Figure 1. Proposed mechanisms of cockroach allergy.

Cockroach allergens, belonging to 12 different groups, are carried by particles that are inhaled to the human lung, where they activate innate and adaptive immune responses. Mechanisms involved in the process include: a) disruption of epithelial integrity by proteases (such as Per a 10) that facilitate allergen penetration, b) activation of release of pro-inflammatory cytokines from the epithelium in a PAR-2 dependent manner by proteases, c) allergen interaction with different receptors (some of which contribute to the uptake of allergens by dendritic cells -TLR, CLR-), and subsequent activation of the adaptive immunity with production of IgE antibodies that bind to the high affinity IgE receptors on mast cells. Numbers indicate the allergen group number. TLR: Toll like receptors, CLR: C-type lectin receptors including mannose receptors, AhR: Aryl hydrocarbon receptor, DC: dendritic cell; T CD4+ and Th2: T cells; B: B cell; MC: mast cell.