PROTEOLYTIC GENERATION OF ANTIGENIC PEPTIDES

CD8表达的T细胞(TCD8+)在根除疾病中起关键作用 细胞内的寄生虫，如病毒。TCD8+识别MHC I类 具有8至10个残基的多肽的络合物中的分子，其来源为 位于细胞质中的病毒蛋白。人们对…有极大的兴趣 多肽产生的机制。有间接的 蛋白酶体与抗原生成有关的证据 多肽。蛋白酶体是一种丰富的大分子结构。 具有多种蛋白酶活性的细胞内的胞浆和细胞核。 它们被认为是能量依赖的蛋白质分解的原因。 其中泛素在靶向蛋白质方面起着重要作用。 毁灭。尽管人们相信至少有一些蛋白质分解作用 发生在细胞质中，还不确定最终的决定因素是否 是否在细胞质中产生，或者是否发生额外的修剪 从细胞质运输出来之后。 我们已经启动了几种方法来评估地点和性质 用于产生抗原肽的蛋白分解机制。 首先，我们生产了表达一种泛素形式的牛痘重组体 改变以干扰泛素靶向的蛋白质分解。第二，我们 设计了一种I类分子的胞浆形式，应该作为 检测胞浆中是否存在抗原肽的探针。

CD8 expressing T cells (TCD8+) play a critical role in eradicating intracellular parasites such as viruses. TCD8+ recognize MHC class I molecules in a complex with peptides of 8 to 10 residues derived from viral proteins located in the cytosol. There is tremendous interest in the mechanism by which peptides are generated. There is indirect evidence that implicates proteasomes in the generation of antigenic peptides. Proteasomes are abundant macromolecular structures present in the cytosol and nucleus in cells with multiple protease activities. They are thought to be responsible for the energy dependent proteolysis in which ubiquitin plays a prominent role in targeting proteins for destruction. Although it is believed that at least some proteolysis occurs in the cytosol, it is uncertain whether the ultimate determinants are generated in the cytosol, or whether additional trimming occurs following transport from the cytosol. We have initiated several approaches to assess the site and nature of proteolytic mechanisms utilized in the generation of antigenic peptides. First, we produced vaccinia recombinants expressing a form of ubiquitin altered to interfere with ubiquitin-targeted proteolysis. Second, we engineered a cytosolic form of class I molecule to that should serve as a probe for the presence of antigenic peptides in the cytosol.