HLA-DP SEQUENCE POLYMORPHISM AND DISEASE PREDISPOSITION

该项目的总体目标是确定以下问题的性质和范围 人类白细胞抗原-DP区的等位基因多样性及其与 这种多态性与人类白细胞抗原相关疾病的易感性有关。各种各样的 许多但不是所有的疾病都与自身免疫有关。 具有特定的血清学定义的人类白细胞抗原II类等位基因和/或 单倍型。最近，基于DNA的鉴定表明，特定的DR和 DQ序列定义的等位基因与特定疾病相关； 易感和非感病等位基因的序列比较显示 班级个体多态位置的潜在重要性 IIβ链。DP基因多态性在疾病易感性中的作用 还没有被研究到同样的程度。DPB1和DPB1的分布 患者和种族匹配的对照中的DPA1等位基因将是 比较了各种疾病的情况。由于强大的联动性 人类白细胞抗原区域内的不平衡，评估DP的作用 多态需要分析人类白细胞抗原(B、DR、DQ、DP)单倍型。我们 已经研究了扩展单倍型的性质和分布 在一个高加索人群体中。我们的项目将专注于家庭，让 明确确定单倍型，我们将比较不同的 在不同种族中发现的单倍型组合。这些 单倍型数据不仅对理解复杂性至关重要 人类白细胞抗原-疾病关联的模式，但也用于定义可能性 在不同人群中寻找人类白细胞抗原相合的骨髓和实体器官捐献者 种族群体。我们关于DP序列的特征的建议 多态，以提炼我们的非放射性寡核苷酸探针DP 打字系统，并应用该方法(斑点印迹和反转点 杂交)对疾病易感性的研究是基于聚合酶 链式反应(PCR)。我们之前的工作是使用DPB1和DPA1引物 聚合酶链式反应扩增用于序列分析的第二外显子 扩展到更多的样本和群体以识别新的等位基因， 发现了一种新的探测器反应性模式。新的等位基因总是 经序列分析证实。重组的关系 观察到的连锁不平衡模式的频率将是 在家庭研究中进行检查，但也使用精子方法进行检查 作图，用聚合酶链式反应对个体连锁基因座进行共扩增 精子。这种短时间内确定重组频率的方法 遗传距离，就像在人类白细胞抗原区域内的距离，可以用来 比较个体之间和个体之间的重组频率 单倍型。从精子中进行的PCR扩增也将被用来尝试 通过分段交换检测新的DPB1等位基因的产生 从拼接中推断可能的基因转化类机制 DPB1基因多态模式。DPB1的系统发育分析 还将在非人灵长类动物的数据集上进行多态研究 DPB1等位基因。这些研究将增加我们对人类白细胞抗原-DP的了解 多态并有助于我们理解其在疾病中的作用 敏感度。

The overall goal of this project is to determine the nature and extent of allelic diversity in the HLA-DP region and to assess the relationship of this polymorphism to HLA-associated disease susceptibility. A variety of diseases, many but not all of which are autoimmune, have been associated with specific serologically defined HLA class II alleles and/or haplotypes. Recently, DNA-based typing has shown that particular DR and DQ sequence-defined alleles were associated with specific diseases; sequence comparisons of susceptible and non-susceptible alleles revealed the potential importance of individual polymorphic positions of the class II beta chains. The role of DP polymorphism in disease susceptibility has not been studied to the same extent. The distribution of DPB1 and DPA1 alleles in patients and in ethnically matched controls will be compared for a variety of diseases. Due to the strong linkage disequilibrium within the HLA region, assessing the role of DP polymorphism requires the analysis of HLA (B,DR,DQ,DP) haplotypes . We have already examined the nature and distribution of extended haplotypes in a Caucasian group. Our project will focus on families, allowing the unambiguous determination of haplotypes and we will compare the different haplotypic combinations that are found in different ethnic groups. These haplotype data are critical not only for understanding the complex patterns of HLA-disease associations but also for defining the likelihood of finding HLA-matched bone marrow and solid organ donors in different ethnic groups. Our proposal to characterize the DP sequence polymorphism, to refine our non-radioactive oligonucleotide probe DP typing system, and to apply this method (both dot blot and reverse dot blot) to disease susceptibility studies is based upon the polymerase chain reaction (PCR). Our previous work using DPB1 and DPA1 primers to PCR amplify the polymorphic second exon for sequence analysis will be extended to additional samples and populations to identify new alleles, revealed as a novel pattern of probe reactivity. New alleles are always confirmed by sequence analysis. The relationship of recombination frequency to the observed patterns of linkage disequilibrium will be examined in family studies but also by using the approach of sperm mapping, the co-amplification by PCR of linked loci from individual sperm. This method for determining recombination frequencies over short genetic distances, like those within the HLA region, can be used to compare recombination frequencies between individuals and between haplotypes. PCR amplification from sperm will also be used to try to detect the generation of new DPB1 alleles by segmental exchange, the putative gene-conversion-like mechanism inferred from the patchwork pattern of DPB1 polymorphism. A phylogenetic analysis of DPB1 polymorphism will also be carried out on a data set of non-human primate DPB1 alleles. These studies will increase our knowledge of HLA-DP polymorphism and contribute to our understanding of its role in disease susceptibility.