Strongyloides stercoralis recombinant NIE antigen shares epitope with recombinant Ves v 5 and Pol a 5 allergens of insects

Abstract

A new recombinant protein (NIE) for immunodiagnosis of human Strongyloides infection has 13% to 18% amino acid identity with antigen 5 insect venom allergen, but the C-terminal segment of NIE showed highest identity with Ves v 5 (yellow jacket) and Pol a 5 (paper wasp). A rabbit polyclonal anti-NIE antibody identified a single band of NIE antigen as well as bands of Pol a 5 and Ves v 5 antigens, and mouse anti-Pol a 5 and anti-Ves v 5 sera reacted with recombinant NIE antigen by Western blot. A cyanogen bromide-digested C-terminal fragment of NIE was reactive with mouse anti-Ves v 5 and Pol a 5 antibodies as well as with rabbit anti-NIE serum. Although IgE and IgG antibodies from pooled sera from Strongyloides-infected patients reacted with Pol a 5 and Ves v 5 recombinant antigens on immunoblots, neither antigen inhibited human IgG reaction with NIE antigen in a competitive enzyme-linked immunosorbent assay.