小鼠肿瘤性早期T细胞可经活化胞内双信号分泌IL_2

研究早期T细胞的分化发育条件,是揭示T细胞功能成熟机理的关键。本文以我室建立的C_2小鼠肿瘤性早期T细胞株作为早期T细胞来源,着重研究此细胞株在不同刺激条件下的IL_2分泌水平,并就此与成熟度不同的胸腺皮质细胞、髓质细胞及脾脏T细胞作了比较。结果表明:C_2小鼠肿瘤性早期T细胞的IL_2分泌能力只有在PMA和钙离子导入剂联合刺激胞内双信号后才能显示。其IL_2分泌水平较胸腺中已有功能发育的髓质细胞为高。

A MURINE EARLY T CELL LINE C_2 CELLS CAN PRODUCE HIGH LEVEL OF INTERLEUKIN 2 THROUGH THE ACTIVA TION OF INTRACELLULAR TRANSDUCTING SIGNALS

C2 cell line,a tumourigenic early T cell line established from cultures of spleen cells of Balb/c origin did not contain constitutive IL2 nor spontaneously secrete IL2.To the conventional stimulus of Con A,C2 cells were unable to respond by IL2 production.Unlike EL4 cells,C2 cells respond poorly to PMA stimulation as estimated by IL2 secretion of 6.4u/ml,which is in sharp contrast to the 132u/ml of IL2 produced by EL4 cells under the same condition.Only under the stimulation of PMA and calcium iono-phore,could C2 cells produce high level of IL2,reaching to the average of 160±22u/ml.By considering the stages of T cell maturation and ability of IL2 production upon the stimulation of PMA and calcium ionophore,the IL2 activity produced by cortical-type thymocytes,medullary-type thymocytes,C2 cells and spleen cells were 11.5±3.1,123.8±12.8,158.7±21.7 and 208.1±21.5u/ml respectivly.It implies that the capability of IL2 production by tumourigenic early T cells is higher than that by more matured medullary thymocytes.The implication of the finding has been discussed.