Increased CD11b(+) Gr-1(+) cell population in the placenta after infection with Toxoplasma gondii

Toxoplasma gondii is an obligate intracellular protozoan pathogen that can cross the placenta, resulting in congenital toxoplasmosis with severe fetal brain abnormalities. The molecular mechanisms of immune responses against T. gondii infection in the placenta have largely remained unclear. An analytical method for characterizing phenotypes of immune cells in the placenta by flow cytometry was established and it was found that numbers of CD11b(+) Gr-1(+) cells in the placenta increased significantly after T. gondii infection. These results suggest that innate immune responses play an important role in immunity against T. gondii infection via the feto-maternal interface.