TRANSGENIC MODEL FOR B CELL TOLERANCE AND AUTOIMMUNITY

这项研究的目标是检查发展和表达 一种与疾病相关的自身抗原DNA的特异性B细胞 非自身免疫和自身免疫的小鼠。我们已经开发出一种转基因(TG) 使用多套TGS的模型系统：Vh3H9重链纯TG， 当它与内源轻链配对时，会产生一种光谱 抗DNA和非DNA结合抗体；Vh3H9重链TG交配 到Vkappa8轻链Tg，导致基本上单一的 抗单链(Ss)DNA谱系；Vh3H9重链TG 与Vlambda1或Vlambda2轻链Tg配对，这两者 与Vh3H9重链结合单链和双链 (Ds)DNA，但亲和力不同。对DNA的耐受性体现在 在这些TGS中有不同的方式。Vh3H9/Vkappa8TGS中的抗单链DNA B 细胞占主导地位，但它们在功能上是沉默的，它们是 被容忍了。我们将调查阻止抗癌的细胞基础是什么 这些小鼠体内有DNA的表达。Vh3H9 TGS扩展了模型以显示 B细胞耐受不同机制在正常小鼠体内的作用 具有抗dsDNA特异性的B细胞：抗dsDNA B细胞缺失或 已经大幅下调了他们的表面免疫球蛋白(Ig)。这个 抗dsDNA B细胞在正常动物和自身免疫动物中的命运 被研究。我们有证据表明Vh3H9/Vkappa8 TGS表达 当处于自身免疫遗传背景时。尚不清楚的是 变化会导致他们的表达。的范围和克隆性 TG抗DNA的表达将直接解决该病的病因 自身免疫力。 我们想知道为什么对DNA的耐受性以不同的方式表现出来。 抗DNA抗体的详细特异性和亲和力 影响B细胞调节的方式将使用 TG重链和轻链TGS的各种组合。抗DNA抗体 从这些TGS产生的抗体是异质性的 他们识别的DNA的形式，与之反应的程度 结构上相关的分子，以及它们对DNA的亲和力。我们 能够确定这些参数中哪些是重要的 决定了B细胞在正常小鼠中的命运。 某些抗DNA的表达与基因表达的直接关系 而病理学是有争议的。哪只蚂蚁- DNA抗体存在于正常动物中，并且存在于 会导致自身免疫动物的疾病。的潜在范围 可由TGS表达的抗DNA抗体可能提供一种 关联特定抗DNA表达的机会 抗体与疾病。这项研究的最终目标是 能够治愈自身免疫性疾病。通过利用丰富的人口 我们可以了解抗DNA抗原提呈细胞(APC)的本质 体内抗原和最终设计的方法来干扰 抗DNA/自身相互作用。

The goal of this study is to examine the development and expression of B cells specific for a disease-associated self-antigen, DNA, in nonautoimmune and autoimmune mice. We have developed a transgenic (TG) model system using multiple sets of TGs: the Vh3H9 heavy chain-only TG, which when paired with endogenous light chains generates a spectrum of anti-DNA and non-Dna binding antibodies; the Vh3H9 heavy chain TG mated to a Vkappa8 light chain TG resulting in an essentially monospecific anti-single strand (ss)DNA repertoire; and the Vh3H9 heavy chain TG mated to either a Vlambda1 or a Vlambda2 light chain TG, both of which when paired with the Vh3H9 heavy chain bind ss and double strand (ds)DNA, but with different affinity. Tolerance to DNA is manifested in different ways in these TGs. In the Vh3H9/Vkappa8 TGs the anti-ssDNA B cells dominate the repertoire yet they are functionally silent, they are tolerized. We will investigate what the cellular basis preventing anti- DNA expression is in these mice. The Vh3H9 TGs extend the model to show that different mechanism of B cell tolerance operate in normal mice on B cells with anti-dsDNA specificity: anti-dsDNA B cells are deleted or have drastically down regulated their surface immunoglobulin (Ig). The fate of the anti-dsDNA B cells in normal versus autoimmune animals will be studied. We have evidence that the Vh3H9/Vkappa8 TGs are expressed when in an autoimmune genetic background. What is not clear is what changes lead to their expression. The extent and the clonality of the TG anti-DNA expression will directly address the etiology of autoimmunity. We want to know why tolerance to DNA is manifested in different ways. How the detailed specificity and avidity of the anti-DNA antibodies influence the way a B cell is regulated will be addressed using the various combinations of TG heavy and light chain TGs. The anti-DNA antibodies generated from these TGs are heterogeneous with respect to the form of DNA they recognize, the extent of reactivity with structurally related molecules, and the avidity they have for DNA. We are in a position to determine which of these parameters are significant in determining the fate of a B cell in normal mice. The direct relationship between expression of certain kinds of anti-DNAs and pathology is controversial. It is not at all established which ant- DNA antibodies are present in normal animals and which are present and contribute to disease in autoimmune animals. The potential range of anti-DNA antibodies that can be expressed by the TGs may provide an opportunity to correlate the expression of particular anti-DNA antibodies with disease. The ultimate goal of this research is to be able to cure autoimmunity. Through the use of the enriched population of anti-DNA antigen presenting cells (APC) we may learn the nature of the in vivo antigen and eventually design methods to interfere with the anti-DNA/self interaction.