A Bacterial Tyrosine Phosphatase Inhibits Plant Pattern Recognition Receptor Activation Researchers report that the Arabidopsis receptor kinase EF-TU RECEPTOR EFR, which perceives the elf18 peptide derived from bacterial elongation factor Tu, is activated upon ligand binding by phosphorylation on its tyrosine residues. Phosphorylation of a single tyrosine residue, Y836, is required for activation of EFR and downstream immunity to the phytopathogenic bacterium Pseudomonas syringae. [Science] Abstract | Press Release NK Cell Intrinsic Regulation of MIP-1α by Granzyme M During Listeria monocytogenes infection, researchers observed markedly reduced secretion of macrophage inflammatory protein-1 alpha (MIP-1α) in livers of Granzyme M-deficient mice, which resulted in significantly impaired natural killer (NK) cell recruitment. [Cell Death Dis] Full Article IL-12 and IL-27 Regulate the Phagolysosomal Pathway in Mycobacteria-Infected Human Macrophages Scientists showed that supplying interleukin (IL)-12 and neutralizing IL-27 enhanced acidification and fusion of mycobacterial-containing phagosomes with lysosomes. [Cell Commun Signal] Full Article Human Metapneumovirus M2-2 Protein Inhibits Innate Immune Response in Monocyte-Derived Dendritic Cells The authors found that human dendritic cells (DC) infected with a virus lacking M2-2 protein expression produced higher levels of cytokines, chemokines and IFNs, compared to cells infected with wild-type virus, suggesting that M2-2 protein inhibits innate immunity in human DC. [PLoS One] Full Article Secreted Candida parapsilosis Lipase Modulates the Immune Response of Primary Human Macrophages Investigators compared the response of human peripheral blood monocyte-derived macrophages to a wild type as well as a lipase deficient C. parapsilosis strain that has been previously established in their lab. Although macrophages phagocytosed both strains with similar efficiency, lipase mutants were killed more efficiently according to fluorescent microscopic analysis. [Virulence] Abstract HIV Polyfunctional Fc-Effector Profiles Mediated by IgG Subclass Selection Distinguish RV144 and VAX003 Vaccines Researchers showed that the RV144 regimen elicited nonneutralizing antibodies with highly coordinated Fc-mediated effector responses through the selective induction of highly functional immunoglobulin G3 (IgG3). By contrast, VAX003 elicited monofunctional antibody responses influenced by IgG4 selection, which was promoted by repeated AIDSVAX B/E protein boosts. [Sci Transl Med] Abstract | Press Release Vaccine-Induced Env V1-V2 IgG3 Correlates with Lower HIV-1 Infection Risk and Declines Soon after Vaccination Investigators demonstrated that HIV-1-specific immunoglobulin G 3 (IgG3) distinguished two HIV-1 vaccine efficacy studies (RV144 and VAX003 clinical trials) and correlated with decreased risk of HIV-1 infection in a blinded follow-up case-control study with the RV144 vaccine. HIV-1-specific IgG3 responses were not long-lived, which was consistent with the waning efficacy of the RV144 vaccine. [Sci Transl Med] Abstract | Press Release Immune Suppression by Neutrophils in HIV-1 Infection: Role of PD-L1/PD-1 Pathway The authors showed that neutrophils in the blood of HIV-1-infected individuals express high levels of program death ligand 1 (PD-L1). PD-L1 is induced by HIV-1 virions, TLR-7/8 ligand, bacterial lipopolysaccharide, and IFNα. [PLoS Pathog] Full Article Reduction of the HIV Protease Inhibitor-Induced ER Stress and Inflammatory Response by Raltegravir in Macrophages Scientists examined the effect of raltegravir on endoplasmic reticulum (ER) stress activation and lipid accumulation in cultured mouse macrophages, primary mouse macrophages, and human THP-1-derived macrophages, and further determined whether the combination of raltegravir with existing HIV protease inhibitor would potentially exacerbate or prevent the previously observed activation of inflammatory response and foam cell formation. [PLoS One] Full Article |