超抗原SEA增强PML-RARα多肽体外诱导特异性CTL杀伤活性的机制

Effects of Staphylococcal Enterotoxin A(SEA) on Cytotoxicity of T Cells Stimulated by PML-RARα Peptide in vitro

目的探讨超抗原SEA体外增强PML-RARα多肽诱导特异性CTL杀伤活性的机制。方法分别将SEA、PML-RARα多肽以及SEA联合PML-RARα多肽与正常人外周血单个核细胞共同培养,利用CCK-8比色法检测诱导后T细胞对NB4和K562细胞株杀伤活性,同时利用流式细胞术测定诱导T细胞表面CD4与CD8表达情况。结果诱导后第20天,SEA能明显增强PML-RARα多肽特异性杀伤NB4细胞株的作用。诱导后第5、10、20天动态检测表明,多肽及SEA联合多肽组CD4+/CD8+比值逐渐降低,其中SEA联合PML-RARα多肽诱导组降低最显著。结论超抗原SEA能明显增强PML-RARα多肽体外诱导特异性CD8+T细胞的增殖与特异性的杀伤作用。

Objective To investigate the Effects of staphylococcal enterotoxin A （SEA） on the cytotoxicity of T cells stimulated by PML-RARa peptide in vitro. Methods Peripheral blood mononuclear cells from healthy donors were cultured with PML-RARa peptide and SEA for 20 days. After induction, the cytotoxicity of T celis 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 cytotoxicity 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 after induction, but the most significantly decreased by PML-RARα peptide with SEA. Conclusion The specific cytotoxicity of CD8^＋ T cells induced by PML- RARα peptide against NB4 cells could be enhanced with superantigen SEA.