title: Native oligodeoxynucleotides specifically active against human immunodeficiency virus type 1 in vitro: a G-quartet-driven effect?
abstract: Among a series of unmodified phosphodiester (PO)-oligodeoxynucleotides (PO-ODNs) complementary to some of the human immunodeficiency virus type 1 (HIV-1) regulatory genes, several PO-ODN sequences complementary to the vpr gene (PO-ODNs-a-vpr, where a-vpr is the antisense vpr sequence) emerged as potent inhibitors (at concentrations of 0.8 to 3.3 microM) of HIV-1 multiplication in de novo infected MT-4 cells, while they showed no cytotoxicity for uninfected cells at concentrations up to 100 microM. Unlike phosphorothioate counterparts, PO-ODN-a-vpr sequences were not inhibitory to HIV-2 multiplication in de novo infected C8166 cells and neither prevented the fusion between chronically infected and bystander CD4+ cells nor inhibited the activity of the HIV-1 reverse transcriptase in enzyme assays. Moreover, they were not inhibitory to HIV-1 multiplication in chronically infected cells. Delayed addition experiments showed that PO-ODNs-a-vpr inhibit an event in the HIV-1 replication cycle following adsorption to the host cell, but preceding reverse transcription. Structure-activity relationship studies indicated that the antiviral activity of the test PO-ODN-a-vpr sequences is not related to an antisense mechanism but to the presence, within the active sequences, of contiguous guanine residues. Physical characterization of the test PO-ODNs suggested that the active structure is a tetramer stabilized by G quartets (i.e., four G residues connected by eight hydrogen bonds).
authors.affiliation: Istituto ICOCEA Consiglia Nazionale delle Ricerche, Bologna, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Tondelli
authors.forename: F P
authors.initials: FP
authors.lastname: Colonna
authors.forename: A
authors.initials: A
authors.lastname: Garbesi
authors.forename: S
authors.initials: S
authors.lastname: Zanella
authors.forename: M E
authors.initials: ME
authors.lastname: Marongiu
authors.forename: S
authors.initials: S
authors.lastname: Corrias
authors.forename: A G
authors.initials: AG
authors.lastname: Loi
authors.forename: P
authors.initials: P
authors.lastname: La Colla
mesh_terms: D019380:Anti-HIV Agents / Q000032:analysis / Q000494:pharmacology*; D002459:Cell Fusion; D002478:Cells, Cultured; D002942:Circular Dichroism; D005814:Genes, Viral; D015658:HIV Infections / Q000821:virology; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors; D015497:HIV-1 / Q000187:drug effects*; D015498:HIV-2 / Q000187:drug effects; D006801:Humans; D009841:Oligonucleotides / Q000032:analysis / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D014779:Virus Replication / Q000187:drug effects
chemical_list: D019380:Anti-HIV Agents; D009841:Oligonucleotides; D054303:HIV Reverse Transcriptase