Studies on M and G antibody response of mice to bovine serum albumin. I. A systematic survey of immunizing conditions.

Abstract

Response of CBA mice with γM and γG antibodies to bovine serum albumin (BSA) was studied in relation to a variety of conditions of antigen administration. The variables in the conditions were doses and physical forms of antigen, and injection routes. It was realized that γG antibody response to soluble BSA and both γM and γG antibody responses to particulate forms of BSA were augmented as the dose was increased. The γM response to soluble BSA was not elevated by an increase in the amount of antigen up to 1 mg. The soluble form was not so immunogenic as the particulate forms, in which alum-precipitated BSA was capable of inducing both γM and γG antibodies to high titers, and heat-denatured BSA elicited preferably antibody. Alum-precipitated BSA and the emulsified BSA were strong inducers for γG antibody response when injected subcutaneously. In any antigen form, γM response was markedly influenced by changing the injection route, the order of decreasing efficiency for antibody being intravenous, intraperitoneal and subcutaneous. The γG antibody response was hardly affected by the injection route. The effect of a single intravenous injection of 0.01 mg of endotoxin, given 1 to 2 hr after antigen injection, on γM and γG antibody production differed according to the antigen administration procedures. Generally speaking, this agent had an enhancing effect when the antigen was given in the particulate forms, and it depressed the response when the antigen was given in the soluble form.