TY - JOUR
T1 - A small, variable, and irregular killer cell Ig-like receptor locus accompanies the absence of MHC-C and MHC-G in gibbons
AU - Abi-Rached, Laurent
AU - Kuhl, Heiner
AU - Roos, Christian
AU - Ten Hallers, Boudewijn
AU - Zhu, Baoli
AU - Carbone, Lucia
AU - De Jong, Pieter J.
AU - Mootnick, Alan R.
AU - Knaust, Florian
AU - Reinhardt, Richard
AU - Parham, Peter
AU - Walter, Lutz
PY - 2010/2/1
Y1 - 2010/2/1
N2 - The killer cell Ig-like receptors (KIRs) of NK cells recognize MHC class I ligands and function in placental reproduction and immune defense against pathogens. During the evolution of monkeys, great apes, and humans, an ancestral KIR3DL gene expanded to become a diverse and rapidly evolving gene family of four KIR lineages. Characterizing the KIR locus are three framework regions, defining two intervals of variable gene content. By analysis of four KIR haplotypes from two species of gibbon, we find that the smaller apes do not conform to these rules. Although diverse and irregular in structure, the gibbon haplotypes are unusually small, containing only two to five functional genes. Comparison with the predicted ancestral hominoid KIR haplotype indicates that modern gibbon KIR haplotypes were formed by a series of deletion events, which created new hybrid genes as well as eliminating ancestral genes. Of the three framework regions, only KIR3DL3 (lineage V), defining the 5′ end of the KIR locus, is present and intact on all gibbon KIR haplotypes. KIR2DL4 (lineage I) defining the central framework region has been a major target for elimination or inactivation, correlating with the absence of its putative ligand, MHC-G, in gibbons. Similarly, the MHCC-driven expansion of lineage III KIR genes in great apes has not occurred in gibbons because they lack MHC-C. Our results indicate that the selective forces shaping the size and organization of the gibbon KIR locus differed from those acting upon the KIR of other hominoid species.
AB - The killer cell Ig-like receptors (KIRs) of NK cells recognize MHC class I ligands and function in placental reproduction and immune defense against pathogens. During the evolution of monkeys, great apes, and humans, an ancestral KIR3DL gene expanded to become a diverse and rapidly evolving gene family of four KIR lineages. Characterizing the KIR locus are three framework regions, defining two intervals of variable gene content. By analysis of four KIR haplotypes from two species of gibbon, we find that the smaller apes do not conform to these rules. Although diverse and irregular in structure, the gibbon haplotypes are unusually small, containing only two to five functional genes. Comparison with the predicted ancestral hominoid KIR haplotype indicates that modern gibbon KIR haplotypes were formed by a series of deletion events, which created new hybrid genes as well as eliminating ancestral genes. Of the three framework regions, only KIR3DL3 (lineage V), defining the 5′ end of the KIR locus, is present and intact on all gibbon KIR haplotypes. KIR2DL4 (lineage I) defining the central framework region has been a major target for elimination or inactivation, correlating with the absence of its putative ligand, MHC-G, in gibbons. Similarly, the MHCC-driven expansion of lineage III KIR genes in great apes has not occurred in gibbons because they lack MHC-C. Our results indicate that the selective forces shaping the size and organization of the gibbon KIR locus differed from those acting upon the KIR of other hominoid species.
UR - http://www.scopus.com/inward/record.url?scp=77949317562&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77949317562&partnerID=8YFLogxK
U2 - 10.4049/jimmunol.0903016
DO - 10.4049/jimmunol.0903016
M3 - Article
C2 - 20026738
AN - SCOPUS:77949317562
SN - 0022-1767
VL - 184
SP - 1379
EP - 1391
JO - Journal of Immunology
JF - Journal of Immunology
IS - 3
ER -