Soluble total antigen derived from Toxoplasma gondii RH strain prevents apoptosis, but induces anti-apoptosis in human monocyte cell line

Abstract

Apoptosis plays crucial role in the pathogenesis of toxoplasmosis, as it limits further development of the disease. The current study aimed to investigate the effects of different concentrations of soluble total antigen (STAg) of Toxoplasma gondii (Nicolle etManceaux, 1908) on the apoptotic and anti-apoptotic pathways. PMA-activated THP-1 cell line was sensed by T. gondii STAg and theexpression patterns of caspase-3, -7, -8, -9, Bax, Bcl-2, and Mcl-1 genes were evaluated. The results showed statistically significantconcentration-dependent overexpression of both Bcl-2 (P-value < 0.0001) and Mcl-1 (P-value = 0.0147). The cas-7 showed overexpressionin all concentrations (P-value < 0.0001). The cas-3 was suppressed in concentrations 100, 80, and 40 μg, but statisticallysignificant downregulated in concentrations 10 and 20 μg. The Bax was suppressed in concentrations 100 to 20 μg, while it slightlydownregulated 1.42 fold (P-value = 0.0029) in concentration 10 μg. The expression of cas-8 and -9 was suppressed in all concentrations.Our results indicated that T. gondii STAg downregulated and suppressed apoptotic and upregulated anti-apoptotic pathways. Theupregulation of cas-7 in this study may indicate the role of T. gondii STAg in activation of inflammatory responses