Cutting edge: CD4 is the receptor for the tick saliva immunosuppressor, Salp15.

摘要: Salp15 is an Ixodes scapularis salivary protein that inhibits CD4+ T cell activation through the repression of TCR ligation-triggered calcium fluxes and IL-2 production. We show in this study binds specifically to CD4 coreceptor on mammalian host cells. associates its C-terminal residues with outermost two extracellular domains CD4. Upon binding CD4, subsequent ligation-induced signaling at earliest steps including tyrosine phosphorylation Src kinase Lck, downstream effector proteins, lipid raft reorganization. These results provide a molecular basis understanding immunosuppressive activity specificity for