Cynoglossus semilaevis ISG15: A Secreted Cytokine-Like Protein That Stimulates Antiviral Immune Response in a LRGG Motif-Dependent Manner

摘要: ISG15 is an ubiquitin-like protein that induced rapidly by interferon stimulation. Like ubiquitin, forms covalent conjugates with its target proteins in a process called ISGylation, which mammals known to play role antiviral immunity. In contrast mammalian ISG15, the function of teleost unclear. this study, we identified and analyzed homologue, CsISG15, from tongue sole (Cynoglossus semilaevis). CsISG15 composed 162 residues possesses two tandem domains highly conserved LRGG motif found all ISG15. Expression occurred wide range tissues was upregulated kidney spleen viral bacterial infection. vitro study primary head (HK) lymphocytes showed megalocytivirus infection caused induction expression extracellular release protein. Purified recombinant (rCsISG15) activated HK macrophages enhanced immune genes lymphocytes, both these effects, however, were significantly reduced when sequence mutated LAAG. Further presence rCsISG15 during intracellular load, whereas antibody blocking Likewise, interference RNAi promoted Taken together, results indicate promotes response that, unlike exerts immunoregulatory effect form unconjugated cytokine. addition, also suggest for other than conjugation.