OBJECTIVETo investigate the genetic stability during the serial passages of non-replicating recombinant adenoviruses based on the novel AdEasy system.

METHODSFour non-replicating adenoviruses expressing rotavirus antigens, which were generated by the AdEasy system, were used as models and continuously propagated on 293 cells for 20 passages. Samples of the infected cells were collected at every 5 passages for the PCR analysis of the inserted rotavirus genes, replication-competent adenoviruses (RCAs) as well as the Western blot examination of the expression of the certain rotavirus genes.

RESULTSThe adenoviruses can be stably propagated on 293 cells. The existence and the stable expression of inserted rotavirus genes were able to be detected during the serial passage. The RCAs were not found within the first 10 passages, but the rvAdG2VP7(o) at passage 15 and the rvAdG2VP7(o) and rvAdG1VP7(o) at passage 20.

CONCLUSIONThe non-replicating adenoviruses showed promising genetic stability during the continuous passage on 293 cells. The RCAs normally will not be detectable within 10 continuous passages. The results indicated the potential of such recombinant adenoviruses in the research and development of the gene therapies and adenoviral-vectored vaccines.

Adenoviridae ; genetics ; isolation & purification ; physiology ; Cell Line ; DNA, Recombinant ; genetics ; Humans ; Serial Passage ; Transgenes ; Virus Replication

OBJECTIVETo observe the regulating effect of hepatitis C virus (HCV) envelop (E) 2 gene immunization-induced immune responses by adenovirus mediated interleukin 12 (IL-12).

METHODSHCV E2 protein was expressed and purified from NIH 3T3 and then used as an antigen to detect antibodies against HCV E2. With 51Cr release, SP2/0 expressing HCV E2 was used as target cell to detect specific cytotoxic T lymphocytes (CTL) response; adenovirus recombined IL-12 was propagated by 293 cell. HCV E2 recombinant and adenovirus recombined IL-12 were injected into the quadriceps femoris muscles and abdominal cavities of 6-8 weeks old BALB/C mice. Sera were collected at 2, 3, and 4 weeks and detected for antibodies for E2. Spleen cells isolated at 4 weeks were analyzed for specific CTL response.

RESULTSIt was found that expression of IL-12 at an undetectable level did enhance HCV E2 gene immunization-induced CTL activity and there was no effect on its hormonal immune response.

CONCLUSIONUsing adenovirus to express interleukin 12 was helpful for regulation of HCV E2 gene immunization-induced immune response. Combined HCV E2 and IL-12 can render a strong anti-HCV CTL activity and may be of use in the development of HCV gene vaccine in the future.

Adenoviridae ; physiology ; Interleukin-12 ; biosynthesis ; genetics ; T-Lymphocytes, Cytotoxic ; immunology ; Viral Envelope Proteins ; genetics ; immunology

Tumor angiogenesis plays a pivotal role in the progress of tumor. Among the various endogenous angiogenic inhibitors discovered, the human plasminogen kringle 5 (K5) has been demonstrated to be a potential inhibitor of the proliferation and migration of vascular endothelial cells in vitro. The replication-incompetent adenovirus (Ad) vector Adeno-X-CMV-K5 (Ad-K5) (where CMV is cytomegalovirus) was constructed and its antiangiogenic effect was tested on vascular endothelial cell and tumor cell. For the construction, the K5 cDNA was fused in-frame with human plasminogen signal sequence and inserted into the eukaryotic expression vector pcDNA3 to form pcDNA3K5. The recombinant plasmid was subcloned into the shuttle plasmid pShuttle under the control of the constitutive CMV immediate-early promoter. The plasmid carrying the cDNA for K5 (pShuttleKS) was then recombined with the Adeno-X viral DNA and transformed into E. coli DH5alpha. The resultant recombinant plasmid pAd-K5 was transfected into human embryonic kidney (HEK) 293 cells with liposome. The adenovirus expressing human plasminogen kringle 5 (Ad-K5) was successfully packaged and propagated in 293 cells, as detected by the cytopathic effect (CPE) on the cells, and the viral titer in the supernatant was 5 x 10(8) pfu/mL by plaque assay. Both human umbilical vein endothelial cell line ECV304 and human breast carcinoma cell line MDA-MB-231 were infected with Ad-K5 and Ad-LacZ, which was used the negative control, and assayed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Compared with uninfected control and Ad-LacZ infected control, Ad-K5 infected group at 80 MOI (multiplicity of infection) significantly inhibited ECV304 proliferation; the difference between uninfected control and Ad-LacZ infected control was not significant. In contrast, there was no significant difference in the proliferation of MDA-MB-231 among all the treatments. In addition, the Ad-K5 at 100 MOI inhibited the differentiation and tube formation of ECV304 on ECMatrix gel. These results suggested that the recombinant replication-defective Adenovirus expressing human plasminogen kringle 5 inhibited the proliferation, differentiation and tube formation of ECV304 and had no effect on the proliferation of MDA-MB-231. Adenovirus mediated human plasminogen kringle 5 gene therapy may be a potential treatment of cancer through angiogenesis inhibition.
Adenoviridae ; genetics ; Cell Line ; Cell Line, Tumor ; Cell Proliferation ; Genetic Vectors ; genetics ; Humans ; Neovascularization, Physiologic ; genetics ; physiology ; Peptide Fragments ; genetics ; physiology ; Plasminogen ; genetics ; physiology ; Polymerase Chain Reaction

Oncolytic adenoviruses (Ads), which are live, replication-competent viruses that can selectively replicate in tumor cells and lead to cell lysis, have been used in tumor therapy. But due to the complexity and high mutability of human tumors, it becomes a major strategy to improve the selectivity, efficacy, and safety of oncolytic Ads. The oncolytic Ads that can express short hairpin RNA, cytokines, suicide gene, and matrix-modulating proteins have higher antitumor activity than the wild type. Tumor-specific promoters, especially hTERT and HRE promoters, increase the selectivity of oncolytic Ads for tumor cells. Moreover, oncolytic Ads surface-modified by polyethylene glycol (PEG), liposomes, biodegradable nanoparticles, and polypeptides have reduced immunogenicity and hepatotoxicity and improved antitumor activity when systemically administered, and the selectivity of oncolytic Ads can be significantly increased when linking PEG to antibodies, small peptides, cytokines, and ligands. Therefore, engineered oncolytic Ads combining the advantages of viral and non-viral vectors, as well as immunotherapy, are a promising strategy for improving the efficacy of targeted virotherapy.
Adenoviridae ; genetics ; physiology ; Animals ; Humans ; Neoplasms ; therapy ; virology ; Oncolytic Virotherapy ; trends ; Virus Replication

Adenovirus remains a significant threat to public health. Recent studies showed that bats can harbor diverse adenoviruses. To further investigate the distribution and genetic diversity of bat adenoviruses in China, we collected throat and anal swab samples of 11 bat species from 6 provinces of China, including Beijing, Hunan, Jiangxi, Yunnan, Guizhou and Hainan. Nested PCR was used to identify potential bat adenoviruses from the samples, and positive results were cloned and sequenced for genetic diversity study. In addition, nucleotide sequence alignments based on corresponding amino acid sequence similarities were used for phylogenetic analyses. Our results showed that about 20% of bat species in China are positive to adenoviruses, and Myotis ricketti is likely to be the most important host of bat adenoviruses in all locations. Moreover, we identified two diverse sequences of bat adenoviruses from the same sample of Ia io in Guizhou province of China. In general, the average nucleotide and amino acid sequence similarities of the conserved region of DNA polymerases of bat adenoviruses are 66.6% and 74.7%, respectively. The differences between bat species and their residences environments may have driven the adaptive evolution of the viruses, leading to the genetic diversity of the bat adenoviruses.
Adenoviridae ; classification ; genetics ; isolation & purification ; physiology ; Animals ; China ; Chiroptera ; virology ; Genetic Variation ; Host Specificity ; Phylogeny

In this research was developed high efficiency method using 125I for directly labeling KH901, a tumor-specific oncolytic recombinant adenovirus, biodistribution of 125I-labeled compound in normal mice was investigated. 125I-KH901 was prepared by N-bromosuccinimide labeling method to find the optimal ratio of labeling response. The compounds were isolated and purified by Sephadex-G10 agarose and the radiochemical purity of compounds was analyzed by paper chromatography. The radioactivity biodistribution in mice was measured at different times after caudal vein injection with 0.1ml 125I-KH901. The labeling yield of 125I-KH901 was 78% and the radiochemical purity was 95% after purification by Sephadex-G10 agarose. Biodistribution revealed that the uptake of 125I-KH901 in liver was higher than in other organs at all time points of the experiment. 125I-KH901 was mainly concentrated in liver, kidneys, spleen and lung. It can be seen that N-bromosuccinimide labeling method is an optimal method with simple steps and high labeling yield in labeling KH901 with 125I. 125I-KH901 has a biodistribution trait which is an advantage to treating liver tumors.
Adenoviridae ; genetics ; physiology ; Animals ; DNA, Recombinant ; genetics ; Female ; Genetic Vectors ; genetics ; Iodine Radioisotopes ; pharmacokinetics ; Male ; Mice ; Mice, Inbred BALB C ; Oncolytic Viruses ; genetics ; physiology

BACKGROUNDTo study the effects of dendritic cells (DC) transfected with recombinant adenovirus encoding Epstein-Barr virus(EBV)latent membrane protein 2A(LMP2A)gene, and to provide evidence for further investigation on the therapeutic vaccine against EBV-associated malignancies.

METHODSDCs were transfected with EBV-LMP2A recombinant adenovirus (Ad5-LMP2A), which was generated by homologous recombination. The expression of LMP2A protein on mature DC transfected with Ad5-LMP2A at different multiplicity of infection(MOI)was analyzed by fluorescence activated cell sorting(FACS), and the dead cells were counted by trypan blue staining. The alteration of surface markers on mature DC including CD1a, CD83, CD40, CD80, HLA?DR was detected by means of FACS before and after transfection. Meanwhile, the functions including stimulating allogenetic T cells reaction and expressing IL12 P40 mRNA on transfected DC were measured by methods of 3H-thymidine uptake and fluorescent semi?quantitative polymerase chain reaction (PCR), respectively.

RESULTSAbout 80% mature DC expressed LMP2A protein and >92% cells were viable after transfection at the MOI of 200 No. significant changes in the surface markers and the cytomorphology of mature DCs were detected during the transfection. Transfected DC still have strong potential to stimulate the proliferation of allogenetic T cells and to express IL-12 P40 mRNA.

CONCLUSIONEBV-LMP2A gene,which was carried by adenovirus vectors, could be transferred into DC with high efficiency. The function of mature DC was not affected significantly by the transfection of Ad5-LMP2A.

Adenoviridae ; genetics ; Cells, Cultured ; Dendritic Cells ; physiology ; Gene Expression ; Genetic Vectors ; Humans ; Recombination, Genetic ; Transfection ; Viral Matrix Proteins ; genetics

OBJECTIVETo investigate the effect of melanoma differentiation associated gene-7/interleukin-24 (mda-7/IL-24) on the hepatocellular carcinoma cell lines and normal liver cell line in vitro.

METHODSHepatocellular carcinoma cell lines HepG2, SMMC7721, Hep3B, MHCC97L, M6 and normal liver cell line L02 were infected with Ad.mda-7. The gene expression of mda-7/IL-24 in these cell lines was confirmed by RT-PCR and ELISA assay. MTT assay and flow cytometry were used to study tumor cell proliferation and cell cycle in vitro. Hoechst staining and cytometry assay after Annexin-V and PI staining were studied to indicate the apoptosis effect.

RESULTSIt was confirmed by RT-PCR that the exogenous mda-7/IL-24 gene expressed in all of these cells. The mda-7/IL-24 protein product was confirmed by assaying the supernatant with ELISA. MTT and apoptosis test indicated mda-7/IL-24 can induce the hepatocellular carcinoma cell lines growth suppression, apoptosis in vitro but not in normal liver cell line L02, cell cycle test revealed mda-7/IL-24 can block cancer cell lines in G2/M but not in L02.

CONCLUSIONSmda-7/IL-24 selectively induces growth suppression, apoptosis in hepatocellular carcinoma lines but not in normal liver cell in vitro.

Adenoviridae ; genetics ; Apoptosis ; genetics ; physiology ; Carcinoma, Hepatocellular ; genetics ; pathology ; physiopathology ; Cell Cycle ; genetics ; physiology ; Cell Line ; Cell Line, Tumor ; Cell Proliferation ; Genetic Vectors ; Hepatocytes ; cytology ; Humans ; Interleukins ; genetics ; physiology ; Liver Neoplasms ; genetics ; pathology ; physiopathology ; Transfection

BACKGROUNDIslet transplantation represents an ideal therapeutic approach for treatment of type 1 diabetes but islet function and regeneration may be influenced by necrosis or apoptosis induced by oxidative stress and other insults. Heme oxygenase-1 (HO-1) is the rate-limiting enzyme in the catabolism of heme into biliverdin, releasing free iron and carbon monoxide. It has also been reported to be an antioxidant enzyme which can improve the function of grafted islets by cytoprotection via free radical scavenging and apoptosis prevention. In the present study, we investigated whether transduction of HO-1 genes into human islets with an adenovirus vector has cytoprotective action on islets cultured in vitro and discuss this method of gene therapy for clinical islet transplantation.

METHODSCadaveric pancreatic islets were isolated and purified in vitro. Transduction efficiency of islets was determined by infecting islets with adenovirus vector containing the enhanced green fluorescent protein gene (Ad-EGFP) at multiplicities of infection (MOI) of 2, 5, 10, or 20. Newly isolated islets were divided into three groups: EGFP group, islets transduced with Ad-EGFP using MOI = 20; HO-1 group, transduced with adenovirus vectors containing the human HO-1 gene using MOI = 20; and control group, mock transduced islets. Insulin release after glucose stimulation of the cell lines was determined by a radioimmunoassay kit and the stimulation index was calculated. Flow cytometry was used to detect apoptotic cells in the HO-1 group and in the control group after induction by recombinant human tumor necrosis factor-alpha (rTNFalpha) and cycloheximide (CHX) for 48 hours.

RESULTSAdenovirus vectors have a high efficiency of gene transduction into adult islet cells. Transduction of islets with the Ad-EGFP was most successful at MOI 20, at which MOI fluorescence was very intense on day 7 after transduction and EGFP was expressed in cultured islet cells for more than four weeks in vitro. The insulin release in the control group was (182.36 +/- 58.96) mIU/L after stimulation by high glucose media (16.7 mmol/L), while insulin release from the HO-1 group and the EGFP group were (270.09 +/- 89.37) mIU/L and (175.95 +/- 75.05) mIU/L respectively. Compared to the control group and the EGFP group, insulin release in the HO-1 group increased significantly (P < 0.05). After treatment with rTNFalpha and CHX the apoptotic ratio of islet cells was (63.09 +/- 10.86)% in the HO-1 group, significantly lower than (90.86 +/- 11.25)% in the control group (P < 0.05).

CONCLUSIONSTransduction of human islets with Ad-HO-1 can protect against TNF-alpha and CHX mediated cytotoxicity. The HO-1 gene also appears to facilitate insulin release from human islets. Transduction of donor islets with the adenovirus vector containing an HO-1 gene might have potential value in clinical islet transplantation.

Adenoviridae ; genetics ; Apoptosis ; drug effects ; Cycloheximide ; pharmacology ; Cytoprotection ; Genetic Therapy ; Heme Oxygenase-1 ; genetics ; physiology ; Humans ; Insulin ; secretion ; Islets of Langerhans ; physiology ; Transduction, Genetic ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVETo investigate the relationship between the expression of COX-2 and liver cancer and construct a recombinant adenovirus encoding human COX-2 antisense RNA, and then to investigate its effects on liver cancer cell proliferation.

METHODSThe expression of COX-2 in 34 cases of hepatocellular carcinoma and in SMMC-7402 and SMMC-7721 cell lines was studied by using immunohistochemical techniques. The shuttle plasmid encoding anti-sense COX-2 was constructed by using cloning COX-2 cDNA fragment in the reverse direction into the pHCMVSPIA. Then the plasmid pJM17 and the shuttle plasmid were co-transferred into 293 cells with lipofectamine for homologous recombination to acquire recombinant adenovirus (Ad-AShcox-2), which was confirmed by PCR. Human hepatocellular carcinoma cell lines SMMC-7402 and SMMC-7721 were transduced in vitro. The cell apoptosis and cell cycle were analyzed by flow cytometry. The cell proliferation was determined by colony-forming efficiency.

RESULTSWe observed COX-2 expression in 82.4% of the hepatocellular carcinomas and SMMC-7402 cell line, but no COX-2 expression in the SMMC-7721 cell line. In addition, the recombinant adenovirus encoding anti-sense COX-2 fragment Ad-AShcox-2 was obtained with a titer of 1.06 x 10(12) PFU/ml. Ad-AShcox-2 reduced the expression of COX-2 and enhanced the percentage of cells into G1/G0 phase in the SMMC-7402 cell line. The difference of apoptotic index between the Ad-AShcox-2 group and the control group was statistically significant in SMMC-7402 but not in SMMC-7721. Similarly, colony-forming rates of SMMC-7402 and SMMC-7721 cell lines after Ad-AShcox-2 being transferred were (2.7+/-0.94)% and (33.6+/-4.24)%, respectively.

CONCLUSIONBy reducing the expression of COX-2 in hepatocellular carcinoma cells with the expression of COX-2, the cells could be inhibited.

Adenoviridae ; genetics ; Apoptosis ; physiology ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Cyclooxygenase 2 ; biosynthesis ; genetics ; Humans ; Liver Neoplasms ; pathology ; Membrane Proteins ; biosynthesis ; genetics ; RNA, Antisense ; biosynthesis ; genetics