在MHC编码的蛋白酶子单元通常不需要处理由MHC I类分子结合的
D Arnold1, J Driscoll, M Androlewicz
1Division of Tumor Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115.
Nature
|November 12, 1992
概括
这项研究表明,蛋白酶体对于抗原处理并不必不可少. 即使没有关键的蛋白酶组分 (LMP2和LMP7),细胞仍然可以通过主要基因相容性复合物I类分子呈现.
科学领域:
- 免疫学 免疫学 免疫学
- 分子生物学分子生物学
- 蛋白质体功能 蛋白质体功能
背景情况:
- 主体自身相容性复合体 (MHC) I类分子为细胞毒性T淋巴细胞呈现,这是细胞免疫的关键步骤.
- 这些的产生和传递从细胞质到细胞内网膜涉及TAP1-TAP2运输体.
- 蛋白酶子单元LMP2和LMP7位于TAP基因附近,这导致了它们参与抗原处理的假设.
研究的目的:
- 研究蛋白质酶子单元LMP2和LMP7在抗原处理途径中的作用.
- 为了确定蛋白酶体是否对于MHC I类分子所呈现的的生成至关重要.
主要方法:
- 使用了缺乏LMP2和LMP7表达的人类淋巴细胞细胞系突变体 (721.174).
- 评估了突变细胞系中稳定组装的MHC类I分子的表达.
- 通过基因转移,通过重组蛋白质体子单元来确认LMP7的身份.
主要成果:
- 在缺乏LMP2和LMP7的细胞中,观察到MHC I类分子表达和正常的处理的完全恢复.
- 基因转移成功重建了一个蛋白质体子单元,证实了LMP7的身份.
- 这些发现挑战了蛋白酶体在抗原处理的这一方面所谓的重要作用.
结论:
- 蛋白质体,特别是LMP2和LMP7子单元,对于由MHC I类分子呈现的的生成是不必要的.
- 这项研究质疑蛋白质体在初级抗原处理途径中的假设参与.
- 不能完全排除LMP2和LMP7在抗原处理中的潜在,更微妙的作用.
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