RESUMEN
Vpr, an auxiliary protein of HIV-1(Human immunodeficiency virus type 1), exerts important functions to promote viral replication and AIDS progression. In this study, we performed a yeast two-hybrid screening assay using human cDNA library to further investigate the molecular mechanism of various functions of Vpr RelB, a key protein in NF-kappaB signaling pathway, was identified as a Vpr interaction protein by co-immunoprecipitation. Further investigations indicated that RelB not only promoted the Vpr-mediated activation of NF-kappaB reporter gene, but also enhanced the transactivation of HIV LTR. Moreover, the results showed that RelB promoted Vpr-induced cell cycle G2/M arrest. Collectively, these results indicated that RelB might interact with Vpr and regulate its transcriptional activation and cell cycle arrest.
Asunto(s)
Humanos , Puntos de Control del Ciclo Celular , División Celular , Fase G2 , Duplicado del Terminal Largo de VIH , Células HeLa , FN-kappa B , Genética , Factor de Transcripción ReIB , Fisiología , Activación Transcripcional , Productos del Gen vpr del Virus de la Inmunodeficiencia Humana , FisiologíaRESUMEN
Gene therapy offers the promise of curing the HIV-infected patients. Specific, potent, and sustained short hairpin RNA (shRNA)-mediated gene silencing is crucial for the successful application of RNA interference technology to therapeutic interventions. To reduce the probability of viral escape mutants, in this study, we constructed lentiviral vector containing vpr and tat shRNA, respectively, furthermore the bispecific lentiviral vector harboring vpr and tat shRNA expression cassettes from U6 promotor and H1 promotor was cotransfected with recombinant plasmid expressing the vpr and tat gene. The result showed that the bispecific lentiviral vector plvx-vpr-tatshRNA could inhibit the vpr and tat effectively,with ratios of 89.20% and 62.00% respectively. When cotransfected with pNL4-3 in 293T cell, plvx-vpr-tatshRNA showed higher efficacy in down regulating the HIV NL4-3 packaging production than the plvx-vprshRNA or plvx-tatshRNA individually. MT4 cell clones transduced with recombinant lentiviral vectors were screened and challenged with HIV NL4-3. P24 ELISA test showed that MT4 transduced with the combinational lentiviral vector could inhibit virus replication efficiently.
Asunto(s)
Humanos , Línea Celular , Regulación hacia Abajo , Terapia Genética , Vectores Genéticos , Genética , Metabolismo , Infecciones por VIH , Terapéutica , Virología , VIH-1 , Genética , Metabolismo , Lentivirus , Genética , Metabolismo , Interferencia de ARN , ARN Interferente Pequeño , Genética , Metabolismo , Usos Terapéuticos , Productos del Gen tat del Virus de la Inmunodeficiencia Humana , Genética , Metabolismo , Productos del Gen vpr del Virus de la Inmunodeficiencia Humana , Genética , MetabolismoRESUMEN
To develop polyclonal antibodies against predicted B cell epitopes in HIV-1 accessory protein Vpr, the prepared consensus Vpr amino acid sequence was used to predict potential B cell epitopes by online softwares (ABCpred and Bcepred), the synthesized polypeptides of B-cell epitopes were subsequently conjugated with keyhole limpet hemocyanin (KLH) and then used to immunize rabbits. The antibody titers were determined by ELISA, and antibody specifity was analyzed by Western-Blotting and immunoprecipitation, respectively. Amino acid residues 3-19 (N) and 82-95 (C) of Vpr were predicted as the potential B cell epitopes. After inoculation of the conjugation of synthesized peptide to KLH, the antibody titers in rabbit sera against N and C peptides reached more than 1:100000 by ELISA. Western-Blotting analysis showed that the polyclonal antibodies reacted with both wild Vpr and fusion protein of GFP with Vpr, no matter Vpr was derived from HIV-1 B subtype or CRF07_BC recombinant form; Immunoprecipitation analysis showed similar reactions to Western-Blotting results. Two B cell epitopes of Vpr were successfully predicted by Bio-informatics methods and polyclonal antibodies against those peptides could be successfully prepared.