title: Viral entry as the primary target for the anti-HIV activity of chicoric acid and its tetra-acetyl esters.
abstract: The antiviral activity of L-chicoric acid against HIV-1 has been attributed previously to the inhibition of HIV-1 integration. This conclusion was based on the inhibition of integrase activity in enzymatic assays and the isolation of a resistant HIV strain with a mutation (G140S) in the integrase gene. Here we show that the primary antiviral target of L-CA and its analogs in cell culture is viral entry. L- and D-chicoric acid (L-CA and D-CA) and their respective tetra-acetyl esters inhibit the replication of HIV-1 (III(B) and NL4.3) and HIV-2 (ROD) in MT-4 cells at a 50% effective concentration (EC(50)) ranging from 1.7 to 70.6 microM. In a time-of-addition experiment, L-CA, D-CA, L-CATA, and D-CATA were found to interfere with an early event in the viral replication cycle. Moreover, L-CA, D-CA, and their analogs did not inhibit the replication of virus strains that were resistant toward polyanionic and polycationic compounds at subtoxic concentrations. Furthermore, HIV-1 strains resistant to L-CA and D-CA were selected in the presence of L-CA and D-CA, respectively. Mutations were found in the V2, V3, and V4 loop region of the envelope glycoprotein gp120 of the L-CA and D-CA-resistant NL4.3 strains that were not present in the wild-type NL4.3 strain. Recombination of the gp120 gene of the L-CA and D-CA resistant strain in a NL4.3 wild-type molecular clone fully rescued the phenotypic resistance toward L-CA and D-CA. No significant mutations were detected in the integrase gene of the drug-resistant virus strains. Although inhibition of HIV integrase activity by L-CA and its derivatives was confirmed in an oligonucleotide-driven assay, integrase carrying the G140S mutation was inhibited to the same extent as the wild-type integrase.
authors.affiliation: Rega Institute for Medical Research, K. U. Leuven, Leuven, Belgium.
authors.forename: W
authors.initials: W
authors.lastname: Pluymers
authors.forename: N
authors.initials: N
authors.lastname: Neamati
authors.forename: C
authors.initials: C
authors.lastname: Pannecouque
authors.forename: V
authors.initials: V
authors.lastname: Fikkert
authors.forename: C
authors.initials: C
authors.lastname: Marchand
authors.forename: T R
authors.initials: TR
authors.lastname: Burke
authors.forename: Y
authors.initials: Y
authors.lastname: Pommier
authors.forename: D
authors.initials: D
authors.lastname: Schols
authors.forename: E
authors.initials: E
authors.lastname: De Clercq
authors.forename: Z
authors.initials: Z
authors.lastname: Debyser
authors.forename: M
authors.initials: M
authors.lastname: Witvrouw
mesh_terms: D019380:Anti-HIV Agents / Q000737:chemistry / Q000494:pharmacology*; D002109:Caffeic Acids; D002478:Cells, Cultured; D004926:Escherichia coli / Q000378:metabolism; D015699:HIV Envelope Protein gp120 / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D019427:HIV Integrase / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D006801:Humans; D019429:Integrase Inhibitors / Q000737:chemistry / Q000494:pharmacology; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000502:physiology / Q000821:virology; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins / Q000187:drug effects / Q000378:metabolism; D013386:Succinates / Q000737:chemistry / Q000494:pharmacology*; D013997:Time Factors; D014779:Virus Replication / Q000187:drug effects
chemical_list: D019380:Anti-HIV Agents; D002109:Caffeic Acids; D015699:HIV Envelope Protein gp120; D019429:Integrase Inhibitors; D011994:Recombinant Proteins; D013386:Succinates; D019427:HIV Integrase; C100435:chicoric acid