Immunogenicity of recombinant envelope glycoproteins derived from T-cell line-adapted isolates or primary HIV isolates - A comparative study using multivalent vaccine approaches

We investigated immunogenic properties of native envelope glycoproteins der ived from HIV-1 (subtype B). Our main objective was to assess whether the d esign of multivalent vaccines affects generation of neutralizing antibodies against primary viruses. Recombinant Semliki Forest virus (SFV) particles producing various HIV-1 envelope glycoproteins were used as vaccine vectors . The following multivalent vaccination approaches were compared: 1) immuni zation with a mixture of recombinant SFV expressing envelope glycoproteins derived from three HIV-1 primary isolates and two T-cell laboratory-adapted (TCLA) viruses; 2) immunization with a mixture of recombinant SFV expressi ng only the envelope glycoproteins derived from three HIV-1 primary isolate s: 3) sequential immunizations with the recombinant SFV expressing the enve lops glycoproteins derived from three HIV-1 primary isolates and two TCLA v iruses, respectively. Two monovalent vaccine approaches using SFV expressin g envelope glycoproteins derived from a single primary isolate or TCLA viru s were also included in the study. The multivalent vaccination strategies b ased on SFV vaccine vectors did not induce more neutralizing antibodies tha n the previously tested TCLA envelope immunogens, which gave disappointing results against primary isolates.