Differential expression of MHC class II antigens and cathepsin L by subtypes of cortical epithelial cells in the rat thymus: an immunoelectron microscopic study.
Differential expression of MHC class II antigens and cathepsin L by subtypes of cortical epithelial cells in the rat thymus: an immunoelectron microscopic study.
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大鼠胸腺皮质上皮细胞亚型 MHC II 类抗原和组织蛋白酶 L 的差异表达：一项免疫电子显微镜研究。
DOI：
10.1093/jmicro/51.3.173
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
T. Fukumoto
中科院分区：
文献类型：
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作者：
Y. Arudchelvan;Y. Nishimura;N. Tokuda;T. Sawada;F. Shinozaki;T. Fukumoto
为了更好地了解胸腺微环境，有必要鉴定与主要组织相容性复合体(MHC)限制性T细胞的形成有关的胸腺皮质上皮细胞(CTECs)的抗原谱。在超微结构上，cTECs可分为四种不同的亚型：被膜下/血管周围(EC1)、浅色(EC2)、中间(EC3)和暗(EC4)细胞。在光镜和电子显微镜水平上对cTECs进行了多项免疫组织化学研究，但未涉及上述亚型。本文从电子显微镜水平分析了不同亚型CTEC中MHC-II类抗原和组织蛋白酶L的表达。结果表明：(1)MHC-II类抗原除在EC1细胞基底面外，在EC2细胞表面和胞浆内空泡中均有表达，仅在EC3和EC4的胞质内空泡中表达；(2)组织蛋白酶L在EC2的胞浆中表达较强且均匀，而在EC1、EC3和EC4的胞浆中表达较弱且不均匀。这些结果表明，MHC-II类抗原的表达和组织蛋白酶L的表达在CTEC亚型中具有异质性，提示EC2在CD_4~+T细胞的发育过程中可能起重要作用。
To better comprehend the thymic microenvironment, it is necessary to identify the antigenic profile of cortical thymic epithelial cells (cTECs) that are involved in the development of major histocompatibility complex (MHC)-restricted T cells. Ultrastructurally, cTECs can be classified into four morphologically distinct subtypes: subcapsular/perivascular (EC1), pale (EC2), intermediate (EC3) and dark (EC4) cells. Several immunohistochemical studies were done on cTECs at the light and electron microscopic levels, but not with reference to the above subtypes. In the present paper, we analysed the expression of MHC class II antigen and cathepsin L by individual cTEC subtypes at the electron microscopic level. We show that (1) MHC class II antigens are expressed on the cell surfaces except on the basal surface of EC1, both on the cell surface and in intracytoplasmic vacuoles of EC2, and only in the intracytoplasmic vacuoles of EC3 and EC4, and (2) that cathepsin L is expressed strongly and uniformly throughout the cytoplasm of EC2, but weakly and non-uniformly in the cytoplasm of EC1, EC3 and EC4. These results show that MHC class II antigen expression and cathepsin L expression is heterogeneous in cTEC subtypes and suggest that EC2 might play a significant role in the development of CD4+ T cells.