INDUCTION OF DELAYED-HYPERSENSITIVITY TO PROTEIN ANTIGENS IN MICE WITHOUT FREUND ADJUVANTS

[摘要] Three ways for inducing tuberculin-type delayed hypersensitivity (DH) in mice to purified protein antigens without Freund adjuvant are described. Four strains of mice compared for susceptibility to sensitization with several antigens ranked SJL > CF-1 > CAF1 = C57B1. Females were more easily sensitized than males. The first way of sensitizing without Freund adjuvant was simply to inject antigen intradermally in saline, but it could be used only with the potent antigen methylated human serum albumin (HSA). Six-mercaptopurine injections during the 1st 5 days of sensitization enhanced such sensitization in CF-1 but inhibited it in CAF1 mice. The 2nd way of sensitizing without adjuvant employed a weaker antigen, chicken conalbumin (CA) and is thus more versatile. It consisted of injecting a saline solution of antigen into a strong 24 h DH dermal reaction to an unrelated antigen (dextran). The 3rd way was simplest and best: Freund adjuvant was replaced with aqueous Evans blue dye. Distilled water solutions of antigen (CA or chicken ovalbumin) and dye injected s.c. induced DH indistinguishable from that induced with the same antigens in Freund adjuvant. Neither antigen, when used in distilled water alone, provoked sensitization. The dye also intensified Arthus sentization. This diazo dye may be a practical, harmless water-soluble substitute for Freund adjuvant for inducing DH or cell-mediated immunity and for intensifying Arthus sensitization.