Genetic Regulation of Vesiculogenesis and Immunomodulation in Mycobacterium tuberculosis Mycobacterium tuberculosis (Mtb) restrains immune responses well enough to escape eradication but elicits enough immunopathology to ensure its transmission. Investigators provide evidence that this host-pathogen relationship is regulated in part by a cytosolic, membrane-associated protein with a unique structural fold, encoded by the Mtb gene rv0431. [Proc Natl Acad Sci USA] Abstract | Full Article Regulation of Nitric Oxide Synthesis, Local Inflammation and Innate Immunity to Pathogens by BET Family Proteins Investigators showed that infection of macrophages with the intracellular bacterial pathogen Listeria monocytogenes causes binding of BET proteins Brd2, Brd3 and, most prominently, Brd4 to the Nos2 promoter and that a profound reduction of Nos2 expression occurred in the presence of the BET inhibitor JQ1. [Mol Cell Biol] Abstract Changes in Immune Cell Populations in the Periphery and Liver of GBV-B-Infected and Convalescent Tamarins (Saguinus labiatus) The authors characterized changes in lymphocyte populations in tamarins with an acute GB virus B (GBV-B) infection, a hepatitis virus of the flaviviridae. Major immune cell populations were monitored in peripheral and intra-hepatic lymphocytes at high viremia or following a period when peripheral virus was no longer detected. [ Virus Res] Abstract Lactobacillus rhamnosus GG Improves Outcome in Experimental Pseudomonas aeruginosa Pneumonia: Potential Role of Regulatory T Cells Investigators aimed to determine the effect of Lactobacillus rhamnosus GG treatment on survival and lung injury in a mouse model of Pseudomonas aeruginosa-induced pneumonia. As increased T regulatory (Treg) cell numbers have been shown to improve outcome in experimental pneumonia, they examined the potential role of Treg cells in probiotic-mediated benefit. [Shock] Abstract HIV Can Non-Lytic CD8+ T Cells Drive HIV-1 Escape? The authors have developed a 3D cellular automaton model of HIV-1 which captures spatial and temporal dynamics. The model reproduces in vivo HIV-1 dynamics at the cellular and population level. Using this model they demonstrated that non-lytic effector mechanisms can select for escape variants but that outgrowth of the variant is slower and less frequent than from a lytic response so that non-lytic responses can potentially offer more durable control. [PLoS Pathog] Full Article Differential Impact of Magnitude, Polyfunctional Capacity and Specificity of HIV-Specific CD8+ T Cell Responses on HIV Viral Set Point Scientists evaluated the differential impact of magnitude, polyfunctional capacity and specificity of the CD8+ response at approximately 6 months post infection on viral set point at 12 months in a cohort of HIV-infected individuals. [J Virol] Abstract Humanized Mice: Novel Model for Studying Mechanisms of Human Immune-Based Therapies Scientists demonstrated that human CD8 T lymphocytes in humanized mice are fully responsive to a novel cell-based secreted heat shock protein gp96HIV-Ig vaccine. They also showed that the gp96HIV-Ig vaccine induces powerful mucosal immune responses in the rectum and the vagina, which are thought to be required for protection from HIV infection. [Immunol Res] Abstract Cellular Interplay among Th17, Th1, and Treg Cells in HIV-1 Subtype “C” Infection The impact of HIV-1 infection on the interplay of Th17/Th1/Treg cells in HIV-1 infected Indian individuals was examined and researchers report that HIV-1 Gag specific peripheral blood Th17 cells were significantly depleted in late infected subjects, compared to early infected subjects and slow progressors. [J Med Virol] Abstract
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