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Objective To investigate the regulation of thymic stromal cells of normal and heat stress injury in mouse thymocytes and its mechanism. Methods 5-week-old BALB / c male mice thymus, made of thymus cell suspension, 43 ° C heat stress 1h, with the first generation of cultured mouse thymic stromal cells (TSC) and 50% of the first generation of thymic stromal cell culture supernatant (TSC-SN) co-cultured thymus cells collected 0, 6, 12, 24, 48 h of culture, counting the total number of thymocytes and survival rate of thymocyte apoptosis by flow cytometry analysis, the expression of Fas Fas-L and HSP70 positive rate and CD4CD8 of lymphocyte subsets, and the interaction of light microscopy and electron microscopy TSC and thymocytes. (1) Thermal stress rate of thymocyte apoptosis, Fas, Fas-L and HSP70 expression increased thymocyte apoptosis and Fas, Fas-L, the expression is closely related. (2) the non-stress thymus cells co-cultured with TSC, the survival rate increased apoptosis rate and Fas, Fas-L expression is reduced, but the total number of cells and CD4 - CD8 - (DP) cells were significantly reduced CD4 to CD8 ~ - and CD4 ~-CD8 ~ (SP) cells was significantly increased. (3) co-cultured with TSC heat stress thymocytes, the total number of cells in a significant reduction in DP cells and SP cells were reduced HSP70 expression than the increase in heat stress control group, apoptosis rate and Fas, Fas-L, the expression lower than the control group cultured alone heat stress, but significantly higher than the the thymocytes group co-cultured with TSC stress. (4) light microscopy and electron microscopy observation of a large number of adhesion and phagocytosis of normal and heat stress thymocytes to the TSC TSC swallowed thymocytes and adhesion thymocyte apoptosis. (5) TSC-SN allows heat stress in vitro thymocyte apoptosis rate and Fas, Fas-L expression positive rate, the normal thymocyte apoptosis rate and Fas expression rate decreased, but should be normal and thermal stimulated thymocyte expression of HSP70 had no significant effect. (1) Fas / Fas-L mediated induction of apoptosis in vitro culture of thymocytes spontaneous and induced by heat stress and death, heat stress induced DP thymocyte apoptosis, increased expression of HSP70 heat stress thymus a sign of cell damage; (2) TSC and normal thymus cells in direct contact with two biological effect, ① phagocytosis clear DP cells; ② may promote some DP cells differentiate into mature SP cells, the DP cells to reduce the increase in SP thymocytes ; (3) DP cells and SP cells in the the heat stress thymus cells may be TSC swallowed, TSC promote the increased heat stress thymocytes HSP70 expression may have a double meaning, not only protect thymocytes, l can promote TSC recognition and phagocytosis has been damaged or apoptotic thymocytes, the role of immune surveillance in the antigen-presenting lIHSP70 heat stress injury thymocytes edge cells also LD the HC identification and swallowed the molecular basis; N) thymocytes protection role in the unstressed Dl TSC was stronger in the heat stress thymocytes, thymocyte expression of Fas, Fas-apoptosis mechanism close ll relations prompted a thymocyte excluded; door) in vitro, T% {N normal and thermal LD ??stress injury thymocytes have a protective effect.
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