infected rhesus macaques, as well as how they recover during effective ART and are affected by ART interruption. [PLoS Pathog] Full Article Prevention of SHIV Transmission by Topical IFN-β Treatment The authors hypothesized that topically applied type 1 interferons might stimulate vaginal innate responses that could protect against HIV transmission. Vaginal administration of interferon (IFN)-β resulted in marked local changes in immune cell phenotype, increasing immune activation and HIV co-receptor expression, yet provided significant protection from simian/human immunodeficiency virus (SHIV) acquisition as IFN response genes were also upregulated. [Mucosal Immunol] Abstract Potent In Vitro Antiviral Activity of Cistus incanus Extract against HIV and Filoviruses Targets Viral Envelope Proteins Researchers demonstrated that Cistus incanus (Ci) herbal products inhibit human immunodeficiency virus (HIV) infections in vitro. Ci extract inhibited clinical HIV-1 and HIV-2 isolates, and, importantly, a virus isolate with multiple drug resistances, confirming broad anti-HIV activity. [Sci Rep] Full Article | Press Release Subscribe to our sister publications: Human Immunology News and Immune Regulation News! |