GENETICS AND PATHOLOGY OF NONOBESE DIABETIC (NOD) MICE

NOD小鼠的自身免疫性胰岛素依赖型糖尿病(IDDM)的发生需要一种固有的非MHC基因和一种复杂的相互作用。尽管一些非MHC胰岛素依赖型糖尿病(IDD)基因的染色体位置已经确定，但它们的实际身份和确切功能仍不清楚。分离这些非MHC Idd基因座并确定它们在免疫发病机制中的作用所采用的策略是在Idd基因座上携带抗性等位基因的NOD小鼠的同源群体。这项建议的目的是结合小鼠遗传学和功能基因组学来识别控制自身反应性CD4和CD8 T细胞外周聚集(“T淋巴聚集”)的基因，并更准确地识别能够延缓糖尿病形成过程的调节性T细胞的性质。一种有针对性的L-选择素基因的破坏将被引入NOD/LT小鼠中，以检验该标记识别外周T调节细胞的假设。为了确定非MHC基因的功能，既可以调节胰岛聚集T细胞的激活，也可以限制它们的聚集，建议进行研究，以建立H2 g7相合的NOR/LT菌株中IDDM抗性的遗传基础。NOR小鼠表现出T效应细胞激活迟缓，这可能在一定程度上是更正常的巨噬细胞数量的结果。一个基因中断的Caspase 1(IL-1β转换酶)基因将被引入到表达NOR的IL-1等位基因的抗糖尿病的chr.2同源基因库中，以测试IL-1基因复合体的候选能力。NOD/LT是CHR9(表现为T淋巴聚集，但抑制效应激活)上非/LT来源耐药基因的同源基因，NOcCB-1是一种新的重组同源基因，将分别用于鉴定控制CD4和CD4T细胞聚集的NOD基因。所提出的方法的组合不仅应该允许对主要的非MHC相关的IDDM易感基因进行分子鉴定，而且还可以在细胞水平上建立它们的致病作用。

Development of autoimmune insulin dependent diabetes mellitus (IDDM) in NOD mice entails a complex interaction between an inherently daibetogenic MHC and numerous non-MHC genes. Although chromosomal locations for a number of the non-MHC insulin dependent diabetes (Idd) genes have been established, their actual identities and precise functions remain unknown. The strategy employed to isolate these non-MHC Idd loci and to establish their contribution to immunopathogenesis has been to make congenic stocks of NOD mice carrying resistance alleles at Idd loci. The objectives of this proposal are to combined mouse genetics and function genomics to identify genes that control peripheral accumulation of autoreactive CD4 and CD8 T cells ("T-lymphoaccumulation") and to identify more precisely the nature of regulatory T cells capable of retarding the diabetogenic process. A targeted disruption of the L- selectin gene will be introduced into NOD/Lt mice to test the hypothesis that this marker identifies peripheral T-regulatory cells. To identify non-MHC genes that function either to regulate activation of islet- accumulation T cells or to limit their accumulation, studies are proposed to establish the genetic basis for IDDM resistance in the H2g7- identical NOR/Lt strain. NOR mice show a retarded activation of T- effector cells that may, in part, be a consequence of a more normal macrophage population. A genetically disrupted Caspase 1 (IL-1beta converting enzyme) gene will be introduced into diabetes-resistant Chr.2 congenic stocks expressing IL-1 alleles from NOR to test the candidacy of the IL-1 gene complex. NOD/Lt stocks congenic for NON/Lt-derived resistance loci on Chr 9 (exhibiting T-lymphoaccumulation, but retarded effector activation), and NOcCB-1, a new recombinant congenic strain, will be used to identify NOD genes controlling CD4 and CD4 T cell accumulation respectively. The combination of approaches proposed should permit not only molecular identification of major non-MHC associated IDDM susceptibility genes, but also establishment of their pathogenic contributions at a cellular level.