The role thymic epithelial cell on induction of tolerance to the allografts : Analysis of immuno-modulatory T cell

小鼠表皮细胞，具有令人惊讶的细胞学相似的胸腺上皮细胞，但不增殖，在普通培养基中，据报道，生长在钙耗尽的培养基。因此，将去钙培养基应用于小鼠胸腺的培养，并成功地从小鼠胸腺获得上皮细胞系IT-76 MHC（在常规培养基中;在低钙培养基中，其为IT-76 M）。IT-76 MHC细胞被鉴定为不同的小鼠胸腺上皮细胞，1）马赛克样排列，2）存在发育良好的桥粒和3）张力丝，和4）细胞角蛋白阳性。已建立的小鼠胸腺上皮细胞的功能研究的实验已经部分进行，和IL-3和集落刺激活性被发现存在于细胞的上清液中，表明胸腺上皮细胞可能作为早期胸腺细胞的生长促进剂，通过其因子。免疫组织化学研究进行IT-76 MHC使用几种抗体的表位的神经内分泌家族。胸腺上皮细胞系表达免疫反应性催产素、加压素、胰岛素样生长因子（IGF）1和2。这些结果表明，可以在分化的T细胞系统之前呈递代表神经内分泌家族的自身抗原。

Mouse epidermal cells, which have a surprising cytological resemblance to thymic epithelial cells but do not proliferate in an ordinary medium, were reported to grow in a calcium-depleted medium. Therefore, the calcium-depleted medium was applied for the culture of the mouse thymus, and successfully, an epithelial cell line, IT- 76MHC (in regular medium ; in low Ca medium, it is IT-76M) was obtained from the mouse thymus. IT-76MHC cells were identified as distinct mouse thymic epithelial cells by 1) mosaic-like arrangement, 2)presence of well-developed desmosome and 3) tonofilaments, and 4) positivity for cytokeratin. Experiments to investigate functions of established mouse thymic epithelial cells have been partly carried out, and IL-3 and colony-stimulating activities were found to be present in the supernatant of the cells, suggesting that thymic epithelial cells may act as a growth promoter for early thymocytes through their factors. Immunohistochemistry studies were performed on IT-76MHC using several antibodies to the epitops of neuroendocrine families. Immunoreactive oxytocin, vasopressin, insulin-like growth factor (IGF) 1 and 2 are expressed by thymic epithelial cell line. These results suggest that could present self antigens representing the neuroendocrine family in front of the differentiating T cell system.