New amphiphilic immunogens by poly(N-isopropylacrylamide)-modified bovine serum albumin

Using poly (N-isopropylacrylamide) co-oligomer with N,N-dimethylacrylamide (DMAAm) (IDc) we prepared polymer-protein conjugates of bovine serum albumin (IDc-BSA). The conjugate underwent reversible hydration-dehydration changes in response to temperature changes and revealed phase separation at body temperature. Mice were immunized by the intravenous, intramuscular or intradermal routes with the IDc-BSA. The intravenous route of single immunization without adjuvants evoked increased primary and secondary specific immune responses to IDc-BSA, whereas the intramuscular and intradermal did not elicit higher antibody production. The intradermal administration of BSA and IDc-BSA together with IFA both gave rise to high immunological activity. It is suggested that the hydrophobic chain aggregation site of the IDc-BSA conjugate at body temperature would increase the adsorptive capacity of BSA on the immunocompetent cells. The efficiency of such ''forced'' interactions of conjugate aggregates (high epitope density) are high enough for the immune response. Copyright (C) 1996 Published by Elsevier Science Ltd