Correlation between the immune response elicited in rabbits by env-recombinant avipox vaccines and the inhibition of HIV-1-specific functions

The fine immunoreactivity of the rabbit humoral response elicited by four e nv-recombinant avipoxviruses and their ability to stimulate a memory T-cell response and a protective immunity have been studied. The antibody specifi city was compared with the serum neutralizing activity and virus-specific T -cell proliferative response. Resistance to challenge by cell-associated HI V-1 was monitored by PCR. Canarypox (CP) and fowlpox (FP) constructs, conta ining the complete env gene (IS+) from the HIV-1(SF2) strain, induced a hig her profile of epitope recognition than their counterparts expressing the e nv gene deleted of the putative immunosuppressive region (IS-). Serum neutr alizing activity was in agreement with fusion inhibition and lymphoprolifer ative response in rabbits immunized with CPIS+, and only partially with FPI S+. Rabbits failed to be infected, but anti- p55 gag-specific antibodies co uld be demonstrated by Western blot. This study confirms the ability of the se non-replicative live recombinant viruses to elicit a complete immune res ponse, capable of inhibiting specific HIV-I functions. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. A ll rights reserved.