Progesterone Can Directly Inhibit the Life Activities of In Vitro through the Progesterone Receptor Membrane Component (PGRMC).

, as an opportunistic pathogen, has special pathogenic effects on pregnant animals and humans. Progesterone (P4) is a critical hormone that supports pregnancy, and its levels fluctuate naturally during early pregnancy. However, little is known about the association of host P4 levels with the infectivity and pathogenicity of . Our study showed that P4 significantly inhibited the invasion and proliferation of tachyzoites, resulting in abnormal cytoskeletal daughter budding and subsequent autophagy in vitro. To investigate the underlying mechanism, we identified a progesterone membrane receptor protein (TgPGRMC) that was localized to the mitochondrion and closely related to the effect of P4 on tachyzoites. The knockout of the gene conferred resistance to P4 inhibitory effects. Our results prove the direct relationship between P4 single factors and in vitro and demonstrate that TgPGRMC is an important link between and P4, providing a new direction for research on infection during pregnancy.