Patent ID: 7847085

Claim:
A recombinant nucleic acid molecule that encodes a recombinant HIV-1 gp120 envelope polypeptide which is useful as an immunogen for priming an antibody response against V3 epitopes of the gp120 polypeptide in a mammal, said nucleic acid molecule comprising: a nucleotide sequence that encodes a source gp120 polypeptide that has been genetically altered by insertion of a first and a second replacement nucleotide sequence each encoding a gp120 replacement V3 loop that is not native to the source gp120 polypeptide, wherein said first and said second encoded replacement V3 loop sequences replace native V1/V2 and V4 loops of the source gp120 polypeptide; wherein each of said first and second replacement nucleotide sequences (i) is different from the other, and (ii) encodes a different replacement V3 loop peptide with a sequence of the same or of a distinct HIV-1 clade that is either the same as, or distinct from, the HIV-1 clade from which the source gp120 polypeptide was obtained, and wherein, upon administration to said mammal, the recombinant gp120 polypeptide primes said antibody response.