New Insights Into Innate Immune Mechanisms Underlying Allergenicity

Allergic diseases, which have reached epidemic proportions, are driven by inappropriate immune responses to a relatively small number of environmental proteins. The molecular basis for the propensity of specific proteins to drive maladaptive, allergic responses has been difficult to define. Recent data suggest that the ability of such proteins to drive allergic responses in susceptible hosts is a function of their ability to interact with diverse pathways of innate immune recognition and activation at mucosal surfaces. This review highlights recent insights into innate immune activation by allergens—via proteolytic activity, engagement of pattern recognition receptors, molecular mimicry of TLR signaling complex molecules, lipid binding activity, and oxidant potential—and the role of such activation in inducing allergic disease. A greater understanding of the fundamental origins of allergenicity should help define new preventive and therapeutic targets in allergic disease.