The time course of biological and immunochemical allergy states induced by anisakis simplex larvae in rats

Abstract

SummaryOral infection by Anisakis simplex third stage larvae (L3) frequently gives rise to an allergic response. To comprehend the allergic and immune responses induced by L3, we investigated the kinetics of specific antibody isotype expression and the time course of biological and immunochemical allergy states using sera prepared from rats orally infected with L3 twice, with an interval of 9 weeks between infections. Biological and immunochemical allergy states were analysed by RBL-2H3 exocytosis and by indirect ELISA for IgE, respectively. The peak IgM at reinfection (RI) was comparable or similar to that at primary infection (PI) both in levels analysed by indirect ELISA and in antigen recognition analysed by Western blot. IgG1 and IgG2a levels were higher and showed accelerated kinetics after RI vs. after PI. However, the level of IgG2b was substantially lower than that of IgG2a. Peak immunochemical and biological allergy states for RI were higher and were reached faster than those for PI. The peak biological allergy state was observed at 1 week postreinfection and this occurred sooner than that for the peak immunochemical allergy state found at 2 weeks postreinfection. Our analysis of the relationship between specific IgE avidity and biological allergy state did not show any meaningful correlation. These results suggest that the allergic response induced by L3 oral infection is predominantly caused by reinfection and that this is accompanied by an elevated IgM level, which further suggests that the biological allergy state might not be related to specific IgE avidity.

Oral inoculation of live or dead third-stage larvae of Anisakis simplex in rats suggests that only live larvae induce production of antibody specific to A. simplex

“…1B). The kinetics of specific antibodies observed in this study during 1-4 weeks after live L3 inoculation was almost identical to that of the previous study using rats inoculated with 20 live L3 (Cho et al 2005). In contrast, the absorbance values of specific antibodies in rats inoculated with dead L3 were lower than those of the cut-off values during the experimental periods, irrespective of the methods used for inactivating L3 (Fig.…”

“…Therefore, the risk of Anisakis-associated allergic reaction by ingestion of properly cooked and frozen fish remains controversial (Daschner et al 2012;Pravettoni et al 2012). Oral inoculation of rats with live L3 is known to be a useful experimental model for analyse of allergic responses in anisakiasis (Cho et al 2005). To date, seven A. simplex excretory-secretory (ES) allergens that were found to be thermostable or resistant to pepsin digestion have been reported.…”

“…According to a previous study (Cho et al 2005) the absorbance value of the specific antibodies, especially IgM and IgE, in primary sensitized rats by inoculation with live L3 were found quickly and were highly elevated after re-inoculation with live L3. In this study, the frozen L3 were inoculated to the primary sensitized rats to confirm the possibility of inducing elevation of specific antibody by ingestion of dead L3.…”

Anisakis simplex: from Obscure Infectious Worm to Inducer of Immune Hypersensitivity

“…In 2006, Cho et al described the specific antibody response in rats that were infected orally with L3 on two occasions at intervals of 9 weeks. The results suggested that the allergic response was elicited by the reinfection (peaking after 1 week) and was accompanied by an elevated IgM level (53). Iglesias and colleagues (117) found some antigens captured by monoclonal antibodies (MAbs) that contain epitopes recognized by human IgE antibodies.…”

“…It has been demonstrated experimentally that rats infected by a single parasite develop higher IgE levels than do rats infected with a high number. Differences have been described between infection and antigen exposure to A. simplex in the sense that reinfection induces a strong Th2 response, whereas antigens alone do so to a lesser degree or not at all (53). In contrast, it has been shown recently that both live parasites and crude extracts of L3 cause allergic reaction in sensitized mice challenged orally with A. simplex proteins, resulting in a striking allergic reaction within as little as 1 hour, accompanied by scratching, irritability, diarrhea, and puffiness around the eyes (237).…”