ANTIGEN PROCESSING FOR PRESENTATION BY CLASS-II MAJOR HISTOCOMPATIBILITY COMPLEX REQUIRES CLEAVAGE BY CATHEPSIN-E
ANTIGEN PROCESSING FOR PRESENTATION BY CLASS-II MAJOR HISTOCOMPATIBILITY COMPLEX REQUIRES CLEAVAGE BY CATHEPSIN-E
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DOI：
10.1002/eji.1830220626
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发表时间：
1992-06-01
影响因子：
5.4
通讯作者：
CHAIN, BM
中科院分区：
文献类型：
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作者：
BENNETT, K;LEVINE, T;CHAIN, BM
抗原呈递细胞对抗原的蛋白水解降解（加工）是激活T淋巴细胞免疫应答的主要调控步骤。然而，负责抗原加工的酶在很大程度上仍未确定。在这项研究中，我们发现组织蛋白酶E，而不是普遍存在的溶酶体组织蛋白酶D，是小鼠抗原呈递细胞系A20中主要的天冬氨酸蛋白酶。这种酶定位于这些细胞内体系统的非溶酶体腔室。使用组织蛋白酶E的高度特异性抑制剂进行的功能研究表明，该酶对该细胞系加工卵清蛋白至关重要。因此，组织蛋白酶E可能在抗原加工中起主要作用，其功能迄今尚不清楚。
Proteolytic degradation (processing) of antigen by antigen-presenting cells is a major regulatory step in the activation of a T lymphocyte immune response. However, the enzymes responsible for antigen processing remain largely undefined. In this study we show that cathepsin E, and not the ubiquitous lysosomal cathepsin D, is the major aspartic proteinase in a murine antigen-presenting cell line, A20. This enzyme is localized to a non-lysosomal compartment of the endosomal system in these cells. Functional studies using a highly specific inhibitor of cathepsin E show that this enzyme is essential for the processing of ovalbumin by this cell line. Thus, cathepsin E, whose function was hitherto unknown, may play a major role in antigen processing.