HIV subtypes and recombination strains-strategies for induction of immune responses in man

Clinical and experimental 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 made by peptides of the coreceptor-ligand interactions. 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. Genetic immunization induced new 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.