Antigenic Competition in IgE, IgG1 and IgG2 Antibody Production in the Mouse

Abstract

A comparative study of the effects of antigenic competition on the IgE, IgG1 and IgG2 antibody production was performed in mice immunized with two unrelated antigens. These antigens were injected as a mixture or in different sites. In addition, the groups of mice received one or three boosters of one or both antigens. The passive cutaneous anaphylaxis titres obtained in several bleedings showed a suppression of IgG1 and IgG2 antibody responses only in the groups injected with the two antigens in the same site, independently of antigenic boosters. The IgE antibody response was diminished when the antigens were given in a mixture, but this effect disappeared after a second booster. In contrast, groups injected with antigens separately started to show a suppressed response only at this time.

Eosinophilic inflammation and airway hyper‐responsiveness are profoundly inhibited by a helminth (Ascaris suum) extract in a murine model of asthma

“…When these allergenic components are added to EWI, there is no change in the eosinophilic inflammation elicited by the OVA challenge (M. F. Macedo‐Soares, Butantan Institute, personal communication), indicating that antigenic competition is not involved in the inhibition of eosinophil infiltration by ASC. In addition, ASC suppresses the IgE antibody production against OVA even when they are injected at separate sites [43], excluding any biochemical effect of the extract on EWI. Although a strong IgE antibody response can be obtained when the allergenic ASC components are injected with an adjuvant like alum, intratracheal instillation of ASC in EWI + ASC‐immunized mice did not lead to an influx of eosinophils into the lung (data not shown).…”