Humoral and cell-mediated immunity in rabbits immunized with live non-replicating avipox recombinants expressing the HIV-1SF2 env gene.
The canarypox (CP) and fowlpox (FP) viruses, which are unable to replicate productively in non-avian species, have been utilized as live vectors carrying the HIV-1SF2 env gene with the putative immunosuppressive (IS) region complete (CPIS+ and FPIS+) or deleted (CPIS- and FPIS-). To determine if these avipox-env recombinants could be utilized to elicit a specific immune response against HIV-1, six groups of rabbits were immunized with CPIS+, CPIS-, FPIS+, FPIS- constructs or their non-engineered wild-type CPwt or FPwt counterparts. After a primary inoculation and successive boosters, env-specific humoral and cell-mediated immunity were demonstrated by ELISA, immunoblots and lymphoproliferation assays. Antibody titres and neutralization activities were higher in CP- than FP-inoculated rabbits, the CPIS+ always showing a similar immunogenic capacity to CPIS-. Evidence is also presented indicating that rabbit sera possess group-specific antibodies, which were, however, unable to cross-neutralize divergent HIV-1 strains. Although the protective capacity against HIV-1 experimental infection has not yet been determined in these animals, our results suggest that these recombinants might represent promising and safer candidate vaccines against HIV-1.
Radaelli
A
A
Institute of Pharmacological Sciences, University of Milano, Italy.
Gimelli
M
M
Cremonesi
C
C
Scarpini
C
C
De Giuli Morghen
C
C
D016915:AIDS Vaccines / Q000276:immunology; D000818:Animals; D000918:Antibody Specificity; D018150:Avipoxvirus / Q000235:genetics*; D015153:Blotting, Western; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D015967:Gene Expression Regulation, Viral / Q000235:genetics; D015752:Genes, env / Q000235:genetics*; D005818:Genetic Engineering; D015483:HIV Antibodies / Q000096:biosynthesis*; D015497:HIV-1 / Q000235:genetics* / Q000276:immunology; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D007111:Immunity, Cellular; D008213:Lymphocyte Activation; D011817:Rabbits; D013601:T-Lymphocytes / Q000166:cytology; D013997:Time Factors; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000276:immunology; D014779:Virus Replication / Q000235:genetics
D016915:AIDS Vaccines; D015483:HIV Antibodies; D007106:Immune Sera; D014614:Vaccines, Synthetic