HLA-DP SEQUENCE POLYMORPHISM AND DISEASE PREDISPOSITION

本项目的总体目标是确定 HLA-DP区域的等位基因多样性，并评估 这种多态性与HLA相关疾病的易感性有关。 各种 许多但并非全部是自身免疫性疾病， 具有特异性血清学定义的HLA II类等位基因和/或 单倍型。 最近，基于DNA的分型显示特定的DR和 DQ序列定义的等位基因与特定疾病相关; 易感和非易感等位基因的序列比较显示， 该类个体多态位置的潜在重要性 II β链。 DP基因多态性在疾病易感性中的作用 没有被研究到同样的程度。 DPB 1的分布和 患者和种族匹配的对照中的DPA 1等位基因将在 与其他疾病相比。 由于联系紧密， HLA区域内的不平衡，评估DP的作用 多态性需要分析HLA（B、DR、DQ、DP）单倍型。我们 我已经研究了扩展单倍型的性质和分布 在一个白人群体中。 我们的项目将侧重于家庭， 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 单倍型数据不仅对于理解复杂的 HLA-疾病关联的模式，也用于定义 寻找HLA匹配的骨髓和实体器官捐赠者， 种族群体。 我们提出的描述DP序列的建议 多态性，以完善我们的非放射性寡核苷酸探针DP 分型系统，并应用此方法（点印迹和反向点 对疾病易感性的研究是基于聚合酶 链反应（PCR）。 我们以前的工作使用DPB 1和DPA 1引物， PCR扩增多态性第二外显子进行序列分析， 扩展到另外的样品和群体以鉴定新的等位基因， 揭示了一种新的探针反应模式。 新的等位基因总是 通过序列分析证实。 重组关系 观察到的连锁不平衡模式的频率将是 在家庭研究中也进行了检查， 作图，通过PCR共扩增来自个体的连锁基因座， 精子 该方法用于确定短时间内的重组频率， 遗传距离，如HLA区域内的遗传距离，可用于 比较个体间和个体间的重组频率 单倍型。 精子的PCR扩增也将用于尝试 通过片段交换检测新DPB 1等位基因的产生， 从拼凑推断出的假定的基因转换样机制 DPB 1多态性的模式。 DPB 1基因的系统发育分析 多态性也将在非人灵长类动物数据集上进行 DPB 1等位基因。 这些研究将增加我们对HLA-DP的认识 多态性，并有助于我们了解它在疾病中的作用 易感性

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.