IL-12对伯氏疟原虫红内期感染小鼠淋巴细胞增殖活性的影响

EFFECTS OF IL-12 ON THE SPLENIC LYMPHOCYTE PROLIFERATION IN MICE WITH BLOOD STAGE PLASMODIUM BERGHEI INFECTION

目的探讨IL12对伯氏疟原虫(P.b)红内期感染小鼠淋巴细胞增殖活性的影响。方法每只BALB/c小鼠接种5×105个感染P.b的RBC,同时每天分别给予0.03或0.15μgIL12处理,用3HTdR掺入法检测脾淋巴细胞增殖转化活性,流式细胞仪测定T淋巴细胞亚群CD4+与CD8+百分比。结果每天给予0.03或0.15μgIL12处理,均可显著增加P.b感染小鼠脾淋巴细胞数量及CD4+、CD8+数。每天给予0.03μgIL12可显著促进脾淋巴细胞的增殖转化,而每天给予0.15μgIL12则明显抑制脾淋巴细胞增殖。结论适当低剂量IL12可促进P.b感染小鼠脾淋巴细胞增殖活性,增强机体抗感染免疫,而较大剂量IL12则抑制脾淋巴细胞增殖活性,甚至可致免疫病理损害。

Objective To explore the effects of IL12 on the splenic lymphocyte proliferation in mice with bloodstage Plasmodium berghei infection. Methods Each of BALB/c mice was infected with 5×10 5 RBC infected P. berghei and administrated with doses 0.03 or 0.15 μg/d of IL12 on the day of infection and daily for 6 days postinfection. The splenic lymphocyte proliferation was determined by  3 HTdR incorporation. Percentages of CD4 + and CD8 + T cells were detected using flow cytometry. Results Following IL12 administration, the mice treated with both doses 0.03 μg/d and 0.15 μg/d showed profound increasing in the number of splenic lymphocyte, as well as profound increasing in the absolute number and percentage of CD4 + and CD8 + T cells. Interestingly, treating with doses 0.03 μg/d of IL12 could significantly enhance splenic lymphocyte proliferative responses. In contrast, a 0.15 μg/d dose significantly inhibited lymphocyte proliferation. Conclusion Appropriate dose of IL12 regulated the development of resistance to P. berghei infection by enhancing splenic lymphocyte proliferative responses. But, higher doses of IL12 significantly inhibited lymphocyte proliferation, which may be detrimental to resistance against P. berghei infection.