title: Truncated gp120 envelope glycoprotein of human immunodeficiency virus 1 elicits a broadly reactive neutralizing immune response.
abstract: Removal of the V1-V3 loops from IIIB gp120 results in a protein, PR12, with altered immunogenicity compared to the full-length protein. Polyclonal immune sera raised in rats using PR12 as immunogen recognizes envelope glycoproteins of clades A, B, C, E, F and G and can neutralize chimeric human immunodeficiency virus type 1 (HIV-1) HXB2 viruses expressing envelopes from primary HIV-1 clades B, C, E and F. These data suggest that the immune response to PR12 is directed toward conserved epitopes expressed by viral glycoproteins of diverse genotypes. Five monoclonal antibodies (mAb) derived from PR12-immunized rats were unable to neutralize virus infectivity; hence the epitopes responsible for the induction of this cross-clade neutralizing activity remain to be elucidated. However, PR12 immune sera were able to compete with the human neutralizing mAb 2G12 for gp120 binding, implying that this epitope may be immunogenic when expressed in the context of this truncated protein.
authors.affiliation: Division of Retrovirology, NIBSC, Blanche Lane, South Mimms, Potters Bar, Herts EN6 3QG, UK1.
authors.forename: S A
authors.initials: SA
authors.lastname: Jeffs
authors.affiliation: School of Biological Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK2.
authors.forename: C
authors.initials: C
authors.lastname: Shotton
authors.affiliation: Division of Virology, University College of London Medical School, Windeyer Building, 46 Cleveland Street, London W1P 6DB, UK3.
authors.forename: P
authors.initials: P
authors.lastname: Balfe
authors.affiliation: School of Animal and Microbial Sciences, University of Reading, Whiteknights, PO Box 228, Reading, Berks RG6 2AJ, UK4.
authors.forename: J A
authors.initials: JA
authors.lastname: McKeating
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D015483:HIV Antibodies / Q000097:blood / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000235:genetics / Q000276:immunology*; D015497:HIV-1 / Q000145:classification / Q000235:genetics / Q000276:immunology*; D006801:Humans; D016296:Mutagenesis; D009500:Neutralization Tests; D010802:Phylogeny
chemical_list: D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120