Immunogenicity of polysaccharides IIP-A-1 and IIP-2 from Isatis indigotica as vaccine adjuvants / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE To investigate the immunogenicity of Isatis indigotica polysaccharides, IIP-A-1 and IIP-2 as vaccine adjuvants. MRTHODS Keyhole limpet hemocyanin (KLH) was linked to IIP-A-1 and IIP-2 respectively to prepare immuno-antigen KLH-IIP-A-1 or KLH-IIP-2. Bovine serum albumin (BSA) was also linked to them respectively to prepare BSA-IIP-A-1 or BSA-IIP-2 as the detecting-antigen. Rabbits were twice immunized with KLH-IIP-A-1 or KLH-IIP-2 (300 pg per rabbit) plus Freund adjuvant (0.65 mL per rabbit) ) by intradermal injection at a 28 d interval. The plates were coated with protein KLH, BSA, BSA-IIP-A-1 or BSA-IIP-2 (5 mg.L") and serum specific antibody titers were determined by ELISA. In the sera of mice immunized with Aftosa plus IIP-A-1, anti-IIP-A-1 IgG, was not found. However, anti-IIP-2 IgG, with a titer of 1400 was found in the serum samples of mice immunized with Aftosa or H1N1 plus IIP-2 respectively. A titer of 1 = 100 was found in the sera of immunized mice co-immunized with HBsAg. CONCLUSION As haptens, IIP-A-1 and IIP-2 could induce the production of antibodies against IIP-A-1 and IIP-2 after being linked to KLH. As an adjuvant, IIP-A-1 doesn't present any immunogenicity, while IIP-2 can induce the production of anti-IIP-2 IgG, in mice when co-immunized with Aftosa, H1N1 or HbsAg.