Prenatal and postnatal exposure to concentrated ambient particulate matter alters the developing immune system of mice (HEM8P.240)

Abstract

Prenatal exposure to certain air pollutants have been shown to cause immunological dysfunction in offspring, however previous experimental studies have yet to evaluate the vulnerability of the immune system throughout the pre- and early postnatal period. Therefore, to more accurately reflect human exposure, mice were exposed to concentrated fine-sized ambient particulate matter (PM2.5) both pre- and postnatally and parameters of immune status were assessed in offspring. Timed-pregnant dams were exposed 6hr/d throughout gestation (GD 0-17) to filtered air or PM2.5. At 5 wks-of-age, blood and spleen were collected from a subset of male and female offspring, and serum samples were analyzed for cytokine levels. Spleens were weighed and splenocytes isolated to assess changes in immune cell profiles by flow cytometry. Of the endpoints analyzed, only female offspring were significantly affected with pre- and postnatal PM2.5 exposure resulting in an 11% reduction of normalized splenic weight and decreased maturation status of splenic B cells (MHCII and CD45R expression) compared to their control counterparts. These sex-specific alterations demonstrate gaps in previous developmental studies that focused only on PM2.5-induced immune effects on male offspring. Together, these results suggest that particulate air pollution negatively impacts the developing immune system, proposing critical consequences for offspring exposed during the pre- and early postnatal period.