Maternal IgE Influence on Fetal and Infant Health.

Immunoglobulin E (IgE) is the most recently discovered and evolved mammalian antibody type, best known for interacting with mast cells (MCs) as immune effectors. IgE-mediated antigen sensing by MC provides protection from parasites, venomous animals, bacteria, and other insults to barrier tissues exposed to the environment. IgE and MCs act as inflammation amplifiers and immune response adjuvants. Thus, IgE production and memory formation are greatly constrained and require specific licensing. Failure of regulation gives rise to allergic disease, one of the top causes of chronic illness. Increasing evidence suggests allergy development often starts early in life, including prenatally, with maternal influence being central in shaping the offspring's immune system. Although IgE often exists before birth, an endogenous source of IgE-producing B cells has not been identified. This review discusses the mechanisms of maternal IgE transfer into the offspring, its interactions with offspring MCs and antigen-presenting cells, and the consequences for allergic inflammation and allergen sensitization development. We discuss the multifaceted effects of pre-existing IgG, IgE, and their glycosylation on maternal IgE transfer and functionality in the progeny. Understanding the IgE-mediated mechanisms predisposing for early life allergy development may allow their targeting with existing therapeutics and guide the development of new ones.