IL-21对恒河猴SHIV特异性CD8~＋T细胞毒性效应的影响

Interleukin-21 enhances the cytotoxic effect of SHIV-specific CD8^+ T cells in SHIV-infected Macaca mulatta

目的探讨白细胞介素21(interleukin 21,IL-21)对SHIV特异性CD8+T细胞毒性效应的影响。方法定时采集16只SHIV感染恒河猴的外周血,应用实时荧光定量RT-PCR测定病毒载量,流式细胞仪测定CD8+T细胞绝对数,并且体外检测经IL-21刺激SHIV特异性CD8+T细胞后其IL-21R、CD107a及胞内穿孔素(perforin)的表达水平。结果体内实验结果表明外周血病毒载量和CD8+T细胞绝对数之间呈一定程度的负相关。体外实验结果表明SHIV特异性CD8+T细胞经IL-21刺激后其细胞表面表达的IL-21R显著上调,而且perforin+CD8+T细胞和CD107a+CD8+T细胞的百分比上升,同未经刺激的对照组相比具有统计学差异。结论 IL-21能够促进SHIV特异性CD8+T细胞的毒性效应。

Objectives To clarify the effects of IL-21 on cytotoxic effect of SHIV-specific CD8＋ T cells.Methods Peripheral blood samples were collected from 16 SHIV-infected rhesus monkeys.Real-time fluorescence quantitative RT-PCR assay was used to determine virus load for SHIV RNA,and absolute amount of CD8＋ T cells were assessed by flow cytometry.The expression of IL-21R,perforin,and CD107a of the CD8＋ T cells in vitro was assayed by flow cytometry after IL-21 stimulation.CD107a mobilization assay was used to measure the degranulation of CD8＋ T cells.Results In vivo study indicated a negative correlation between the virus load and the absolute number of CD8＋ T cells.Compared with the medium control,the expression of IL-21R on the surface of CD8＋ T cells was significantly increased.Moreover,percentages of both CD107a＋ CD8＋ T cells and perforin＋ CD8＋ T cells were higher than those of the control.Conclusions Administration of IL-21 upregulates cytotoxic effect of peripheral CD8＋ T cells in SHIV-infected rhesus monkeys.