Howard C J, Sopp P, Parsons K R
AFRC Institute for Animal Health, Compton, Berkshire, U.K.
Immunology. 1992 Oct;77(2):228-34.
L-selectin (LECAM-1, LAM-1) was expressed by a high proportion of CD4+ and CD8+ T cells, as well as almost all of the gamma delta T-cell receptor (TcR)+ (WC1+) T cells, isolated from blood, lymph nodes or tonsils. CD4+ T cells in the lamina propria of the gut villi and CD8+ T cells in the villous epithelium as well as the majority of WC1+ T cells in the gut mucosa were L-selectin-. The proportion of T cells from Peyer's patches that synthesized the molecule was intermediate between the value for blood and gut mucosa. Expression of L-selectin therefore marks T cells in cattle with a distinct tissue distribution that correlates with its function as the peripheral node homing receptor. The proportion of CD4+ and CD8+ T cells in the circulation that were L-selectin+ decreased with age. Unlike CD45R, expression of L-selectin was not related to CD4 T-cell memory as judged by proliferation in transformation assays to soluble antigen. Three-colour immunofluorescent staining demonstrated four subpopulations of CD4 and CD8 T lymphocytes in peripheral blood mononuclear cells (PBMC) that were CD45R+, L-selectin+; CD45R+, L-selectin-; CD45R-, L-selectin+; CD45R-, L-selectin-. CD4(4) memory cells were CD45R- and L-selectin+ or L-selectin-. Taken with earlier studies the reported observations demonstrated that only one of the four phenotypes of the CD4+ T cells in blood is present in the lamina propria of the gut villi and these are CD45R-, L-selectin-. Two of the four phenotypes of CD8+ T cells were present in the gut epithelium; these were CD45R+, L-selectin- or CD45R-, L-selectin-. Expression of the bovine molecule was not rapidly down-regulated on T cells following activation by exposure to phorbol myristate acetate.
L-选择素（LECAM-1、LAM-1）在从血液、淋巴结或扁桃体分离出的高比例CD4⁺和CD8⁺T细胞以及几乎所有γδT细胞受体（TcR）⁺（WC1⁺）T细胞中表达。肠绒毛固有层中的CD4⁺T细胞、绒毛上皮中的CD8⁺T细胞以及肠道黏膜中的大多数WC1⁺T细胞均不表达L-选择素。派尔集合淋巴结中合成该分子的T细胞比例介于血液和肠道黏膜的值之间。因此，L-选择素的表达标记了牛体内具有独特组织分布的T细胞，这与其作为外周淋巴结归巢受体的功能相关。循环中L-选择素⁺的CD4⁺和CD8⁺T细胞比例随年龄下降。与CD45R不同，通过对可溶性抗原的转化试验中的增殖判断，L-选择素的表达与CD4 T细胞记忆无关。三色免疫荧光染色显示外周血单核细胞（PBMC）中的CD4和CD8 T淋巴细胞有四个亚群，分别为CD45R⁺、L-选择素⁺；CD45R⁺、L-选择素⁻；CD45R⁻、L-选择素⁺；CD45R⁻、L-选择素⁻。CD4（4）记忆细胞为CD45R⁻且L-选择素⁺或L-选择素⁻。结合早期研究，报告的观察结果表明，血液中CD4⁺T细胞的四种表型中只有一种存在于肠绒毛固有层，即CD45R⁻、L-选择素⁻。CD8⁺T细胞的四种表型中有两种存在于肠道上皮；即CD45R⁺、L-选择素⁻或CD45R⁻、L-选择素⁻。牛分子的表达在暴露于佛波酯肉豆蔻酸酯激活T细胞后不会迅速下调。
