Investigation of Killer Cell Immunoglobulin‐Like Receptors KIR 2 DL 2 and KIR 2 DL 3 Diversity and Identification of Ten Novel KIR 2 DL 3 Alleles in the Chinese Han Population

KIR 2 DL 2 and KIR 2 DL 3 are important inhibitory receptors that recognize a subset of HLA ‐C allelic products carrying Ser77 and Asn80. In this study, we have determined KIR 2 DL 2 and KIR 2 DL 3 diversity in the Chinese Han population by a PCR sequence‐based typing. Based on sequencing, the coding regions of 166 Chinese Han individuals, seven new polymorphic sites (238G>A, 405G>A, 476A>G, 550G>A, 608G>A, 789T>C, 947T>C) were found. KIR 2 DL 2*00301, *00101, KIR 2 DL 3*00101,*00201,*013, *015 and ten new KIR 2 DL 3 variants ( KIR 2 DL 3*00105, 00106, 00107, 00108, 019, 020, 021, 022, 023 and 024 ) were identified, of which KIR 2 DL 3*00101 was the most frequent allele. Compared with the sequences of KIR 2 DL 3*00101, all sequences of 2 DL 3*00105, 2 DL 3*00106, 2 DL 3*00107 and 2 DL 3*00108 had one nucleotide substitution(789T>C, 261C>T, 489G>A and 405G>A),but none resulted in amino acid change. An A>G substitution was observed in nucleotide position 476 in 2 DL 3*019, 608 G>A in 2 DL 3*020, 824T>C in 2 DL 3*021 and 238 G>A in 2 DL 3*023. In addition, 2 DL 3*022 probably arose from 2 DL 3*00201 with a nucleotide substitution G>A at 550. There were more HLA ‐C1 positive individuals than HLA ‐C2. In conclusion, the data of allelic polymorphism for KIR 2 DL 2 and KIR 2 DL 3 were obtained in the Chinese Han population and ten novel KIR 2 DL 3 alleles were identified.