Savion S, Itoh T, Hertogs H, Shoham J
Department of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.
Immunology. 1989 Aug;67(4):496-501.
The effect of direct contact between thymic stromal cells and thymocytes on differentiation markers and functions of the latter was studied. The thymic stromal cells included two epithelial and one fibroblast cell lines, previously described. Murine thymocytes were incubated with confluent monolayers of these cells or their supernatants for 24 hr, using monolayers of non-thymic cells and their supernatants as controls. Then, the thymocytes were tested for changes in expression of several surface antigens [Thy-1, Lyt-1, Lyt-2, L3T4, IL-2-receptor (IL-2R)], spontaneous [3H]thymidine incorporation (STI), lectin-induced proliferative response (PR) and lymphokine (IL-2 and IL-3) production. All three thymic stromal cell lines reduced the expression of Thy-1, Lyt-1 and Lyt-2 significantly. The expression of L3T4 was also reduced in some of the experiments, while IL-2R was not expressed by the thymocytes, neither before nor after the co-culture. The thymic stromal cell lines also increased the spontaneous [3H]thymidine incorporation and lymphokine production by the thymocytes and inhibited their proliferative response to lectins. Under the same experimental conditions, the culture supernatants of the thymic stromal cells and the non-thymic cells did not have any effect on the thymocytes, either when collected and used separately or when used in a co-culture system which allowed thymocyte contact with the medium but not with the stromal cells (Transwell system). These results suggest a specific effect of thymic stromal cells, epithelial as well as fibroblasts, on thymocyte maturation. The effect is mediated by direct cell contact and not by secreted factors.
研究了胸腺基质细胞与胸腺细胞直接接触对后者分化标志物和功能的影响。胸腺基质细胞包括先前描述的两种上皮细胞系和一种成纤维细胞系。将小鼠胸腺细胞与这些细胞的汇合单层或其上清液孵育24小时，以非胸腺细胞的单层及其上清液作为对照。然后，检测胸腺细胞几种表面抗原[Thy-1、Lyt-1、Lyt-2、L3T4、白细胞介素-2受体（IL-2R）]表达的变化、自发[3H]胸腺嘧啶核苷掺入（STI）、凝集素诱导的增殖反应（PR）和淋巴因子（IL-2和IL-3）产生。所有三种胸腺基质细胞系均显著降低了Thy-1、Lyt-1和Lyt-2的表达。在一些实验中，L3T4的表达也有所降低，而胸腺细胞在共培养前后均未表达IL-2R。胸腺基质细胞系还增加了胸腺细胞的自发[3H]胸腺嘧啶核苷掺入和淋巴因子产生，并抑制了它们对凝集素的增殖反应。在相同实验条件下，胸腺基质细胞和非胸腺细胞的培养上清液，无论是单独收集和使用，还是用于允许胸腺细胞与培养基接触但不与基质细胞接触的共培养系统（Transwell系统）时，对胸腺细胞均无任何影响。这些结果表明，胸腺基质细胞（上皮细胞和成纤维细胞）对胸腺细胞成熟具有特异性作用。这种作用是由细胞直接接触介导的，而不是由分泌因子介导的。
