Abstract: Objective Objective To explore the effects of the purified Plasmodium falciparum（P. f）antigen on the T lymphocytes of the peripheral blood of healthy people in vitro. M Methods ethods The peripheral blood mononuclear cells（PBMCs）isolated from healthy donators were cultured with purified P. f antigen（5 μg/ml）and normal RBC （nRBC）antigen（5 μg/ml），in addition， the group in which only IL?2 added was set as a negative control. After cultured for 12 d，the corresponding antigens were used to re?stimulated the activated T cells in the two stimulated groups for 20 h. Then the cells were collected，the proliferations of the T cells labeled by CFSE were analyzed，and the secretion condition of IL?4 and IFN?γ of the cells were detected by flow cytome? try. Results Results After amplification，the proliferative index（PI）of CD4+ T cells that were stimulated with P. f antigen was signifi? cantly higher than those in the nRBC antigen group and the negative control group（both P＜0.05），but there was no significant difference between the PIs of γδ T cells in the above three groups（P＞0.05） . Meanwhile，the percentages of the CD4+ T cells se? creting IL?4+ in the P. f antigen group was significantly higher than those in the other two groups（both P＜0.05），while the per? centages of T cells secreting IFN?γ in the 3 groups had no significant difference（P＞0.05） . Conclusion Conclusion The purified P. f anti? gen could effectively stimulate the proliferation of CD4+ T cells in peripheral blood of healthy people，and the latter can play a role in immunoregulation through secreting IL?4 preferentially.

Key words: Plasmodium falciparum；Antigen； Immunological function；T lymphocyte；IL?4； IFN?γ

摘要： 目的 目的 探讨恶性疟原虫抗原对健康人外周血T淋巴细胞免疫功能的影响。方法 方法 健康成人外周血单个核细胞 （PBMC） 体外分别用恶性疟原虫 （P. f） 抗原 （5 μg/ml） 和正常红细胞 （nRBC） 抗原 （5 μg/ml） 进行刺激， 同时给予IL?2维持细 胞增殖， 另外设立只加IL?2的阴性对照组进行培养。培养12 d时， 刺激组细胞再用对应的抗原刺激20 h， 用流式细胞仪 检测T淋巴细胞亚群分泌IL?4和IFN?γ的情况， 并用羧基荧光素乙酰乙酸琥珀酰亚胺酯 （Carboxyfluorescein diacetate， suc? cinimidyl ester， CFSE） 标记法检测T细胞增殖反应。结果 结果 健康人PBMC经P. f抗原刺激扩增后CD4+ T细胞的增殖指数 （PI） 明显高于nRBC抗原刺激组和阴性对照组 （P均＜0.05）， 但3组γδ T的PI差异无统计学意义 （P＞0.05）。P. f抗原组 分泌IL?4的CD4+ T细胞百分率明显高于nRBC抗原组和阴性对照组 （P均＜0.05）， 但3组分泌IFN?γ的CD4+ T细胞百分 率差异无统计学意义 （P＞0.05）。结论 结论 P. f抗原在体外可刺激健康人外周血CD4+ T细胞增殖活化， 后者通过优先分泌 IL?4而发挥免疫调节作用。

关键词: 恶性疟原虫； 抗原； 免疫功能； T细胞； IL?4； IFN?γ