title: Inhibition of HIV-1 transcription and virus replication using soluble Tat peptide analogs.
abstract: The human immunodeficiency virus type 1 (HIV-1) transactivator Tat protein is essential for efficient viral gene expression and virus replication. The Tat core domain, a stretch of 12 amino acids between the cysteine-rich and the basic domain, is conserved in all HIV isolates and required for interaction with a number of cellular transcriptional regulatory proteins. Here we demonstrate that soluble peptide analogs of the Tat core domain (amino acid 36-50) are able to effectively block LTR transactivation. In transfection experiments, Tat core peptide analogs containing amino acid substitutions at position 41 and 44 inhibited Tat transactivation of an HIV-1 LTR-CAT reporter construct up to 80-fold. In contrast, inhibition of other promoters such as HTLV-I and CMV was approximately 2-fold. Tat peptide analog 36-50 (41/44) inhibited HIV virus replication by 85% in latently infected U1 cells induced with Tat. Furthermore, U1 cells treated with the Tat peptide 36-50 (41/44) analog showed markedly delayed virus transmission when cocultivated with parental U937 cells. Interestingly, while both short and long peptide analogs (amino acids 36-50 vs 36-72) inhibited Tat transactivation in transient assays, the short peptides were more effective inhibitors of virus replication in U1 cells. The Tat peptide analog did not decrease expression of cellular genes including beta-actin, GAPDH, and histone H2B.
authors.affiliation: Laboratory of Molecular Virology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: F
authors.initials: F
authors.lastname: Kashanchi
authors.forename: M R
authors.initials: MR
authors.lastname: Sadaie
authors.forename: J N
authors.initials: JN
authors.lastname: Brady
mesh_terms: D000595:Amino Acid Sequence; D015496:CD4-Positive T-Lymphocytes; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D018920:Coculture Techniques; D004268:DNA-Binding Proteins; D018274:Electroporation; D005656:Fungal Proteins / Q000096:biosynthesis; D015696:Gene Products, tat / Q000737:chemistry* / Q000502:physiology*; D017930:Genes, Reporter; D015497:HIV-1 / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D011533:Proviruses / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis; D012367:RNA, Viral / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000187:drug effects*; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D014779:Virus Replication / Q000187:drug effects*; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D015696:Gene Products, tat; D009842:Oligopeptides; D010446:Peptide Fragments; D012333:RNA, Messenger; D012367:RNA, Viral; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D054322:tat Gene Products, Human Immunodeficiency Virus; D015500:Chloramphenicol O-Acetyltransferase