Phosphorothioate oligonucleotides inhibit human immunodeficiency virus type 1 fusion by blocking gp41 core formation.
Several studies have shown that phosphorothioate oligodeoxynucleotides (PS-ONs) have a sequence-independent antiviral activity against human immunodeficiency virus type 1 (HIV-1). It has also been suggested that PS-ONs inhibit HIV-1 by acting as attachment inhibitors that bind to the V3 loop of gp120 and prevent the gp120-CD4 interaction. Here we show that PS-ONs (and their fully 2'-O-methylated derivatives) are potent inhibitors of HIV-1-mediated membrane fusion and HIV-1 replication in a size-dependent, phosphorothioation-dependent manner. PS-ONs interact with a peptide derived from the N-terminal heptad repeat region of gp41, and the HIV-1 fusion-inhibitory activity of PS-ONs is closely correlated with their ability to block gp41 six-helix bundle formation, a critical step during the process of HIV-1 fusion with the target cell. These results suggest that the increased hydrophobicity of PS-ONs may contribute to their inhibitory activity against HIV-1 fusion and entry, because longer PS-ONs (>or=30 bases) which have a greater hydrophobicity are more potent in blocking the hydrophobic interactions involved in the gp41 six-helix bundle formation and inhibiting the HIV-1-mediated cell-cell fusion than shorter PS-ONs (<30 bases). This novel antiviral mechanism of action of long PS-ONs has implications for therapy against infection by HIV-1 and other enveloped viruses with type I fusion proteins.
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Andrew
A
Vaillant
Jean-Marc
JM
Juteau
Hong
H
Lu
Shuwen
S
Liu
Carol
C
Lackman-Smith
Roger
R
Ptak
Shibo
S
Jiang
D002460:Cell Line; D015700:HIV Envelope Protein gp41 / Q000737:chemistry*; D023581:HIV Fusion Inhibitors / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D008561:Membrane Fusion / Q000187:drug effects; D009841:Oligonucleotides / Q000494:pharmacology*; D013873:Thionucleotides / Q000494:pharmacology*
D015700:HIV Envelope Protein gp41; D023581:HIV Fusion Inhibitors; D009841:Oligonucleotides; D013873:Thionucleotides