EXPRESSION OF VIRAL PROTEINS IN TRANSGENIC MICE

在转基因小鼠中表达单个病毒蛋白， 回答病毒发病机制中的两个基本问题： 诱导针对病毒的免疫反应的机制，以及 一种特定的病毒蛋白对细胞代谢的影响， vivo？ 为了解决第一个问题的一个例子，诱导免疫 反应，水泡性口炎病毒的包膜糖蛋白G， 血清型印第安纳州，在转基因中表达。 当这些老鼠 用纯化的G蛋白免疫，或者当用重组 表达这种蛋白质的牛痘病毒，只有IgM抗体而没有IgG抗体 形成能够中和野生型印第安纳州VSV。然而，回应 中和抗体是正常的， 使用印第安纳州VSV。因此，耐受性被破坏，自身免疫被破坏。 当野生型病毒用于免疫时，而不是当G 蛋白质以其他方式存在。这些小鼠可能成为 病毒感染可能是人类自身免疫现象的原因， 触发事件。 为了解决第二个问题的一个例子，我们已经表达了 调节蛋白Tax的人逆转录病毒HTLV-L已知是 与某些类型的T细胞白血病和热带痉挛性 下肢轻瘫到目前为止，我们已经发现， 转基因小鼠可引起胸腺发育不全，但没有大体病理学。 因为在这些小鼠中，Tax蛋白是在一种可诱导的 促进剂，我们将能够在未来的研究效果更高 表达的水平。然而，在一个转基因系中，Tax转基因是 显然插入到宿主基因中，其产物是 椎骨的正常胚胎发育：当 转基因纯合子，显示脊椎严重畸形 以半椎体、隐性脊柱裂、椎体融合为特征 身体和弯曲的短尾巴的分子表征， 我们已经定位到小鼠11号染色体上的相应基因位于 路上了

Individual viral proteins are expressed in transgenic mice in order to answer two fundamental questions in viral pathogenesis: what are the mechanisms of induction of an immune response against a virus and what effect does a particular viral protein have on the metabolism of a cell in vivo? To address an example of the first question, induction of an immune response, the envelope glycoprotein G of vesicular stomatitis virus, serotype Indiana, was expressed in transgenics. When these mice are immunized with purified G protein, or when challenged with a recombinant vaccinia virus expressing this protein, only IgM and not IgG antibodies able to neutralize wildtype Indiana VSV are formed. However,the response with neutralizing antibodies is normal when the corresponding wildtype Indiana VSV is used. Thus, tolerance breaks down, and autoimmunity is established, when wildtype virus is used for immunization, and not when G protein is presented in other ways. These mice may become a model for those autoimmune phenomena of humans for which viral infections may be the triggering event. To address an example of the second question, we have expressed the regulatory protein Tax of the human retrovirus HTLV-L known to be associated with certain forms of T-cell leukemias, and tropical spastic paraparesis. To date we have found that low level Tax expression in transgenic mice may cause a thymic hypoplasia but no gross pathology. Since in these mice the Tax protein is under the control of an inducible promoter, we will be able in the future to study the effect of higher levels of expression. However, in one transgenic line the Tax transgene is apparently inserted into a host gene whose product is neccessary for normal embryonic development of the vertebra: mice of this line, when homozygous for the transgene, show a severe malformation of the vertebra characterized by hemivertebrae, spina bifida occulta, fusions of vertebral bodies, and short kinky tails. The molecular characterization of the corresponding gene that we have mapped to mouse chromosome 11 is under way.