Cellular and Genetic Basis of Systemic Lupus

描述(由申请人提供)：众所周知，遗传学在系统性红斑狼疮(SLE)的发病机制中起着重要作用。该项目的长期目标是了解这种疾病的基因控制。在过去的几年里，我们表征了一种新的鼠标型号NZM2328。这种病毒的雄性和雌性都有循环中的抗核抗体(ANA)。在男性中，急性肾小球肾炎(GN)常见，没有严重的蛋白尿。然而，女性有严重的蛋白尿，急性和慢性肾炎，早期死亡。在(NZM2328XC57L/J)F1 X NZM2328的回交分析中，1号染色体的一个区域已被确定为控制急性和慢性肾炎(GN)。它们被指定为Agnz1和Cgnz1。此外，4号染色体上一个被命名为Adnz1的基因被证明与抗ANA和抗dsDNA抗体的产生有关。NZM.C57Lc1和NZM.C57Lc4分别用C57L/J和NZM.C57Lc4替换NZM2328中的相关区域，获得两个同源品系。NZM.C57Lc1女性的蛋白尿和肾小球肾炎明显减少，而NZM.C57Lc4女性的蛋白尿严重，GN无ANA。令人惊讶的是，在NZM.C57Lc1中没有发现ANA和抗dsDNA，这表明1号染色体上的Adnz1基因座也与ANA的产生有关。这些结果导致了一种假设，即分离的基因控制自身抗体(ANA、抗组蛋白和抗dsDNA抗体)的产生和结束器官损伤。这种竞争性更新应用集中在1号染色体上控制三种不同表型的基因片段。具体目标1：通过杂交获得NZM.C57Lc1同源菌株和染色体内重组子定位小组(F1XF1)，精细定位控制急性GN、慢性GN和ANA及相关抗体产生的1号染色体的遗传区域，包括Agnz1、Cgnz1和Adaz2。这将使我们能够在与三种表型中的每一种表型相关的区域中确定候选基因；具体目标2：确定一组连续的重叠基因组克隆(重叠群)，其覆盖感兴趣的候选基因，并对这些重叠克隆进行测序以确定候选基因中的多态；具体目标3：确定候选基因的功能及其在形成观察到的表型中的作用；以及具体目标4：验证等位基因转基因或基因敲打技术的易感性。本研究结果可能明确狼疮性肾炎发病机制的重要关卡，为治疗干预提供新的靶点。

DESCRIPTION (provided by applicant): It is well established that genetics plays a major role in the pathogenesis of systemic lupus erythematosus (SLE). The long-term goal of this project is to understand the genetic control of this disease. During the past several years, we have characterized a new mouse model, NZM2328. Both males and females of this strain have circulating anti-nuclear antibodies (ANA). In the males, acute glomerulonephritis (GN) is seen frequently without severe proteinuria. However, the females have severe proteinuria, acute and chronic GN with early mortality. In a backcross analysis of (NZM2328XC57L/J)F1 X NZM2328, a region of chromosome 1 has been identified to control acute and chronic glomerulonephritis (GN). These have been designated as Agnz1 and Cgnz1. In addition, a locus designated as Adnz1 on chromosome 4 was shown to be linked to the production of anti-ANA and anti-dsDNA antibodies. Two congenic lines, NZM.C57Lc1 and NZM.C57Lc4 were generated by replacing the relevant region in NZM2328 with that of C57L/J respectively. NZM.C57Lc1 females have markedly reduced proteinuria and GN while those of NZM.C57Lc4 have severe proteinuria and GN without ANA. Surprisingly, ANA and anti-dsDNA are not seen in NZM.C57Lc1 suggesting that a locus, Adnz1 on chromosome 1 also contributes to ANA production. These results have led to the hypothesis that separate genes control autoantibody (ANA, anti- histone and anti-dsDNA antibodies) production and end organ damage. This competitive renewal application focuses on the genetic segment on chromosome 1 controlling three distinct phenotypes. Four specific aims are proposed: Specific Aim 1: To generate NZM.C57Lc1 congenic strains and a mapping panel of intrachromosomal recombinants by intercross breeding (F1XF1) to fine map the genetic region of chromosome 1, containing Agnz1, Cgnz1 and Adaz2, which control acute GN, chronic GN and ANA and related Ab production. This will enable us to identify candidate genes in the region relating to each of the three phenotypes; Specific Aim 2: To identify a set of contiguous overlapping genomic clones (contigs), which cover the candidate genes of interest and to sequence these contigs to define polymorphisms in the candidate genes; Specific Aim 3: To identify the functions of the candidate genes and their role in shaping the observed phenotypes; and Specific Aim 4: To validate susceptibility by allele transgenesis or gene knockin technology. The results of this research may identify important checkpoints for the pathogenesis of lupus nephritis, providing new targets for therapeutic intervention.