Effects of cholera toxin on the lymphoid system II. Selective augmentation of delayed footpad reaction in mice.

Effects on immune responses to sheep erythrocytes (SRBC) were examined at various intervals after an intravenous injection of 1 microgram of cholera toxin in DDD and AKR mice. Delayed footpad reaction was augmented by pretreatment with cholera toxin 1, 7 or 10 days before immunization in both strains. The delayed reaction was not suppressed even in the presence of a prominent antibody production. In mice given cholera toxin, macrophage migration inhibition was not positive 5 days after immunization, but became weakly positive 10 days after immunization. Antibody production against SRBC especially of IgG class, was facilitated, when cholera toxin was given one day before immunization, on the other hand, antibody production was suppressed irrespective of immunizing routes and mouse strains. Similar results were observed in guinea pigs which were injected with 1 microgram of cholera toxin 0 or 7 days before immunization with bovine gamma globulin in complete or incomplete Freund's adjuvant. Erythema was augmented strikingly by cholera toxin, while macrophage migration inhibition was affected scarcely.