Bacterial-Derived Uracil as a Modulator of Mucosal Immunity and Gut-Microbe Homeostasis in Drosophila Investigators showed that bacterial-derived uracil acts as a ligand for dual oxidase-dependent reactive oxygen species generation in Drosophila gut and that the uracil production in bacteria causes inflammation in the gut. The acute and controlled uracil-induced immune response is required for efficient elimination of bacteria, intestinal cell repair, and host survival during infection of nonresident species. [Cell] Abstract | Graphical Abstract Safety and Immunogenicity of a Novel Multivalent OspA Vaccine against Lyme Borreliosis in Healthy Adults: A Double-Blind, Randomized, Dose-Escalation Phase I/II Trial The authors investigated the safety and immunogenicity of adjuvanted and non-adjuvanted vaccines containing protective epitopes from Borrelia species outer surface protein A (OspA) serotypes in healthy adults. [Lancet Infect Dis] Abstract | Press Release Dual Function of the McaS Small RNA in Controlling Biofilm Formation Researchers demonstrated that multicellular adhesive (McaS) activates synthesis of the exopolysaccharide ß-1,6 N-acetyl-D-glucosamine (PGA) by binding the global RNA-binding protein CsrA, a negative regulator of pgaA translation. The McaS RNA bears at least two CsrA-binding sequences, and inactivation of these sites compromises CsrA binding, PGA regulation, and biofilm formation. [Gene Dev] Abstract | Press Release Indoleamine 2,3-Dioxygenase Activity Contributes to Local Immune Suppression in the Skin Expressing Human Papillomavirus Oncoprotein E7 Investigators showed that indoleamine 2, 3-dioxygenase (IDO) 1, an IFN-γ inducible immunoregulatory molecule, is more highly expressed by langerin-ve dermal dendritic cells from keratin-14 promoter (K14E7) skin than nontransgenic control skin. Furthermore, inhibiting IDO activity using 1-D/L-methyl tryptophan promotes K14E7 skin graft rejection. [J Invest Dermatol] Abstract STAT4-Dependent and Independent Th2 Responses Correlate with Protective Immunity against Lung Infection with Pneumocystis murina Although it is clear that the loss of CD4+ T cells is a predisposing factor for the development of Pneumocystis pneumonia, specific Th mechanisms mediating protection are not well understood. Th1, Th2, and Th17 responses have each been implicated in protective responses during infection. As STAT4 may promote Th1 and Th17 development, yet antagonize Th2 development, scientists investigated its role in Pneumocystis murina host defense. [J Immunol] Abstract HIV Vaccine-Induced Plasma IgA Specific for the C1 Region of the HIV-1 Envelope Blocks Binding and Effector Function of IgG Scientists investigated the hypothesis that IgA could attenuate the protective effect of IgG responses through competition for the same envelope (Env) binding sites. They report that Env-specific plasma IgA/IgG ratios are higher in infected than in uninfected vaccine recipients in RV144. [Proc Natl Acad Sci USA] Abstract | Press Release Impaired CD4+ T Cell Stimulation of NK Cell Anti-Fibrotic Activity may Contribute to Accelerated Liver Fibrosis Progression in HIV/Hepatitis C Virus Patients The authors showed that CD4+ T cells are able to stimulate anti-fibrotic natural killer (NK) cell activity via interleukin-2 mediated up-regulation of NKG2D. Human immunodeficiency virus (HIV) induced loss of CD4+ T cells together with an impaired activity of CD4+ T cells may contribute to accelerate progression of liver fibrosis observed in co-infection. [J Hepatol] Abstract Altered T Cell Subsets in HIV-1 Natural Viral Suppressors (Elite Controllers) with Hepatitis C Infection Scientists investigated T cell phenotypic changes in association with hepatitis C virus (HCV) infection. Natural viral suppressors (NVS) without HCV and normal controls had similar T cell phenotypes. However, NVS with HCV had lower naive cell proportions compared to NVS without HCV. [AIDS] Abstract Consensus HIV-1 FSU-A Integrase Gene Variants Electroporated into Mice Induce Polyfunctional Antigen-Specific CD4+ and CD8+ T Cells Multiparametric FACS demonstrated that CD8+ and CD4+ T cells of gene-immunized mice stimulated with integrase-derived peptides secreted IFN-γ, IL-2, and TNF-α. The multi-cytokine responses of CD8+ and CD4+ T-cells correlated with the loss of in vivo activity of the luciferase reporter gene co-delivered with pVaxIN plasmids. [PLoS One] Full Article Lack of Correlation between the Size of HIV Proviral DNA Reservoir and the Level of Immune Activation in HIV-Infected Patients with a Sustained Undetectable HIV Viral Load for Ten Years The persistence of HIV residual replication in patients with an undetectable plasma viral load (pVL) may limit immune recovery and facilitate inflammation-induced comorbidities. Researchers aimed to evaluate any correlation between immune restoration and intracellular HIV-DNA in cART-treated patients with a sustained undetectable pVL. [J Clin Virol] Abstract Histamine Enhances HIV-1-Induced Modulation of Dendritic Cells to Skew Naïve T Cell Differentiation toward Regulatory T Cells The authors investigated histamine-assisted HIV-1 modulation of dendritic cell (DC) functions. Histamine and HIV-1 showed a synergistic role in induction of interleukin (IL)-10; histamine inhibited HIV-1-induced IL-12 production from monocyte-derived DCs (MDDCs); notably, histamine augmented HIV-1-induced MDDC functional polarization and skewed naïve T cell differentiation toward regulatory T cells. [Virology] Abstract Remember to subscribe to our sister publications: Human Immunology News and Immune Regulation News! |