Rapid evolution of NK cell receptor systems demonstrated by comparison of chimpanzees and humans

• Published in: Immunity (Cambridge, Mass.) Vol. 12; no. 6; pp. 687 - 698
• Main Authors: Khakoo, S I, Rajalingam, R, Shum, B P, Weidenbach, K, Flodin, L, Muir, D G, Canavez, F, Cooper, S L, Valiante, N M, Lanier, L L, Parham, P
• Format: Journal Article
• Language: English
• Published: United States 01-06-2000
• Subjects: Animals; Antigens, CD - chemistry; Binding Sites, Antibody; Binding, Competitive - immunology; Cell Lineage - genetics; Cell Lineage - immunology; Clone Cells; Conserved Sequence; Evolution, Molecular; Histocompatibility Antigens Class I - metabolism; Humans; killer cell inhibitory receptors; Killer Cells, Natural - immunology; Killer Cells, Natural - metabolism; Lectins, C-Type; Membrane Glycoproteins - antagonists & inhibitors; Membrane Glycoproteins - chemistry; Molecular Sequence Data; NK Cell Lectin-Like Receptor Subfamily C; NK Cell Lectin-Like Receptor Subfamily D; Pan troglodytes - immunology; Receptors, Immunologic - antagonists & inhibitors; Receptors, Immunologic - biosynthesis; Receptors, Immunologic - chemistry; Receptors, Immunologic - physiology; Receptors, KIR; Receptors, Natural Killer Cell; Sequence Homology, Amino Acid; Structure-Activity Relationship
• ISSN: 1074-7613
• DOI: 10.1016/s1074-7613(00)80219-8

That NK cell receptors engage fast-evolving MHC class I ligands suggests that they, too, evolve rapidly. To test this hypothesis, the structure and class I specificity of chimpanzee KIR and CD94:NKG2 receptors were determined and compared to their human counterparts. The KIR families are divergent, with only three KIR conserved between chimpanzees and humans. By contrast, CD94:NKG2 receptors are conserved. Whereas receptors for polymorphic class I are divergent, those for nonpolymorphic class I are conserved. Although chimpanzee and human NK cells exhibit identical receptor specificities for MHC-C, they are mediated by nonorthologous KIR. These results demonstrate the rapid evolution of NK cell receptor systems and imply that "catching up" with class I is not the only force driving this evolution.