新的HLA-A等位基因A~*0290的认定

目的确认1个中国人群中的HLA新等位基因。方法使用PCR-SSP和测序为基础的分型技术,分析确认HLA-A的新等位基因与A*02010101的差异。结果先证者HLA-A位点有1个等位基因的核苷酸序列与已知的HLA等位基因均不同,该基因和A*02010101的差异在第2外显子区域的292位碱基C>G,导致74编码子CAC>GAC,编码的氨基酸由组氨酸(His)变成天冬氨酸(Asp)。结论该基因为HLA新的等位基因,2005年10月被世界卫生组织HLA因子命名委员会正式命名为HLA-A*0290。     

聚合酶链反应方法检测外周血淋巴细胞HLA-A mRNA方法学的建立及在肾移植中的初步应用

目的通过建立检测宿主外周血淋巴细胞(PBL)表面HLA-AmRNA表达程度的实时荧光定量逆转录聚合酶链反应(RT-FQ-PCR)方法,检测肾移植患者移植后外周血淋巴细胞表面HLA-AmRNA的表达程度,探讨其在诊断移植后早期排斥反应的发生的价值及机体免疫状态的关系。方法以6-磷酸葡萄糖脱氢酶(G6PDH)作内参照,用Taqman探针荧光定量技术,建立检测PBLHLA-AmRNA的RT-FQ-PCR方法;并检测35例随访移植患者的不同时间的60个标本和60名正常人的阈循环数(Ct),然后用REST软件分析PBLHLA-AmRNA的表达水平。结果正常人和51个移植标本的PBLHLA-AmRNA对G6PDH的相对表达量分别为0·036±0·012和0·026±0·015(双侧t=1·981,P<0·05),提示服用免疫抑制药(目前临床用药剂量均偏大)后患者PBLHLA-AmRNA表达减弱,机体免疫状态低,无排斥反应发生但易导致感染、肿瘤等并发症的产生;其中9个移植标本的PBLHLA-AmRNA对G6PDH的相对表达量为0·042±0·017(双侧t=2·002,P<0·05),提示较其他51例移植标本患者PBLHLA-AmRNA表达增强的患者,经病例回访查询发现该5例移植患者在这期间有排斥反应(根据临床表现、肾功能检查、影像学及核医学检查的临床排斥反应期)的发生,其中1例在移植后6个不同时间的标本显示2次有增高,每次经治疗后均降低。结论建立的宿主PBLHLA-AmRNART-FQ-PCR检测方法简便、特异、重复性好、可信度高,可用于肾移植后PBLHLA-AmRNA表达水平的检测,评估机体的免疫状态,预测排斥反应的发生。     

中国鲁南地区汉族人群HLA-A,B,DRB1高分辨等位基因多态性分析

本研究旨在分析中国鲁南地区汉族人群HLA-A、B、DRB1等位基因的高分辨多态性分布特征。采用PCR-SBT对中国鲁南地区688名无血缘关系的汉族健康人群进行HLA-A、B、DRB1位点高分辨基因分型,并对分型结果做统计学分析。结果表明：688例样本A、B、DRB1座位分别检出31、63、39个等位基因,其中频率大于0.05的常见等位基因为A＊24：02、A＊30：01、A＊11：01、A＊02：01、A＊33：03、A＊02：06、B＊13：02、B＊44：03、B＊51：01、B＊46：01、B＊15：01、B＊58：01、DRB1＊07：01、DRB1＊15：01、DRB1＊09：01和DRB1＊08：03。上述A、B、DRB1位点常见等位基因累计基因频率分别为0.7223、0.4432、0.5453。最常见的A＊-B＊-DRB1＊单倍型是A＊30：01-B＊13：02-DRB1＊07：01（0.1151）,最常见的两位点连锁单倍型分别是A＊30：01-B＊13：02（0.1303）、A＊30：01-DRB1＊07：01（0.1157）和B＊13：02-DRB1＊07：01（0.1307）。结论：获得了中国鲁南汉族人群HLA-A、B、DRB1高分辨等位基因和单倍型分布特征,为评估该地区患者找到HLA匹配供者的机率,为合理选择移植供者及移植免疫、HLA与疾病相关性研究提供了参考数据。     

淋巴细胞HLA-A mRNA方法学建立及在乙型肝炎病毒感染患者中的应用

目的建立外周血淋巴细胞HLA-A mRNA的检测方法,探讨其在慢性乙型肝炎、肝炎后肝硬化、肝癌患者中的应用价值。方法改良法提取人外周血淋巴细胞RNA,应用逆转录-聚合酶链反应(RT-PCR)一步法扩增HLA-A mRNA,琼脂糖凝胶电泳结果采用Bandscan软件分析相对灰度值,半定量HLA-A的基因表达。结果半定量HLA-A所得平均相对灰度值在慢性乙型肝炎组、肝硬化组、肝癌组、正常对照组分别为0．54±0．21、0．34±0．27、0．22±0．16、0．95±0．19。慢性乙型肝炎组、肝硬化组、肝癌组均明显低于正常对照组(P<0．05),慢性乙型肝炎组与肝癌组,肝硬化组与肝癌组相比差异有统计学意义(P<0．05),慢性乙型肝炎组与肝硬化组有下降趋势。结论成功建立检测HLA-A基因的RT-PCR一步法,从基因转录水平上证实慢性乙型肝炎、肝炎后肝硬化、肝癌患者外周血淋巴细胞HLA-A下调,且与相应患者细胞免疫功能减弱密切相关。     

Identification of hepatitis C virus 1b-derived peptides recognized by both cellular and humoral immune systems in HCV1b(+) HLA-A24(+) patients.

Despite scientific advances, the therapeutic options for hepatitis C virus (HCV) are limited by poor response rates. HCV1b is particularly resistant to standard interferon therapy. The inhibition of the progression of chronic hepatitis and liver cirrhosis and the prevention of the occurrence and recurrence of hepatocellular carcinoma (HCC) are important and thus, there is a need for new therapeutic modalities for HCV1b infection. We, therefore, investigated highly immunogenic peptides and report in this study three novel candidate peptides (at positions 711-720 in envelope 2 protein, 885-893 in non-structural protein 2 and 1716-1724 in non-structural protein 4B) among 35 peptides of conserved regions of HCV1b proteins containing HLA-A24 binding motifs tested. Namely, HCV(711-720), HCV(885-893) and HCV(1716-1724) induced HLA-A24-restricted and peptide-specific cytotoxic T lymphocytes (CTLs) activity in peripheral blood mononuclear cells (PBMCs) from 7, 6 and 5 of 12 patients and also were recognized by plasma of 8, 5 and 7 of 12 HCV1b(+) patients, respectively. These results may provide new insight into the development of a peptide-based specific immunotherapy for HCV1b(+) HLA-A24(+) patients.     

A novel mouse model for immunogenic evaluation of human HBV vaccines

To prepare a human HBV vaccine, investigators need an animal model that can help them screen and prioritize vaccine candidates. In this study, HBV/HLA-A2.1 double transgenic mice (dTg), confirmed by analysis of genomic integration and by observation of long-term expression of HBV and HLA genes, were generated for the first time. The HBV/HLA-A2.1 dTg not only display tolerance to HBV antigens (Ags), but also have the ability to process and present HLA-A2 restricted antigenic epitopes. The animals vaccinated with HLA-A2 restricted HBc_18–27 or HBs_183–191 epitope peptide vaccine induced effective HLA-A2 restricted peptide-specific cytolytic T lymphocyte responses. This was supported by the evidence of cytotoxicity assay, ELISPOT and tetramer staining analysis. Furthermore, T cell tolerance against HBV Ags in HBV/HLA-A2.1 dTg was broken by the HBc_18–27 or HBs_183–191 peptide vaccine. In conclusion, HBV/HLA-A2.1 dTg was demonstrated to be useful model for in vivo immunogenicity testing of human HBV-based vaccines.     

HLA-A29 and Birdshot Chorioretinopathy

Birdshot chorioretinopathy primarily affects patients of European descent. At least 96%, if not all patients, are HLA-A29 carriers. HLA-A*29:01 and HLA-A*29:02, the two main subtypes of HLA-A29, differ only by a single mutation. In the general population HLA-A*29:02 is most frequent in whites, while HLA-A*29:01 is more frequent in Asians. The differential distribution of HLA-A*29:01 and HLA-A*29:02 has been actively debated as an explanation for the selective development of the disease in patients of European descent, but is no longer a valid argument. Another factor, probably not HLA linked, is either protective in Asians and in Africans or, conversely, triggers an autoimmune reactivity that is possibly present in whites and absent in Asians and in Africans. HLA-A*29:02 transgenic mice in which a spontaneous posterior uveitis is observed after 6 months of age provide further evidence that the HLA-A29 molecule plays a role in the pathogenesis of the disease.     

siRNA沉默HLA-A2表达的hMSCs对人异体T淋巴细胞分泌IFN-γ和IL-2功能的影响

目的探讨应用siRNA技术下调HLA-A2表达的人骨髓间充质干细胞(human mesenchymal stemcells,hMSCs)对人异体T淋巴细胞分泌功能的调节作用。方法从成人骨髓中分离和培养hMSCs,并且通过免疫细胞化学检测其表面标志;利用人工合成HLA-A2靶向小分子干扰RNA转染至第3代hMSCs,然后将转染前后的hMSCs,与经植物血凝素(PHA)刺激的人异体T淋巴细胞共同培养。用ELISA分别检测各培养上清液中T淋巴细胞分泌IFN-γ和IL-2的水平。结果原代培养3d后,约70%hMSCs贴壁生长,7d后细胞迅速增殖,进入对数生长期,14d左右进入平台期,第3代细胞多呈梭形生长,形态比较均一,hMSCs表面抗原CD44、CD166阳性。HLA-A2靶向小分子干扰RNA转染3天后,可见少量细胞死亡,免疫荧光染色可见细胞核和部分胞浆呈阳性表达。转染HLA-A2靶向小分子干扰RNA的和未转染的hMSCs均能抑制人T淋巴细胞分泌IFN-γ和IL-2,转染后的hMSCs抑制作用强于未转染的hMSCs(<0.05)。结论体外沉默HLA-A2基因表达可增强hMSCs抑制PHA刺激人T淋巴细胞分泌因子。