Sensitivity of HIV-1 to neutralization by antibodies against O-linked carbohydrate epitopes despite deletion of O-glycosylation signals in the V3 loop
| Autor: | Henrik Clausen, Gregers J. Gram, John-Erik Stig Hansen, Jens Ole Nielsen, Sigvard Olofsson, Britt Jansson |
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| Rok vydání: | 1996 |
| Předmět: |
Threonine
Glycosylation Molecular Sequence Data Mutant Enzyme-Linked Immunosorbent Assay HIV Antibodies HIV Envelope Protein gp120 V3 loop Sensitivity and Specificity Protein Structure Secondary Epitope Neutralization Serine Epitopes chemistry.chemical_compound Neutralization Tests Virology Humans Point Mutation Amino Acid Sequence Cloning Molecular Sequence Deletion biology General Medicine Recombinant Proteins chemistry Biochemistry Polyclonal antibodies HIV-1 Mutagenesis Site-Directed biology.protein |
| Zdroj: | Archives of Virology. 141:291-300 |
| ISSN: | 1432-8798 0304-8608 |
| DOI: | 10.1007/bf01718400 |
| Popis: | It has been suggested that threonine or serine residues in the V3 loop of HIV-1 gp120 are glycosylated with the short-chain O-linked oligosaccharides Tn or sialosyl-Tn that function as epitopes for broadly neutralizing carbohydrate specific antibodies. In this study we examined whether mutation of such threonine or serine residues could decrease the sensitivity to infectivity inhibition by Tn or sialosyl-Tn specific antibodies. All potentially O-glycosylated threonine and serine residues in the V3 loop of cloned HIV-1 BRU were mutagenized to alanine thus abrogating any O-glycosylation at these sites. Additionally, one of these T-A mutants (T308A) also abrogated the signal for N-glycosylation at N306 inside the V3-loop. The mutant clones were compared with the wild type virus as to sensitivity to neutralization with monoclonal and polyclonal antibodies specific for the tip of the V3 loop of BRU or for the O-linked oligosaccharides Tn or sialosyl-Tn. Deletion of the N-linked oligosaccharide at N306 increased the neutralization sensitivity to antibodies specific for the tip of the loop, which indicates that N-linked glycosylation modulates the accessibility to this immunodominant epitope. However, none of the mutants with deletions of O-glycosylation signals in the V3 loop displayed any decrease in sensitivity to anti-Tn or anti-sialosyl-Tn antibody. This indicates that these broadly specific neutralization epitopes are located outside the V3 loop of gp 120. |
| Databáze: | OpenAIRE |
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