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采用两种体外建系的小鼠胸腺基质细胞（ＴＳＣ）系，即上皮样ＴＳＣ（ＭＴＥＣ１）和树突状ＴＳＣ（ＭＴＳＣ４），观察其对胸腺细胞凋亡的影响。小鼠胸腺细胞在体外培养过程中，可自发地出现细胞凋亡的特征，表现为ＤＮＡ呈梯度断裂片段，细胞经ＦＡＣＳ分析出现亚二倍体ＤＮＡ波峰，以及Ｆｅｕｌｇｅｎ′ｓ染色镜检所见的ＤＮＡ凝聚和断裂。胸腺细胞在与ＴＳＣ共育后，在ＭＴＥＣ１组可见其凋亡过程受到抑制和存活率的增加；在ＭＴＳＣ４组，仅在共育１２至１８小时时，见到胸腺细胞凋亡加强，而其存活率不受影响。结果提示在胸腺细胞发育过程中，其阴性选择作用的主要机制之一的ＰＣＤ过程受不同来源的胸腺基质细胞的调节。
Two kinds of mouse thymic stromal cells (TSC) lines, namely, epithelial TSC (MTEC1) and dendritic TSC (MTSC4) were established in vitro to observe their effects on thymocyte apoptosis. During the in vitro culture of mouse thymocytes, the characteristics of apoptotic cells spontaneously appear as a gradient fragment of DNA. The sub-diploid DNA peaks of the cells were analyzed by FACS, as well as those seen by Feulgen’s staining DNA coalesces and breaks. Thymocytes co-cultured with TSC showed inhibition of apoptosis and increased survival rate in MTEC1 group. In MTSC4 group, thymocyte apoptosis was enhanced only 12 to 18 hours after co-culture, and its survival Rate is not affected. The results suggest that PCD process, one of the major mechanisms of negative selection in thymocyte development, is regulated by different origins of thymus stromal cells.