title: The immunosuppressant rapamycin represses human immunodeficiency virus type 1 replication.
abstract: The immunosuppressive macrolide rapamycin is used in humans to prevent graft rejection. This drug acts by selectively repressing the translation of proteins that are encoded by an mRNA bearing a 5'-polypyrimidine tract (e.g., ribosomal proteins, elongation factors). The human immunodeficiency virus type 1 (HIV-1) carries a polypyrimidine motif that is located within the tat exon 2. Treatment of human T lymphoid cells with rapamycin resulted in a marked diminution of HIV-1 transcription when infection was performed with luciferase reporter T-tropic and macrophage-tropic viruses. Replication of fully infectious HIV-1 particles was abolished by rapamycin treatment. The rapamycin-mediated inhibitory effect on HIV-1 production was reversed by FK506. The anti-HIV-1 effect of rapamycin was also seen in primary human cells (i.e., peripheral blood lymphocytes) from different healthy donors. Rapamycin was shown to diminish basal HIV-1 long terminal repeat gene expression, and the observed effect of rapamycin on HIV-1 replication seems to be independent of the virus-specific transactivating Tat protein. A constitutive beta-actin promoter-based reporter gene vector was unaffected by rapamycin treatment. Kinetic virus infection studies and exposure to reporter viruses pseudotyped with heterologous envelope proteins (i.e., amphotropic murine leukemia virus and vesicular stomatitis virus G) suggested that rapamycin is primarily affecting the life cycle of HIV-1 at a transcriptional level. Northern blot analysis confirmed that this compound is selectively targeting HIV-1 mRNA synthesis.
authors.affiliation: Centre de Recherche en Infectiologie, Hôpital CHUL, Centre Hospitalier Universitaire de Québec, and Département de Biologie Médicale, Faculté de Médecine, Université Laval, Ste-Foy, Québec, Canada G1V 4G2.
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Roy
authors.forename: Jean-Sébastien
authors.initials: JS
authors.lastname: Paquette
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Fortin
authors.forename: Michel J
authors.initials: MJ
authors.lastname: Tremblay
mesh_terms: D000199:Actins / Q000235:genetics; D015152:Blotting, Northern; D015696:Gene Products, tat / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D016325:HIV Long Terminal Repeat / Q000187:drug effects; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007202:Indicators and Reagents; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000473:pathology; D010957:Plasmids / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020123:Sirolimus / Q000494:pharmacology*; D016559:Tacrolimus / Q000494:pharmacology; D014162:Transfection; D014407:Tumor Cells, Cultured; D014779:Virus Replication / Q000187:drug effects*; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D000199:Actins; D015696:Gene Products, tat; D007166:Immunosuppressive Agents; D007202:Indicators and Reagents; D012333:RNA, Messenger; D054322:tat Gene Products, Human Immunodeficiency Virus; D020123:Sirolimus; D016559:Tacrolimus