THE MECHANISM OF ACTION OF ADJUVANTS

Abstract : The adjuvant effect of endotoxins in rabbits and mice was studied to clarify the mechanism of the action of adjuvants. The adjuvant action of endotoxin on antibody formation was found to be the result of a rapid and direct effect on the immunologically competent cells which causes an increase in the number of young blast cells. These either secrete antibodies themselves or mature into antibody secreting plasma cells, particularly at the level of the germinal centers. This is due to the stimulation of the mitotic activity of these blast cells. The adjuvant effect of endotoxins was evident in the early stages of antibody response. Later, if sufficient antigen is not available or repeatedly administered, the effects of the initial dose of endotoxin becomes less obvious.