Specificity of a BCG-induced pulmonary granulomatous response in rabbits.

The specificity of Bacillus Calmette Guérin (BCG)-induced accelerated pulmonary granuloma formation has been evaluated in rabbits by cross sensitization-challenge experiments by using another granulomagenic organism, Corynebacterium granulosum. BCG-sensitized rabbits responded to challenge with homologous but not heterologous antigen, indicating that BCG-induced accelerated granuloma formation displays specificity characteristic of immunological reactions. These differences were also observed in local pulmonary delayed hypersensitivity, as determined by the migration inhibition test. The relationship between local pulmonary delayed hypersensitivity and the accelerated granulomatous response is discussed.