Humoral immune responses induced by Gymnorhynchus gigas extracts in BALB/cmice

The aim of this study was to determine if the plerocercoid larvae of Gymnor hynchus gigas, a common cestode of the ray's bream (Brama rail), possess an tigenic compounds potentially capable of provoking anaphylactic episodes. A murine experimental model, using BALB/c mice, was developed to study the h umoral immune response induced by G. gigas extracts. A highly specific humo ral immune response was detected and cross-reactions were not observed betw een parasite and host antigens. The presence of IgM and IgG3 levels suggest the presence of thymus-independent antigens in the parasitic extract. The IgG antibody class showed the highest levels, with the IgG1 the predominant subclass. These IgG1 levels are in accordance with the supposed presence o f a type I allergic reaction after the ingestion of G. gigas plerocercoids parasitizing fish, as well as inducing anaphylaxia in fish. These results i ndicate that somatic products released from ingested larvae of G. gigas cou ld induce the development of a Th2 response capable of causing allergic dis orders.