Neutralizing cross-reactive and non-neutralizing monoclonal antibodies to HIV-1 gp120.
Amino acid sequences inducing neutralizing antibodies to HIV-1 were sought. Murine monoclonal antibodies (MAbs) were characterized by their reactivity with the envelope precursor gp160 or the Escherichia coli recombinant DNA products pB1 and pE3 representing the carboxy- and amino-terminal halves of mature envelope gp120. Fine mapping of the MAb determinants was performed using defined 15-mer synthetic peptides spanning the entire envelope gp120 region of HIV-1. One group of MAbs recognizes epitopes (amino acids 304-323) occurring in a small region with variable and conserved amino acid sequences of gp120. These MAbs mediate neutralization of the HIV-1 strain HTLV-IIIB (HIV-1IIIB) which was used for immunization. Nine out of 11 primary HIV-1 isolates were neutralized well or moderately well. In addition, prominent serological reactivity was noted with peptide sequences of strains of various European or American origins, but not with two HIV-1 strains of African origin. The cross-reactivity contrasts with previously described type-specific reactions to other sequences of this region. The reactivity to the short conserved site GPGR with its flanking amino acids may explain the broad sequence cross-reactivity seen with our neutralizing MAbs. Two other MAbs recognize conserved epitopes (amino acids 79-103) situated in the amino-terminal region of gp120. These MAbs did not neutralize HIV-1IIIB.
Akerblom
L
L
Department of Veterinary Microbiology, Faculty of Veterinary Medicine, Biomedical Center, Uppsala, Sweden.
Hinkula
J
J
Broliden
P A
PA
Mäkitalo
B
B
Fridberger
T
T
Rosen
J
J
Villacres-Eriksson
M
M
Morein
B
B
Wahren
B
B
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D015153:Blotting, Western; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D015686:Gene Products, env / Q000276:immunology; D015483:HIV Antibodies / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D019302:HIV Envelope Protein gp160; D015497:HIV-1 / Q000276:immunology*; D007114:Immunization; D051379:Mice; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010449:Peptide Mapping; D011498:Protein Precursors / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology
D000911:Antibodies, Monoclonal; D000939:Epitopes; D015686:Gene Products, env; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D019302:HIV Envelope Protein gp160; D011498:Protein Precursors; D011994:Recombinant Proteins