绒毛滋养细胞HLA-C基因多态性与不明原因早期复发性流产的关系

目的:探讨绒毛滋养细胞HLA-C基因与不明原因早期复发性流产(URSA)的关系.方法:留取早期URSA患者33例(早期URSA组)及正常早孕妇女29例(对照组)的绒毛组织,提取基因组DNA,DNA测序法分析绒毛滋养细胞HLA-C1、HLA-C2基因,Fisher精确概率法计算两组间差异.结果:①两组的HLA-C1、HLA-C2基因在绒毛组织中呈不平衡表达,均以HLA-C1基因占明显优势.早期URSA组HLA-C1基因频率(66.67%)与对照组(81.03%)比较,差异无统计学意义(P=0.657);早期URSA组HLA-C2基因频率(33.33%)高于对照组(19.07%)(P=0.007).②在早期URSA组中HLA-C1/C2基因型(66.67%)占明显优势;对照组中HLA-C1/C1基因型占明显优势(65.52%);早期URSA组的HLA-C1/C1和HLA-C1/C2基因型频率与对照组比较,差异有统计学意义(P=0.039;P=0.001).结论:早期URSA患者HLA-C1/C1基因型频率降低、HLA-C1/C2基因型增加,导致单倍型HLA-C1频率降低,HLA-C2基因频率升高,HLA-C1、HLA-C2失衡可能与早期URSA的发病相关.     

HLA-Cw基因常规检测区外第1、5、6、7外显子核苷酸序列测定的研究及临床应用

目的 研究中国人群HLA-Cw基因第1、5、6、7外显子的分子遗传多态性,探讨增加第1、5 6 7外显子核苷酸序列测定在临床组织配型工作中的重要性及意义.方法 应用PCR-SBT法,对324份样本的HLA-Cw基因第2、3、4外显子作常规测序分型.对检出的模棱两可结果,设计HLACw第1、5 6 7外显子序列测序引物并优化测序反应条件,增加第1、5、6、7外显子核苷酸序列分析.结果 对HLA-Cw基冈第2、3、4外显子常规检测,一次性获得等位基因前4位数分型结果 的样本占23.8%(77/324);出现模棱两可结果的样本数占76.2%(247/324),检出的模棱两可等位基因组合有73种;增加HLA-Cw基因的第1、5、6、7外显子多态性检测,可解决Cw* 030201/030202、030301/0320N、Cw* 040101/0409N/0430、Cw* 070201/0750、Cw* 0403/0409N/0430和Cw* 080101/0822等10种常见的模棱两可等位基因组合.结论 在临床HLA-Cw基因配型中增加第1、5、6、7外显子多态性检测,有助于解决测序分型中的模棱两可的结果 和提高HLA-Cw基因分型精确度,对临床组织配型工作具有重要意义.     

一个无效新等位基因C*01∶37N的鉴定及其序列分析

目的 鉴定中国汉族人群中新发现的一个HLA-C无效等位基因,并对国际上业已公布的HLA-C无效等位基因的突变情况进行分析.方法 采用分子克隆和单倍体测序的方法,鉴定1例HLA-C基因测序分型结果异常样本的分子生物学基础.结果 检出了一个C*01新变异等位基因,其序列与C*01∶02∶01最相近,但存在编码区nt 363 G＞A点突变,位于第三外显子的第97密码子由TGG直接变成终止密码子TGA,导致一个无效等位基因,其序列提交国际GenBank(序列号:GU592508)和IMGT/HLADatabase(HWS10010188).结论 该无效等位基因已被世界卫生组织(WHO)HLA因子命名委员会正式命名为C*01∶37N.

Abstract：

Objective To identify a novel HLA-C null allele in a Chinese Han individual and characterize the nucleotides mutations of HLA-C null alleles reported currently. Methods The molecular basis of a sample with inconclusive sequencing result was clarified by traditional cloning and haplotype sequencing. Results A novel HLA-C * 01 variant allele was identified. Its sequence was very similar to allele C * 01∶02∶01. There was a single nucleotide mutation at the coding sequence nt 363 G＞ A (codon 97TGG＞TGA) in exon 3. The genomic sequence of this novel allele was submitted to GenBank with the accession number GU592508 and the IMGT/HLA Database (HWS10010188). Conclusions The novel variant null allele has been officially named C * 01∶37N by the WHO Nomenclature Committee for factors of the HLA System.     

Identification of a novel HLA-C allele, Cw*0406, in a Singapore Malay

A novel allele, C*0406, has been identified and is characterised by a single nucleotide substitution at position 196 of exon 3 when compared with its closest related allele, C*0403. The latter is found in 4/69 Chinese and 7/80 Malays while Cw*0406 was found in only one Malay individual within the study populations. The data suggest that Cw*0406 may have arisen as a relatively recent genetic event either by gene conversion or as a simple point mutation variant of Cw*0403.     

Uterine NK Cells and Trophoblast HLA Class I Molecules

PROBLEM: To investigate the proposal that NK cells in decidua may control trophoblast migration during implantation of the human placenta. METHOD: Use Mab specific for HLA-G and for HLA-C in association with flow cytometry and immunoprecipitation to determine the expression of these HLA molecules by trophoblast. Expression of Killer inhibitory/activatory receptors (KIR/KAR) and the CD94 receptor by decidual NK cells was also studied. RESULTS: Extravillous trophoblast expressed HLA-G and HLA-C in both β₂m-associated form and as free heavy chains. KIR and KAR are expressed by decidual NK cells. The repertoire of receptors varied between different women and also between blood and decidual NK cells from the same women. The expression of CD94 was also different between blood and decidual NK cells. CONCLUSION: The recognition of HLA-G/HLA-C by KIR/KAR and CD94 could provide a mechansm by which decidual NK cells control trophoblast migration.     

A human monoclonal antibody against HLA-Cw1 and a human monoclonal antibody against an HLA-A locus determinant derived from a single uniparous female

Abstract: Two human monoclonal antibodies (HuMAbs) with widely different HLA specificities were raised from a uniparous HLA-seropositive female. Screening against a large panel of serologically HLA-typed lymphocytes in the complement-dependent cytotoxicity test showed that one of these HuMAbs, VP6G3, was specific for HLA-Cwl, thereby constituting the first HuMAb against an HLA-C locus product. The second HuMAb, VP5G3, was directed against an HLA-A-encoded determinant shared by HLA-A11, -A25, -A26 and -A66. The epitopes responsible for binding were determined by comparing the aminoacid sequences and were pinpointed to the 6K/9F combination for HuMAb VP6G3, and 163R with a critical contribution of aminoacids present at positions 166/167 for HuMAb VP5G3.     

Identification of a novel HLA-Cw*07 variant (Cw*0714) in a German Caucasian family

We report herein the identification of a new HLA-Cw*07 allele in two members of a German Caucasian family. This novel allele, designated as Cw*0714, differs from Cw*07011 and Cw*0706 by two nucleotide changes: one at codon 66 (AAC-->AAG) in the exon 2, leading to an amino acid change from Asn to Lys; and another silent substitution at codon 99 (TAT-->TAC) in the exon 3. The latest substitution (T-->C at the third position of codon 99) was not seen in any of the HLA-Cw*07 alleles reported so far, thus being characteristic to the new HLA-Cw*0714 allele.     

Characterization of a new HLA-C allele: Cw*1606

HLA-Cw*16 is a relatively common HLA-C specificity among Caucasoids, with Cw*1601 being the most frequent allele. We report herein the identification by sequence-based typing of a new HLA-Cw*16 allele in a Spanish Caucasoid blood donor. The novel allele, designated Cw*1606, differs from Cw*1601 by two nucleotide changes at positions 361 (T to A) and 368 (A to C) in exon 3, which leads to two amino acid changes from Trp (TGG) to Arg (AGG) and from Tyr (TAT) to Ser (TCT) at codons 97 and 99 in the alpha2 domain, respectively. Sequence comparisons suggest that the new HLA-Cw*1606 variant could have arisen from an intralocus gene conversion event.     

Molecular diversity of the HLA-C locus in unrelated marrow transplantation

Abstract: The diversity of HLA-C exon-2 alleles in 56 HLA-A, B, DRB and DQB1-matched patient-unrelated marrow donor pairs was examined by non-cloning polymerase chain reaction-based sequencing of genomic DNA. This method allows simultaneous analysis of both alleles in heterozygous samples. All Cw5-positive individuals encoded a sequence which differed from the published Cw*0501 sequence at position 61. Among 82 samples assigned a single antigen by serologic testing, 64 (78%) were heterozygous for two distinct alleles when tested by sequencing. Cw*1202, 1601 and 15 were identified in samples for which no phenotype could be assigned (C "blank"). Finally, 7 of the 56 HLA-A, B, DRB, DQB1-matched pairs (12.5%) were mismatched for one or both HLA-C alleles. We conclude that sequence-based methods constitute the optimal strategies for typing HLA-C alleles in the unrelated marrow transplant population.