An O-linked carbohydrate neutralization epitope of HIV-1 gp 120 is expressed by HIV-1 env gene recombinant vaccinia virus.
Previous studies have disagreed about the presence of O-linked carbohydrate epitopes on gp 120 of HIV, although antibodies against short-chain O-linked glycans neutralize HIV infection and block syncytium formation in vitro. To settle this question, we analysed the O-linked glycans of gp 120 by chemical methods using purified HIV-1 gp 120 from cells infected with recombinant vaccinia virus solely expressing gp 160 or gp 120. Alkaline borohydride degradation of recombinant gp 120 released monosaccharides and also slightly larger structures (di/trisaccharides) by a beta-elimination, confirming the presence of simple O-linked oligosaccharides. The functional activity as neutralisation epitopes of the O-linked oligosaccharides expressed on recombinant gp 120 was preserved, since fusion between uninfected CD4+ cells and cells infected with recombinant vaccinia was blocked by monoclonal antibodies to the O-linked oligosaccharides of gp 120. Although the mechanism for HIV induction of O-linked oligosaccharide neoantigens is unknown, these results indicate that the O-linked neutralization epitopes are inherent to the glycoprotein itself, and that the unusual appearance of simple O-linked oligosaccharides on gp 120 is independent of any interaction between the host cell and retroviral genes other than env.
Hansen
J E
JE
Department of Infectious Diseases, Hvidovre Hospital, Denmark.
Clausen
H
H
Hu
S L
SL
Nielsen
J O
JO
Olofsson
S
S
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000951:Antigens, Neoplasm / Q000276:immunology; D015295:Antigens, Tumor-Associated, Carbohydrate; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology; D002459:Cell Fusion / Q000276:immunology; D002460:Cell Line; D002850:Chromatography, Gel; D000939:Epitopes / Q000235:genetics / Q000276:immunology; D015752:Genes, env / Q000235:genetics* / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D015497:HIV-1 / Q000235:genetics* / Q000276:immunology; D009844:Oligosaccharides / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D014616:Vaccinia virus / Q000235:genetics / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D015295:Antigens, Tumor-Associated, Carbohydrate; D000956:Antigens, Viral; D000939:Epitopes; D015699:HIV Envelope Protein gp120; D009844:Oligosaccharides; D011994:Recombinant Proteins; C040286:Tn antigen