HLA-C Expression Level In Chinese Han Population And HLA-KIR Receptor Distribution In Yunnan Dulong Population

ObjectiveTo determine peripheral blood and cord blood HLA-C expression level and their relative factors in Chinese population;to provide basic data for defining permissible and non-permissible HLA-C mismatch in hematopoietic stem cell transplantation.MethodsHigh-resolution HLA-C sequencing typing performed using PCR-SBT in peripheral blood and cord blood.Peripheral blood and cord blood were analyzed by flow cytometry for HLA-C antigen expression level;Peripheral blood and cord blood were analyzed by qPCR for total HLA-C mRNA transcription level using locus-specific primer.Peripheral blood was analyzed by qPCR for HLA-C*01:02,C*07;02,C*06:02 and C*03:04 mRNA transcription level using allele-specific primer.The rs2395471 genotypes were determined by Sanger sequencing.We analyzed the association between rs2395471 genotypes and HLA-C antigen expression level and linkage disequilibrium(LD)relationships between rs2395471 genotypes and HLA-C allotypes.ResultsAmong 105 healthy volunteers,seventeen HLA-C alleles were detected.Mean level of HLA-C antigen expression level in peripheral blood was 258 ± 86(MFI).There was significant difference in each HLA-C antigen expression level.HLA-C antigen expression level were higher for C*01:02,14:02 and lower for C*03:02,07:01,07:02,08:01 and 12:02.Mean level of HLA-C mRNA transcription level in peripheral blood was 0.77(2-??Ct).Variation of each HLA-C mRNA transcription is small.HLA-C*06:02 and 15:02 showed higher mRNA transcription level,with statistic significance(P<0.05).Among 150 cord blood samples,eighteen HLA-C alleles were detected.Mean level of HLA-C mRNA transcription level was 0.42(2-??Ct).There was no significant difference for HLA-CmRNA transcription level in cord blood.HLA-C antigen expression level was highest for rs2395471_AA genotype,lowest for rs2395471_GG genotype and moderate for rs2395471_AG genotype in Chinese Han population.rs2395471_A was in complete linkage disequilibrium with HLA-C*04:02,04:01,06:02,12:02,14:02,15:02 and rs2395471_G was in complete linkage disequilibrium with HLA-C*03:02,03:03,03:04,07:02,08:01.ConclusionPeripheral blood HLA-C antigen expression level and mRNA transcription level were associated with HLA-C allotypes in Chinese Han population.HLA-C alleles were in complete linkage disequilibrium with rs2395471 genotypes.HLA-C alleles can be divided into higher expression level and lower expression level groups,according to rs2395471 genotypes.Allele-specific primer qPCR is more a reflection of HLA-C mRNA transcription level than locus-specific primer qPCR.Cord blood HLA-C antigen expression level and mRNA transcription level were at lower level.ObjectiveTo analyze the polymorphisms and gene frequencies of killer immunoglobulin-like receptors(KIR)and HLA and the combinations of KIR/HLA in Yunnan Drung population,the results will provide the basis for further studying the functions of KIR/HLA in anthropology,transplantation immunity and disease association.MethodThe study population consisted of 152 unrelated healthy individuals which were randomly selected from the Drung ethnic minority.The presence and absence of KIR genes were typed using multiplex PCR-SSP(sequence-specific priming).The genotypes were designated according AFND(The Allele Frequency Net Database).High-resolution HLA sequencing was performed by PCR-SBT(sequence-based typing).Differences in frequency were assessed by the standard ?2 test in SPSS version 19.0.A dendrogram was constructed by the neighbor-joining method and visualized with MEGA software.ResultIn Drung population,All 16 known KIR genes were detected.The framework genes KIR2DL4,3DL2,3DL3,and 3DP1 were detected in all individuals along with KIR2DL1,2DL3,and 2DP1.KIR2DS4 and KIR3DL1 were with high frequencies(97%and 98%).However,the frequency was lower for KIR2DL2(7%),2DL5(30%),2DS1(28%),2DS2(7%),2DS3(20%),2DS5(11%)and 3DS1(28%).A total of 10 KIR genotypes were identified,in which the genotypes named ID 1(66.4%),ID2(9.2%)and ID8(14.5%)were predominant.There were 8 different haplotypes,in which the haplotypes named A1(81.9),B1(8.9%)and B2(5.3%)were predominant.The frequencies of HLA-C1 and C2 were 92.1%and 7.9%respectively.The frequencies of HLA-A and-B containing Bw4 were 5.3%and 6.6%respectively.Inhibitory KIR/HLA-C pairs were detected in all individuals.The individuals contained one,two and three KIR/HLA-C pairs accounting for 86.9%,8.5%and 4.6%all individuals.For the KIR/HLA-Bw4 pairs,both KIR3DL1+HLA-Bw4 and KIR3DS1+HLA-Bw4 showed lower frequencies(12.5%and 1.3%,respectively).The individuals contained both KIR3DL1+HLA-Bw4 pairs and KIR3DS1+HLA-Bw4 pairs accounting for 5.3%.The most individual in our study had no KIR/HLA-Bw4 pair(80.9%).ConclusionDistinctive features of the distribution of KIR,HLA and the KIR/HLA pairs were observed in Yunnan Drung population.Inhibitory KIR/HLA pairs were predominant pairs.