1例造血干细胞捐献者HLA新等位基因A~*33∶88家系调查及A~*33∶88模拟蛋白质三级空间结构分析  

Investigation for the heritage of a new HLA allele A* 33:88 in a hematopoietic stem cell donor and analysis of its 3D model structure

作　　者：裴永峰 李恒聪 黄惠妮 吴国光 PEI Yongfeng LI Hengcong HUANG Huini WU Guoguang(Nanning Institute of Transfusion Medicine, Nanning Blood Center, Nanning 530007, China)

机构地区：[1]南宁中心血站输血医学研究所,南宁530007

出　　处：《山东医药》2017年第7期23-26,共4页Shandong Medical Journal

基　　金：广西壮族自治区卫生厅科技研究计划项目(Z2010198);南宁市科学研究与技术开发计划项目(201003048C-3)

摘　　要：目的对1例造血干细胞捐献者HLA新等位基因A*33:88进行家系调查,初步分析A*33:88模拟蛋白质三级空间结构。方法 1例造血干细胞捐献者(先证者)及其父母,抽取先证者及父母静脉血5 m L,检测先证者及其父母ABO、Rh红细胞血型。取抗凝全血200μL,提取DNA后采用多聚酶链式反应-基于测序的分型技术(PCR-SBT)方法进行HLA分型(HLA-A、HLA-B、HLA-DRB1位点分型)。采用SWISS-MODEL方法,以同源性最高的HLA-A*3α链为模板进行构建,得到模拟的A*33:88蛋白质三级结构并进行分析。结果先证者及其父母血型均为O型,Rh血型均为D/Cc Ee,符合遗传规律。先证者HLA-A位点分别为A*11∶01、A*33∶88,先证者父亲为A*33∶03、A*33∶03,先证者母亲为A*11∶01、A*11∶01,A*33∶88和A*33∶03∶01的差异是在第3外显子475位的G>A,密码子135由GCG变为ACG,编码的氨基酸由丙氨酸(A)转变为苏氨酸(T)。A*33∶88模拟蛋白质三级空间结构与A*33∶03∶01模拟蛋白质三级空间结构相比,编码氨基酸在135位由非极性疏水氨基酸(A)转变为极性亲水氨基酸(T),改变的氨基酸位于抗原肽结合区α-螺旋(132-178)位置,此位置为抗原(多肽)结合凹槽的侧壁。结论 HLA新等位基因A*33:88(HWS10022752)不由先证者母方突变所致,可能由父方产生突变所致,该突变能正常遗传给后代。A*33:88的蛋白质模拟三级空间结构分析,显示替代氨基酸位于抗原肽结合区α-螺旋上。Objective To investigate the heritage of a novel human leukocyte antigen（ HLA） allele A＊ 33： 88 in a hematopoietic stem cell donor and to analyze its 3D model structure of HLA molecule. Methods One hematopoietic stem cell donor（ proband） and their parents were included,and then,5 m L proband and parental venous blood was collected to detect their blood groups of ABO,Rh red blood cells. We took anticoagulated whole blood 200 μL to extract DNA. Subsequently,HLA typing（ HLA-A,HLA-B,HLA-DRB1 site typing） was performed using polymerase chain reaction sequencing-based typing（ PCR-SBT）. The A＊ 33： 88 protein 3D structure was constructed by the SWISS-MODEL on the basis of taking the HLA-A＊ 3α chain with the highest homology as the template to construct,after that,we analyzed the 3D structure of the protein. Results The proband and their parents’ blood groups were O-type,Rh blood group was D / Cc Ee,which was consistent with genetic law. The HLA-A genotype of the donor was A＊ 11∶ 01 and A＊ 33： 88,the HLA-A genotype of the donor’s father was A＊ 33∶ 03 and A＊ 33∶ 03,the HLA-A genotype of the donor’s mother was A＊ 11∶ 01 and A＊ 11∶ 01. The difference between A＊ 33： 88 and A＊ 33： 03 ∶ 01 was in the third exon at position 475 G 〉 A（ codon 135 GCG 〉 ACG）,and Gla（ A） was changed to Thr（ T）. We compared the 3D model structure between A＊ 33∶ 88 and A＊33∶ 03∶ 01. The encoded amino acid at residue 135 was changed from polar non-polar hydrophobic amino acid（ A） to polar hydrophilic amino acid（ T）. The altered amino acid was located at the α-helix（ 132-178） position of the antigen peptide binding region, which was the side wall of the antigen polypeptide. Conclusions The new allele A ＊ 33： 88（ HWS10022752） is generated from proband father’s mutation,which can be passed to his children. According to its 3D model structure,the amino acid substitution is located in α-helices of antigenic peptide-biding region.

关 键 词：人类白细胞抗原 等位基因 人类白细胞抗原新等位基因 A＊33 人类白细胞抗原基因 

分 类 号：R392.2[医药卫生—免疫学]