Biological effects of Corynebacterium parvum: IV. Adjuvant and inhibitory activities on B lymphocytes

The PFC response to the thymus-independent antigen SIII (type 3 pneumococcal polysaccharide) was amplified in mice injected 4 days previously with killed Corynebacterium parvum. This adjuvant activity was demonstrable with high (2–50 μg) but not low (0.1–0.5 μg) doses of SIII. Induction of tolerance was unaffected. Depression of the response resulted from simultaneous injection of SIII with either C. parvum or Bordetella pertussis, while prior treatment with the latter was without effect. Responsiveness to SIII was transiently but potently suppressed in spleen cells transferred into lethally irradiated, C. parvum pretreated mice. Although C. parvum is an effective B cell adjuvant, other data imply that it acts indirectly on these lymphocytes. It is argued that both adjuvant and suppressive activities of C. parvum on the B cell response to SIII are most probably mediated by activated macrophages.