Kagnoff M F
Department of Medicine, University of California at San Diego, La Jolla 92093, USA.
Am J Physiol. 1998 Mar;274(3):G455-8. doi: 10.1152/ajpgi.1998.274.3.G455.
-gamma delta T cells are located in the paracellular space between epithelial cells. In the human colon and small intestine, 5-40% of intraepithelial lymphocytes (IEL) are gamma delta T cells, and in mice an even greater proportion of IEL are gamma delta T cells. The gamma delta T cell receptor repertoire in the human intestine undergoes marked changes in V region gene usage and junctional diversity during development from fetus to newborn to adult, suggesting that gamma delta T cells may mediate qualitatively or quantitatively different functions at various stages of development. gamma delta IEL have been shown to produce cytokines and growth factors and to influence epithelial cell proliferation and differentiation, as well as the mucosal development of immunoglobulin A B cells. gamma delta IEL also manifest cytolytic activity. However, the ligands recognized by intestinal gamma delta T cells and the role they play in intestinal immune responses, in immune defense to enteric pathogens, and in the pathogenesis of intestinal disease are thus far largely unknown.
γδ T细胞位于上皮细胞之间的细胞旁间隙。在人类结肠和小肠中，5%至40%的上皮内淋巴细胞（IEL）是γδ T细胞，而在小鼠中，IEL中γδ T细胞的比例更高。从胎儿到新生儿再到成人的发育过程中，人类肠道中的γδ T细胞受体库在V区基因使用和连接多样性方面发生显著变化，这表明γδ T细胞在发育的各个阶段可能介导性质或数量上不同的功能。γδ IEL已被证明能产生细胞因子和生长因子，并影响上皮细胞的增殖和分化，以及免疫球蛋白A B细胞的黏膜发育。γδ IEL也表现出细胞溶解活性。然而，肠道γδ T细胞识别的配体以及它们在肠道免疫反应、对肠道病原体的免疫防御和肠道疾病发病机制中所起的作用，目前在很大程度上尚不清楚。
