TRANSGENIC ANALYSIS OF BCL X IN AUTOIMMUNITY

来自实验模型的证据表明，编程细胞中的缺陷 淋巴细胞的死亡或凋亡可以通过以下方式促进自身免疫： 干扰正常的淋巴死亡途径我们最近的研究 实验室提示凋亡bcl-2家族成员bcl-x 调节基因，为淋巴细胞提供重要的生命信号。Bcl-x 在CD 4 O交联后诱导mRNA和蛋白质表达 B细胞上的受体或T和B淋巴细胞的促分裂原活化。 此外，过表达的bcl-x保护未成熟的B淋巴细胞 来自表面免疫球蛋白M交联引发的细胞凋亡的线 (IgM)在B细胞的阴性选择模型中。 在这项研究中，我们建议直接检查bcl-x在 介导自身免疫表型，并探讨bcl-x 在B的负选择、耐性诱导和体细胞突变中 细胞我们的具体目标是：（1）。生成两行B细胞 转基因小鼠，一种表达Long同种型（bcl-xL），一种生命蛋白， 另一个表达Short（bcl-xS），一种死亡蛋白。的影响 bcl-xL表达失调对B细胞发育和活化的影响 细胞将进行研究，预测这些小鼠将 易患自身免疫和/或淋巴瘤相反，转基因小鼠 对于B谱系内的bcl-xS，可能具有受损的发育或 降低了B细胞免疫反应。2）。bcl-xL基因对免疫抑制的影响 将在鸡蛋溶菌酶中检查诱导和阴性选择 B细胞耐受模型系统，以及bcl-xL在体细胞免疫耐受中的作用 将评估生殖中心内的突变。3）。最后，bcl-xL和 将bcl-xS B细胞转基因小鼠与NZW遗传基因小鼠回交， 背景将同系bcl-x/NZW小鼠与NZB小鼠交配， 将检查所得的BWF 1雌性以测试转基因是否 加速（长期）或消除（短期）疾病发作和严重程度， 系统性狼疮的模型 系统性自身免疫性疾病的病理生理学的新见解是 如果我们要在治疗方面取得重大进展， 自身免疫性患者拟议的实验将测试 死亡抑制基因失调简单假设 B细胞中的bcl-x可导致自身免疫性疾病。这些实验 可能会提高我们对bcl-x作为解毒剂的作用的理解， 免疫系统中的死亡。此外，这些研究可能表明， 通过靶向凋亡途径治疗自身免疫的治疗方法 在B淋巴细胞中。

Evidence from experimental models indicate that defects in programmed cell death, or apoptosis of lymphocytes can contribute to autoimmunity by interfering with normal lymphoid death pathways. Recent studies from our laboratory suggest that bcl-x, a member of the bcl-2 family of apoptosis regulatory genes, provides important life signals for lymphocytes. Bcl-x mRNA and protein expression are induced following crosslinking of the CD4O receptor on B cells or mitogen activation of both T and B lymphocytes. Furthermore, overexpressed bcl-x protects an immature B lymphocyte cell line from apoptosis triggered by crosslinking of surface immunoglobulin M (IgM) in a model for negative selection of B cells. In this study we propose to directly examine the role of bcl-x in mediating an autoimmune phenotype, and to explore the influence of bcl-x in negative selection, tolerance induction, and somatic mutation of B cells. Our specific aims are to: l). Generate two lines of B cell transgenic mice, one expressing the Long isoform (bcl-xL), a life protein, and the other expressing Short (bcl-xS), a death protein. The influence of dysreguIated bcl-xL expression on the development and activation of B cells will be studied, with the prediction that these mice will be predisposed to autoimmunity and/or lymphoma. In contrast, mice transgenic for bcl-xS within the B lineage may have impaired development or diminished B cell immune responses. 2). The influence of bcl-xL on anergy induction and negative selection will be examined in the hen egg lysozyme model system for B cell tolerance, and the role for bcl-xL on somatic mutation within germinal centers will be assessed. 3). Finally, bcl-xL and bcl-xS B cell transgenic mice will be backcrossed onto the NZW genetic background. Congenic bcl-x/NZW mice will be bred with NZB mice, and the resulting BWF1 females will be examined to test whether the transgenes accelerate (Long) or abrogate (Short) disease onset and severity in this model for systemic lupus. New insights into the pathophysiology of systemic autoimmune disease are required if we are to make significant improvements in treatment of our patients with autoimmunity. The proposed experiments will test the straightforward hypothesis that dysregulation of the death repressor gene bcl-x in B cells can lead to autoimmune disease. These experiments are likely to improve our understanding of the role of bcl-x as an antidote to death in the immune system. Furthermore, these studies may suggest gene therapy approaches to treat autoimmunity by targeting apoptotic pathways in B lymphocytes.