Figure 1: Allergenic determinants associated to house dust mite. The identified HDM allergens present in mite bodies and faeces display, together with IgE-binding and T-cell epitopes, at least one allergenic determinant able to trigger innate immunity: glycan structure to engage CLRs, hydrophobic pocket to transport lipids which, in turn, can stimulate TLRs, and protease activity to activate PAR-2 and more likely other cell surface receptors. HDM allergens are commonly associated with microbial endosymbiotic PAMPs from the house dust including at least LPS, β-glucans, chitin, and flagellin (crystal structure of cell-surface flagellin 2ZBI from RCSB PDB).