Abstract
The plaque technique of Cunningham and Szenberg was used to demonstrate the adjuvant effect of sonicated schizophyllan (SPG-S), a glucan produced by Schizophyllum commune, on antibody formation.
1) The pretreatment of mice with SPG-S, as well as the original schizophyllan, was proved to increase the number of plaque-forming cells of the spleen after immunization with sheep red blood cells (SRBC). The highest adjuvant effect of SPG-S was obtained by a dose of 2.5-5.0 mg/kg.
2) The administration of SPG-S caused a significant increase in both anti-SRBC IgM and IgG antibody-producing cells in the mouse spleen after the immunization. The number of these cells reached a peak 4 and 6 days, respectively, after the injection of antigen.
3) SPG-S showed a remarkable adjuvant effect when injected by the intramuscular, intraperitoneal, and intravenous route, but not by the subcutaneous route.
4) Examination of time intervals between SPG-S and antigen injections revealed that SPG-S presented a most conspicuous adjuvant effect when injected 24 hours before the administration of antigen.
