Compositions and methods for the treatment and prophylaxis of multiple strains and subtypes of hiv-1

Abstract

A self-adjuvanting immunogenic composition comprising multiple immunogens, each immunogen comprising a lipopeptide cap, a universal T helper sequence and an immunodominant HIV-1 Tat B cell epitope. The immunogen also comprises one or more linker sequences and/or polar charged amino acid sequences. The HIV-1 Tat B cell epitope of each immunogen has an amino acid sequence of V-D-P-Xaa7-L-Xaa9-P-W-Xaa12-Xaa13-Xaa14-Xaa15-Xaa16-amide SEQ ID NO: 1, in which the amino acid positions at Xaa7, Xaa9 and Xaa12 are selected from specific amino acid residues choices and in which the amino acid positions at Xaa13-Xaa16 may be absent or specific amino acid residue choices. The lipopeptide is a dipalmitoyl-S-glyceryl-cysteine or a tripalmitoyl-S-glyceryl cysteine or N-acetyl (dipalmitoyl-S-glyceryl cysteine), each with an optional neutral amino acid linker. Optional polar sequences of at least four charged polar amino acids enhance solubility of the immunogen and are located at the carboxy terminal end of the lipopeptide cap, optionally flanked by neutral linker amino acids, or elsewhere in the immunogen. In the composition, each immunogen differs from another immunogen by an amino acid variation at amino acid position Xaa7, Xaa9 or Xaa12 of the immunodominant HIV-1 Tat epitope. Such compositions can induce anti-HIV-1 Tat antibodies with geometric mean titers of greater than 1,000,000 on multiple HIV-1 Tat variants, when employed to immunize a subject, without any extrinsic adjuvant.