Point mutation in the beta sheet of the HLA-C alpha2 domain generates a novel HLA-C allele,HLA-Cw*08012, in a Puyuma Aboriginal individual in Taiwan

We report herein the identification of a new HLA-C allele using sequence-based typing (SBT). This novel allele, HLA-Cw*08012, was found in an Aboriginal individual from the Puyuma tribe in the southern part of Taiwan. This individual was typed by the SBT method as having an HLA genotype of HLA-A*2402/2402, HLA-B*1502/4801, HLA-Cw*08011/08012, HLA-DRB1*15011/08032, HLA-DRB5*01011, and DPB1*0501/1401. This new allele differs from HLA-Cw*08011 in one of the nucleotides of the polymorphic exon 3 at codon 99 [TAT-->TAC; both code for tyrosine]. This residue is located in the beta sheet of the HLA-C alpha2 domain. This new allele was detected in a few individuals of the Puyuma tribe in Taiwan, but has not yet been observed in other populations in Taiwan.     

The role of KIR2DL3/HLA-C*0802 in Brazilian patients with rheumatoid vasculitis

OBJECTIVES:

Rheumatoid arthritis is a polygenically controlled systemic autoimmune disease. Rheumatoid vasculitis is an important extra-articular phenotype of rheumatoid arthritis that can result in deep cutaneous ulcers. The objective of this study was to establish a correlation between the frequency of major histocompatibility complex class I/II alleles and killer immunoglobulin-like receptor genotypes in patients with cutaneous rheumatoid vasculitis.

METHODS:

Using the Scott & Bacon 1984 criteria to diagnose rheumatoid vasculitis and after excluding any other causes such as diabetes, atherosclerosis, adverse drug reactions, infection, and smoking, patients who met the criteria were selected. All of the selected rheumatoid vasculitis patients presented deep cutaneous ulcers. Identification of the major histocompatibility complex class I/II and killer immunoglobulin-like receptor genotypes was performed by polymerase chain reaction assays of samples collected from the 23 rheumatoid vasculitis patients as well as from 80 controls (40 non-rheumatoid vasculitis RA control patients and 40 healthy volunteers).

RESULTS:

An association between the presence of the HLA-DRB1*1402 and HLA-DRB1*0101 alleles and cutaneous lesions in rheumatoid vasculitis patients and a correlation between the inhibitor KIR2DL3 and the HLA-C*0802 ligand in rheumatoid vasculitis patients were found.

CONCLUSION:

An association was found between the presence of the HLA-DRB1*1402 and HLA-DRB1*0101 alleles and the development of cutaneous lesions in rheumatoid vasculitis patients. Additionally, the HLA-C*0802 ligand protects these individuals from developing cutaneous lesions.     

广西壮族人群HLA-C基因多态性与神经纤维瘤病Ⅰ型相关性

目的探讨广西壮族人群HLA-C基因多态性与神经纤维瘤病Ⅰ型的相关性。方法选取15例广西壮族神经纤维瘤病Ⅰ型患者作为病例组,45例壮族健康个体为对照组,应用等位基因特异性PCR技术比较2组HLA-C基因多态性有无差异。结果病例组和对照组的C1/C1基因型频率分别为40%与20%,C1/C2基因型频率分别为53%和44%,2组比较均无显著性差异(P>0.05)。病例组和对照组的C2/C2基因型频率分别为7%和36%,C1等位基因频率分别为67%和42%,2组比较均有显著性差异(P<0.05)。结论广西壮族神经纤维瘤病Ⅰ型患者HLA的C2/C2基因型和C1等位基因频率高于广西壮族正常人群,而HLA-C2等位基因则较低。     

HLA-C sequence based typing: nucleotide analysis from exon 1 through exon 8. Identification of a new allele: Cw*0718

At present, 128 HLA-Cw alleles have been described. Twenty-four of 128 display critical polymorphisms in contributing to allele identification outside exons 2 and 3. As a matter of fact, complete resolution of Cw*030201, Cw*030202, Cw*0409N, Cw*0501, Cw*0503, Cw*070101, Cw*070102, Cw*070401, Cw*0706, Cw*0711, Cw*0718, Cw*120201, Cw*120202, Cw*150501, Cw*150502, Cw*1701, Cw*1702, Cw*1703, Cw*1801 and Cw*1802 alleles requires nucleotide analysis of exons 1, 4, 5, 6 and 7. Moreover, some alleles (Cw*04010101, Cw*04010102, Cw*07020101 and Cw*07020102) showing nucleotide differences outside the coding regions of HLA-C gene (intron 2) have been reported. High resolution sequence based typing (SBT) developed in this study involves two DNA amplifications and 12 direct sequencing reactions and allows the analysis of HLA-C polymorphisms from exon 1 through exon 8, including intron 2. This typing procedure identifies all 128 Cw alleles described so far. Nevertheless, a number of ambiguous heterozygous typing results may be expected, this being the major drawback of SBT methods. A total of 201 samples were HLA-C typed using SBT strategy here described. The sequence of exons 6, 7 and 8 of HLA-Cw*070102 allele was elucidated. A novel HLA-Cw*07 allele, Cw*0718, was identified in two samples. Cw*0718 differs from the Cw*070101 allele by a unique nucleotide position within exon 6, resulting in an amino acid substitution at codon 324 (Ala-->Val) in the cytoplasmic region of the molecule.     

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.     

Octapeptide but not nonapeptide from HIV-1 p24gag protein upregulates cell surface HLA-C expression

Objectives   The HLA-Cw3 molecule has been reported to present peptides derived from HIV-1 p24^gag protein to a cytotoxic T lymphocyte clone. We have shown previously that the synthetic octapeptide 145–152 derived from the p24^gag sequence upregulated cell surface HLA-C expression on HLA-Cw*0303⁺ cells. Here, we examined the question of whether the nonapeptide 144–152 also exerts a similar effect.
Methods   The HLA-Cw*0303⁺ B-LCL PAJ and control HLA-Cw3-negative cells B-LCL HAJ and T-LCL 500/C9 were used. HLA expression on peptide-pulsed and non-pulsed cells was evaluated using specific antibodies and flow cytofluorimetry. Binding of dansylated peptides onto different cell lines was measured spectrofluorimetrically.
Results   The HIV-1 p24^gag octapeptide upregulated cell surface HLA-C on PAJ (Cw*0303⁺) cells, whereas the nonapeptide did not. HLA-A2 expression was not affected by these peptides. Specificity of the effect of octapeptide was confirmed by the lack of HLA-C upregulation on HLA-Cw3^– cells and by lower binding of dansylated petide to the HLA-Cw3^- cells HAJ and 500/C9.
Conclusions   The above results indicate that HLA-Cw*0303 preferentially binds the octapeptide rather than the nonapeptide derived from HIV-1 p24^gag protein .     

Identification of a new HLA-Cw*07 allele,HLA-Cw*0743, from a Chinese hematopoietic stem cell donor

A new allele of the human leukocyte antigen C (HLA-C) locus was identified during routine HLA typing of a Chinese hematopoietic stem cell donor in Beijing, China. Sequence analysis of exons 2 and 3 of the HLA-C gene revealed the novel polymorphism. The closest matched allele was HLA-Cw*0710. A comparison of the two alleles showed that HLA-Cw*0743 carried a nucleotide substitution of C to A at codon 99 in exon 3, resulting in an amino acid substitution of serine to tyrosine with no obvious change in protein structure. Both Haiyan Zhu and Dandan Zhao are co-first authors.     

一例供者携带的C* 03:100等位基因的测序分析

目的 检测与分析1例骨髓志愿捐献者携带的等位基因C* 03:100.方法 采用快速DNA提取试剂盒从全血样本中提取基因组DNA,经HLA-C基因商品化测序分型试剂盒扩增,纯化后的扩增产物作为模板由试剂盒配套的第2,3和4外显子正反向测序引物及自行研制的第5外显子正反向、第6外显子正向和第7外显子反向测序,经乙醇/醋酸钠/EDTA纯化的测序反应产物于ABI PrismTM 3730测序仪电泳检测.结果 将电泳后的数据导入Assign-SBT 3.5.1.45分析软件分析,分型结果为C*03:02:02,03:100.结论 临床移植配型HLA-C基因分型增加第5,6和7外显子区域的多态性检测可提高分型结果的准确性,对临床组织配型工作具有重要意义.