Liposome as an adjuvant for the production of estradiol anti-bodies

Abstract

Mice immunized with liposome associated estradiol-bovine serum albumin conjugate (E₂-BSA) showed a significantly higher estradiol-specific immune response than did mice injected with the free conjugate. The conjugation of estradiol with BSA is imperative, since injection of liposomes with estradiol in the lipid bilayer was found to be ineffective in inducing an immune response. Entrapment of E₂-BSA in neutral and positively charged liposomes was found to be a potent mode of immunostimulation, even better than emulsification in complete Freund's adjuvant (CFA). Covalent liposome surface association of E₂-BSA induced a good immunopotentiation. However, the response was lower than that observed with the entrapped conjugate. The affinity and the specificity of antisera, raised in different ways, were determined.