Differential glycosylation of MHC class II molecules on gastric epithelial cells: Implications in local immune responses
Differential glycosylation of MHC class II molecules on gastric epithelial cells: Implications in local immune responses
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DOI：
10.1016/s0198-8859(02)00386-5
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发表时间：
2002-05-01
期刊：
影响因子：
2.7
通讯作者：
Reyes, VE
中科院分区：
文献类型：
--
作者：
Barrera, C;Espejo, R;Reyes, VE
II类主要组织相容性复合体（MHC）表达是抗原呈递细胞（APC）的标志。人胃上皮细胞（GEC）表达II类MHC，并且在幽门螺杆菌感染期间这种表达增加，这是上皮细胞附近或之间发现的CD 4 T细胞的数量增加。这些观察结果表明，人GEC充当APC。为了表征和比较II类MHC复合物与常规APC中存在的那些，通过双向电泳分离来自GEC和B细胞的免疫沉淀的II类MHC作为原型APC。尽管两种细胞表型的II类MHC组成相似，但它们的电泳迁移率不同。方法消除碳水化合物，无论是酶与endoglycosidase-H或封闭衣霉素，揭示了偏差是由于在两种细胞表型的糖基化的差异。当去糖基化的II类MHC α链、β链和来自两种细胞表型的不变链混合并在同一凝胶中运行时，核心蛋白具有相同的迁移模式。由于II类MHC蛋白糖基化的差异可能影响T细胞的肽选择和/或识别，因此GEC表达的II类MHC糖基化的显著差异在考虑其作为局部APC的潜在作用时可能是重要的。
Class II major histocompatibility complex (MHC) expression is a hallmark of antigen presenting Cells (APC). Human gastric epithelial cells (GEC) express class II MHC and this expression increases during infection with Helicobacter pylori is does the number of CD4 T cells found adjacent or in between epithelial cells. These observations suggested that human GEC act as APCs. To characterize and compare class II MHC Complexes with those present in conventional APC, immunoprecipitated class II MHC from GEC and B cells, as prototypic APC, were separated by two-dimensional electrophoresis. Allthough the composition of class II MHC from both cell phenotypes was similar, their electrophoretic mobility differed. Methodical elimination of carbohydrates, either enzymatically with endoglycosidase-H or blocking with tunicamycin, revealed that the deviations were due to differences in glycosylation in both cell phenotypes. When deglycosylated class II MHC alpha chains, beta chains, and the invariant chain from both cell phenotypes were mixed and run in the same gel, the core proteins had identical migration patterns. Because differences in glycosylation of class II MHC proteins may affect peptide selection and/or recognition by T cells, the noted differences in glycosylation of class II MHC expressed by GEC could be important in considering their potential role as APC locally.