Selective and specific inhibition of 24 hour skin reactions in the guinea-pig. I. Immune deviation: description of the phenomenon and the effect of splenectomy.

Strong 24 hour skin reactions occur in guinea-pigs immunized with antigen in Freund's complete adjuvant. These reactions were reduced by the injection of 1 mg of the same antigen, in either the soluble or alum precipitated form, 14 days before immunization with antigen in Freund's complete adjuvant. There was also a reduction in the corneal reaction, which has been regarded as an index of delayed hypersensitivity. This phenomenon was called immune deviation. The phenomenon was demonstrated for bovine γ-globulin, human serum albumin, bovine serum albumin, egg albumin, diptheria toxoid, haemocyanin, purified protein derivative (PPD) and dinitrophenylated proteins. Ten mg of soluble bovine γ-globulin caused considerable reduction of the circulating antibody level and of the 24 hour skin reaction. Alum precipitated bovine γ-globulin and smaller doses of soluble antigen reduced the skin reaction but had less effect on the antibody level. Similar results were obtained with human serum albumin. This suggested that the conditions for eliciting immune paralysis and immune deviation were different. Immune deviation was obtained with either footpad or intravenous injections and with as little as 100 μg of antigen. Alum precipitated bovine γ-globulin caused immune deviation when given 14, 7 or 1 day before or 1 day after immunization with antigen in Freund's complete adjuvant. It was inactive when given 6 days after immunization. Splenectomy had no effect on the production or deviation of 24 hour skin reactions. Alum precipitated antigen had a variable and usually slight effect on the level of antibody following immunization with the same antigen in Freund's complete adjuvant. There was, however, a qualitative alteration in the antibody. The sera of guinea-pigs, which had been deviated by a prior injection of bovine serum albumin or bovine γ-globulin, showed only a γ line of antibody on immunoelectrophoresis, while the sera of control guinea-pigs also showed the γ line characteristically seen in guinea-pigs immunized with antigen in Freund's complete adjuvant. It was concluded that immune deviation was distinct from classical immune paralysis and that the immunologically specific reduction of the 24 hour skin reactions might be due, at least in part, to a selective loss of delayed hypersensitivity.