TLR5-Mediated Sensing of Gut Microbiota Is Necessary for Antibody Responses to Seasonal Influenza Vaccination Vaccination of Trl5−/− mice resulted in reduced antibody titers and lower frequencies of plasma cells, demonstrating a role for TLR5 in immunity to trivalent inactivated influenza vaccine. TLR5-mediated sensing of flagellin promoted plasma cell differentiation directly and by stimulating lymph node macrophages to produce plasma cell growth factors. [Immunity] Abstract | Press Release Dysfunctional CD8+ T Cells in Hepatitis B and C Are Characterized by a Lack of Antigen-Specific T-Bet Induction Investigators report that high expression of T-bet in virus-specific CD8 T cells during acute hepatitis B virus and hepatitis C virus infection was associated with spontaneous resolution, whereas T-bet deficiency was more characteristic of chronic evolving infection. [J Exp Med] Abstract | Press Release Eosinophil-Derived IL-10 Supports Chronic Nematode Infection Findings indicate that eosinophils are specifically recruited to sites of infection at the earliest stage of muscle infection, consistent with a local response to injury. By producing IL-10 at the initiation of infection, eosinophils expand IL-10+ myeloid dendritic cells and CD4+IL-10+ T lymphocytes that inhibit inducible NO synthase expression and protect intracellular larvae. [J Immunol] Abstract Infection with Host-Range Mutant Adenovirus 5 Suppresses Innate Immunity and Induces Systemic CD4+ T Cell Activation in Rhesus Macaques To gain some insight into how adenovirus 5 (Ad5) infection affects the immune system of rhesus macaques (RM), 18 RM were infected with a host-range mutant Ad5 by three mucosal inoculations. There was a delay of two to six weeks after the first inoculation before plasmacytoid dendritic cell frequency and function increased in peripheral blood. [PLoS One] Full Article B Cell Subsets Are Activated and Produce Cytokines during Early Phases of Francisella tularensis LVS Infection Based on work with the murine tularemia model, researchers report that F. tularensis LVS infects peritoneal CD19+ cells – exclusively B-1a cells – early after intraperitoneal infection in vivo. [Microb Pathog] Abstract HIV IFN-Stimulated Gene LY6E in Monocytes Regulates the CD14/TLR4 Pathway but Inadequately Restrains the Hyperactivation of Monocytes during Chronic HIV-1 Infection Scientists report that the IFN-stimulated gene lymphocyte Ag 6 complex, locus E (LY6E) is a negative immune regulator of monocytes. In the setting of chronic HIV infection, the upregulation of LY6E was correlated with reduced CD14 level on monocytes; however, the immunosuppressive effect of LY6E was not adequate to remedy the hyperresponsiveness of activated monocytes. [J Immunol] Abstract Frequency and Phenotype of B Cell Subpopulations in Young and Aged HIV-1 Infected Patients Receiving ART Investigators evaluated the distribution of B cell subpopulations in young and aged healthy individuals and HIV-1 infected patients, treated and naïve to treatment. B cell populations were characterized for the expression of inhibitory molecules and activation markers; the capacity of B cells to respond to activation signals through up-regulation of IL-6 expression was also evaluated. [Retrovirology] Abstract | Full Article Early Preservation of CXCR5+ PD-1+ Helper T Cells and B Cell Activation Predict the Breadth of Neutralizing Antibody Responses in Chronic HIV-1 Infection By monitoring longitudinally a cohort of HIV-1 infected subjects, the authors observed that the preservation of CXCR5+ CD4+ T helper cell frequencies and activation status of B cells during the first year of infection correlates with the maximum breadth of plasma neutralizing antibody responses during chronic infection, independently of viral load. [J Virol] Abstract Distortion of Memory Vδ2 γδ T Cells Contributes to Immune Dysfunction in Chronic HIV Infection Scientists found a dynamic change in memory Vδ2 γδ T cells, skewed toward an activated and terminally differentiated effector memory phenotype TEMRA Vδ2 γδ T cell, which may account for the dysfunction of Vδ2 γδ T cells in HIV disease. [Cell Mol Immunol] Abstract PBMC of HIV-Infected Patients Contain CD8 T Cells that Form Conjugates with and Kill HIV-Infected Autologous CD4 T Cells Researchers propose that CD4 T cell annihilation in HIV-infected patients results, at least in part, from the interactions of perforin-rich CD8 T cells with autologous, HIV-infected CD4 T cells. [Immunology] Abstract Immunomodulation of Antiretroviral Drug-Suppressed Chronic HIV-1 Infection in an Oral Probiotic Double-Blind Placebo-Controlled Trial Scientists hypothesized that an oral probiotic could improve the residual immune activation in chronic treated HIV-1 infection, and tested a Bacillus coagulans GBI-30, 6086 capsule probiotic in HIV-1-infected persons with suppressed viremia on stable antiretroviral therapy in a three-month double-blind placebo-controlled trial. [AIDS Res Hum Retroviruses] Abstract | Press Release Don’t forget to subscribe to our sister publications: Human Immunology News and Immune Regulation News! |