Natural Regulatory T Cells Inhibit Production of Cytotoxic Molecules in CD8+ T Cells during Low-Level Friend Retrovirus Infection Researchers previously showed that the level of Friend retrovirus replication determines the cytotoxic pathway for the control of viral infection. In low-level infection only the Fas pathway is active, whereas cytotoxic molecules are not produced. Here, they elucidated the role of CD4+ regulatory T cells in suppressing the exocytosis pathway during an asymptomatic low-level infection. [Retrovirology] Full Article Mucosal Pre-Exposure to Th17-Inducing Adjuvants Exacerbates Pathology after Influenza Infection The authors tested the hypothesis that mucosal pre-exposure to Th17-inducing adjuvants can promote disease exacerbation upon subsequent infection with influenza virus. Mice mucosally pre-exposed to Th17-inducing adjuvants, such as type II heat-labile enterotoxin or cholera toxin, resulted in increased morbidity and exacerbated lung inflammation upon subsequent infection with influenza virus. [Am J Pathol] Abstract Mycobacterium avium Biofilm Attenuates Human Mononuclear Phagocyte Function by Triggering Hyper-Stimulation and Apoptosis during Early Infection The reasoning behind how Mycobacterium avium subsp. hominissuis (MAH) biofilm is allowed to establish and persist without being cleared by the innate immune system is currently unknown. To identify the mechanism responsible for this, investigators developed an in vitro model using THP-1 human mononuclear phagocytes co-cultured with established MAH biofilm and surveyed various aspects of the interaction including phagocyte stimulation and response, bacterial killing, and apoptosis. [Infect Immun] Abstract Human Immune Responses to Plasmodium falciparum Infection: Molecular Evidence for a Suboptimal THalphabeta and TH17 Bias Over Ideal and Effective Traditional TH1 Immune Response Using microarray analysis, this study showed up-regulation of toll-like receptors 1, 2, 4, 7, 8, NF-kappaB, TNF, p38-MAPK, and MHC molecules in human peripheral blood mononuclear cells following infection with Plasmodium falciparum. The results showed that in early malaria, selected immune response-related genes were up-regulated including alpha beta and gamma interferon-related genes, as well as genes of IL-15, CD36, chemokines, TRAIL and IgG Fc receptors. [Malar J] Abstract | Press Release HIV Antibody-Mediated Immunotherapy of Macaques Chronically Infected with SHIV Suppresses Viremia A new generation of anti-HIV-1 monoclonal antibodies, possessing extraordinary potency and breadth of neutralizing activity, has recently been isolated from infected individuals. Here researchers examined two of the new antibodies, directed to the CD4-binding site and the V3 region, for their ability to block infection and suppress viremia in macaques infected with the R5 tropic simian-human immunodeficiency virus (SHIV)-AD8, which emulates many of the pathogenic and immunogenic properties of HIV-1 during infections of rhesus macaques. [Nature] Abstract | Press Release IFI16 Senses DNA Forms of the Lentiviral Replication Cycle and Controls HIV-1 Replication Using ssDNAs derived from HIV-1 proviral DNA, researchers report that this DNA form potently induces the expression of IFNs in primary human macrophages. This response was stimulated by stem regions in the DNA structure and was dependent on IFN-inducible protein 16 (IFI16), which bound immunostimulatory DNA directly and activated the stimulator of IFN genes -TANK-binding kinase 1 – IFN regulatory factors 3/7 pathway. [Proc Natl Acad Sci USA] Abstract | Press Release MCPIP1 Restricts HIV Infection and Is Rapidly Degraded in Activated CD4+ T Cells Scientists showed that the previously reported immune regulator monocyte chemotactic protein-induced protein 1 (MCPIP1) restricts HIV-1 production in CD4+ T cells. While the ectopic expression of MCPIP1 in cell lines abolished the production of HIV-1, silencing of MCPIP1 enhanced HIV-1 production. [Proc Natl Acad Sci USA] Abstract Evidence for Innate Immune System Activation in HIV-1 Infected Elite Controllers Soluble biomarkers were measured in cryopreserved plasma by ELISA and electrochemilluminescence-based assays from 68 Elite Controllers, 68 ART-treated patients with suppressed viremia and 35 HIV- participants. Cryopreserved PBMC were used to assess monocyte phenotype and function and interferon-inducible gene expression. [J Infect Dis] Abstract
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