Anti-glioma effect of combination of bFGF-siRNA and Vpr in nude mice / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the anti-glioma effect of recombinant adenovirus mediated combined gene therapy of bFGF-siRNA and HIV1-Vpr in vivo.</p><p><b>METHODS</b>Mouse glioma model was established by injecting 5 × 10(6) LN229 cells into BALB/c-nu nude mice. 30 nude mice were randomly divided into 5 groups: the negative control group, mock group, bFGF-siRNA group, Vpr group and combined therapy group, which at regular intervals were injected with PBS, rAd5-null, rAd5-bFGF-siRNA, rAd5-Vpr, rAd5-bFGF-siRNA plus rAd5-Vpr, respectively. The tumor volume was recorded every third day to draw a growth curve. After four weeks treatment, the mice were killed and specimens were taken. HE, immunohistochemical and TUNEL staining were performed to observe the cell morphology, detect the changes of relevant target proteins and cell apoptosis, respectively. Also the ultrastructural changes were observed by electron microscopy.</p><p><b>RESULTS</b>The tumor growth inhibition rates were 36.9%, 37.2% and 58.6% in the bFGF-siRNA group, Vpr group and combined therapy group, respectively, and the combined therapy group showed the most significant effect (P < 0.05). Also the results of HE, immunohistochemical and TUNEL staining revealed that the combined therapy group had the best effects on proliferation inhibition and apoptosis induced in glioma cells (P < 0.05). The most significant ultrastructural changes were observed in the combined therapy group.</p><p><b>CONCLUSION</b>The combined gene therapy of bFGF-siRNA with Vpr shows a prominent and synergistic anti-glioma effect compared with that of mono-gene therapy in nude mice.</p>

Enhanced protein production of Vif and APOBEC3G by HIV-1 Vpr / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Goal of this study was to test the potential regulatory effects of Vpr on Vif and Vif-mediated degradation of APOBEC3G.</p><p><b>METHODS</b>The Vpr effect was first tested in a fission yeast RE007 strain that carries a single integrated copy of vpr gene in the chromosome and transformed with a vif-expressing plasmid. Similar tests were also carried out in a muristerone A vpr-inducing HEK293 mammalian cell line that were transfected with the plasmids expressing vif and/or APOBEC3G. Western Blot analyses were used to measure the corresponding protein levels under different experimental conditions.</p><p><b>RESULTS</b>Expression of HIV-1 vpr appears to enhance the protein levels of Vif both in fission yeast and mammalian cells. A similar enhancement effect of APOBEC3G by Vpr was also detected in mammalian cells. Interestingly, however, the increased Vif protein level by Vpr did not result in more APOBEC3G degradation than without Vpr, indicating a potential regulatory effect of Vpr on Vif-mediated proteolysis of APOBEC3G.</p><p><b>CONCLUSION</b>To our knowledge, this is the first report describing a potentially conserved and regulatory effect of HIV-1 Vpr on Vif and Vif-mediated protein degradation of APOBEC3G.</p>

Gene therapy targeting for carcinoma regulated by E2F-1 promoter / 中华外科杂志

<p><b>OBJECTIVE</b>To study the selective effect to tumor cells mediated by a recombinant adenoviral vector carrying E2F-1 promoter.</p><p><b>METHODS</b>The AdEasy-1 adenoviral vector system was used in this experiment. Several recombinant adenovirus with tumor-targeting E2F-1 promoter were constructed and then the E2F-1 promoter gene was checked by PCR and sequencing. The two adenovirus expressing GFP gene which is regulated by E2F-1 promoter or CMV promoter were used to respectively transfect tumor cells and non-proliferating normal cells, then observed and analyzed the different results caused by different promoters. Vpr gene was cloned into the targeting recombinant adenovirus. The new adenovirus named rvAdE2F-1/vpr was used to transfect tumor cells SMMC-7721, LS174T and non-proliferating normal cells H292, L-02. The surviving rate of each group was registered; the level of E2F-1 protein expressed in normal and tumor cell lines were checked by Western Blot.</p><p><b>RESULT</b>E2F-1 promoter can regulate the downstream gene GFP selectively expressed in LS174T and its activity in LS174T was similar with CMV promoter's; Vpr gene regulated by E2F-1 promoter can suppress the proliferation of tumor cells and no toxicity to normal cells; In all of the tumor cells, a much higher level of E2F-1 was expressed compared with normal cell lines. E2F-1 promoter's activity correlated well with E2F-1 protein levels.</p><p><b>CONCLUSIONS</b>E2F-1 promoter can control a selective cell killing to cancer cells, with no effect to normal cells. The system of E2F-1 promoter is a useful method for tumor-targeting gene therapy.</p>

HIV-1 viral protein R (Vpr) & host cellular responses.

During infection of host cells by HIV-1, active host-pathogen interactions take place. The final balance between these interactions determines the efficiency of viral infection and subsequent disease progression. HIV-infected cells respond to viral invasion with various antiviral strategies such as innate, cellular and humoral immune antiviral defense mechanisms. On the other hand, the virus has also developed tactics to suppress these host cellular responses. Among the many viral offensive strategies, viral protein R (Vpr) plays a particularly active role. Vpr involved in nuclear transport of the viral pre-integration complex, activation of viral transcription, induction of cell cycle G2/M arrest and apoptosis of the host cells. However, specific roles of these Vpr activities in viral pathogenesis and their contribution to disease progression are not fully understood. HIV-1 defective for some or all of these Vpr activities have been associated with slow disease progression in some patients. With regard to the host responses to vpr gene expression, studies show that Vpr is specifically targeted by CD8 T-lymphocytes during acute viral infection and that the host innate immune response may also play a crucial role in suppressing the effects of Vpr on various cellular activities. The effect of host cellular responses to vpr gene expression and its roles in nuclear transport, cell cycle G2/M regulation and induction of apoptosis are discussed in this review. Strategies with potential application for future antiviral therapies directed at suppressing Vpr activities are described.

Evaluation of protective immunity induced by a recombinant baculovirus expressing two structural proteins of bovine viral diarrhea virus in calves

Two groups of calves were vaccinated with a double recombinant baculovirus expression product of a previously developed construct [rec-NE0], expressing the nucleoprotein [N] and the envelope glycoprotein [E0] of the NADL strain of bovine viral diarrhea virus [BVDV]. The baculovirus expression product, in rec-NE0 vaccine, were immunogenic in calves as viral neutralizing antibody [VN-Ab] titers of 2 to 8 were detectable following booster vaccination. Vaccinated and non-vaccinated calves were challenge exposed with either the homologous BVDVI-NADL or the local heterologous BVDV2-Iman strains. Vaccine-induced immunity conferred partial protection against homologous viral challenge exposure, focused in reducing severity and duration of clinical signs of disease, compared to non-vaccinated calves. However, neither systemic spread nor shedding of the challenge virus could be prevented by vaccination. The rec-NE0 vaccine could not cross-protect calves against heterologous virus challenge exposure. Findings of this study suggest that N and E0 regions of the BVDV genome comprise important antigenic epitopes. Furthermore, they share a role in protective immunity against BVDV infection. Immunogenicity of N and E0 along with the existing antigenic diversity among viruses should be considered in future development of recombinant vaccines for pestivirus control