人类白细胞抗原（HLA）系统及其生物医学意义

ＨＬＡ（ｈｕｍａｎｌｅｕｋｏｃｙｔｅａｎｔｉｇｅｎ，人类白细胞抗原）系统是目前所知人体最复杂的多态系统。自１９５８年发现（ＪｅａｎＤａｕｓｓｅｔ）第一个ＨＬＡ抗原，到７０年代，ＨＬＡ便成为免疫遗传学、免疫生物学和生物化学等学科的一个重要新兴研究领域。...     

mPEG修饰HLA抗原的方法学研究

为了研究mPEG有效修饰HLA抗原,阻断HLA抗原与其相应抗体间特异性免疫反应的方法．在22℃,pH7．4的PBS介质中,采用浓度梯度法修饰淋巴细胞表面HLA抗原．结果显示经mPEG处理后的淋巴细胞表面HLA-1类抗原与其相应抗体间的微量淋巴细胞毒试验为阴性．由此可以得出结论,经mPEG修饰后可以完全阻断HLA—I类抗原与其相应抗体间的特异性免疫反应．     

HLA—DR抗原与多肽的结合

ＨＬＡ┐ＤＲ抗原与多肽的结合姜良勇王福庆（上海第二医科大学生化教研室,上海２０００２５）关键词人类白细胞抗原系统ＨＬＡ抗原肽人类白细胞抗原系统（ＨＬＡ）是迄今所知人类最复杂、多态性程度最高的遗传系统。ＨＬＡ中某些等位基因与疾病的相关性已为人们所熟知,...     

中国汉族人群人类白细胞抗原HLA不同基因座位间的基因重组

人类白细胞抗原(human leucocyte antigen, HLA)复合体基因座位间的重组、重组热点、连锁不平衡与疾病易感性的关联性研究已成为免疫遗传学与人类后基因组学等研究领域的研究重点与焦点. 本文报道了在中国汉族人群中发现的10例HLA复合体中的基因重组家系. 采集重组家系的2~3代家庭成员的外周血标本, 首先对其HLA-Ⅰ, Ⅱ类区域的5个经典基因位点进行PCR-SSP低、高分辨率基因分型及SBT分析, 然后再进行遗传家系分析研究, 确定HLA基因重组相关位点, 并对重组家系的单体型进行了群体统计学分析. 结果发现, 在10例HLA重组家系中有8例重组发生在HLA-A/Cw位点之间, 其中4例重组发生在A*02-Cw*03单体型中, 2例重组发生在A*24-Cw*03单体型中; 1例重组发生在HLA-B/DRB1位点之间, 还有1例重组发生在HLA-B/Cw位点之间. 群体统计学分析发现, A*02-Cw*03单体型呈一定程度的连锁不平衡但不是很强(Δ/δ_(Δ) = 3.0, Δ_(r) = 0.30); 另有3个单体型虽呈强连锁不平衡却发生了重组事件, 即A*33-Cw*03 (Δ/δ_(Δ) = 7.22, Δ_(r) = 0.51), A*30-Cw*06(Δ/δ_(Δ) = 10.37, Δ_(r) = 0.93)和 B*13-Cw*03(Δ/δ_(Δ) = 7.69, Δ_(r) = 0.38), 这说明重组可能是打破旧的连锁不平衡来产生新的连锁不平衡的重要原因. 本文绘制了每个重组家系成员的HLA单体型, 并建立了中国汉族人群的HLA重组遗传图谱, 初步定位重组发生的范围并分析了位点间重组与连锁不平衡的关系, 这为更深入地研究HLA重组事件奠定了基础.     

人类白细胞抗原-G分子结构与功能

人类白细胞抗原G（humanleukocyteantigen．G,HLA—G）属于非经典的HLAI类分子,是机体内一个重要的免疫耐受分子。HLA—G分子可通过与受体结合直接抑制多种免疫活性细胞的生物学功能,或通过诱导产生免疫调节细胞间接抑制机体的免疫应答。研究显示,HLA-G基因多态性及分子表达在母胎免疫、器官移植、肿瘤的发生发展、感染和自身免疫中均有重要意义。     

人类白细胞抗原与鼻咽癌的相关性

鼻咽癌是一种多因素影响的复杂性疾病, 其发病具有显著的地理分布差异。Epstein-Barr(EB)病毒感染与鼻咽癌发病密切相关已得到公认, 但环境因素及遗传因素在鼻咽癌的发病中也具有重要作用。在鼻咽癌的遗传相关因素中, 位于6号染色体上具有高度多态性的人类白细胞抗原(Human leukocyte antigen, HLA)与鼻咽癌发病风险相关在多个研究组中被报道。随着DNA测序技术的发展, 高分辨基因分型技术的应用, HLA新等位基因数目呈指数级的上升, 更多的HLA全基因序列被研究者所报道。近年来, 等位基因关联性分析、微卫星连锁不平衡分析及全基因组关联性分析的研究结果均证实了6号染色体HLA区域与鼻咽癌具有显著关联。为了进一步探讨遗传相关性因子HLA在鼻咽癌发生发展中的作用, 文章着重综述了HLA与鼻咽癌相关性研究的最新进展, 为鼻咽癌HLA相关性研究提供新的思路。     

人类白细胞抗原的检测以及与临床疾病的关系

人类白细胞抗原(HLA)的检测最初用于器官移植,但近年来,HLA作为免疫遗传基因在与免疫调节有关的疾病中所扮演的重要角色愈来愈受到重视。本就HLA的检测方法以及与某些临床疾病的关系加以论述。     

HLA 抗原的DNA 分型

HLA系统定位于6p2l.3, 是人体内最复杂的遗 传多态性系统,在免疫调控过程中发挥重要作用。 HLA I类基因区域包括HLA-A, B, C, E, F, G基因 和11个假基因“‘’。HLA一A, B和C基因座编码A, B 和C抗原a链(44kd),它通过第三个功能区与受痊于 第15号染色体的月,微球蛋白链(12kd）作非共价结 合构成杭原分子,其多态性取决于。链的第一、二功能 区。HLA-E, F和G基因编码I类样产物,其功能未 明。I类抗原分布于任何有核全』饱表面,主要参与提 供外来伉原给T细胞毒细胞「’“’。HLA II类基因座在 HLA-D区,主要包括HLA-DR, DQ和DP三个}2 区。DR亚区有6个基因座：DRA, DRB1, DPB2, DRB3, DRB4和DRB5, 其中DRB2为假基因;DQ 亚区有4个居因座：DQA1, DQB1, DQA2和DQB2, 其中DQA2和DQB2未知有产物表达;DP亚区也 有4个基因座：DPA1, DPB1, DPA2和DPB2,其 中DPA2和DPB2为假基因。此外,还有DO和DN 两个新亚区,各具有DOB和DNA（注意勿与脱氧核塘 核酸的缩写DNA相混淆）,分别产生DO(链和DNa 链「‘’。11类抗原HLA-DR, DQ和DP存在于B淋巴 细胞、巨噬细胞和激活的T淋巴细胞表面, 由。链 (32-35kd）和R链(28-30kd）非共价组成。。链无 多态性或多态性程度不高,R链的第一功能区呈现高 度多态性。11类抗原参与提皇外来伉原给T辅助细 胞,后者在识别外来伉原的同时识别HLA 11类坑 原「,,’。据1987年第十届国际组织相容性试验专题会 议报道,HLA系统检出148种抗原特异性,其中A基 因座24种,B基因座52种,C基因座11种,D区26 种,DR亚区20种,DQ亚区9种和DP亚区6种。 HLA-A, B, C, DR和DQ抗原系由特异性同种异 体抗血清检出,HLA-D和DP抗原则由纯合分型细胞 (HTC)和预致敏淋巴细胞分型(PLT）方法检出,两者 是以混合淋巴细胞培养(MLC）方法为基础的。近年 发展用蛋白质化学方法研究HLA系统抗原多态性L77o 自1975年Southern印迹法〔247间世后,运用HLA系 统基因探针通过分析限制性片段长度多态性(Restriction Fragment Length Polymorphism, RFLP）在DNA. 水平上进行分型。八十年代中期开始,聚合酶链反应 (Polymerase Chain Reaction, PCR）技术的创立为分 子生物学发展开辞了一个新起点。许多研完Hl.h系 统的实验室竞相运用PCR技术,结合等位基因特异的 寡核昔酸（Allele-specific Oligonucleotide, ASO)或 顺序特异的寡核普胶(Sequence-specific Oligonucleotide, SSO)探针对HLA系统进行寡核昔酸分型,2_3 也有直接利用PCR扩增产物作RFLP分沂进行DNA 分型「'6,,"' + O DNA分型方法适用于任何有核细袍, 显示的结果与血清学或细胞学分型结果高度对应,而 且能够发现血清学或细抱学方法不能检测的额外特异 性,在理论上有助于进一步研究HLA系统基因的结构 和功能。对一些无法作常规分型的病例如裸露淋巴细 胞综合征、严重联合免疫缺乏症等,DNA分型叮解决 骨髓移植供受体配型问题‘哪’。     

HLA复合体与感染性疾病的关系

人类白细胞抗原（ＨＬＡ）是人类主要组织相容性复合体（ＭＨＣ）的基因产物,为目前已知的最复杂的人类基因复合体。由于ＭＨＣ分子在个体免疫调节中起主要作用,故其在控制个体对疾病的易感性方面也起重要作用。本文总结了近年来ＨＬＡ复合体与感染性疾病相关性的研究进展。     

Human leukocyte antigen (HLA) complex and anti-thyroidal antibodies in Graves' disease

The study aimed at: 1) assessing occurrence of HLA-A, HLA-B and HLA-C antigens in patients with Graves' disease in comparison with control group of healthy individuals; 2) determining relationship between circulating serum antimicrosomal and antithyroglobulin antibodies and selected HLA complex antigens. Human leukocyte antigens A, B, and C were detected with serological technique using cytotoxicity test. Thyroidal antimicrosomal and antithyroglobulin antibodies were titrated with radioimmunological solid phase technique while anti-membrane antibodies with immunoenzyme technique. The study involved 50 patients with Graves' disease and 50 healthy individuals. HLA-B8, HLA-B15, HLA-B35, and HLA-Cw3 antibodies were detected more frequently in patients with Graves' disease than in the healthy individuals. Antimicrosomal and antithyroglobulin antibodies were detected in the same group in 76% and 58% of patients, respectively whereas anti-membrane antibodies in 92% of patients. Comparison of the occurrence of thyroidal antimicrosomal and antithyroglobulin antibodies with the presence of HLA-B8, HLA-B35, HLA-B15, and HLA-Cw3 antigens did not show statistically significant correlation between these two parameters.     

Human leukocyte antigen (HLA)-C polymorphisms are associated with a decreased risk of rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune rheumatological disease thought to have substantial genetic contributions. Several genetic factors involved in the susceptibility to psoriasis and psoriatic arthritis (PsA) have been identified with genome-wide association studies, including human leukocyte antigen (HLA)-C, junction adhesion molecule 2 (JAM2) and REL. Psoriasis and PsA may share many features in common with RA. We hypothesized that this polymorphism may contribute to RA susceptibility in a Chinese population. We studied HLA-C rs10484554 C/T, HLA-C rs12212594 T/C, HLA-C rs12191877 C/T, JAM2 rs2829866 A/T and REL rs702873 G/A polymorphisms in 520 patients with RA and 520 controls in a Chinese population. HLA-C rs12191877 C/T polymorphism was in complete linkage disequilibrium (LD) (D′ = 1.0, r ² = 1.0) with HLA-C rs10484554 C/T polymorphism. When the HLA-C rs10484554 CC homozygote genotype was used as the reference group, the TT/CT genotypes were associated with a significantly decreased risk for RA (adjusted OR = 0.72, 95 % CI = 0.52–0.99, p = 0.044). We found that the HLA-C rs12191877 C/T polymorphism was also associated with a decreased risk of RA. HLA-C rs12212594 T/C, JAM2 rs2829866 A/T and REL rs702873 G/A polymorphisms were not associated with the risk of RA. These results provide evidence that HLA-C polymorphisms are associated with a decreased risk of RA.     

Human leukocyte antigen (HLA) class I restricted epitope discovery in yellow fewer and dengue viruses: importance of HLA binding strength

Epitopes from all available full-length sequences of yellow fever virus (YFV) and dengue fever virus (DENV) restricted by Human Leukocyte Antigen class I (HLA-I) alleles covering 12 HLA-I supertypes were predicted using the NetCTL algorithm. A subset of 179 predicted YFV and 158 predicted DENV epitopes were selected using the EpiSelect algorithm to allow for optimal coverage of viral strains. The selected predicted epitopes were synthesized and approximately 75% were found to bind the predicted restricting HLA molecule with an affinity, K(D), stronger than 500 nM. The immunogenicity of 25 HLA-A*02:01, 28 HLA-A*24:02 and 28 HLA-B*07:02 binding peptides was tested in three HLA-transgenic mice models and led to the identification of 17 HLA-A*02:01, 4 HLA-A*2402 and 4 HLA-B*07:02 immunogenic peptides. The immunogenic peptides bound HLA significantly stronger than the non-immunogenic peptides. All except one of the immunogenic peptides had K(D) below 100 nM and the peptides with K(D) below 5 nM were more likely to be immunogenic. In addition, all the immunogenic peptides that were identified as having a high functional avidity had K(D) below 20 nM. A*02:01 transgenic mice were also inoculated twice with the 17DD YFV vaccine strain. Three of the YFV A*02:01 restricted peptides activated T-cells from the infected mice in vitro. All three peptides that elicited responses had an HLA binding affinity of 2 nM or less. The results indicate the importance of the strength of HLA binding in shaping the immune response.     

Human leukocyte antigen profile in HIV-1 infected individuals and AIDS patients from Chongqing, China

HIV/AIDS is currently the leading cause of infectious disease mortality around the world. Since many alleles and/or haplotypes of HLA have been reported to be associated with progressive HIV infection, more detailed information on the HLA profile in HIV‐1 infected individuals in Chongqing, southwest China would facilitate further understanding of HIV‐1 infection, help AIDS vaccine design and the planning of effective preventive strategies. In this study, we performed 4‐digit resolution HLA‐A, B, DRB1 genotyping of 759 HIV‐1 seropositive individuals using PCR‐SSO methods. Six alleles were found at more than 10% high frequency: A*1101, A*0201, A*2402, B*4601, B*4001 and DRB1*0901. The most common 2‐ and 3‐locus haplotypes were A*0201‐B*4601, A*1101‐B*4001, A*1101‐B*4601, A*3303/1‐B*5801, A*0201‐B*4601‐DRB1*0901, A*1101‐B*4601‐DRB1*0901 and A*3303/1‐B*5801‐DRB1*0301. 690 HIV‐1 seropositive individuals with records of CD4 counts were divided into two groups: an AIDS patient group comprising 216 subjects with AIDS‐defining symptoms and CD4 counts below 200 cells/mm³ and an asymptomatic, HIV seropositive group of 474 subjects with a stable CD4 count of no less than 200 individuals. In the AIDS patient group, A*3303/1 and B*5801 alleles and the A*3303/1‐B*5801 haplotype were significantly underrepresented as compared to the HIV‐infected group, whereas A*1101‐B*4001, A*1101‐B*1502, A*2402‐B*4801 haplotypes and five common haplotypes from two groups were significantly overrepresented. HLA‐A or B and HLA‐Bw6‐Bw6 homozygotes were also overrepresented in the AIDS patients group. Our observations suggest that the presence of the B*3501 allele, A*2402‐B*4801, common 2‐locus and 3‐locus haplotypes, HLA‐A or B and Bw6‐Bw6 homozygosity may predict a poor disease outcome in HIV‐1 infection. However, HIV‐1 infected individuals who have B*5801 alleles, A*3303/1‐B*5801 haplotype and are heterozygous for Bw4‐Bw6 are more likely to be resistant to progression of AIDS in this Chinese population.     

HLA antigen,gene, and haplotype frequencies in Thailand

Summary Antigen, gene, and haplotype frequencies as well as phenotype distribution of the HLA system were studied in a series of 213 individuals in northern Thailand. The series consisted of 160 northern Thais, 23 Thai individuals from various other regions of Thailand, and 25 persons of Chinese origin. Most frequently found were the alleles HLA-A11 and HLA-Bw40 and the haplotype HLA-A2, B-. Phenotype distribution followed a Hardy-Weinberg expectation. Significant differences were found especially between our results for the alleles of locus B and the results of a series from Bangkok reported by Chiewsilp and Chanarat (1976).     

Mutation of Cys-67 alters the thermodynamic stability of the human leukocyte antigen HLA0-B*2705

The B pocket of the class I major histocompatibility complex-encoded protein HLA-B*2705 has recently been suggested to be responsible for the misfolding of this HLA haplotype and thus to induce susceptibility to autoimmune inflammatory diseases. Four mutants of the B*2705 heavy chain were refolded in the presence of three control peptides. The monitoring of the thermal unfolding of the B*2705-peptide complexes by circular dichroism spectroscopy showed that all heterotrimeric mutants were markedly less stable than the corresponding complexes with the wild-type heavy chain. Among the four heavy chain mutations, the C67S change was investigated for unfolding and peptide binding properties because this position may mediate disulfide pair bridging and alter T-cell recognition of HLA-B*2705. Wild-type heterotrimers completely unfold in a single transition at mild acidic pH whereas increase of the pH to mild basic conditions induce only a partial biphasic unfolding. Cys-67 seems to play a crucial role in controlling the thermodynamic stability of the B*2705-peptide complexes as the C67S mutant unfolds faster and with a single transition, independent of pH. Fluorescence polarization and size exclusion chromatography of unfolding intermediates suggest that the peculiar unfolding of the B*2705 wild-type heavy chain cannot be explained by modified peptide binding properties but more likely by the formation of high molecular weight species.     

Importance of human leukocyte antigen (HLA) class I and II alleles on the risk of multiple sclerosis

Multiple sclerosis (MS) is a complex disease of the central nervous system of unknown etiology. The human leukocyte antigen (HLA) locus on chromosome 6 confers a considerable part of the susceptibility to MS, and the most important factor is the class II allele HLA-DRB1*15:01. In addition, we and others have previously established a protective effect of HLA-A*02. Here, we genotyped 1,784 patients and 1,660 healthy controls from Scandinavia for the HLA-A, HLA-B, HLA-C and HLA-DRB1 genes and investigated their effects on MS risk by logistic regression. Several allele groups were found to exert effects independently of DRB1*15 and A*02, in particular DRB1*01 (OR = 0.82, p = 0.034) and B*12 (including B*44/45, OR = 0.76, p = 0.0028), confirming previous reports. Furthermore, we observed interaction between allele groups: DRB1*15 and DRB1*01 (multiplicative: OR = 0.54, p = 0.0041; additive: AP = 0.47, p = 4 × 10(-06)), DRB1*15 and C*12 (multiplicative: OR = 0.37, p = 0.00035; additive: AP = 0.58, p = 2.6 × 10(-05)), indicating that the effect size of these allele groups varies when taking DRB1*15 into account. Analysis of inferred haplotypes showed that almost all DRB1*15 bearing haplotypes were risk haplotypes, and that all A*02 bearing haplotypes were protective as long as they did not carry DRB1*15. In contrast, we found one class I haplotype, carrying A*02-C*05-B*12, which abolished the risk of DRB1*15. In conclusion, these results confirms a complex role of HLA class I and II genes that goes beyond DRB1*15 and A*02, in particular by including all three classical HLA class I genes as well as functional interactions between DRB1*15 and several alleles of DRB1 and class I genes.     

Assembly and dissociation of human leukocyte antigen (HLA)-A2 studied by real-time fluorescence resonance energy transfer

Class I major histocompatibility complex (MHC) heterodimer, composed of human leukocyte antigen (HLA)-A2 heavy chain and human beta(2)-microglobulin (beta(2)m), was produced by denaturation and gel filtration of the recombinant water-soluble HLA-A2/beta(2)m/peptide ternary complex in 8 M urea Tris-HCl buffer, followed by refolding of the separated chains without peptide. Peptide affinity and kinetics of the ternary complex formation and dissociation were investigated in real time by monitoring the fluorescence resonance energy transfer (FRET) from intrinsic HLA-A2 heavy-chain tryptophans to a dansyl fluorophore conjugated to the bound peptide. Peptide binding to the heterodimer was a second order process with rate constants linearly dependent upon temperature in Arrhenius coordinates over 0-20 degrees C. The binding rate constant of pRT6C-dansyl [ILKEPC(dansyl)HGV] at 37 degrees C evaluated by extrapolation of the Arrhenius plot was (2.0 +/- 0.5) x 10(6) M(-1) s(-1). Association of the heavy chain with beta(2)m was a first order process, apparently controlled by a conformational transition in the heavy chain. One of these conformations bound to beta(2)m to form the heavy chain/beta(2)m heterodimer whereas the second conformer oligomerized. Peptide dissociation from the ternary complex was a first-order reaction over the temperature range 20-37 degrees C, suggesting that the ternary complex also exists in two conformations. Taken together, the present data suggest that association of beta(2)m changes the HLA-A2 heavy-chain conformation thereby promoting peptide binding. Peptide dissociation from the ternary complex induces dissociation of the heavy-chain/beta(2)m heterodimer thereby causing oligomerization of the heavy chain. The lability of the HLA-A2/beta(2)m heterodimer and the strong tendency of the "free" heavy chain to oligomerize may provide an efficient mechanism for control of antigen presentation under physiological conditions by reducing the direct loading of HLA with exogenous peptide at the cell surface.     

Human leukocyte antigen alleles,genotypes and haplotypes frequencies in renal transplant donors and recipients from West Central India

BACKGROUND:

Human leukocyte antigen (HLA) is comprised of a highly polymorphic set of genes which determines the histocompatibility of organ transplantation. The present study was undertaken to identify HLA class I and class II allele, genotype and haplotype frequencies in renal transplant recipients and donors from West Central India.

MATERIALS AND METHODS:

HLA typing was carried out using Polymerase Chain Reaction-Sequence Specific Primer in 552 live related and unrelated renal transplant recipients and donors.

RESULTS:

The most frequent HLA class I and class II alleles and their frequencies in recipients were HLA-AFNx0101 (0.1685) and AFNx0102 (0.1649), HLA-BFNx0135 (0.1322), and HLA-DR beta 1 (DRB 1)FNx0115 (0.2192), whereas in donors, these were HLA-AFNx0102 (0.1848) and AFNx0101 (0.1667), HLA-BFNx0135 (0.1359), and HLA-DRB1FNx0115 (0.2409). The two-locus haplotype statistical analysis revealed HLA-AFNx0102-B61 as the most common haplotype with the frequency of 0.0487 and 0.0510 in recipients and donors, respectively. Further, among the three locus haplotypes HLA-AFNx0133-BFNx0144-DRB1FNx0107 and HLA-AFNx0102-BFNx0161-DRB1FNx0115 were the most common haplotypes with frequencies 0.0362 and 0.0326, respectively in recipients and 0.0236 and 0.0323, respectively in donors. Genotype frequency revealed a high prevalence of genotype HLA-AFNx0102/AFNx0124 in recipients (0.058) compared to donors (0.0109) whereas low prevalence of HLA-AFNx0101/AFNx0102 in recipients (0.0435) than in donors (0.0797). The phylogenetic and principal component analysis of HLA allele and haplotype frequency distribution revealed genetic similarities of various ethnic groups. Further, case control analysis provides preliminary evidence of association of HLA-A genotype (P < 0.05) with renal failure.

CONCLUSION:

This study will be helpful in suitable donor search besides providing valuable information for population genetics and HLA disease association analysis.