Washington E A, Katerelos M, Cahill R N, Kimpton W G
Laboratory for Foetal and Neonatal Immunology, School of Veterinary Science, University of Melbourne, Parkville, Victoria, Australia.
Int Immunol. 1994 Dec;6(12):1891-7. doi: 10.1093/intimm/6.12.1891.
Tissue-selective streaming of T cells is considered to be a critical element in the integration of normal immune responses in intact animals. The results presented in this paper show that while there were major subsets of gut-homing T cells present in intestinal lymph, there were considerable differences in the tissue tropism of T cell populations circulating in lymph draining gut and peripheral lymph nodes. Thus, while CD4+ cells returned preferentially to their tissue of origin, gamma delta T cells showed a strong migratory preference for peripheral lymph nodes regardless of their tissue of origin. In contrast, although a population of gut-homing CD8+ cells was present in ileal lymph, CD8+ T cells from peripheral lymph nodes homed equally well to gut and lymph nodes. There were also considerable differences in the expression of L-selectin on T cells circulating in the two compartments. L-selectin was down-regulated on alpha beta T cells present in ileal lymph but not on gamma delta T cells which expressed the highest levels of L-selectin of all T cell subsets. It is suggested that gut-homing alpha beta T cells which have down-regulated L-selectin are formed in the gut-associated lymphoid tissues in response to gut antigens while the migratory properties of gamma delta T cells are ontogenetically determined, independent of antigen.
T细胞的组织选择性流动被认为是完整动物正常免疫反应整合中的关键要素。本文呈现的结果表明，虽然肠道归巢T细胞的主要亚群存在于肠道淋巴中，但在引流肠道的淋巴和外周淋巴结中循环的T细胞群体的组织嗜性存在相当大的差异。因此，虽然CD4 +细胞优先返回其起源组织，但γδ T细胞无论其起源组织如何，都对外周淋巴结表现出强烈的迁移偏好。相比之下，虽然回肠淋巴中存在一群肠道归巢的CD8 +细胞，但来自外周淋巴结的CD8 + T细胞对肠道和淋巴结的归巢能力相同。在两个区室中循环的T细胞上L-选择素的表达也存在相当大的差异。L-选择素在回肠淋巴中存在的αβ T细胞上被下调，但在γδ T细胞上未被下调，γδ T细胞在所有T细胞亚群中表达最高水平的L-选择素。有人认为，下调L-选择素的肠道归巢αβ T细胞是在肠道相关淋巴组织中响应肠道抗原而形成的，而γδ T细胞的迁移特性是由个体发育决定的，与抗原无关。
