Environmental Estrogens Alter Signaling in Immune Cells That Promotes the Development of Childhood Asthma

The goal of this project is to test the hypothesis that fetal exposure to environmental estrogens (EEs) enhances allergic sensitization initiating cell signaling in antigen-presenting and/or T cells, which leads to epigenetic alterations that promote the development of asthma. Cord blood mononuclear cells (CB-MNCs) were separated into CD4+T and CD8+T populations, incubated overnight in media with steroid-depleted serum, and then exposed to various concentrations (fM-pM) of estradiol, bisphenol A (BPA) and Bisphenol S (BPS). Supernatant from cell culture was collected for quantifying immunomodulatory cytokines. Intracellular signaling was assessed in a plate assay in cells that were fixed, permeabilized, blocked, and incubated with anti-phospho ERK (pARK), anti-phosphoAKT (pAKT) or anti-phospho EZH2 histone methyl transferase (pEZH2). Phosphatase activity was assessed using secondary antibody and colorimetrical measurement. The signals were normalize to the number of cells in each well. Current experiments suggest that estradiol, BPA and BPS significantly increase the phosphorylation of ERK, AKT and EZH2 in human MNCs, including CD8+T and CD4+T cells. The dose response to BPA and BPS indicate high sensitivity and typical non-monotonic responses. The concomitant increases in the exposure of EEs and prevalence of asthma, raise the possibility that EEs may be a factor in the increasing prevalence of childhood asthma. Understanding the molecular and cellular basis for EE’s asthma promoting effects in animal models and human epidemiological studies will inform public policy concerning EE exposures, and may ultimately allow the design of future prevention measures, and potentially, new molecular-based treatments for childhood asthma.