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Human immune response to allergens of house dust mite, Dermatophagoides pteronyssinus. III. Cross‐reactivity of bystander idiotopes on allergen‐specific IgE antibodies

1988; Wiley; Volume: 18; Issue: 1 Linguagem: Inglês

10.1002/eji.1830180112

1521-4141

Jean-Marie Saint-Remy, Serge Lebecque, Philippe M. Lebrun,

Food Allergy and Anaphylaxis Research

Abstract Rabbits were inoculated with affinity‐purified human antibodies to the common house dust mite Dermatophagoides pteronyssinus (DPT) to produce anti‐idiotypic (Id) antibodies. The Id carried by human IgE antibodies were studied in a radio‐immunoassay in which specific anti‐DPT IgE were first insolubilized on rabbit F(ab′) 2 fragments against human Fcϵ. In a single individual specific anti‐DPT IgE antibodies shared bystander idiotopes ( i.e. idiotopes located outside the antigen‐binding site) with IgG antibodies of the same specificity, since the adsorption on insolubilized anti‐DPT IgG almost completely eliminated the binding of anti‐Id antibodies to IgE. This differed from our previous observations (J.M. R. Saint‐Remy et al., Eur. J. Immunol. 1986. 16 : 575) wherein distinct paratope‐associated idiotopes were identified on IgG and IgE anti‐DPT antibodies. The frequency of cross‐reactions between idiotopes of anti‐DPT IgE antibodies observed in ten unrelated individuals was less than 10% for bystander idiotopes. This finding confirmed the private character of the above idiotopes that we found earlier on anti‐DPT IgG antibodies. However, one anti‐Id antibody preparation was found to react with bystander idiotopes of anti‐DPT IgE of most individuals, thereby suggesting the existence of a recurrent idiotope. The low frequency of inter‐individual bystander idiotope cross‐reactivity contrasted with the public character of paratope‐associated idiotopes.