title: Transcriptional suppression of in vitro-integrated human immunodeficiency virus type 1 does not correlate with proviral DNA methylation.
abstract: Persistence of human immunodeficiency virus type 1 (HIV-1) constitutes a major obstacle in the control of HIV-1 infection. Here we investigated whether the CpG methylation of the HIV-1 promoter can directly influence the expression of the HIV-1 genome and thereby contribute to the persistence and latency of HIV-1. The levels of CpG methylation in the promoter of HIV-1 were studied after bisulfite-induced modification of DNA in five Jurkat clonal cell lines transduced by an HIV-1 long terminal repeat (LTR)-driven retroviral vector and expressing enhanced green fluorescent protein (GFP) and in primary resting memory T cells challenged with HIV-1 or with an HIV-1-derived retroviral vector. Basal HIV-1 promoter activities were low or undetectable in three tested HIV-1 LTR-GFP clones, one of which encoded the Tat protein, and they reached medium or high levels in two other clones. The CpG dinucleotide that occurred in a latently infected clonal cell line 240 nucleotides upstream of the transcription start remained methylated after reactivation of HIV-1 transcription with 10 nM phorbol-12-myristate-13-acetate. In two clones showing a medium promoter activity and in resting memory T cells, the HIV-1 LTR was generally not methylated. Our results show that the methylation profiles of the HIV-1 LTR, including those present in latently infected cells, are low and do not correlate with the transcriptional activity. We suggest that, in a noncloned cellular population in which the HIV-1 proviruses are randomly integrated in the human genome, HIV-1 latency is imperfectly controlled by CpG methylation and is inherently accompanied by residual replication.
authors.affiliation: INSERM U372, Unité de Pathogénie des Infections à Lentivirus, Parc Scientifique et Technologique de Luminy, 13276 Marseille, France.
authors.forename: Marjorie
authors.initials: M
authors.lastname: Pion
authors.forename: Albert
authors.initials: A
authors.lastname: Jordan
authors.forename: Angelique
authors.initials: A
authors.lastname: Biancotto
authors.forename: Franck
authors.initials: F
authors.lastname: Dequiedt
authors.forename: Françoise
authors.initials: F
authors.lastname: Gondois-Rey
authors.forename: Sophie
authors.initials: S
authors.lastname: Rondeau
authors.forename: Robert
authors.initials: R
authors.lastname: Vigne
authors.forename: Jiri
authors.initials: J
authors.lastname: Hejnar
authors.forename: Eric
authors.initials: E
authors.lastname: Verdin
authors.forename: Ivan
authors.initials: I
authors.lastname: Hirsch
mesh_terms: D001483:Base Sequence; D018899:CpG Islands; D019175:DNA Methylation; D004279:DNA, Viral / Q000235:genetics* / Q000378:metabolism*; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D007156:Immunologic Memory; D066298:In Vitro Techniques; D019169:Jurkat Cells; D008164:Luminescent Proteins / Q000235:genetics; D011401:Promoter Regions, Genetic; D011533:Proviruses / Q000235:genetics / Q000378:metabolism; D013489:Suppression, Genetic; D013601:T-Lymphocytes / Q000276:immunology; D014161:Transduction, Genetic; D014775:Virus Activation / Q000235:genetics; D016662:Virus Integration / Q000235:genetics
chemical_list: D004279:DNA, Viral; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins