Dimorphic Motifs in D0 and D1 D2 Domains of Killer Cell Ig-Like Receptor 3DL1 Combine to Form Receptors with High, Moderate, and No Avidity for the Complex of a Peptide Derived from HIV and HLA-A*2402

作者：Sharma Deepti; Bastard Karine; Guethlein Li**eth A; Norman Paul J; Yawata Nobuyo; Yawata Makoto; Pando Marcelo; Thananchai Hathairat; Dong Tao; Rowland Jones Sarah; Brodsky Frances M; Parham Peter^*

来源：The Journal of Immunology, 2009, 183(7): 4569-4582.

DOI：10.4049/jimmunol.0901734

Comparison of mutant killer cell Ig-like receptor (KIR) 3DL1*015 substituted at natural positions of variation showed that tryptophan/leucine dimorphism at position 283 uniquely changes receptor conformation and can strongly influence binding of the A24nef tetramer. Dimorphic motifs at positions 2, 47, and 54 in DO and 182 and 283 in D1 D2 distinguish the two 3DL1 lineages, typified by 3DL1*005 and 3DL1*015. The interlincage recombinant, KIR3DL1*001, combines DO of 3DL1*005 with D1 D2 of 3DL1*015 and binds A24nef more strongly than either parent. In contrast, the reciprocal recombinant with DO from 3DL1*015 and D1 D2 from 3DL1*005 cannot bind A24nef. Thus, DO polymorphism directly affects the avidity of the KIR3DL1 ligand binding site. From these observations, multiple sequence alignment, and homology modeling, we constructed structural models for KIR3DL1 and its complex with A24nef. In these models, D0, D1, and D2 come together to form a binding surface for A24nef, which is contacted by all three Ig-like domains. A central pocket binds arginine 83, the only Bw4 motif residue essential for KIR3DL1 interaction, similar to the binding of lysine 80 in HLA-C by KIR2DL1. Central to this interaction is a salt bridge between arginine 83 of Bw4 and glutamate 282 of 3DL1, which juxtaposes the functionally influential dimorphism at position 283. Further 3DL1 mutants were tested and shown to have A24nef-binding properties consistent with the models. A24nef was not bound by KIR3DS1, the activating counterpart of KIR3DL1. Moreover, introducing any one of three residues specific to KIR3DS1,serine 163, arginine 166, or leucine 199, into 3DL1*015, abrogated A24nef binding. The Journal of Immunology, 2009, 183: 4569-4582.

• 出版日期2009-10-1