Killer cell receptors: keeping pace with MHC class I evolution.

摘要: NK cells express receptors that bind to polymorphic determinants of MHC class I heavy chains. ligands vary greatly between mammalian species, and the use distinct molecular families cell by humans mice suggests too can be evolving rapidly. The KIR (killer inhibitory receptor) family are found in primates recognize epitopes relatively recent origin primate evolution. Therefore, molecules have probably evolved receptor function more recently than C-type lectins, which represented both mice. Individual for they no ligand, demonstrating a looseness coupling expression their ligands. However, study single donor every expresses at least one self-HLA allotype, consistent with missing self hypothesis. Thus NK-cell receptor-class interaction appears control repertoire during ontogeny individual has potential selective factor influencing diversity evolution populations species.