Lenz L L, Dere B, Bevan M J
Department of Immunology, University of Washington, Seattle, 98195, USA.
Immunity. 1996 Jul;5(1):63-72. doi: 10.1016/s1074-7613(00)80310-6.
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.
通过表达克隆，我们鉴定出细胞内细菌病原体单核细胞增生李斯特菌的一个受H2-M3限制的表位。皮摩尔浓度的氨基末端N-甲酰化六肽fMIGWII可靶向细胞，使其被CD8+细胞毒性T细胞裂解，而非甲酰化肽的活性则低约100倍。该表位的185个氨基酸蛋白质来源的序列预测为一种跨膜蛋白，其保留了N末端并呈现N（外）-C（内）拓扑结构。这种膜方向解释了该表位免受细菌细胞中存在的去甲酰化酶影响的原因，并为吞噬细胞通过液泡TAP非依赖机制呈递受H2-M3限制的细菌表位的能力提供了解释。
