Shortening of the Period of Primary Immune Response by the Prior Injection of Freund's Adjuvant

Abstract

–ANTIGENS in water-in-oil emulsions are known to be more effective than those dissolved or suspended in saline to give the specific antibodies of high titres in the circulation of animals^1–3, but the mode of action of the adjuvant has remained unsettled. One of the possible interpretations is that antigens are released slowly from the emulsion and stimulate continuously the antibody forming mechanism during the course of immune response. Recently, Dresser^4,5 found that the subcutaneous injection of Freund's adjuvant without the antigen enhanced the antibody response against bovine γ-globulin given to mice intravenously. This suggests that the non-specific influence emanating from the adjuvant activates the immune machinery to elicit the specific antibody. The question arises whether such an activation by the adjuvant occurs concurrently with the stimulus of a specific antigen throughout the period of immune response, or whether it can precede the specific stimulation. If the latter is the case, treatment of animals with the adjuvant prior to the antigen administration is expected to shorten the period of primary immune response.