HMGB1对淋巴细胞增殖、凋亡及Th1/Th2、Tc1/Tc2漂移的影响

目的:探索HMGB1是否参与淋巴细胞免疫功能的调节.方法:系列浓度HMGB1单独或与ConA联合刺激培养小鼠脾淋巴细胞.MTT法检测细胞增殖,流式细胞术(FCM)检测细胞凋亡、细胞表面CD3、CD8及细胞内IL-4、IFN-γ表达.结果:(1)HMGB1时间-剂量依赖性调节淋巴细胞增殖,而不影响其凋亡.(2)不同HMGB1浓度和刺激时间不影响淋巴细胞Th1、Th2及Th1/Th2变化,但10 μg/L和100 μg/L HMGB1刺激12～24 h,Th1亚群占优势;培养12～24 h,淋巴细胞Tc1亚群明显减少,Tc2无变化.Tc1/Tc2变化显示,1 μg/L和10 μg/L HMGB1刺激,Tc1亚群占优势.(3)培养12～24 h,上清中IL-2增加,sIL-2R减少,IL-2/sIL-2R比例升高20～50倍,尤以10 μg/L HMGB1刺激明显.结论:低剂量HMGB1可增强淋巴细胞免疫功能.

Effect of high mobility group box 1 protein on proliferation and apoptosis and balance between Th1/Th2 and Tc1/Tc2 of lymphocytes in vitro

AIM: To explore whether extracellular high mobility group B1 protein (HMGB1) plays a role in regulation of lymphocytejmediated immune. METHODS: Lymphocytes originated from mice spleens were stimulated with concentration gradient HMGB1 or combined with ConA in vitro. Then, the proliferation of lymphocytes was assayed with MTT, quantitative and qualitative analysis of apoptosis in lymphocytes and expression of CD3 and CD8 on cells surface and IL-4 and IFN-gamma within cells were assessed using flow cytometry. Levels of interleukin-2 (IL-2) and soluble IL-2R (sIL-2R) of culture supernatant were assayed by ELISA. RESULTS: (1) HMGB1 regulated the proliferation of lymphocytes in a time- and dose-dependent manner, but did not influence the apoptosis of lymphocytes. (2) The ratio of Th to Tc increased from 2.6:1 at culturejhour 0 to 5-7: 1 at culturejhour 12 and 24, but that did not change with the stimulation of HMGB1. There were no significant difference in the population and percentage of Th1 and Th2, as well as Tc1 and Tc2, when stimulated with HMGB1. However, HMGB1 in concentrations of 10 and 100 mug/L favored Th1 differentiation, and 1 and 10 mug/L HMGB1 favored Tc1 differentiation. (3) Levels of IL-2 were increased, and sIL-2R decreased, significantly, when stimulated with 10 mug/L HMGB1 for 12 h, thus the ratio of IL-2 to sIL-2R was markedly higher, as compared with 0 and 1000 mug/L HMGB1 (P<0.05 or P<0.01). CONCLUSION: Low dose HMGB1 could be in favor of the bias of Th1 and Tc1, and improve the lymphocytejmediated immune.