TRANSGENIC ANALYSIS OF BCL X IN AUTOIMMUNITY

来自实验模型的证据表明，程序化细胞中的缺陷 淋巴细胞的死亡或凋亡可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 实验室研究表明，bclx是bcl2家族中的一员。 调节基因，为淋巴细胞提供重要的生命信号。BCL-x CD4O的交联会诱导mRNA和蛋白质的表达 B细胞上的受体或T和B淋巴细胞的有丝分裂原激活。 此外，过表达的bclx可以保护未成熟的B淋巴细胞 表面免疫球蛋白M交联物引发的细胞凋亡 (IGM)在B细胞阴性选择模型中。 在本研究中，我们建议直接检测bcl-x在 介导一种自身免疫表型，并探讨bclx的影响 B的负选择、耐性诱导和体细胞突变 细胞。我们的具体目标是：L)。生成两行B细胞 转基因小鼠，一只表达长异构体(Bclxl)的转基因小鼠，一种生命蛋白， 另一个表达死亡蛋白短蛋白(bcl-xs)。的影响 Bclxl表达异常在B细胞发育和活化中的作用 将对细胞进行研究，预测这些小鼠将是 易患自身免疫病和/或淋巴瘤。相比之下，转基因小鼠 对于B系中的BCL-X，可能有发育障碍或 B细胞免疫反应减弱。2)。BCL-XL对无能的影响 将在鸡蛋溶菌酶中检测诱导和负选择。 B细胞耐受模型系统及bclxl在体细胞中的作用 将评估生发中心内的突变。3)。最后，BCL-XL和 BCL-XS B细胞转基因小鼠将回交到NZW基因 背景资料。同基因bclx/NZW小鼠将与NZB小鼠配种，并 由此产生的BWF1雌性将被检查以测试转基因 加速(长期)或消除(短期)疾病的发病和严重程度 系统性红斑狼疮模型。 对系统性自身免疫性疾病的病理生理学的新见解 如果我们要在我们的治疗方面取得重大改善 有自身免疫力的病人。拟议中的实验将测试 简单的假设是死亡抑制基因的失调 B细胞中的bclx可导致自身免疫性疾病。这些实验是 可能会提高我们对bclx作为解毒剂的作用的理解 免疫系统中的死亡。此外，这些研究可能表明基因 通过靶向凋亡通路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.