Confronting the hypervariability of an immunodominant epitope eliciting virus neutralizing antibodies from the envelope glycoprotein of the human immunodeficiency virus type 1 (HIV-1).
Antibody mediated and cell mediated immune responses to the envelope glycoproteins gp120 and gp41 of the human immunodeficiency virus (HIV-1) are considered important for protection against infection and for attenuation of disease symptoms after infection. Virus neutralizing antibodies are mostly subtype specific and primarily directed against epitopes on a hypervariable loop from the V3 region of HIV-1 gp120. Such epitopes are recognized by helper and cytotoxic T-cells suggesting that all protective immune responses to HIV-1 are predominantly subtype specific. The extraordinary primary sequence variability of gp120 indicates that a combination of subtype specific components will be required to design a broadly effective protective immunogen against HIV-1. Peptides from hypervariable loops of the V3 region of 21 distinct HIV-1 isolates (clones) were synthesized and used to raise rabbit antisera. The antisera contained high levels of antibodies recognizing the homologous peptides and the parent gp120 sequence. The serological cross-reactivity between the distinct peptides was evaluated and related to amino acid divergence. The corresponding relationship approximated a linear regression with a correlation coefficient r = 0.718. The 21 peptides were combined into a single immunogen which elicited broadly reactive antibodies recognizing all 21 peptides as well as gp120 from the only isolate tested, HIV-1 IIIB. The results suggest the possibility of developing broadly protective HIV-1 immunogens by combining judiciously selected subtype specific peptides derived from envelope glycoproteins of divergent virus isolates.
Lindsley F. Kimball Research Institute, New York Blood Center, NY 10021.
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AR
Neurath
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Strick
D000595:Amino Acid Sequence; D015153:Blotting, Western; D003429:Cross Reactions; D000939:Epitopes; D015483:HIV Antibodies / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D015700:HIV Envelope Protein gp41 / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010446:Peptide Fragments / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology
D000939:Epitopes; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D015700:HIV Envelope Protein gp41; D010446:Peptide Fragments; D011994:Recombinant Proteins