湖南籍汉族人群HLA-DM多态性分析

ＨＬＡ ＤＭ位于ＨＬＡ Ⅱ类基因区的ＤＱ/ＤＰ位点之间 ,参与ＨＬＡ Ⅱ类抗原提呈外源性抗原的过程 ,并有一定的多态性。有文献报道ＨＬＡ ＤＭ与类风湿性关节炎[1] 、糖尿病[2 ] 等自身免疫性疾病相关。本文用ＰＣＲ/ＳＳＯ的方法对湖南籍汉族人群进行ＨＬＡ ＤＭ的ＤＮＡ分型 ,以了解ＤＭ多态性在湖南人群中的分布情况 ,现将结果报告如下。1　对象与方法1 1　研究对象　收集湘雅医院的献血者 ,82人 ,其中男性 4 9人 ,女性 33人 ,年龄 2 0～ 5 0岁。均健康且连续三代为湖南籍人。1 2　主要试剂　引物和探针参照 12届国际组织相容性会议(12ｔｈＩＨＷＣ)所定方法由上海生物工程公     

HLA-DM基因夫妇共享率与子痫前期相关性

目的:探讨HLA-DM基因夫妇共享率与子痫前期的相关性。方法:用PCR-SSO方法分别测定30对子痫前期患者夫妇及63对正常孕妇夫妇的HLA-DM基因型。结果:夫妇共享等位基因数为2个时,子痫前期组的例数明显多于正常妊娠组,差异有显著性(P﹤0.05);HLA-DM的各等位基因型在子痫前期组夫妇共享率与正常妊娠组夫妇共享率差异无显著性。结论:夫妇共享HLA-DM基因数与子痫前期发病有关。     

Protein sorting within the mhc class II antigen-processing pathway

Major histocompatibility complex (MHC) class II molecules are required for the presentation of antigenic peptides that are derived predominantly from internalized proteins. The assembly of MHC class II/peptide complexes occurs within endosomal compartments of antigen-presenting cells (APCs). Therefore, for assembly to occur, MHC class II molecules, foreign proteins, and accessory molecules must be sorted to appropriate intracellular sites. My laboratory is trying to understand how proteins are sorted to various antigen-processing compartments as well as to conventional endosomal organelles. Using chimeric marker proteins and a variety of biochemical and genetic approaches, we are addressing the specificity of protein sorting and the mechanisms by which sorting signals are deciphered. By using a similar chimeric protein approach to target endogenous proteins to distinct compartments, we hope to address the role of processing events in each compartment in the generation of MHC class II ligands.     

系统性红斑狼疮HLA-DM基因与环境危险因素研究

目的探索HLA-DM基因及其与环境危险因素的交互作用对系统性红斑狼疮(SLE)发病的影响.方法采取病例对照研究,用PCR-RFLP的方法确定HLA-DM的基因型,用非条件logistic模型分析SLE的危险因素,用广义线性模型分析环境与基因的交互作用.结果共检测到3种DMA与4种DMB等位基因,其分布在SLE组与正常对照组分布一致.logistic模型分析显示SLE的环境危险因素有5个(潮湿、精神刺激、日晒、刀豆、扁桃体感染),女性个人婚育史因素有3个(出生时母亲的年龄、月经初潮年龄、流产次数).广义线性模型分析提示HLA-DMB*0102与扁桃体感染的交互项效应达到显著水平.结论有多个环境危险因素与SLE的发病有关,HLA-DM基因的遗传多态性对SLE发病及活动性没有独立作用,但HLA-DM基因与某些环境因素存在交互作用.     

Surface expression of HLA-DM on dendritic cells derived from CD34-positive bone marrow haematopoietic stem cells

HLA-DM has been known to be largely absent from the cell surface of antigen-presenting cells, accumulating instead in the intracellular compartment. In this study, we demonstrated that a population of HLA-DM-positive (HLA-DM+) dendritic cells (DCs) can be identified in an in vitro culture of CD34+ bone marrow haematopoietic stem cells. CD34+ bone marrow cells of healthy donors were used to generate DCs with the recombinant human cytokines granulocyte-macrophage colony-stimulating factor (GM-CSF), tumour necrosis factor alpha (TNF-alpha) and stem cell factor (SCF), both with and without interleukin 4 (IL-4). Flow cytometric analysis demonstrated that HLA-DM+ cells comprised 2.5 +/- 0.9% and 1.8 +/- 0.4% of the CD34+ cell-derived progeny in the presence of GM-CSF, TNF-alpha and SCF after 7 d and 14 d of culture respectively. The number of HLA-DM molecules expressed per HLA-DM+ cell on d 7 was significantly higher than that on d 14 (1410 +/- 47 versus 370 +/- 25, P < 0.05). The addition of IL-4 to the cytokines from the commencement of culture increased the proportion of HLA-DM+ cells and increased the number of HLA-DM molecules per HLA-DM+ cell significantly (P < 0.05). Although most of the HLA-DM+ cells expressed CD1a, CD80 or CD86 antigen, only a small proportion of CD1a+, CD80+ or CD86+ cells expressed HLA-DM. About half the HLA-DM+ cells expressed CD83. The addition of IL-4 resulted in a decrease in the expression of CD83 on the HLA-DM+ cells on d 7. Microscopic evaluations of sorted HLA-DM+ cells revealed the characteristic morphological features of DCs. Primary mixed lymphocyte cultures demonstrated that the HLA-DM+ cells elicited a vigorous proliferation of allogeneic T cells. The level of antigen-specific T-cell activation induced by antigen-pulsed, chloroquine-treated HLA-DM+ cells was substantially higher than that induced by HLA-DM- cells (P < 0.05). These results show that HLA-DM can be used as a useful DC lineage-specific marker, as well as a tool for the characterization of DCs and human immunotherapy.     

Human mast cells present antigen to autologous CD4+ T cells

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Polymorphisms of HLA-DM genes in Japanese patients with psoriasis vulgaris

We analysed the polymorphisms of HLA-DM genes in 85 unrelated Japanese patients with psoriasis vulgaris and 52 healthy controls using the polymerase chain reaction-restriction fragment length polymorphism method. The frequency of DMA*0101 was decreased (79% vs. 89%, P < 0.05) and that of DMA*0102 was increased (20% vs. 11%, P < 0.05) in the patients. However, neither of these remained significant after P-values were corrected for the number of comparisons made (Pc > 0.05). As we reported previously, HLA-C molecules are assumed to play a more important part than HLA-DM genes in the development of psoriasis vulgaris.     

三氯乙烯药疹样皮炎免疫相关基因易感性的研究

目的了解HLA-DM基因在三氯乙烯药疹样皮炎和正常对照者中的分布情况,探索三氯乙烯药疹样皮炎的易感性基因,为其危害防治提供依据.方法将病例组及对照组基因组DNA应用降落式PCR扩增,结合限制性片断长度多态性检测方法和直接测序,确定其DMA及DMB等位基因型和基因型,比较两组之间DMA和DMB等位基因型和基因型出现频率.结果病例组HLA-DMA*0101等位基因频率明显高于对照组(71.3%,对照组为55.0%,P＜0.05);病例组HLA-DMB*0103等位基因频率明显高于对照组(P＜0.05);对照组HLA-DMA*0102-*0102纯合子比例明显高于病例组(P＜0.05);病例组HLA-DMB*0101-*0102杂合子比例明显低于对照组(P＜0.05).结论DM基因多态性可能与三氯乙烯药疹样皮炎的易感性有关.