IDENTIFICATION OF AUTOIMMUNE GENES IN LPR/LPR MICE

遗传因素在自身免疫性疾病中的表达 无论是老鼠还是人类。这些基因在很大程度上是没有特征的；此外， 它们的基因产物和作用机制尚不清楚。一个隐性的 在MRL小鼠中发生的突变，LPR，导致严重的 伴有异常T细胞亚群扩张的淋巴结病 泛发性自身免疫性疾病。提出了一种“反向”遗传方法。 鉴定LPR基因座的突变或缺陷基因产物 与LPR相互作用导致肾脏疾病的MRL基因。方法 依赖于定义这些基因的物理位置。RFLV和 微卫星多态将作为标记在两个不同的 对临床至关重要的隐性基因的杂交分离 以及这些小鼠的血清学疾病。将对肾脏组织学进行评分 并与基因分析和自身抗体谱相关联。这个 LPR对小鼠Chr 19的定位将得到确认并饱和 使用来自流排序的鼠标Chr 19库的克隆的映射将是 已执行。最感兴趣的将是定义MRL数量性状 易感肾炎的基因座(QTL)。每一个的详细映射 将使用可用的克隆进行基因组的相关区域 定位到特定的染色体片段和可能位于 基因组的那个区域。如有必要，一个特定于亚染色体的 将生成文库或染色体微切割文库以 允许对一个已识别的QTL区域进行饱和作图。长 小白鼠相关区域的范围限制部位分析 基因组将被执行。如果像很可能的那样，一个或多个自身免疫基因座 都在小鼠和小鼠之间基本保守的染色体片段内 人类基因组，这些研究可能确定染色体的位置 人类的“自身免疫基因”。各种策略，包括使用 染色体跳跃和小鼠酵母人工染色体文库 除了远程限制映射外，还将用于更精确地 确定负责的关键基因(S)的分子位置 遗传易感性。与MRL加减/加减小鼠的比较 将有助于确定LPR突变，也将用于比较 CBA/KJ与一株新的LPR基因突变 CBA/KJ-LPR(CG)。对于其他定位的“自身免疫基因”，候选基因 可能是由它们的染色体位置所暗示的。单项的定义 倾向于自身免疫的基因应该有基本的洞察力 转化为老鼠和人类疾病的分子基础。

Genetic factors contribute to the expression of autoimmune diseases in both mice and humans. These genes are largely uncharacterized; moreover, their gene products and mechanisms of action are unknown. A recessive mutation, lpr, that occurred in MRL mice results in profound lymphadenopathy with expansion of an unusual subpopulation of T cells and generalized autoimmune disease. A "reverse" genetic approach is proposed to identify the mutant or deficient gene products of the lpr locus and MRL genes that interact with lpr to result in renal disease. The method relies on defining the physical location of these genes. RFLV and microsatellite polymorphisms will be used as markers in two different crosses segregating for the recessive genes that are critical to clinical and serologic disease in these mice. The renal histology will be scored and correlated with the genotype analyses and autoantibody profiles. The localization of lpr to mouse Chr 19 will be confirmed and saturation mapping using clones from a flow sorted mouse Chr 19 library will be performed. Of most interest will be defining the MRL quantitative trait loci (QTL) that predispose to nephritis. Detailed mapping of each relevant region of the genome will be undertaken using available clones localized to the specific chromosome segment and clones likely to be in that region of the genome. If necessary, a subchromosome specific library or a chromosome microdissection library will be generated to allow saturation mapping of one of the identified QTL regions. Long range restriction site analyses of the relevant regions of the mouse genome will be performed. If, as is likely, one or more autoimmune loci are within a chromosomal segment largely conserved between the mouse and human genome, these studies may identify the chromosomal location of human "autoimmune genes". A variety of strategies including the use of chromosome jumping and a mouse yeast artificial chromosome library, in addition to long range restriction mapping will be used to more precisely define the molecular location of the critical gene (s) responsible for genetic predisposition. Comparison with MRL-plus-minus/plus-minus mice will be useful for determining the lpr mutation as will comparison of CBA/KJ with a new mutation at the lpr locus in a strain designated CBA/KJ-lpr(cg) . For other localized "autoimmune genes", candidate genes may be suggested by their chromosomal location. Definition of a single gene that predisposes to autoimmunity should allow fundamental insight into molecular basis for disease in mice and humans.