Age interference of lymphokine production by lung derived lymphocytes.

Young adult and aged guinea pigs, 1 and 3 years old respectively, were sensitized intranasally with Bacillus Calmette Guérin (BCG). Lung lavage cells were harvested at 2, 3, 6 and 7 weeks following sensitization and tested for migration inhibitory factor (MIF) production in Mackaness chambers with purified protein derivative (PPD). Oil induced normal pig macrophages were used as indicator cells. Aged guinea pigs, compared to young adult guinea pigs, showed significant delay and reduced levels of MIF production at 2 to 3 weeks. Delayed hypersensitivity skin reaction (DHS) to PPD was also less pronounced at 6 weeks. Senescent immune lung cells were inhibitory to migration of indicator cells in absence of PPD.