Nieburgs A C, Picciano P T, Korn J H, McCalister T, Allred C, Cohen S
Cell Immunol. 1985 Feb;90(2):439-50. doi: 10.1016/0008-8749(85)90208-4.
Cultures of thymic epithelial cells were generated and maintained in valine-free minimum essential medium (MEM) supplemented with 690 mg/liter of D-valine. These cultures have been maintained for 1 year through multiple passages by trypsinization of 60-70% confluent monolayers. Large and small epithelial cells were present in early cultures. They were separated into two stable subpopulations based on (1) their differential growth rates and (2) their differential adherence to the culture substratum. These morphologically distinct cell populations, TECS and TECL, were 100% keratin positive and contained cells with desmosomes and tonofilaments, all characteristics of epithelial cells. Esterase analysis of both cell populations revealed a 1 and 9% esterase-positive cell population in cultures of keratin-positive small (TECS) and large (TECL) cells, respectively. The percentages of esterase-positive cells corresponded to the 2 and 10% populations of TECS and TECL, respectively, that contained both desmosomes and phagolysosomes. These results establish conditions for the long-term propagation of pure thymic epithelial cells. Such cultures can be used to study the functional interactions between epithelial cells and lymphoid cells. Morphologic and histochemical analyses have identified subsets of these cells which may prove to have differential effects on thymocyte proliferative and developmental processes.
胸腺上皮细胞培养物在无缬氨酸的最低必需培养基（MEM）中生成并维持，该培养基添加了690毫克/升的D - 缬氨酸。这些培养物通过对60 - 70%汇合的单层细胞进行胰蛋白酶消化传代，已维持了1年。早期培养物中存在大、小上皮细胞。根据（1）它们不同的生长速率和（2）它们对培养底物的不同贴壁能力，将它们分离为两个稳定的亚群。这些形态学上不同的细胞群体，即小胸腺上皮细胞（TECS）和大胸腺上皮细胞（TECL），100%角蛋白呈阳性，并且含有具有桥粒和张力丝的细胞，这些都是上皮细胞的特征。对这两个细胞群体的酯酶分析显示，在角蛋白阳性的小细胞（TECS）和大细胞（TECL）培养物中，酯酶阳性细胞群体分别为1%和9%。酯酶阳性细胞的百分比分别对应于TECS和TECL中同时含有桥粒和吞噬溶酶体的2%和10%的细胞群体。这些结果为纯胸腺上皮细胞的长期增殖建立了条件。这样的培养物可用于研究上皮细胞与淋巴细胞之间的功能相互作用。形态学和组织化学分析已经鉴定出这些细胞的亚群，这些亚群可能对胸腺细胞增殖和发育过程具有不同的影响。
