ABSTRACT
There is growing evidence that early-life environmental exposures are contributing to the
increasing prevalence of allergic diseases including food allergy. Food allergy rates, particularly
for peanut, have increased dramatically in industrialized countries over the last few decades,
suggesting environmental factors are driving the epidemic. Recent studies show that inhalational
or cutaneous exposure to peanut within the home may be a risk factor for peanut allergy. In
addition to food antigens, the indoor exposome also includes immunostimulatory agents, such as
microbial products and air pollutants, which can act as adjuvants and promote allergic
sensitization to antigens. Whether exposure to environmental adjuvants influences peanut allergy
development is unclear. We have developed a novel mouse model that mimics inhalational
exposure to environmental peanut within the home. We have found that co-exposure to inhaled
peanut and indoor dust, which contains environmental adjuvants to which children are exposed,
induced allergic sensitization and the development of peanut allergy in mice. Moreover, we have
found that co-exposure to inhaled peanut and air pollutants, including diesel exhaust particles and
particulate matter, also induced peanut allergy in our animal model. In this proposal, we will
determine if exposure to environmental adjuvants in indoor dust is associated with peanut
sensitization in infants, and also investigate the mechanisms by which environmental adjuvants
(e.g., indoor dust, air pollutants) promote peanut allergy development. In Aim 1, we will use an
airway sensitization animal model and primary human bronchial epithelial cell culture system to
compare the adjuvant activity of indoor dust samples collected from the homes of peanut-
sensitized and nonsensitized infants, and determine if adjuvant activity is associated with peanut
sensitization status. In Aim 2, we will use animal models to define the innate immune signaling
pathways required for indoor dust-mediated airway sensitization to peanut. In Aim 3, we will
investigate the immunological mechanisms by which inhaled air pollutants promote peanut allergy
development in our animal model. These studies will greatly expand our understanding of how
the indoor exposome influences food allergy development and help direct future environmental
interventions aimed at preventing peanut allergy in children.