Murine fetal resorption and experimental pre-eclampsia are induced by bothexcessive Th1 and Th2 activation

It has been proposed that immune responses in mammalian normal pregnancy ar e Th2-like, thereby protecting the fetus and placenta from being rejected. Administration of exogenous Th1 cytokines into pregnant mice is reported to induce fete-placental resorption. However, the effects of exogenous Th2 cy tokines and Th2 directed responses in pregnant animals have not been well s tudied. In this study, we examined IL-4 and IL-12, which play decisive role s in the development of Th2 and Th1 responses, respectively, in the inducti on of fetal resorption and development of experimental pre-eclampsia. Trans fer of either IL-4 and/or IL-12 stimulated splenocytes from BALB/C virgin f emale mice into BALB/C pregnant mice mated with either C57BL/6 or BALB/C ma le mice resulted in fetal resorption and glomerular nephritis associated wi th hypertension and proteinuria. In mice treated with IL-12 stimulated sple nocytes, fatty liver degeneration associated with bile retention was observ ed. These results indicate that both excessive Th1 and Th2 activation contr ibute to the development of fetal resorption and pre-eclampsia, but that Th 1 is critical to the development of liver degeneration. (C) 2000 Elsevier S cience Ireland Ltd. All rights reserved.