Specific inhibition of antibody production. II. Paralysis induced in adult mice by small quantities of protein antigen.

A state of immunological paralysis has been induced in adult CBA mice by intraperitoneal injections of small quantities of bovine γ globulin (BGG). The minimum paralysing dose of BGG has been found to be between 50 and 200 μg. A dose as small as 2 μg. has been found to have a slight paralysing effect. The time necessary for the induction of paralysis by 50 μg. to 2 mg. of BGG in CBA mice is 3–4 days. Paralysis is induced by only one component of BGG; this component is incapable of inducing an antibody response unless an injection of adjuvant is made at the same time or slightly before the injection of the antigen. The BGG is centrifuged at an RCF of 20,000–30,000 to remove particulate matter. Failure to remove the particulate matter leads to sporadic immune responses in groups of mice injected with the protein. Mice given a paralysing injection of BGG were subsequently challenged by an injection of BGG in Freund's adjuvant. The result of this challenge was tested by an injection of radioactively-labelled antigen and the elimination of this antigen from the circulation of the challenged mice was followed for several days. Immune elimination' can easily be distinguished from non-immune elimination'. The presence of antibody to the non-paralysing components of BGG in sera from paralysed mice was confirmed using the Ouchterlony geldiffusion technique.