旋毛虫感染经PD-1途径对BCG免疫小鼠细胞因子产生的影响  

TRICHINELLA SPIRALIS INFECTION IMPACTS ON THE BCG-INDUCED CYTOKINE PRODUCTION IN MICE VIA PD-1 PATHWAY

作　　者：黄京京[1] 呼延旭 庄清慧 康宁 杜素琴 程喻力[1] 诸欣平[1] HUANG Jing-Jing;HU Yan-Xu;ZHUANG Qing-Hui;KANG Ning;DU Su-Qin;CHENG Yu-Li;ZHU Xin-Ping(Department of Parasitology,School of Basic Medical Sciences,Capital Medical University,Beijing 100069,China;Tongzhou Municipal Center for Disease Control and Prevention,Beijing 101100,China)

机构地区：[1]首都医科大学基础医学院人体寄生虫学教研室,北京100069 [2]北京市通州区疾病预防控制中心,北京101100

出　　处：《寄生虫与医学昆虫学报》2019年第3期137-144,共8页Acta Parasitologica et Medica Entomologica Sinica

基　　金：国家自然科学基金项目(81572016);国家自然科学基金项目(81672042)

摘　　要：探讨PD-1信号通路在旋毛虫感染影响卡介苗(Mycobacterium bovis bacille Calmette-Gu erin,BCG)免疫小鼠细胞因子产生中的作用。首先,以旋毛虫肌幼虫(400条/只)分别感染C57BL/6遗传背景野生(WT)小鼠和PD-1基因缺失(PD-1^-/-)小鼠,于感染后42 d处死小鼠,分离脾淋巴细胞以刀豆蛋白A(Concanavalin A,ConA)刺激培养48 h,ELISA检测培养上清中Th1型IFN-γ、IL-2、TNF-α,Th2型IL-4,和调节性TGF-β、IL-10细胞因子水平;进而,在上述相同感染条件下,于感染后28 d接种BCG,分别于免疫后7和28 d分离WT小鼠和PD-1^-/-小鼠的脾淋巴细胞,用卡介菌纯蛋白衍生物(purified protein derivative,PPD)体外刺激培养48 h,ELISA检测细胞培养上清中上述细胞因子分泌水平。结果显示,在单纯旋毛虫感染及感染后BCG免疫条件下,各细胞因子变化趋势趋于一致。WT小鼠感染组Th1型IFN-γ、IL-2水平明显低于未感染组,Th2型IL-4及调节性TGF-β、IL-10水平明显高于未感染组(P<0.05),TNF-α水平无显著差异。而PD-1^-/-小鼠中,与未感染组相比,感染组Th1型IFN-γ、IL-2和TNF-α的下降水平,以及Th2型IL-4和调节性TGF-β、IL-10的上升水平较WT小鼠明显减小。上述结果表明,旋毛虫感染可经PD-1信号通路抑制BCG免疫诱导的Th1型细胞因子的产生,而促进Th2型细胞因子IL-4及调节性细胞因子的IL-10和TGF-β的生成。本研究为蠕虫感染抑制抗结核疫苗保护性效果的潜在机制提供了实验依据。To explore the role of PD-1 in effects of Trichinella spiralis infection on Mycobacterium bovis bacille Calmette-Guérin(BCG)-induced cytokine production in mice.First,wild-type(WT)and PD-1 deficient(PD-1^-/-)mice bred on the C57BL/6 background were each infected with 400 infective T.spiralis muscle larvae and sacrificed at day 42 post infection.The splenocytes were isolated and cultured with stimulation of concanavalin A(ConA).The levels of Th1 cytokine IFN-γ,IL-2,TNF-α,Th2 cytokine IL-4 and regulatory cytokine TGF-β,IL-10 in the supernatants were measured by ELISA.Further,mice were immunized with BCG at day 28 post T.spiralis infection.The splenocytes collected respectively at day 7 and day 28 BCG immunization with or without T.spiralis infection were stimulated with BCG purified protein derivative(PPD).The levels of cytokines in the supernatants were measured by ELISA.The results showed that the tendencies of cytokine alteration were consistent in the two studies.In WT mice,the levels of Th1 cytokine IFN-γ,IL-2 in mice infected with T.spiralis were significantly lower than that of non-infected mice.The levels of Th2 cytokine IL-4 and regulatory cytokine TGF-β,IL-10 in infected mice were significantly higher than non-infected mice(P<0.05).No difference of the level of TNF-αwas found between mice with or without T.spiralis infection.In PD-1^-/-mice,the differences of decreased IFN-γ,IL-2 and increased TGF-β,IL-10 and IL-4 in infected mice were diminished compared with that in WT mice.The results demonstrate that T.spiralis infection may suppress the BCG-induced Th1 cytokine,but enhance Th2 and regulatory cytokine production through PD-1 pathway.This study provides experimental evidence for the potential mechanism that helminth infection suppresses the protective efficacy of BCG vaccination against tuberculosis.

关 键 词：旋毛虫 程序性死亡分子1 卡介苗 细胞因子 

分 类 号：R73[医药卫生—肿瘤]