ANTI-SM B CELLS OF MRL/LPR MICE

这项建议的长期目标是了解B 细胞的发育和选择导致产生 MRL/MP-LPR/LPR(MRL/LPR)小鼠的自身抗体。这种品系的小鼠 发展为类似系统性狼疮的自发性自身免疫性疾病 红斑狼疮(SLE)。我们已经开始研究B细胞对 SM颗粒，一种存在于所有细胞的细胞核中的核糖核蛋白。这个 人类对这种粒子的自发反应是系统性红斑狼疮的诊断， MRL/LPR小鼠是唯一一种自发地发展成 对这种抗原的反应。系统性红斑狼疮与Sm反应的相关性研究 暗示了这种疾病的病因学和 这些自身抗体的产生。我们之前的分析表明 Sm特异性B细胞是由DNA选择的，但也表明 第二种抗原的参与，推测是Sm。我们在目标1中建议 验证Sm是这种反应中的选择性抗原的假设。这 将通过鉴定多种抗Sm抗体的突变来实现 杂交瘤，并确定它们的分布是否有偏见，一个 突变B细胞抗原选择的指征。此外，通过 使用转染瘤抗体我们将确定是否观察到 突变改善了Sm和DNA的结合。在目标2中，我们将研究基础 用于抗Sm杂交瘤的双重Sm和DNA结合。我们建议 DNA结合主要由H链和Sm决定 结合主要由L链决定。这一假设将是 通过检测Sm和DNA结合检测产生的转染瘤 VH或VK不同的抗体。在目标3中，我们将生成 用抗Sm和抗Sm/DNA的VH和VK基因转基因小鼠 杂交瘤。转基因小鼠将被杂交到正常和 自身免疫遗传背景以检查这些基因的免疫调节 正常小鼠的细胞及其在自身免疫小鼠中的失调。

The long term objective of this proposal is to understand the events in B cell development and selection that lead to the production of autoantibodies in MRL/Mp-lpr/lpr (MRL/lpr) mice. Mice of this strain develop a spontaneous autoimmune disease that resembles systemic lupus erythematosus (SLE). We have begun a study of the B cell response to the Sm particle, a ribonucleoprotein present in the nuclei of all cells. The spontaneous response to this particle in humans is diagnostic of SLE, and MRL/lpr mice are the only mouse model that spontaneously develops a response to this antigen. The correlation of the response to Sm and SLE suggests an essential relationship between the etiology of the disease and the production of these autoantibodies. Our previous analysis indicates that Sm-specific B cells are selected by DNA, but also indicates the involvement of a second antigen, presumably Sm. We propose in Aim 1 to test the hypothesis that Sm is a selecting antigen in this response. This will be accomplished by identifying the mutations in multiple anti-Sm hybridomas, and determining whether their distribution is biased, an indication of antigen selection of mutant B cells. In addition, through the use of transfectoma antibodies we will determine whether the observed mutations improve Sm and DNA binding. In Aim 2 we will examine the basis for the dual Sm and DNA binding of anti-Sm selected hybridomas. We propose that DNA binding is determined principally by the H chain and that Sm binding is determined principally by the L chain. This hypothesis will be tested by measuring Sm and DNA binding of generated transfectomas antibodies that differ in the VH or Vk. In Aim 3 we will generate transgenic mice using VH and Vk genes of anti-Sm and anti-Sm/DNA hybridomas. Transgenic mice will be crossed onto both normal and autoimmune genetic backgrounds to examine the immunoregulation of these cells in normal mice and their disregulation in autoimmune mice.