Cross-Reactivity between Schistosoma mansoni Antigens and the Latex Allergen Hev b 7: Putative Implication of Cross-Reactive Carbohydrate Determinants (CCDs)

Abstract

IgG antibodies produced by rabbits immunized against S. mansoni antigens cross-reacted with aqueous soluble constituents of a variety of allergens. The antibody cross-reactivity was largely sensitive to degradation by treatment of the target antigens with sodium meta-periodate, suggesting the cross-reactivity was due to carbohydrate determinants that were common to both the schistosome and the allergens (CCDs). The reaction between the rabbit antibodies and a 43 kDa molecule in a rubber latex extract was analysed further: tandem mass spectrometry identified the latex molecule as allergen Hev b 7. Rabbit anti-schistosome IgG antibodies purified by acid-elution from solid-phase latex Hev b 7 reacted with the S. mansoni egg antigens IPSE/alpha-1 and kappa-5 and cercarial antigens SPO-1 and a fatty acid-binding protein. Moreover, purified anti-S. mansoni egg, latex cross-reactive antibodies reacted with antigenic constituents of some fruits, a result of potential relevance to the latex-fruit syndrome of allergic reactions. We propose that IgG anti-schistosome antibodies that cross-react with allergens may be able to block IgE-induced allergic reactions and thus provide a possible explanation for the hygiene hypothesis.

Antigenic cross‐reactivity between Schistosoma mansoni and peanut: a role for cross‐reactive carbohydrate determinants (CCDs) and implications for the hygiene hypothesis

“…Results in Fig. confirm the earlier indications that extensive IgG cross‐reactivity occurs between S. mansoni and peanut antigens/allergens. The non‐reactivity of the anti‐SmSEA antibodies against any of the antigens/molecules in the three tissue extracts from mouse is an indication that the cross‐reactivity of the purified antibodies with antigens in extracts of peanut and those in other plants with potential to cause allergy in humans is not a ubiquitous property of rabbit sera in general.…”

“…We have previously demonstrated that rabbit anti‐schistosome IgG antibodies cross‐react with many different constituents of plants and invertebrates that are allergic to humans . The cross‐reactivity between S. mansoni egg and cercarial antigens and a 43 000 MW molecule in natural rubber latex was investigated in detail and the latter was found to be latex allergen Hev b 7.…”

“…Allergy to latex is now less important so the methods used in that study were here extended to investigate the extent to which they might be applied to another allergen, namely peanut, allergy to which is currently of more significance than that to latex and the constituents of which were also shown to be antigenically cross‐reactive with S. mansoni …”

“…Tandem mass spectrometry (MS) was performed on a Waters Corporation Q‐TOF 2 instrument according to methods described in ref. .…”

Worms: Pernicious parasites or allies against allergies?

“…High levels of anti‐ Ascaris IgG4 have been negatively associated with allergen SPT positivity, while in a S. mansoni ‐endemic area—although higher levels of both IgE and IgG4 were found in infected individuals—a higher ratio of IgE to IgG4 predicted clinical allergic symptoms, just as in allergen‐specific immunotherapy . As many helminth products are homologous to common allergens, IgG4 responses raised against helminth products may also bind and block IgE epitopes on allergens, reducing responses to allergens and directly reducing SPT responses . Mechanistic research into the role of IgE and/or IgG4 is hampered by the lack of good experimental animal models, as IgG4 does not exist in mice.…”