Mycobacterial components responsible for the induction of a chronic immunological inflammatory response in rabbit lungs.

Fractions of the tubercle bacillus were examined for their capacity to produce an allergic pulmonary granulomatous response in rabbits. We found that emulsions containing old tuberculin and even old tuberculin alone in an emulsion could induce a pulmonary inflammatory reaction comparable in intensity to that produced with killed BCG. Emulsions lacking old tuberculin failed to produce an allergic pulmonary inflammatory response. The significance of these results in relation to immunological and nonimmunological chronic inflammation is discussed.