Exposure to dehydroepiandrosterone in utero affects T-cell function in males only

Maternal stress can affect the growth, behavior and immune function of the offspring. Some of these effects are thought to be mediated by maternal glucocorticoids secreted in response to stress. The purpose of the present study was to establish whether dehydroepiandrosterone (DHEA), a weak androgen that is also secreted in response to stress, contributes to the sequelae of prenatal stress in the offspring. Therefore, pregnant rats were treated with different doses of DHEA in the drinking water from day 8 of gestation until parturition, when DHEA treatment was discontinued. Body weights of prepubertal male and female offspring of DHEA-treated dams were significantly and dose responsively lower than those of controls. In contrast, thymic weights were significantly higher in the DHEA offspring. Prenatal DHEA treatment reduced the splenic lymphocyte proliferative response to the T cell mitogen concanavalin A in prepubertal males only, while decreasing the mRNA levels of interleukin-2 receptor alpha and gamma subunits. The anterior pituitary expression of pro-opiomelanocortin (POMC) mRNA was increased in prepubertal males only. These data suggest that decreased body weight seen after prenatal stress can be mediated by either DHEA or glucocorticoids. The persistent increase in thymus weight is a new finding that may be very specific to prenatal DHEA treatment. In conclusion, the decreased T cell function and increased POMC expression found in this study indicate that prenatal-stress-induced immune suppression and altered hypothalamic-pituitary-adrenal activity can be, at least in part, DHEA mediated.