Bias Of Human Macrophages THP-1 Induced By The Dominant Genotype Of Toxoplasma Gondii Wh3 Strain In China

Objective To study the bias of macrophages induced by Toxoplasma gondii wh3 strain(genotype Chinese 1).Methods THP-1 Macrophages were infected with Toxoplasma gondii wh3 strain,RH strain and ME49 strain respectively.After 6 h and 24 h of infection,the supernatant and macrophages were collected.The concentrations of IL-6,IL-10,TNF-α and TGF-β in the supernatant were detected by ELISA.The mRNA transcription levels of M1 or M2 macrophages markers of genes iNOS,arginase-1 and TNF-α,IL-12,TGF-β,and IL-10 were detected by q RT-PCR,and the expression levels of iNOS and arginase-1 were analyzed by Western blotting.Results The contents of IL-6 and TNF-α reached their peaks in the macrophages infected with ME49 strain after 6h and 24 h,and the highest levels of IL-10 and TGF-β were found after infection with RH strain.However,the content of cytokines in the supernatants of macrophages fell in between RH strain and ME49 strain following infection with Wh3 strain.Additionally,mRNAs of inflammatory factors and cytokines in macrophages were detected after 6 h and 24 h postinfection,It was noted that the iNOS,TNF-α and IL-12 which represent Th1 dominant response were significantly increased after infection with T.gondii ME49 strain,while expression of arginase-1,IL-10 and TGF-β that is associated with Th2 dominanr response was significantly elevated in the macrophages of RH strain infection.We also found that the levels of mRNAs located between RH strain and ME49 strain.The similar results of iNOS and arginase-1 expression were obtained when examined by Western blotting..Conclusion T.gondii Wh3 strain of genotype Chinese 1 has the capacity of inducing M1 skewing of human macrophages which is lower than Me49 strain,suggesting that Chinese 1 Toxoplasma might evoke host innate immunity and cause pathogenesis different from the parasite of type Ⅰ or type Ⅱ.