Induction of Apoptosis in Toxoplasma gondii Infected Hela Cells by Cisplatin and Sodium Azide and Isolation of Apoptotic Bodies and Potential Use for Vaccination against Toxoplasma gondii

Background: Toxoplasma gondii can infect a wide range of mammalians, especially humans. It controls several intracellular signals for the inhibition of apoptosis. This study aimed to investigate the apoptogenic effect of cisplatin and sodium azide on T. gondii infected HeLa cells and isolate apoptotic bodies (blebs) as a potent stimulator of the immune system. Methods: The cytotoxic properties of cisplatin and sodium azide (NaN3) on HeLa cells were evaluated by MTT assay. Moreover, the apoptogenic activity of cisplatin and NaN3 was studied using flow cytometry (Annexin V/PI double staining) and scanning electron microscopy (SEM). Finally, apoptotic bodies were separated by centrifugation. Results: MTT assay data showed that the survival rate of cells treated with different concentration of NaN3 was significantly reduced, compared to negative control groups. Concerning cisplatin, only concentration of 20 μM had not a significant impact on the cell viability; however, the other concentration of cisplatin significantly reduced cell viability, compared to negative control groups. The level of early apoptosis in uninfected HeLa cells was higher compared to infected HeLa cells treated with cisplatin and NaN3. Finally, apoptotic bodies were separated from T. gondii infected HeLa cells treated with cisplatin. Conclusion: Apoptosis was induced in both uninfected and infected HeLa cells with T. gondii and apoptotic bodies were isolated from infected cells. Therefore, further studies on apoptotic bodies are required in order to find a proper candidate for vaccine preparation against T. gondii infections.