Immunization of rabbits with nematode Ascaris lumbricoides antigens induces antibodies cross-reactive to house dust mite Dermatophagoides farinae antigens.

There are controversial reports on the relationship between helminthic infection and allergic diseases. Although IgE cross-reactivity between nematode Ascaris antigens and house dust-mite allergens in allergic patients have been reported, whether Ascaris or the mite is the primary sensitizer remains unknown. Here we found that immunization of naïve animals with Ascaris lumbricoides (Al) antigens induced production of antibodies cross-reactive to mite antigens from Dermatophagoides farinae (Df). Sera from Bangladeshi children showed IgE reactivity to Ascaris and mite extracts. IgG from rabbits immunized with Al extract exhibited reactivity to Df antigens. Treatment of the anti-Al antibody with Df antigen-coupled beads eliminated the reactivity to Df antigens. In immunoblot analysis, an approximately 100-kDa Df band was the most reactive to anti-Al IgG. The present study is the first step towards the establishment of animal models to study the relationship between Ascaris infection and mite-induced allergic diseases.