Influência da proteína de choque térmico de 70 kDa de Toxoplasma gondii (TgHSP 70) na modulação da apoptose de células trofoblásticas (Linhagem BeWo)

Abstract

Toxoplasmosis is an important zoonotic disease due to ability of its causal agent, Toxoplasma gondii, to infect large number of vertebrates and to be associated with congenital infection. Additionally, the parasite requires the heat shock protein of 70 kDa (TgHSP70) for stage conversion. HSP 70 protein displays the ability to modulate various signaling pathways, including the apoptosis by due anti apoptotic mechanisms. Thus, the objective of this study was to investigate the role of heat shock protein of T. gondii (TgHSP 70) on BeWo trophbastic cell line. In order to determine whether TgHSP70 can prevent apoptosis arsenic trioxide (As2O3) and arsenite sodium (NaAs02) were used to induce apoptosis on BeWo and infected with the RH and ME49 strains. To achieve the effect of TgHSP70 on apoptosis, purification and treatment of cells with recombinant TgHSP70 was carried out. Immunocytochemical assay using M30 antibody was performed to evaluated the expression of cytokeratin 18. Also As2O3 was used to induce apoptosis in BeWo cells. This cells their and followed by ME 49 and RH strains infection. The amount of TgHSP 70 expression was evaluated by qPCR analysis. Our results showed that BeWo trophoblastic cells treated with TgHSP 70 protein present lower levels of apoptosis even in the presence of inducers such as NaAsO2 and As2O3. The RH strain of T. gondii has a tendency to modulate apoptosis in BeWo cells compared to cells infected with ME 49 strain. Moreover, our qPCR results revelead that RH strain induces TgHSP70 expression in those cells. Finally, these data suggest that TgHSP70 can be directly associated to the decrease of apoptosis in BeWo cells.