HLA-DQB1*02:106鉴定和相关单体型分析及蛋白三级结构分析  

HLA-DQB1*02:106 identification,related haplotype analysis and molecular structure analysis

作　　者：王天菊 齐珺 李恒新 王满妮 王小芳 WANG Tian-Ju;QI Jun;LI Heng-Xin;WANG Man-Ni;WANG Xiao-Fang(Xi'an Blood Center,High Resolution HLA Typing Laboratory,Xi'an 710061,China)

机构地区：[1]西安市中心血站HLA高分辨分型确认实验室,西安710061

出　　处：《中国免疫学杂志》2021年第19期2385-2390,2395,共7页Chinese Journal of Immunology

基　　金：西安市科技计划项目[20YXYJ0009(5),201805095YX3SF29(4)]资助。

摘　　要：目的:鉴定分析1例携带人类白细胞抗原(HLA)罕见等位基因DQB1*02:106,分析其核苷酸和氨基酸序列,预测分析其氨基酸残基改变在编码蛋白分子三维空间结构的影响并分析其家系遗传单体型。方法:应用直接测序(PCR-SBT)和序列特异性寡核苷酸探针(PCR-SSOP)对1例急性髓细胞白血病患者进行异基因造血干细胞移植前HLA-A/B/C/DQB1/DRB1高分辨确认分型时发现DQB1位点存在模棱两可,应用下一代测序技术(NGS)确定HLA-DQB1分型;分析其与同源性最高的HLA-DQB1等位基因氨基酸差异和位置,用Swiss-Model分析差异氨基酸位置,Phyre2软件进行同源建模后FATCAT在线软件对分子间三维结构进行差异比对。结果:该个体HLA-DQB1位点的结果为HLA-DQB1*02:106;与同源性最高的HLADQB1*02:01:01:01相比,在第3外显子619位置G突变为A,并导致相应的175位密码子由GTG变为ATG,编码氨基酸由缬氨酸变为蛋氨酸。该突变位置为β2链β片层,DQB1*02:106和DQB1*02:01分子β1和β2链均方根偏差(RMSD)为1.65。经家系分析,DQB1*02:106相关的单体型为A*31:01-B*15:18-C*04:01-DRB1*03:01-DQB1*02:106。结论:确认并分析了1个能够稳定遗传的HLA-DQB1罕见等位基因及家系单体型,经同源建模显示罕见等位基因HLA-DQB1*02:106与常见基因型存在氨基酸三维结构差异,提示移植医生应予以关注。Objective:To identify and analyze a rare human leukocyte antigen(HLA)allele DQB1*02:106,analyze its nucle-otide and amino acid sequence,predict and analyze the impact of its amino acid residue changes on the three-dimensional structure and analyze its family genetic haplotype.Methods:Polymerase chain reaction-sequence based typing method(PCR-SBT)and poly-merase chain reaction-sequence specific oligonucleotide probes(PCR-SSO)were conducted for HLA-A/B/C/DQB1/DRB1 high reso-lution genotyping on a patient with acute myeloid leukemia before allogeneic hematopoietic stem cell transplantation,DQB1 locus was ambiguous.Then next generation sequencing(NGS)was used to identify the HLA-DQB1 allele.By analyzing the amino acid difference and position of HLA-DQB1 allele with the highest homology,positions of different amino acids were used to analyzed using Swiss-Model,encoded molecular protein structure were models and analyzed with Phyre2 and FATCAT software.Results:Results of HLA-DQB1 locus is HLA-DQB1*02:106 which differs from the closest matching allele DQB1*02:01 at position 619 where G>A,which changed the condone 175 from GTG>ATG with amino acid change Val to Met.Modeling of the three-dimensional structure of the encoded protein molecule indicates that the amino acid residues variation is located at theβpleated sheet of theβ2 domain.The root mean square deviation(RSMD)between DQB1*02:106 and DQB1*02:01 moleculeβ1 andβ2 chain is 1.65.The haplotype in associ-ation with DQB1*02:106 may be deduced as A*31:01-B*15:18-C*04:01-DRB1*03:01-DQB1*02:106.Conclusion:A rare allele of HLA-DQB1 and related haplotype that can be inherited stably were confirmed and analyzed.Homology modeling of rare genotype DQB1*02:106 and common genotype presented three-dimensional structure differentiation,that prompts transplant doctor to pay attention.

关 键 词：人类白细胞抗原 罕见等位基因 单体型 HLA分子三维结构模拟分析 

分 类 号：R392.2[医药卫生—免疫学]