Antigenic cross-reactivity between Schistosoma mansoni and allergenic invertebrates putatively due to shared glycanic epitopes

Abstract

previous studies have shown that rabbit igG antibodies against Schistosoma mansoni egg antigens (SmSEA) cross-react with allergens in natural rubber latex, peanuts and grass and tree pollens. Here we describe antigenic molecules that cross-react with rabbit anti-S. mansoni igG antibodies in extracts of the house dust mite (HDM) Dermatophagoides farinae, the Australian cockroach (ACR) Periplaneta australasiae and in the venom of the honey bee Apis mellifera (HBV). tandem mass spectrometry identified the cross-reactive allergens as Der f 15 in HDM, two homologues of the Periplaneta americana cockroach allergen Cr-PI/Per a 3 in ACR and two isoforms of the allergen Api m 1 (phospholipase A2: PLA2) in HBV. Cross-reactive rabbit anti-SmSEA IgG antibodies eluted from the three invertebrate allergens reacted with S. mansoni egg antigens and variably with schistosome cercarial and worm antigens. treatment of the electroblotted allergens with sodium metaperiodate abrogated most of the cross-reactivity of the rabbit anti-SmSEA antibodies, suggesting it was due to cross-reactive carbohydrate determinants (CCDs). Furthermore, analyses of the allergens' amino acid sequences indicated that they had potential for both N-and O-linked glycosylation. A potential role for the CCDs shared by the schistosome and invertebrates in inducing an allergy-protective effect, as proposed by the hygiene hypothesis, is discussed.

Helminth infection induces non-functional sensitization to house dust mites

“…However, none of the subjects presented any cutaneous sensitization against common respiratory allergens or clinical symptoms of allergy. In contrast to El-Faham et al's report [24], our analysis of molecular IgE sensitization allows us to suggest that CCD cross-reactivity is not the unique mechanism of allergen sensitization during helminth infection, and that sensitization against peptidic epitopes occurs.…”

“…The IgE Dpt and Asc level were not affected by the Phl p 4 depletion, confirming results from Hamid et al who showed that IgE targeting core β-1,2-xylose and/or α-1,3-fucose substituted N-glycans does not play a role in Dpt and Asc sensitization [23]. However, N-glycans are not unique CCDs, and other carbohydrate species may exist in Dpt extract [24].…”

IgE Epitope Analysis for Scy p 1 and Scy p 3, the Heat-Stable Myofibrillar Allergens in Mud Crab

“…In this research, the structures of Scy p 1 and Scy p 3 mutants were altered, and the increased surface hydrophobicity could expose more hydrophobic regions on the allergen surface, resulting in the embedding of epitopes within the molecule, thus reducing IgE-binding capacity . Furthermore, disulfide bonds, glycosylation sites, and calcium-binding sites could affect the allergenicity of allergens. ,, Scy p 3 as a member of the EF-hand family that contained calcium-binding sites also had a pair of intermolecular disulfide bonds (Cys36–Cys130) that maintained spatial structure stability and a glycosylation site N 99 G 100 T 101 on the sequence. Thus, the IgE-binding capacity of Scy p 3 mutants (C36A, D66A, and N99A) significantly decreased compared to other mutants, mainly due to particular sites on the structure.…”

Are humanized IgE reporter systems potential game changers in serological diagnosis of human parasitic infection?

“…Another important potential source of false-positive results in conventional serological methods caused by CCDs is the occurrence of a high level of cross-reactivity between parasite-and plant-derived glycans recognized by IgG, as shown for Schistosoma mansoni in several studies by Michael J. Doenhoff and his co-workers (El-Faham et al 2020;Igetei et al 2017Igetei et al , 2018. However, the relevance of these findings for IgE responses has yet to be examined.…”