Nonspecific stimulation of lymphocytes by tuberculin.

Lymphocytes from uninfected, nonimmune mice can be stimulated to proliferate and produce antibody to diverse antigens in culture when exposed to the purified protein derivative of tuberculin or unheated tuberculin culture filtrate. Lymphocytes from numerous inbred strains of mice respond to tuberculin, but no true low responder strain has been found as yet. The evidence presented suggests that a subpopulation of B cells, which are distinct from those activated by lipopolysaccharide endotoxin, respond to tuberculin. The results of digestion experiments with insolubilized enzymes suggest that the nonspecific activating principles in tuberculin are protein.