Immunology of Infectious Disease News Volume 3.33 | Sep 2 2015

Counter Inhibition between Leukotoxins Attenuates Staphylococcus aureus Virulence
Researchers demonstrated that the leukotoxins LukSF-PV and LukED antagonize each other’s cytolytic activities on leukocytes and erythrocytes by forming inactive hybrid complexes. [Nat Commun] Full Article

Twenty-Eight Years of Poliovirus Replication in an Immunodeficient Individual: Impact on the Global Polio Eradication Initiative
The authors describe an individual who has been excreting type 2 vaccine-derived poliovirus for twenty eight years as estimated by the molecular clock established with VP1 capsid gene nucleotide sequences of serial isolates. Using a range of in vivo and in vitro assays they show that the viruses are very virulent, antigenically drifted and excreted at high titer suggesting that such chronic excreters pose an obvious risk to the eradication program. [PLoS Pathog] Full Article | Press Release

Halothane Modulates the Type I Interferon Response to Influenza and Minimizes the Risk of Secondary Bacterial Pneumonia through Maintenance of Neutrophil Recruitment in an Animal Model
The authors demonstrated that halothane mitigates the risk of secondary bacterial pneumonias postflu through modulation of the effects of type I interferon. [Anesthesiology] Abstract | Press Release

Myeloid-Related Protein 8 Induces Self-Tolerance and Cross-Tolerance to Bacterial Infection via TLR4- and TLR2-Mediated Signal Pathways
Scientists report that myeloid-related protein 8 (Mrp8) triggered TNF-α and IL-6 release via a Toll-like receptor 4 (TLR4)-dependent manner. Pre-stimulation of murine macrophages and human monocytes with Mrp8 induced self-tolerance to Mrp8 re-stimulation and cross-tolerance to lipopolysaccharide, bacterial lipoprotein, gram-negative and gram-positive bacterial challenges, with substantially attenuated TNF-α and IL-6 release. [Sci Rep] Full Article

The Contribution of Chlamydia-Specific CD8⁺ T Cells to Upper Genital Tract Pathology
Investigators evaluated whether antigen-specific CD8⁺ T cells mediate chlamydial pathology. Chlamydia-specific interferon-γ and tumor necrosis factor -α production from purified splenic CD8⁺ T cells of OT-1 mice was minimal, whereas responses in OT-1 mice replete with wild type (WT) CD8⁺ T cells were comparable to those in WT animals. [Immunol Cell Biol] Abstract

Borrelia burgdorferi Elongation Factor EF-Tu Is an Immunogenic Protein during Lyme Borreliosis
Researchers studied the immunogenicity, surface localization, and function of B. burgdorferi elongation factor Tu (EF-Tu). They found that EF-Tu is highly immunogenic in mice, and EF-Tu antibodies were readily detected in Lyme disease patients. [Emerg Microbes Infect] Full Article

HIV

Cell-to-Cell Transmission of HIV-1 Is Required to Trigger Pyroptotic Death of Lymphoid-Tissue-Derived CD4 T Cells
Researchers showed that cell-to-cell transmission of HIV is obligatorily required for activation of this death pathway. Cell-free HIV-1 virions, even when added in large quantities, fail to activate pyroptosis. [Cell Rep] Full Article | Graphical Abstract | Press Release

Adenosine Deaminase Regulates Treg Expression in Autologous T Cell-Dendritic Cell Cocultures from Patients Infected with HIV-1
As regulatory T cells produce the immunomodulatory molecule adenosine, investigators aimed to assess the potential of adenosine removal to revert the suppression of anti-HIV responses exerted by regulatory T cells. [J Leukoc Biol] Abstract

HIV-1 Protease Cleaves the Serine-Threonine Kinases RIPK1 and RIPK2
Scientists found that receptor-interacting protein kinase 1 (RIPK1) and RIPK2 but not other members of the RIP kinase family are cleaved by HIV-1 protease. RIPK1 and RIPK2 were cleaved during HIV-1 infection of T cell lines or primary activated CD4⁺ T cells. [Retrovirology] Full Article

Higher Frequency of NK and CD4⁺ T-Cells in Mucosa and Potent Cytotoxic Response in HIV Controllers
Researchers evaluated the frequency, phenotype and activity of T and NK cells in peripheral blood and gut mucosa in a cohort of Colombian HIV controllers. Gag-stimulated CD8⁺ T-cells and cytokine-stimulated NK cells were tested for cytotoxic activity. [PLoS One] Full Article

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UC San Diego Scientists Investigate Global Hemorrhagic Fever Bacterial Disease
An international research team, headed by Joseph Vinetz, MD has been awarded a 5-year, $1.89 million cooperative agreement to carry out translational research studies of leptospirosis, an infectious and sometimes fatal bacterial disease endemic in much of the world. [UC San Diego Health] Press Release

NIBSC Develops New-CE Marked Virus Triplex for NAT PCR Blood Testing – HBC, HCV, HIV
NIBSC announced the availability of a very low positive triplex reagent (NIBSC Code 14/198) for NAT assays containing hepatitis B (HBV), hepatitis C (HCV) and human immunodeficiency virus-1 (HIV-1). [National Institute for Biological Standards and Control (NIBSC)] Press Release

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NEW Faculty Positions – Virology (NYU School of Medicine)

NEW Postdoctoral Scientist – Innate and Adaptive Immune Response to S. Aureus Infection (Cedars-Sinai)

PhD Positions – Infection Biology and Immunology (ZIBI Graduate School)

Postdoctoral Position – HIV Vaccine Immunology (Dana-Farber Cancer Institute)

Postdoctoral Fellow – Molecular Microbiology/Immunology (The University of Tennessee)

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Research Assistant – Immunotherapy for HIV Infection (California Institute of Technology)

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