Cytomegalovirus Vectors Violate CD8+ T Cell Epitope Recognition Paradigms Scientists found that simian immunodeficiency virus (SIV) protein-expressing rhesus cytomegalovirus vectors elicit SIV-specific CD8+ T cells that recognize unusual, diverse, and highly promiscuous epitopes, including dominant responses to epitopes restricted by class II major histocompatibility complex molecules. [Science] Abstract | Press Release T Cell Regulation Mediated by Interaction of Soluble CD52 with the Inhibitory Receptor Siglec-10 Researchers found that human and mouse antigen-activated T cells with high expression of the lymphocyte surface marker CD52 suppressed other T cells. CD52hiCD4+ T cells were distinct from CD4+CD25+Foxp3+ regulatory T cells. Their suppression was mediated by soluble CD52 released by phospholipase C. [Nat Immunol] Abstract | Press Release The Unfolded Protein Response Element IRE1α Senses Bacterial Proteins Invading the ER to Activate Retinoic-Acid Inducible Gene 1 and Innate Immune Signaling Investigators report that inositol-requiring-1α (IRE1α), an endoplasmic reticulum (ER) protein that signals in the unfolded protein response, is activated to induce inflammation by binding a portion of cholera toxin as it co-opts the ER to cause disease. [Cell Host Microbe] Abstract | Graphical Abstract Depleting Tumor-Specific Tregs at a Single Site Eradicates Disseminated Tumors Scientists showed that intratumoral coinjection of anti-CTLA-4 and anti-OX40 together with CpG depleted tumor-infiltrating Tregs. This in situ immunomodulation, which was performed with low doses of antibodies in a single tumor, generated a systemic antitumor immune response that eradicated disseminated disease in mice. [J Clin Invest] Full Article A TSPO Ligand Is Protective in a Mouse Model of Multiple Sclerosis Results showed that etifoxine attenuated experimental autoimmune encephalomyelitis (EAE) severity when administered before the development of clinical signs and also improved symptomatic recovery when administered at the peak of the disease. In both cases, recovery was correlated with diminished inflammatory pathology in the lumbar spinal cord. Modulation of translocator protein (TSPO) activity by etifoxine led to less peripheral immune cell infiltration of the spinal cord, and increased oligodendroglial regeneration after inflammatory demyelination in EAE. [EMBO Mol Med] Abstract | Press Release Anti-CD47 Antibody-Mediated Phagocytosis of Cancer by Macrophages Primes an Effective Antitumor T-Cell Response Scientists showed that anti-CD47 antibody-mediated phagocytosis of cancer by macrophages can initiate an antitumor T-cell immune response. Using the ovalbumin model antigen system, anti-CD47 antibody-mediated phagocytosis of cancer cells by macrophages resulted in increased priming of OT-I T cells (CD8+) but decreased priming of OT-II T cells (CD4+). [Proc Natl Acad Sci USA] Abstract | Press Release Construction of Self-Recognizing Regulatory T Cells from Conventional T Cells by Controlling CTLA-4 and IL-2 Expression To determine the molecular basis of regulatory T (Treg) cell suppressive activity and their self-skewed T-cell receptor repertoire formation, investigators attempted to reconstruct these Treg-specific properties in conventional T (Tconv) cells by genetic manipulation. They showed that Tconv cells rendered IL-2 deficient and constitutively expressing transgenic cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) were potently suppressive in vitro when they were preactivated by antigenic stimulation. [Proc Natl Acad Sci USA] Abstract CD11chighCD8+ Regulatory T Cell Feedback Inhibits CD4 T Cell Immune Response via Fas Ligand-Fas Pathway The authors identified CD11chighCD8+ T cells as a new subset of CD8+ regulatory T cells. During Listeria monocytogenes and Staphylococcus aureus infection, two subsets of CD8 T cells were classified according to the expression level of CD11c, including CD11clowCD8+ and CD11chighCD8+ T cells. CD11clowCD8+ T cells, existing during the whole period of infection, act as conventional activated T cells to kill target cells in a perforin-dependent manner. [J Immunol] Abstract Don’t forget to subscribe to our sister publications: Human Immunology News and Immunology of Infectious Disease News! |