摘要
目的分析在中国人群中鉴定出的46个HLA新等位基因的特征,为造血干细胞移植患者选择HLA基因相合供者提供帮助。方法根据PCR直接测序法(polymerase chain reaction sequence-based typing,PCR-SBT)及单等位基因组特异性测序得到的新等位基因序列,分析碱基突变类型和位置、氨基酸突变类型和性质变化,构建蛋白分子三维结构模型。结果46个HLA新等位基因包括A位点11个、B位点13个、C位点13个、DRB1位点3个、DQB1位点6个。碱基突变数57个,其中53个为点突变,3个缺失,1个插入。氨基酸突变既有同义突变(12个),也有错义突变(40个)以及移码突变(4个)。氨基酸的性质有22个未发生改变,其余30个则发生了不同的性质改变。HLA-Ⅰ类分子突变的位置大多发生在胞外区,包括α1结构域(13个)、α2结构域(11个)、α3结构域(15个),也有少部分发生在跨膜区(4个)、胞浆区(1个),还有1个发生在先导序列。HLA-Ⅱ类分子的所有突变都发生在胞外区,包括β1结构域9个和β2结构域2个。三个缺失突变的新等位基因都发生了蛋白质翻译的提前终止。对4个多碱基突变的新等位基因核酸片段序列在EMBL-EBI数据库中进行查找比对,分析其突变可能是通过基因转换而生成的。结论我们对这些新等位基因的分析展示了可能促成HLA多态性进化的不同机制,这些资料将有助于临床医生为造血干细胞移植患者找到HLA基因相合的供者,提高配型成功率。
Objective This study aims to analyze the characteristics of 46 new HLA alleles identified in the Chinese indivivduals and provide insights into selecting HLA-matched donors for hematopoietic stem cell transplantation patients.Methods Based on the sequences of the new alleles obtained by PCR-SBT and group-specific allele amplification sequencing methods,we analyzed the types and positions of nucleotide mutations,amino acid substitutions and their property changes,and constructed three-dimensional structural models of the protein molecules.Results The 46 new HLA alleles include 11 HLA-A,13 HLA-B,13 HLA-C,3 HLA-DRB1 and 6 HLA-DQB1 loci.There are 57 base mutations,of which 53 are point mutations,3 are nucleotide deletions,and 1 is a nucleotide insertion.The amino acid mutations include both synonymous mutations(12)and missense mutations(40),as well as frameshift mutations(4).Of the amino acid substitutions,22 did not alter the nature of the amino acids,while the remaining 30 resulted in different changes in amino acid properties.Mutations in HLA classⅠmolecules mostly occurred in the extracellular regions,including the α1 domain(13),α2 domain(11),andα3 domain(15),with a few in the transmembrane region(4),cytoplasmic region(1),and 1 in the leader sequence.All mutations in HLA class Ⅱ molecules occurred in the extracellular regions,including the β1 domain(9)and β2 domain(2).The three new alleles with deletion mutations resulted in premature termination of protein translation.The nucleotide sequences of the four new alleles with multiple base mutations were searched and aligned in the EMBL-EBI database to analyze whether the mutations might have been generated through gene conversion.Conclusion Our analysis of these new alleles demonstrates the different mechanisms that may contribute to the evolution of HLA polymorphism.These findings will help clinicians identify HLA-matched donors for hematopoietic stem cell transplantation patients and improve the success rate of matching.
作者
李冬妹
张丹
敬媛媛
王洁
王丽君
李伟
贾延军
LI Dongmei;ZHANG Dan;JING Yuanyuan;WANG Jie;WANG Lijun;LI Wei;JIA Yanjun(Beijing Red Cross Blood Center,Beijing 100088)
出处
《临床输血与检验》
2025年第6期821-829,共9页
Journal of Clinical Transfusion and Laboratory Medicine
基金
北京市科技计划项目(No.Z241100009124007)资助。
