Effect of heparin on the priming with a protein antigen in mice.

Heparin has been found to stimulate or suppress the priming activity of a protein antigen (cock muscle phosphorylase-b) in mice depending on the various parameters (the dose of antigen, timing of administration, etc.). The adjuvant effect of endotoxin on priming was potentiated by a single dose of heparin injected 10-12 hours after immunization. Optimal doses of heparin incorporated into Freund's incomplete adjuvant also enhanced the humoral immune response first of all the development of 7 S immunologic memory. The possible mechanisms are discussed.