Identification of an H2-M3-restricted Listeria epitope: Implications for antigen presentation by M3
Identification of an H2-M3-restricted Listeria epitope: Implications for antigen presentation by M3
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DOI：
10.1016/s1074-7613(00)80310-6
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发表时间：
1996-07-01
期刊：
影响因子：
32.4
通讯作者：
Bevan, MJ
中科院分区：
文献类型：
--
作者：
Lenz, LL;Dere, B;Bevan, MJ
利用表达克隆技术，我们鉴定了单核细胞增多性李斯特菌胞内致病菌的H2-M3限制性表位。氨基末端N-甲酰化六肽fMIGWII的皮摩尔浓度为CD8(+)细胞毒性T细胞裂解的靶细胞，而非甲酰化肽的活性大约降低100倍。该表位185个氨基酸蛋白来源的序列预测了一个保留其N末端的跨膜蛋白，并呈N-OUT-C-IN拓扑结构。这种膜取向解释了细菌细胞中存在的变形酶对表位的保护，并解释了吞噬细胞通过空泡敲击不依赖机制呈现H2-M3限制性细菌表位的能力。
Using expression cloning, we have identified an H2-M3-restricted epitope of the intracellular bacterial pathogen Listeria monocytogenes. Picomolar concentrations of an amino-terminal N-formylated hexapeptide, fMIGWII, targeted cells for lysis by CD8(+) cytotoxic T cells, while the nonformylated peptide was approximately 100-fold less active. The sequence of the 185 aa protein source of this epitope predicts a transmembrane protein that retains its N terminus and assumes an N-out-C-in topology. This membrane orientation offers an explanation for the protection of the epitope from deformylases present in the bacterial cell and suggests an explanation for the ability of phagocytes to present H2-M3-restricted bacterial epitopes via a vacuolar TAP-independent mechanism.