Increased Expression of Toxoplasma Gondii GRA1 Suppresses Host Cell Apoptosis

Suppression of host cell apoptosis enable Toxoplasma gondii to proliferate, but the mechanism is not well understood. We explore the relationship between the expression of T. gondii dense granule protein 1 (GRA1) and host HeLa cell apoptosis. We inserted the T. gondii gra1 coding gene into a pET32a vector and produced recombinant GRA1 (rGRA1) in E. coli Rosetta strain. We then immunized rabbits with rGRA1 to produce anti-GRA1 serum and infected HeLa cells with T. gondii tachyzoites. We determined the expression of T. gondii GRA1 by Western blotting with anti-GRA1 serum and determined apoptosis of HeLa cells via the Annexin V-FITC/PI method. All the experiments were repeated for three times in the same condition. The expression of GRA1 decreased gradually after T. gondii infection. The rate of HeLa cell apoptosis increased more rapidly in the infected cells than in the uninfected cells. Our results suggest that the suppression of host cell apoptosis is related to the expression of T. gondii GRA1 expression.