Environmental exposures during pregnancy: Mechanistic effects on immunity

Abstract

In human studies, it is well established that exposures during embryonic and fetal development periods can influence immune health. Coupled with genetic predisposition, these exposures can alter lifetime chronic and infectious disease trajectory, and, ultimately, life expectancy. Fortunately, as research advances, mechanisms governing long‐term effects of prenatal exposures are coming to light and providing the opportunity for intervention and risk reduction. For instance, human association studies have provided a foundation for the association of prenatal exposure to particulate matter with early immunosuppression and later allergic disease in the offspring. Only recently, the mechanisms mediating this response have been revealed and there is much we have yet to discover. Although cellular immune response is understood for many exposure scenarios, molecular pathways are still unidentified. This review will provide commentary and synthesis of the current literature regarding environmental exposures during pregnancy and mechanisms determining immune outcomes. Shared mechanistic features and current gaps in the state of the science are identified and discussed. To such purpose, we address exposures by their immune effect type: immunosuppression, autoimmunity, inflammation and tissue damage, hypersensitivity, and general immunomodulation.

Air pollution and children’s health—a review of adverse effects associated with prenatal exposure from fine to ultrafine particulate matter

“…PM 2.5 also affects the immune system, although only a handful of human studies relevant to early life exposure are published to date [ 21 , 22 ]. Herr et al [ 23 ] observed that prenatal exposure to PM 2.5 shifted lymphocyte distributions representative of the neonatal adaptive immune response in umbilical cord blood.…”

Air Pollution, Neonatal Immune Responses, and Potential Joint Effects of Maternal Depression

“…Our finding that gestational exposure to air pollution is linked to global decreases in cytokine responses at birth begs the question of whether cytokine levels measured at birth have an effect on health across the course of the child’s life. Some studies have found lower levels of cord blood cytokines associated with a greater likelihood of adverse child health outcomes such as wheeze, eczema, and other allergic disorders [ 56 ], supporting the idea that decreases in cytokine responses at birth are related to later health [ 57 ]. In Project Viva, a study of 446 mother-child pairs found that lower levels of cord blood IFN-γ were associated with a higher risk of acute lower respiratory infection in the first year of life [ 58 ].…”

Omics approaches: interactions at the maternal–fetal interface and origins of child health and disease

“…An altered intrauterine homeostasis can lead to neuro-immune and peripheral immunologic alterations, and thus can impact long-term health and result in lifelong disabilities. 36 – 39 Immune system reprogramming in the fetus can occur during critical immunotoxic prenatal windows during the prenatal period 40 due to exposures to inflammation or infection, and can skew immune responses, thus contributing to disease processes and mortality. 34 …”