CHARACTERIZATION OF IMMUNE-RESPONSES TO EXPERIMENTAL POLYVALENT SUBUNIT VACCINES ASSEMBLED IN ISCOMS

Immune responses to experimental polyvalent subunit vaccines assembled in a particulate adjuvant/delivery system, iscoms, are described. The fusion protein ZZ-MS comprises structures of staphylococcal protein A (ZZ) and the Plasmodium falciparum malaria antigen Pf155/RESA (M5). M HC congenic mice were immunized with ZZ-MS conjugated to iscoms contai ning human influenza virus antigen (flu ag, MS-flu-isc) or to iscom ma trix (iscom particles without flu ag, MS-isc). Comparison of antibody and T-cell responses to MS-isc and M5-flu-isc demonstrated that the fl u ag in MS-flu-isc exhibits carrier-related helper functions and that the assembly of immunogens in MS-flu-isc did not result in any apparen t antigenic competition. In addition, assembly of ZZ-MS and flu ag in iscoms induced an alteration of the IgG subclass profile of the antibo dy response to M5. The results suggest that assembly of immunogens in iscoms may be a useful approach to the design of subunit vaccines but that both quantitative and qualitative aspects of the immunogenic prop erties of such constructs should be scrutinized. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.