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

Michael J Doenhoff,Joseph E Igetei,Ronald G Stanley,Marwa El-Faham,Susan Liddell,Heidi R Fuller,Gabriele Schramm

doi:10.1371/journal.pone.0159542

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.

Highlights

In areas with advanced health systems there has in recent decades been a steep rise in the incidence of asthma, allergies and other disorders of the human immune system [1]
In preliminary experiments we found that rabbit IgG antibodies raised against Sm480, a high molecular weight, glycosylated Schistosoma mansoni antigen [33], cross-reacted extensively with a great variety of the constituents of plants and invertebrates that are associated with allergic reactions in humans
IgG antibodies from rabbits immunized with S. mansoni antigens crossreact with a variety of plant allergens and vice versa

Summary

Introduction

In areas with advanced health systems there has in recent decades been a steep rise in the incidence of asthma, allergies and other disorders of the human immune system [1]. The ‘hygiene hypothesis’ is often invoked as an explanation, i.e., due to more hygienic living conditions and/ or their prevention by vaccinations, populations have become less afflicted by parasitic and microbial infections (sometimes referred to as ‘old friends’ [2]) and the patterns of maturation of human immune systems are different from those that pertained to prehygienic, infection-rife eras [3] One consequence of this dysfunction is an inappropriate and pathological immune response to environmental and air-borne antigens that are the causes of asthma and allergies, and which ‘normal’ immune responses would have rendered innocuous. Allergies and asthma are the outcome of a disordered immune response in which Th2 cells are the main driving force and the production of specific IgE antibody results in a propensity for hypersensitive reactivity against allergen molecules. We discuss the possibility that IgG anti-schistosome antibodies that cross-react with allergens may be able to block IgE-induced allergic reactions and provide a possible explanation for the hygiene hypothesis

Materials and Methods

Results

51 ADYFDIIAGT STGGLITTML TAPNEDKKPM YQAKDIKDFY LENCPKIFPK

51 MLTESTFKNL SCTFKFGEEF DEKTSDGRNV KSVVEKNSES KLTQTQVDPK

Discussion