Objective:To investigate the effects of staphylococcal enterotoxin A (SEA) on the cytotoxicity of T cells stimulated by PML-RARα peptide in vitro. Methods: Peripheral blood mononuclear cells (MNC) from healthy donor ...Objective:To investigate the effects of staphylococcal enterotoxin A (SEA) on the cytotoxicity of T cells stimulated by PML-RARα peptide in vitro. Methods: Peripheral blood mononuclear cells (MNC) from healthy donor were obtained by density gradient centrifugation on Ficoll-Hypaque,MNC were cultured with PML-RARα peptide and SEA for 20 days. After induction,the cytotoxicity of T cells induced against NB4 and K562 cell lines were examined by Cell Counting Kit-8 (CCK-8). The CD4 and CD8 surface markers on the harvested CD3+ T cells were detected by flow cytometry (FCM). Results: The cyto-toxicity of T cells induced by PML-RARα peptide with SEA was higher than that of T cells induced only by PML-RARα peptide against NB4 cells. The FCM assay showed that the ratio of CD4+/CD8+ T cells were gradually decreased in both groups of PML-RARα peptide whether with SEA or not at the intervals of day 5,10 and 20 day after induction,but the most significantly decreased by PML-RARα peptide with SEA. Conclusion: The specific cytotoxicity of T cells induced by PML-RARα peptide against NB4 cells could be enhanced with superantigen SEA.展开更多
Objective: To evaluate whether realgar could down-regulate human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity in acute promyelocytic leukemia cell line-NB4 cells. Methods: The expre...Objective: To evaluate whether realgar could down-regulate human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity in acute promyelocytic leukemia cell line-NB4 cells. Methods: The expression of hTERT-mRNA was analyzed by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Telomerase activity was determined by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA). Flow cytometry using PI staining was applied to analyze the cell cycle and apoptosis. Results: Treatment of NB4 cells with 155, 300, 600 μg/L realgar reduced telomerase activity significantly accompanying with decrease of hTERT-mRNA and increasing cell apoptosis. G2/M phase arrest appeared when treated with realgar in 300, 600 μg/L. Conclusion: It is suggested that telomerase activity of NB4 cells can be specifically inhibited by realgar through the down-regulation of hTERT gene expression. G2/M phase arrest and apoptosis by realgar in NB4 cells might be related to the reduction of telomerase activity and hTERT-mRNA expression.展开更多
基金Supported by grants from the Science and Technology Commission of Guangdong Province (No.06025169,No.2005B50301016)the Key Laboratory of Pathophysiology of Jinan University
文摘Objective:To investigate the effects of staphylococcal enterotoxin A (SEA) on the cytotoxicity of T cells stimulated by PML-RARα peptide in vitro. Methods: Peripheral blood mononuclear cells (MNC) from healthy donor were obtained by density gradient centrifugation on Ficoll-Hypaque,MNC were cultured with PML-RARα peptide and SEA for 20 days. After induction,the cytotoxicity of T cells induced against NB4 and K562 cell lines were examined by Cell Counting Kit-8 (CCK-8). The CD4 and CD8 surface markers on the harvested CD3+ T cells were detected by flow cytometry (FCM). Results: The cyto-toxicity of T cells induced by PML-RARα peptide with SEA was higher than that of T cells induced only by PML-RARα peptide against NB4 cells. The FCM assay showed that the ratio of CD4+/CD8+ T cells were gradually decreased in both groups of PML-RARα peptide whether with SEA or not at the intervals of day 5,10 and 20 day after induction,but the most significantly decreased by PML-RARα peptide with SEA. Conclusion: The specific cytotoxicity of T cells induced by PML-RARα peptide against NB4 cells could be enhanced with superantigen SEA.
基金Supported by Xi'an Foundation of Science and Technology Program(200016)
文摘Objective: To evaluate whether realgar could down-regulate human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity in acute promyelocytic leukemia cell line-NB4 cells. Methods: The expression of hTERT-mRNA was analyzed by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Telomerase activity was determined by polymerase chain reaction enzyme-linked immunoassay (PCR-ELISA). Flow cytometry using PI staining was applied to analyze the cell cycle and apoptosis. Results: Treatment of NB4 cells with 155, 300, 600 μg/L realgar reduced telomerase activity significantly accompanying with decrease of hTERT-mRNA and increasing cell apoptosis. G2/M phase arrest appeared when treated with realgar in 300, 600 μg/L. Conclusion: It is suggested that telomerase activity of NB4 cells can be specifically inhibited by realgar through the down-regulation of hTERT gene expression. G2/M phase arrest and apoptosis by realgar in NB4 cells might be related to the reduction of telomerase activity and hTERT-mRNA expression.