Background: Inthehousedustmite(HDM)Dermatophagoides pteronyssinus,Derp 1,2,5,7,21,and23havebeenidentifiedasthemostimportantallergens.Theaimof thisstudywastodefinehypoallergenicpeptidesderivedfromthesequencesofthe sixallergensandtousethepeptidesandthecompleteallergenstostudyantibody, Tcell,andcytokineresponsesinsensitizedandnonsensitizedsubjects. Methods: IgE reactivity of HDM-allergic and non-HDM-sensitized individuals to 15 HDM allergens was established using ImmunoCAP ISAC technology. Thirtythree peptides covering the sequences of the six HDM allergens were synthesized. Allergens and peptides were tested for IgE and IgG reactivity by ELISA and ImmunoCAP,respectively.Allergenicactivitywasdeterminedbybasophilactivation. CD4+TcellandcytokineresponsesweredeterminedinPBMCculturesbyCFSEdilu-tionandLuminextechnology,respectively. Results: HousedustmiteallergicsshowedIgEreactivityonlytocompleteallergens, whereas 31 of the 33 peptides lacked relevant IgE reactivity and allergenic activity.IgGantibodiesofHDM-allergicandnonsensitizedsubjectsweredirectedagainst peptideepitopesandhigherallergen-specificIgGlevelswerefoundinHDMallergics. PBMCfromHDM-allergicsproducedhigherlevelsofIL-5whereasnon-HDM-sensitized individuals mounted higher levels of IFN-gamma, IL-17, pro-inflammatory cytokines,andIL-10. Conclusion: IgG antibodies in HDM-allergic patients recognize peptide epitopes whicharedifferentfromtheepitopesrecognizedbyIgE.Thismayexplainwhynaturallyoccurringallergen-specificIgGantibodiesdonotprotectagainstIgE-mediated allergicinflammation.AmixofhypoallergenicpeptidescontainingTcellepitopesof themostimportantHDMallergenswasidentified.
K E Y W O R D Sallergen,housedustmiteallergy,recombinantallergen,syntheticpeptide,Tcellepitope ThisisanopenaccessarticleunderthetermsoftheCreativeCommonsAttribution-NonCommercialLicense,whichpermitsuse,distributionandreproduction inanymedium,providedtheoriginalworkisproperlycitedandisnotusedforcommercialpurposes.