The Haptene-Protein Complex in Canine Anaphylaxis

Abstract

Recent studies of specific allergic and immune reactions against artificial protein-crystalloid conjugates have suggested that the superficial crystalloids of a protein molecule are the essential units of specific antigenicity. If so, the whole theory of specific immunity must be rewritten in terms of sub-colloidal antigenic “determinants”. Most of these studies, however, are inconclusive. This is due in part to the high haptene-protein ratios almost invariably used. In many cases the conjugates were “carriers” of no less than 150 to 200 haptene “determinants”. Moreover, from the point of view of clinical medicine, both rabbit antiserum and guinea pig anaphylaxis distort the quantitative perspective. We have, therefore, repeated some of the classical tests, using haptene-protein complexes of relatively low ratios, with dogs as the experimental animals. The proteins used in this work were horse serum (HS), cow serum (CS), dog serum (DS), egg white (EW) and crystallized excelsin (Ex). Conjugation was made with benzoyl (Bz) and benzene-sulfonyl (Su) radicals, the quantitative relationships being such as to give final products with an average of from 25 to 40 haptene groups per protein molecule. This represents an approximate 20% haptene saturation. Dogs were sensitized by a single intracardial injection of 40 mg. protein per kg. of body weight. This is the optimum sensitizing dose with HS. Anaphylactic tests were made 3 weeks later, the routine shock dose being 80 mg. protein by kg. of body weight injected intravenously. This is about 10 times the minimum shock dose with HS.