Type I Interferons (IFNs) are important cytokines for innate immunity against viruses and cancer. Sixteen human type I IFN variants signal through the same cell-surface receptors, IFNAR1 and IFNAR2, yet they can evoke markedly different physiological effects. The crystal structures of two human type I IFN ternary signaling complexes containing IFNα2 and IFNω reveal recognition modes and heterotrimeric architectures that are unique among the cytokine receptor superfamily but conserved between different type I IFNs. Receptor-ligand cross-reactivity is enabled by conserved receptor-ligand "anchor points" interspersed among ligand-specific interactions that "tune" the relative IFN-binding affinities, in an apparent extracellular "ligand proofreading" mechanism that modulates biological activity. Functional differences between IFNs are linked to their respective receptor recognition chemistries, in concert with a ligand-induced conformational change in IFNAR1, that collectively control signal initiation and complex stability, ultimately regulating differential STAT phosphorylation profiles, receptor internalization rates, and downstream gene expression patterns.
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http://dx.doi.org/10.1016/j.cell.2011.06.048 | DOI Listing |
Curr Issues Mol Biol
December 2024
Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Albany, CA 94710, USA.
Abrin, a toxin of the rosary pea plant (), has been implicated as causing an autoimmune demyelinating disease in humans, but the exact mechanisms responsible for the induction of these demyelinating conditions are still unknown. Certain superantigen microbial toxins such as Staphylococcus enterotoxin type A, type D, type E or streptococcal pyrogenic exotoxin type C also lead to various diseases including autoimmune disorders of the nervous system. Here, the effect of abrin toxin on the immune reaction was studied in human CD4 T-cell lines, and its inhibition of protein synthesis in kidney cells.
View Article and Find Full Text PDFCurr Res Microb Sci
November 2024
CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology; CAS Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.
RIG-I and MDA5 are members of RIG-I-like receptors (RLRs) that detect viral RNA within the cytoplasm and subsequently initiate antiviral immune responses. Necroptosis is a form of programmed cell death (PCD) executed by mixed lineage kinase domain-like (MLKL), which, upon phosphorylation by receptor-interacting protein kinase 3 (RIPK3), causes necrotic cell death. To date, no link between RLRs and necroptosis has been observed during bacterial infection.
View Article and Find Full Text PDFOncogene
December 2024
Department of Gastrointestinal Medical Oncology, Harbin Medical University Cancer Hospital, Harbin, China.
Insufficient tumor cell-intrinsic interferon response represents a major obstacle in immune checkpoint blockade (ICB) therapy, particularly in anti-PD-1 treatment. Although cholesterol metabolism has been demonstrated to be a critical regulator of anti-tumor immune responses, whether cholesterol influences tumor cell-intrinsic interferon response in microsatellite instability (MSI) colorectal cancer (CRC) remains unknown. Through comprehensive siRNA library screening and Gene Set Enrichment Analysis (GSEA), we identified mevalonate kinase (MVK) as a crucial negative regulator of tumor cell-intrinsic interferon response in MSI CRC cells.
View Article and Find Full Text PDFJ Thorac Oncol
December 2024
Moores Cancer Center, University of California San Diego, La Jolla, CA 92037, USA; Department of Medicine, University of California San Diego, La Jolla, CA 92037, USA; Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
Introduction: Copy-number (CN) loss of chromosome 9p, or parts thereof, impair immune response and confer ICT resistance by direct elimination of immune-regulatory genes on this arm, notably IFNγ genes at 9p24.1, and type-I interferon (IFN-I) genes at 9p21.3.
View Article and Find Full Text PDFJ Inflamm Res
December 2024
Department of Nephrology, Peking University Third Hospital, Beijing, 100191, People's Republic of China.
Background: Immunoglobulin A nephropathy (IgAN) and lupus nephritis (LN) are the most prevalent primary and secondary glomerular diseases, respectively, with several similarities in clinical presentations. Common pathogenic mechanisms in IgAN and LN have been well investigated by previous studies. However, the manifestation mechanism of these two independent diseases carrying distinct immunofluorescent pathological features is still unknown considering the similarities between them.
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