The accumulation of Rho GTPases in the parasitophorous vacuole membrane (PVM) of T. gondii tachyzoites (1000×). (A) The tachyzoites of T. gondii RH strain infected human 16-HBE cells were fixed with paraformaldehyde and permeablized with Triton X-100. The anti-RhoA and Rac1 primary antibodies were used to bind with the endogenous GTPases, then a FITC conjugated secondary antibody was used to bind with the primary antibodies. The endogenous RhoA and Rac1 accumulated on the PVM are visualized with a fluorescence microscope. (B-C) COS-7 cells were transfected with 3 μg of pECFP-N1-RhoA-WT and pECFP-N1-Rac1-WT, respectively. Forty-eight hr after transfection, these cells were infected with tachyzoites of T. gondii RH strain (B) or Pru strain (C). Regardless of the virulence of the tachyzoites used for infection, the overexpressed CFP-RhoA and CFP-Rac1 in host cells were recruited to the T. gondii PVM. Bars: 10 μm.