Interactions of glucocorticoids and heparin on the humoral immune response of mice.

Interactions of glucocorticoids and heparin on the humoral immune response of mice to SRBC have been studied. Heparin injected subcutaneously in a depot-form 2 hours before immunization restores the antibody-forming ability of mice immuno-suppressed by hydrocortisone, through pretreatment of mice only with heparin 3 days before immunization decreases the PFC-count in the spleen. Cortisone (ip) and heparin (sc) per se injected at about the time of immunization with suboptimal doses of SRBC resulted only in a slight stimulating or no effect on spleen PFC count and serum antibody level. Cortisone and heparin applied in combination, however, exerted a stimulatory effect on the humoral immune response to SRBC. The route of steroid administration pointed to the significance of macrophages in this phenomenon. As the cooperative effect of heparin + cortisone on the humoral immune response shows a good correlation with their cooperative effect on in vivo (3H)dThd incorporation and thymidine kinase activity of spleen, it was hypothesized that an in vivo mitogenic activity for the spleen cells was responsible for the adjuvant effect observed.