COMPARATIVE SELECTIVITY OF ADJUVANTS FOR HUMORAL AND CELL-MEDIATED-IMMUNITY .1. EFFECT ON THE ANTIBODY-RESPONSE TO BOVINE SERUM-ALBUMIN AND SHEEP RED-BLOOD-CELLS OF FREUNDS INCOMPLETE AND COMPLETE ADJUVANTS, ALHYDROGEL, CORYNEBACTERIUM-PARVUM, BORDETELLA-PERTUSSIS, MURAMYL DIPEPTIDE AND SAPONIN

Abstract

A comparison was made of 7 recognized adjuvants, Freund''s incomplete [FIA] and complete [FCA], alhydrogel, C. parvum [Propionibacterium acnes], B. pertussis, muramyl dipeptide [MDP] and saponin, administered with BSA [bovine serum albumin] or SRBC [sheep red blood cells] by the s.c. route of immunization. Strong selectivity and differences in potency were revealed in relation to these 2 antigens. Only FIA, FCA, alhydrogel and MDP promoted the primary response to 50 .mu.g of BSA, and FIA was significantly superior to FCA. Immunological memory to a low dose (0.5 .mu.g) of BSA, which did not evoke a primary response with any adjuvant, was potentiated by alhydrogel and by MDP and, relatively poorly, by FIA. Radioimmunoelectrophoresis showed that potentiation of the response with MDP was confined to Ig[immunoglobulin]G1, whereas alhydrogel, FIA and FCA stimulated IgG1 and IgG2. Saponin was outstandingly the best adjuvant for primary and secondary hemagglutinin responses to SRBC. Of the others, alhydrogel for the primary and alhydrogel and B. pertussis for the secondary were active to a lesser degree. The relative potency of adjuvants differs markedly according to the antigen used, and saponin may be a particularly effective adjuvant for antigens in cell membranes.