Inhibitory immunization using complete Freund's adjuvant on ongoing eosinophilia induced by repeated...

Ongoing eosinophilia, in guinea pigs repeatedly sensitized with dinitrophenylated (DNP)-Ascaris antigen (DNP-Asc) into the peritoneal cavity, was suppressed significantly by complementary immunizations with a heterologous antigen, e.g., ovalbumin (OA) or bovine gamma-globulin (BGG) emulsified in complete Freund's adjuvant (CFA). Challenge injections of DNP-OA or DNP-BGG elicited peritoneal eosinophilia in animals that were sensitized repeatedly with DNP-Asc. Under these conditions, antigen specificity in suppressive immunization was studied. Eosinophilia, induced by DNP-OA challenge, was suppressed by immunization with either OA in CFA or BGG in CFA. However, Asc (homologous carrier of sensitizing antigen) elicited no suppression. Additionally, CFA, used as an adjuvant, played an important role in suppressive immunization, but CFA alone had no effect in suppressing peritoneal eosinophilia. Anti-DNP antibody, detected by hemagglutination test or passive cutaneous anaphylaxis, was not affected by complementary immunization. These results suggested that peritoneal eosinophilia was suppressed concomitantly by a supplemental immunization in an antigen-nonspecific manner. Eosinophilia in the bone marrow also was suppressed significantly by complementary immunization, but the pattern was quite different from that shown in the peritoneal cavity. The first nuclear cell response peak after challenging, including eosinophils, was stanched completely by CFA itself. The second nuclear cell peak, on day 5, recovered, but eosinophil response continued to be suppressed.