RESUMO
Transcription of the HIV-1 provirus genome is regulated by a complex interplay between viral regulatory proteins and cellular transcription factors that interact with the viral long terminal repeat (LTR) region of HIV-1. However, several cellular transcription factors have been identified that can interact with the HIV-1 LTR; the significance of all of these factors is not clearly understood. In this study we have characterized the LTR region of different subtypes of HIV-1 with regard to nucleotide sequence and promoter activity. The LTR regions of HIV-1 from peripheral blood mononuclear cells of 29 infected individuals originating from 10 different geographical regions were sequenced and further analyzed for promoter/enhancer activity in transient transfection of HeLa cells, in the context of a reporter gene and in the context of the complete virus genome. We found several subtype-specific LTR sequences of the various HIV-1 strains, such as an insertion that created a potential third NF-kappaB site in the LTR of the subtype C strains. The USF-binding site in the NRE also contained subtype-specific sequences. Interestingly, the promoter/enhancer activities of the subtype C LTRs were higher than the activities of the other subtypes analyzed here (subtypes A, B, D, E, and G), suggesting that the potential third NF-kappaB site may confer higher LTR activity or that the subtype C NRE may be less potent. Thus, our data suggest that genetic diversity of the LTR may result in HIV-1 subtypes with different replicative properties.
Assuntos
Ampliador HIV/genética , Infecções por HIV/genética , Repetição Terminal Longa de HIV/genética , HIV-1/genética , Regiões Promotoras Genéticas/genética , Adulto , África/etnologia , Sequência de Bases , Sítios de Ligação , Cloranfenicol O-Acetiltransferase , Ensaio de Imunoadsorção Enzimática , Feminino , Proteína do Núcleo p24 do HIV/metabolismo , Infecções por HIV/etnologia , Células HeLa , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , NF-kappa B/metabolismo , Reação em Cadeia da Polimerase , Alinhamento de Sequência , Suécia/etnologia , TransfecçãoRESUMO
OBJECTIVE: To determine whether short peptides corresponding to the RGPGR motif of the V3 loop of gp 120 have anti-human immunodeficiency virus type 1 (anti-HIV-1) activity. DESIGN/METHODS: Short peptides were tested against the HIV-1 laboratory strains and clinical isolates. RESULTS: The tripeptide glycyl-prolyl-glycine amide (GPG-NH2) inhibited the replication of both laboratory strains and 47 clinical isolates, including 19 strains that were resistant to other drugs or that were from patients with failing therapy. The 50% inhibitory concentrations values were 2.7 to 37 microM. Phenotypic change of two isolates from nonsyncytia-inducing to syncytia-inducing did not change their sensitivity to GPG-NH2. The tripeptide added to the antiviral effect of both zidovudine and ritonavir. CONCLUSIONS: The tripeptide GPG-NH2 is a nontoxic compound that inhibits the replication of HIV-1 by an apparently new mode of action. Glycyl-prolyl-glycine-NH2 might prove useful by itself or as a lead compound for the treatment of drug-resistant HIV-1. Glycyl-prolyl-glycine-NH2 is currently undergoing phase I/II human clinical trials in Sweden.
Assuntos
Amidas/farmacologia , Fármacos Anti-HIV/farmacologia , Proteína gp120 do Envelope de HIV/química , HIV-1/efeitos dos fármacos , Oligopeptídeos/farmacologia , Fragmentos de Peptídeos/química , Replicação Viral/efeitos dos fármacos , Fármacos Anti-HIV/química , Resistência Microbiana a Medicamentos , Sinergismo Farmacológico , Proteína gp120 do Envelope de HIV/farmacologia , Inibidores da Protease de HIV/farmacologia , HIV-1/isolamento & purificação , HIV-1/fisiologia , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Estrutura Molecular , Oligopeptídeos/química , Fragmentos de Peptídeos/farmacologia , Inibidores da Transcriptase Reversa/farmacologia , Ritonavir/farmacologia , Zidovudina/farmacologiaRESUMO
OBJECTIVE: To determine whether the peptide glycyl-prolyl-glycine amide (GPG-NH2) corresponding to a conserved motif in the tip of the third hypervariable region of gp120 affected the early events in the human immunodeficiency virus type 1 (HIV-1) replication. DESIGN/METHODS: Glycyl-prolyl-glycine amide was tested for its effect on HIV-1 adsorption, co-receptor usage, proviral DNA synthesis, messenger RNA (mRNA) synthesis and splicing, translation, tat/TAR transactivation, and virus protease activity. RESULTS: Glycyl-prolyl-glycine amide did not appear to affect the early events of the virus replication. HIV-1 having glycine-leucine-glycine instead of GPG in the V3 loop and the mutants deleted of the GPG motif were still inhibited by the peptide. Glycyl-prolyl-glycine-NH2 had no discernible effect on any of the other steps in the virus replication cycle tested. The only effect observed was an increased sodium dodecyl sulfate polyacrylamide amide gel electrophoresis mobility of gp160/120 at high concentrations of GPG-NH2. CONCLUSIONS: The tripeptide GPG-NH2 is a nontoxic compound that inhibits the replication of HIV-1 by an apparently new mode of action.