A NON-SPECIFIC DEPRESSANT EFFECT ON THE IMMUNOLOGICAL RESPONSE

The antibody response of mice to intraperitoneally injected sheep red cells was found to be markedly depressed by the injection of isogenic mouse red cells (1,2) given 1–3 days before the antigen. If the isogenic cells were administered at the same time or 1 day after the antigen, the antibody response was not affected. Other non-antigenic substances such as a 5% solution of amino acids exercised a similar depressant effect. The depression of the antibody response did not occur when the isogenic red cells were given intraperitoneally and the antigen by another route. When the effect of specific cells or agents on the antibody response is to be examined it is frequently necessary to make two injections. Only one of the two should be made by the intraperitoneal route.