The mode of action of immunological adjuvants. II. Generation of a potent precursor of antibody-forming cell by adjuvant.

The mode of action of mycobacterial adjuvants was studied in mice, using a 'plaque size' technique and purified adjuvants, wax D and AD6. Data were obtained which suggest that the adjuvants do not act directly on antibody-forming cells or memory cells but on their precursors. The injection of the adjuvants alone apparently caused the generation of competent precursor cells in the spleen as well as in the bone marrow of mice, which developed large plaques and the generation of memory cells developing large plaques upon antigenic stimulation.