Study on the functions and mechanism of immune functions of human telomerase reverse transcriptase regulating dendritic cells treating sepsis

摘要

OBJECTIVE: We analyzed the functions and mechanisms of immune functions of human telomerase reverse transcriptase regulating dendritic cells (DC) treating sepsis of mice models. MATERIALS AND METHODS: Eighty clean grade Balb/c animals aged from 6 to 8 weeks, weighted from 18 g to 22 g were selected for this study. The DC cells were harvested from the animals and cultivated to transfect with the recombinant eukaryotic expression plasmid hTERT-IRES2-EGFP construct. The LPS (E. coli 0111:B4, 5 mg/kg) was injected into the abdominal cavity of mice to establish sepsis models. Afterwards, animals were divided randomly into the sepsis group (A group), the group of hTERT transfecting DC (B group), the group of DC un-transfected (C group) with 25 mice in each group. 5 mice were in the normal control group (D group), without any treatment. An equivalent volume of normal saline was injected into the abdominal cavity of A group. Subsequently, 1 ml of cell suspension (105/ml) was transfected into B and C groups respectively. Five animals from A, B, C groups and one animal from group D were sacrificed after 24h, 48h, 72d, 7d and 10d respectively. RESULTS: It was found that median survival time of the group of hTERT transfecting DC was remarkably higher than that of the untransfected group and the sepsis group. The average scores of the pathology of kidney and intestine at each time were significantly lower than that of the other two groups (p<0.05). At each time point, in the group of hTERT transfecting DC, levels of CRP and Cr were remarkably lower than that of the other two groups; HLA-DR, CD40 of immune phenotype and the expression level of peripheral blood T cells MHC-II molecules were significantly higher than that of the other two groups; the expression level of IL-12 and TNF-a were significantly lower than that of the other two groups; apoptosis rate of DC were significantly lower than that of the other two groups; the content and activity of NF-κB were significantly higher than that of the other two groups (p<0.05). CONCLUSIONS: The telomerase reverse transcriptase gene can raise the expression and maturity of DC, reduce apoptosis, induce cytokine secretion, reduce the inflammatory response and increase the survival time.