HIV subtypes and recombinant strains -Strategies for induction of immune responses in man

Experimental and clinical studies of HIV-1 subcomponents were made in order to increase their immunogenicity. HIV subtype envelopes A, B and C have been compared and a detailed analysis of the coreceptor - ligand interactions made by synthetic peptides. We identified a direct interaction between HIV-1 envelope and a cellular receptor at the amino acid level. Both the viral subtype and its tropism appeared to influence inhibition of infection. Gene segments from reverse transcriptase (RT) of HIV-1 with mutations decreased their in vitro and in vivo expression and immunogenicity with an increasing number of drug-induced mutations. Genetic immunization induced new HIV-specific cytotoxic responses while proteins appeared to efficiently boost previous responses. One HIV-1 subtype B antigen was strongly immunogenic in a human immunotherapeutic trial and permitted better survival at 2 years of the study in patients with poor prognosis.