Changes of human decidual natural killer cells cocultured with YFP-Toxoplasma gondii: implications for abnormal pregnancy

Abstract

To investigate the changes of human decidual natural killer (dNK) cells cocultured with Toxoplasma gondii in vitro and to infer implications on pregnancy. Case-control study. College and hospital. Decidual tissue was obtained from 85 patients undergoing voluntary abortion during the first trimester of gestation (6-12 weeks). None. The dNK cells were isolated and infected with YFP-Toxoplasma gondii. Cells were observed by fluorescence and confocal microscopy. The CD56(bright)CD16(-)/CD56(dim)CD16(+) dNK ratio, expression of KIR2DL4, ILT-2, and NKG2D on dNK cells were analyzed by flow cytometry and the cytotoxic activity of infected dNK cells were evaluated. The CD56(dim)CD16(+)/CD56(bright)CD16(-) dNK ratio was significantly elevated at 12, 24, and 48 hours after YFP-T. gondii infection. Expression of KIR2DL4, ILT-2, and NKG2D were increased after infection, but NKG2D were significantly higher than those of KIR2DL4 and ILT-2. Both the CD56(dim)CD16(+)/CD56(bright)CD16(-) dNK ratio and NKG2D expression were correlated with dNK cytotoxic activity. Enhanced dNK cytotoxicity due to increased CD16 and NKG2D expression may contribute to abnormal pregnancy outcomes observed with maternal infection with T. gondii.