Cord factor is associated with the maintenance of the chronic inflammatory reaction caused by mycobacteria

The distribution of an aqueous suspension of cord factor (CF) from Mycobacterium bovis BCG in several mouse organs was examined after intravenous injection, and the correlation between evolution of the inflammatory granulomatous reaction and the presence of CF in these organs was determined. CF was preferentially deposited in the lungs and liver, and the kinetics of the pulmonary and hepatic inflammatory reaction, evaluated by determining the indices for these organs, showed a gradual increase on day 2 after injection, reached a peak around the fifth day, and declined thereafter. Histological analysis showed that on day 5 both the lungs and the liver were diffusely damaged by a mononuclear inflammatory infiltrate arranged in a granulomatous manner and consisting predominantly of histiocytes. CF elimination was more marked in the liver than in the lungs: 2 d after injection 76% of the material deposited in the liver had been eliminated. Little or no CF was detected in the liver and lungs by day 16, when the inflammatory reaction was also substantially decreased. A second CF dose administered 8 d after the first exacerbated the inflammatory process in both the lungs and the liver, indicating that the intensity of this process depends on CF concentration in the lesion site.