INDUCTION OF AUTOIMMUNITY WITH IDIOTYPES

我们建立了一种新的系统性红斑狼疮实验模型 其中针对70 K U1 RNP核自身抗原的自身抗体， 双链DNA和免疫沉积性肾小球肾炎可诱导， 通过免疫球蛋白轻链免疫BALB/c小鼠。 该光 链属于一组MRL-lpr/lpr单克隆抗体（Ab-2） 被单克隆抗68 KU 1 RNP多肽MRL-lpr/lpr抗体识别 28/12（Ab-1）。 单克隆抗体28/12本身具有一个独特型标记， MRL-lpr/lpr抗DNA抗体。 Ab-2的VL区中的序列是 与U1 RNP的抗原区中的氨基酸序列同源 多肽。 我们的首要任务是确定 Id-28/12网络。 我们已经开始全面审查 代表性Ab-2的结构。 我们计划确定 这些Ab-2的氨基酸序列之间存在相关性， 它们在BALB/c小鼠中诱发自身抗体产生的能力。 与70 D RNP自身抗原的抗原性区域的任何关系都将是 特别感兴趣。 将采用三大战略： cDNA克隆的测序;（B）免疫球蛋白的体内测定， 序列和定量表征的免疫化学和 独特型特性;和（c）用合成肽免疫， 氨基酸序列对应于CDR 3轻链G的氨基酸序列。在 在进行这些结构研究的同时， Id-28/12网络的血清学、独特型和免疫病理学 模型 该项目的这一部分需要免疫化学和独特型 血清和单克隆抗体以及免疫病理学分析 有关机关的调查。 从免疫的小鼠获得的杂交瘤 与Id-LGG的结合也将为测序V基因提供材料。 诱发自身抗体。 这些序列的确定将测试 假设一个独特型可能是选择压力驱动一个 克隆相关的自身免疫反应 我们还计划进行调查， 确定对Id-LCG的自身免疫反应是否是MHC限制性的。 进一步 自发的Id-28/12网络的研究将在 MRL-+/+小鼠。 我们将研究Ab-1的发展， Ab-2网络的组成部分（即哪一个首先出现？），和分析 在年轻和老年MRL-+/+小鼠中， VL CDR 3与原型自身抗原模拟CDR 3相关。 我们将 也验证了对沙门氏菌RE的免疫反应 脂多糖可以触发相应抗体的产生 ID-28/12网络的Ab-2 我们将获得的信息将 用于开发新的治疗策略，特别是 强调诱导（或恢复）免疫的可能性 与自身抗原模拟相对应的合成肽的耐受性 Ab-2的表位。

We have developed a new experimental model of systemic lupus erythematosus in which autoantibodies against the 70K U1 RNP nuclear autoantigen, double-strand DNA and immune-deposit glomerulonephritis can be induced in BALB/c mice by immunization with an immunoglobulin light chain. This light chain belongs to a set of MRL-lpr/lpr monoclonal antibodies (Ab-2) recognized by monoclonal anti-68KU1 RNP polypeptide MRL-lpr/lpr antibody 28/12 (Ab-1). Monoclonal antibody 28/12 itself has an idiotypic marker of MRL-lpr/lpr anti-DNA antibodies. A sequence in the VL region of Ab-2 is homologous to an amino acid sequence in an antigenic region of the U1 RNP polypeptide. Our first priority is to define the structural basis of the Id-28/12 network. We have already begun a comprehensive examination of the structure of representative Ab-2's. We plan to establish whether a correlation exists between the amino acid sequences of these Ab-2's and their ability to evoke the production of autoantibodies in BALB/c mice. Any relationship to the antigenic region of the 70D RNP autoantigen will be of particular interest. Three major strategies will be employed: (a) sequencing of cDNA clones; (b) in vivo assays of immunoglobulins with known sequences and with quantitatively characterized immunochemical and idiotypic properties; and (c) immunization with synthetic peptides whose amino acid sequences correspond to those of the CDR3 light chain G. In parallel with these structural studies we are conducting an investigation of the serology, idiotypes, and immunopathology of the Id-28/12 network model. This part of the project, entails immunochemical and idiotypic analyses of serum and monoclonal antibodies as well as immunopathological investigations of relevant organs. Hybridomas obtained from mice immunized with Id-LGG will also provide material for sequencing the V genes of the evoked autoantibodies. Determination of these sequences will test the hypothesis that an idiotype can be the selective pressure driving a clonally related autoimmune response. We also plan investigations to determine if autoimmune responses to Id-LCG are MHC-restricted. Further studies of the spontaneous Id-28/12 network will be conducted in the MRL-+/+ mouse. We will examine the development over time of the Ab-1 and Ab-2 components of the network (i.e. which one appears first?), and analyze the frequency in young and old MRL-+/+ mice of monoclonal antibodies with VL CDR 3's related to the prototypic autoantigen-mimicking CDR3. We will also test the hypothesis that an immune response to Salmonella RE lipopolysaccharide can trigger the production of antibodies corresponding to the Ab-2 of the Id-28/12 network. The information we will obtain will be used for the development of new therapeutic strategies, with particular emphasis on the possibility of inducing (or restoring) immunological tolerance with synthetic peptides corresponding to autoantigen-mimicking epitopes of Ab-2.