Angiogenesis effects of adenovirus-mediated gene transfer of VEGF-B on chronic ischemic myocardium

Objective: To study the angiogenesis effects of adenovirus-mediated gene transfer of VEGF-B on chronic ischemic myocardium. Methods: Domestic pigs underwent thoracotomy and placement of an ameroid constrictor on the circumflex coronary artery. Four weeks later, Ad. VEGF-B, Ad. LacZ or PBS were administrated directly into the myocardium at 10 sites in the circumflex distribution (109 PFU or 100 μl) according to groups. Echocardiography and ex vivo coronary angiography were performed. The injection sites around myocardium were harvested and subjected to histological analysis and immunochemical staining. Results: E-chocardiography assessment 4 weeks after vector administration demonstrated significant improvement of regional wall systolic function. Collateral vessel development assessed by angiography was also significantly greater in Ad. VEGF-B animals than that in control animals. Vascular density analysis revealed a mean of 43±5 neovessels per high-power field in Ad. VEGF-B group versus 19±4 and 17±6

Recombinant adenovirus vector Ad-hIL-10 protects grafts from cold ischemia-reperfusion injury following orthotopic liver transplantation in rats

BACKGROUND: Interleukin 10 (IL-10), a Th2 type cytokine, modulates inflammatory responses by inhibiting the production of proinflammatory cytokines. This study was designed to investigate the protective effects of adenovirus-mediated human IL-10 (Ad-hIL-10) gene transfer on protecting grafts from cold ischemia-reperfusion injury following orthotopic liver transplantation in rats. METHODS: Adenoviruses encoding hIL-10 or beta-galactosidase (Ad-lacZ) were injected via the superior mesenteric vein into prospective donor animals. The donor liver was harvested 48 hours after transduction, and stored for 12 hours at 4 degrees C in lactated Ringer's solution prior to transplantation. The rats were divided into saline, Ad-lacZ, and Ad-hIL-10 groups. Liver function test, histopathological examination, reverse transcriptase-polymerase chain reaction (RT-PCR), and Western blotting were performed at 24 hours after transplantation in the three groups. RESULTS: Liver function (ALT and AST) was significantly improved, and the Suzuki score was significantly decreased in the Ad-hIL-10 group. The levels of hepatic TNF-alpha, MIP-2, ICAM-1 mRNA, and NF-kappa B protein in the Ad-hIL-10 group were significantly decreased. The expression of hIL-10 mRNA was detected by RT-PCR in Ad-hIL-10-treated grafts but not in controls treated with saline or Ad-lacZ. CONCLUSIONS: Donor pretreatment with Ad-hIL-10 down-regulates the expression of proinflammatory cytokines TNF-alpha, MIP-2, and ICAM-1 mRNA. hIL-10 protects against hepatic cold ischemia-reperfusion injury, at least in part, by suppressing NF-kappa B activation and subsequent expression of proinflammatory mediators. (Hepatobiliary Pancreat Dis Int 2010; 9: 144-148)

Immunological tolerance of human hepatocyte xenograft induced by adenovirus vector-mediated CTLA4Ig gene transfer

BACKGROUND:Systemic administration of CTLA4Ig has been applied in inducing immunological tolerance of hepatocyte implants,but has potential for systemic immune inhibition.This study was designed to induce hepatocyte immunological tolerance by locally expressing CTLA4Ig in an attempt to improve the effectiveness of cell transplantation.METHODS:A normal human liver cell line(L02) was transfected with adenovirus vector containing the CTLA4Ig gene(Ad-CTLA4Ig-EGFP) in vitro,and the expression of CTLA4Ig by transfected cells was assessed by fluorescent imaging and immunocytochemical staining.Transfected cells then were injected into the spleen of Sprague-Dawley rats,the survival of cells was determined by immunohistochemistry,and the immune status was examined through CD4 + and CD69 + T cellcounts and ELISA detection of IL-2 in peripheral blood.RESULTS:L02 cells expressed CTLA4Ig in the cytoplasm for >4 weeks.Surviving L02 cells were observed in the experimental group at 3 and 4 weeks post-transplantation,while none was detected in the control group.Furthermore,the percentages of CD4 + and CD4 + CD69 + T cells in the CTLA4-transfected group were 24.5% and 45.1%,markedly lower than those in the control group at 4 weeks post-transplantation(P<0.01).Furthermore,the IL-2 level was also lower in the CTLA4transfected group than in the control group.CONCLUSION:Adenovirus-mediated CTLA4Ig gene transfer into human hepatocytes has the potential to become an effective method of inducing immunological tolerance in hepatocyte transplantation.

Construction of adenovirus vectors encoding the lumican gene by gateway recombinant cloning technology

AIM： To construct adenovirus vectors of lumican gene by gateway recombinant cloning technology to further understand the role of lumican gene in myopia. METHODS： Gateway recombinant cloning technology was used to construct adenovirus vectors. The wild-type （wt） and mutant （mut） forms of the lumican gene were synthesized and amplified by polymerase chain reaction （PCR）. The lumican cDNA fragments were purified and ligated into the adenovirus shuttle vector pDown- multiple cloning site （MCS）-/internal ribozyme entry site （IRES）/enhanced green fluorescent protein （EGFP）. Then the desired DNA fragments were integrated into the destination vector pAV.Desld yielding the final expression constructs pAV.Exld-CMV〉wt-lumican/IRES/ EGFP and pAV.Exld-cytomegalovirus （CMV） 〉mutlumican/IRES/EGFP, respectively.RESULTS： The adenovirus plasmids pAV.Exld-CMV〉 wt-lumican/IRES/EGFP and pAV.Exld-CMV 〉mutlumican/IRESlEGFP were successfully constructed by gateway recombinant cloning technology. Positive clones identified by PCR and sequencing were selected and packaged into recombinant adenovirus in HEK293 cells. CONCLUSION： We construct adenovirus vectors containing the lumican gene by gateway recombinant cloning technology, which provides a basis for investigating the role of lumicangene in the pathogenesis of high myopia.

In situ tumor vaccination with adenovirus vectors encoding measles virus fusogenic membrane proteins and cytokines

AIM: To evaluate whether intratumoral expression of measles virus fusogenic membrane glycoproteins H and F (MV-FMG), encoded by an adenovirus vector Ad.MV-H/ F, alone or in combination with local coexpression of cytokines (IL-2, IL-12, IL-18, IL-21 or GM-CSF), can serve as a platform for inducing tumor-specifi c immune responses in colon cancer. METHODS: We used confocal laser scanning microscopy and flow cytometry to analyze cell-cell fusion after expression of MV-FMG by dye colocalization. In a syngeneic bilateral subcutaneous MC38 and Colon26 colon cancer model in C57BL/6 and BALB/c mice, we assessed the effect on both the directly vector-treated tumor as well as the contralateral, not directly vector- treated tumor. We assessed the induction of a tumor- specific cytotoxic T lymphocyte (CTL) response with a lactate dehydrogenase (LDH) release assay. RESULTS: We demonstrated in vitro that transduction of MC38 and Colon26 cells with Ad.MV-H/F resulted in dye colocalization, indicative of cell-cell fusion. In addition, in the syngeneic bilateral tumor model we demonstrated a signifi cant regression of the directly vector-inoculated tumor upon intratumoral expression of MV-FMG alone or in combination with the tested cytokines. We observed the highest anti-neoplastic efficacy with MV-FMG and IL-21 coexpression. The degree of tumor regression of the not directly vector-treated tumor correlated with the anti-neoplastic response of the directly vector-treated tumor. This regression was mediated by a tumor-specifi c CTL response. CONCLUSION: Our data indicate that intratumoral expression of measles virus fusogenic membraneglycoproteins is a promising tool both for direct tumor treatment as well as for tumor vaccination approaches that can be further enhanced by cytokine coexpression.

Gene therapy for allergic rhinitis with recombinant adenovirus vector containing CTLA4Ig in mice

Objective: To examine the role of recombinant adenovirus vector containing CTLA4Ig gene(Ad-CTLA4Ig) in the treatment of induced allergic rhinitis in mice.Methods: Allergic rhinitis was induced by sensitizing and challenging with ovalbumin(OVA).Ad-CTLA4Ig was intraperitoneally injected 30 min before OVA challenge.Adenovirus vector without inserted CTLA4Ig cDNA served as the control.The symptoms and morphological changes of nasal mucosa of each group were observed, and the serum levels of IgE against OVA were detected with ELISA.Results: There were no obvious symptoms and pathological changes in Ad-CTLA4Ig treated group, in which the serum OVA-specific IgE levels were significantly lower than that in control groups(P< 0.05).Conclusion: Ad-CTLA4Ig prevents and treats allergic rhinitis of mice,implying the possibility of the usage of Ad-CTLA4Ig against allergic rhinitis in clinic in future.

CONSTRUCTION OF THE DICISTRONIC ADENOVIRUS VECTOR EXPRESSING BIOACTIVE HUMAN INTERLEUKIN-12

The full-length cDNA encoding the subunits p40 and p35 of human interleukin12(hIL12) were cloned separately by RTPCR, linked together by internal ribosomal entry site (IRES) of encephalomyocarditis virus which initiates capindependent translation to form a dicistronic gene fragment. The dicistronic fragment was placed between the cytomegalovirus (CMV) promoter and SV40 polyA signal to form a dicistronic expression cassette. Subsequently, the dicistronic expression cassette was inserted into E1 region of Ad5 genome in cosmid vector pAx1cw of E1substitution type. By homologous recombination with EcoT22Idigested Ad5 DNATPC in 293 cells, the replicationdeficient recombinant adenoviruses of hIL12 were generated efficiently. After infected with hIL12 recombinant adenoviruses in vitro, 293 cells, human hepatocellular carcinoma cells HepG2, and primary human skin fibroblasts expressed and secreted hIL12 at comparable levels (30～60ng/ 106cells/24hr), which could stimulate the proliferation and IFNγ production of human lymphoblasts. These suggest that the dicistronic adenovirus vector of hIL12 could effectively mediate the expression of bioactive hIL12 and might be used in cancer gene therapy.

Construction and Expression of Human PTEN Tumor Suppressor Gene Recombinant Adenovirus Vector

The recombinant defective adenovirus vector carrying human PTEN tumor suppressor gene was constructed by using AdEasy-1 system and its expression was detected in human breast cancer cell line MDA-MB-468. Human PTEN cDNA was cloned into adenovirus shuttle plasmid pAdTrack-CMV to generate a recombinant plasmid pAdTrack-CMV-PTEN, then homologeous recombination was carried out in the E. coli BJ5183 by contransforming linearized shuttle vector with adenovirus backbone plasmid pAdEasy-1. The newly recombined defective adenovirus vector Ad- PTEN containing green fluorescent protein （GFP） was packaged and propagated in 293 cells. After being purified by cesium chloride gradient centrifugation, the adenovirus was transfected into human breast cancer cell line MDA-MB-468 in vitro. The expression of PTEN mRNA and protein in infected human breast cancer cell line MDA-MB-468 was detected by RT-PCR and Western blot respectively. The recombinant defective adenovirus vector carrying PTEN gene was constructed successfully. The viral titer of purified adenovirus was 2. 5 × 10^10 pfu/mL, and about 70 % breast cancer cells were infected with Ad-PTEN when multiplicity of infection （MOI） reached 50. The exogenous PTEN mRNA and protein were expressed in MDA-MB-468 cells infected with Ad-PTEN by RT-PCR and Western blot. The recombinant defective adenovirus vector of PTEN gene was constructed successfully using AdEasy-1 system rapidly, which paved a sound foundation for gene study of breast cancer.

THE ROLE OF RECOMBINANT Rb GENE ADENOVIRUS VECTOR IN THE GROWTH OF LUNG ADENOCARCINOMA CELLS

Objective: To study the role of the most extensively studied tumor suppressor gene, retinoblastoma (Rb) gene, on the growth of lung adenocarcinoma cell line GLC 82 and explore a gene therapy approach for lung adenocarcinoma Methods: The recombinant Rb gene adenovirus vector was constructed, the control virus which carries LacZ gene was producted by the same method Infection effects were detected by biochemical staining of β gal and immunohistochemical analysis of Rb protein The Rb cDNA of infected cells were determined by PCR The cell growth rate and cell cycle were observed by cell counting and flow cytometry Results: The constructed recombinant adenovirus vector could infect effectively the cells with high level expression of Rb cDNA and Rb protein The transfection of wild type Rb gene could suppress GLC 82 cell proliferation and decrease the cellular DNA synthesis Conclusions: These results showed the possibility of using recombinant Rb gene adenovirus vector in the gene therapy of cancer to inhibit the growth of cancer

CONSTRUCTION OF A RECOMBINANT ADENOVIRUS VECTOR OF HUMAN PAPILLOMAVIRUS TYPE 16 L1_E7C

Objective: Human papillomaviruses are closely associated with human cervical cancer, especially HPV types 16 and 18. At present, HPV can not be produced in large quantity; it also has tumorgenicity and these properties of HPV have seriously hampered the development of HPV vaccine. HPV type 16 LI proteins can assembled into virus-like particles (VLP), which are morphologically identical to the nature virion. In order to develop the recombinant adenovirus vectors of HPV, we constructed a recombinant adenovirus shuttle plasmid pCA14 L1-E7C. Methods: Human papillomavirus type 16 LI open reading frame without terminator codon (TAA) (5559–7152) and E7C (682–855) were amplified using PCR. The L1 and E7C fragments were inserted into pGEM-T easy vectors by T-A strategy, named pTAL1 and pTAE7C. pTAL1 was cut with Hind III and BgIII, the pTAE7C with BamHI and ClaI. The L1 DNA fragment, E7C and pBluesscript SK were ligated together using T4 DNA ligase. pBSL1-E7C and pBSL1-E7C was digested with Hind III and Xhol. The L1-E7C fragment was inserted into adenovirus shuttle plasmids pCA14, named pCA14L1-E7C. DNA sequence results indicated that The L1-E7C DNA fragment can encode the HPV16L1-E7 fusion protein correctly. Results: The L1 and E7C DNA fragments were amplified by PCR and recombinant plasmid pTAL1, pTAE7C, pBSL1-E7C and pCA14L1-E7C were constructed correctly. The pCA14L1-E7C can be used in the further research work, cotransfected the 293 cell with the parent adenovirus pBHG10. Conclusion: Our results indicated that we have constructed a HPV16L1-E7 fusion DNA fragments and the adenovirus shuttle plasmids pCAL1-E7C for the further research.

Preparation and identification of monoclonal antibodies against the adenovirus vector

Objective:To prepare and identify monoclonal antibodies(McAbs)against the capsid proteins of adenovirus vector.Methods:BALB/c mice were immunized with a mixture of the purified adenovirus vector(Adv)and Al(OH)3.McAbs were produced using cell fusion technique in a conventional way.The sensitivity and specificity of monoclonal antibodies was identified by indirect enzyme linked immunosorbent assay(ELISA),immunocytochemical staining and Western blotting. Results:Six strains of hybridoma cells(A4H11,A8C7,F1H5,G1D2,G4E3 and H2G8)that can stably secrete the IgG1 McAb against Adv were obtained.After 3 months subculture and low concentration of serum adapting culture,six strains retained their stability to secrete McAb.The ascites titers were between 1:106 and 1:108.Western blot analysis demonstrated that all the McAbs reacted with one protein(about 114 kDa)which is present in wild type 3 adenovirus(wtAd3),wild type 5 adenovirus (wtAd5),wild type 7 adenovirus(wtAd7)and adenovirus vector.Conclusion:Successfully prepared six strains of hybridoma cell secreted monoclonal antibodies against the hexon proteins of adenovirus vector,and provided the substantial foundation of preclinical research of adenovirus vectors.

Construction and expression of SET gene and siRNA recombinant adenovirus vectors

Objective:To construct SET gene recombinant adenovirus vector and SET gene small interfering RNA(SiRNA) recombinant adenovirus vector for over-expression or knock-down of SET levels. Methods:The cDNA sequence of SET was cloned by reverse transcriptive polymerase chain reaction(RT-PCR) and the SET gene fragment was subcloned into adenovirus shuttle plasmid pAdTrack-CMV to construct the shuttle plasmid pAdTrack-SET.The shuttle plasmid pAdtrack-SET was transformed into BJ5183 cells with the adenoviral backbone pAdEasy-1 to obtain the homologous recombinant Ad-CMV-SET and the recombinant Ad-CMV-SET was packaged and amplified in the AD293 cells.The expression of SET in AD293 cells was detected by Western blot.In addition,we constructed SET gene SiRNA recombinant adenovirus vector(Ad-H1-SiRNA/SET) and its efficacy of knockdown of SET protein was detected in infected GC-2spd(ts) cells by Western blot. Results:The recombinant adenovirus vectors,both SET gene recombinant adenovirus vector Ad-CMV-SET and SET gene SiRNA recombinant adenovirus vector Ad-H1-SiRNA/SET,were proven to be constructed successfully by the evidence of endonulease digestion and sequencing.AD293 cells infected with either recombinant adenovirus vector of Ad-CMV-SET or Ad-H1-SiRNA/SET were observed to express GFP.The expression of SET protein was up-regulated significantly in AD293 cells infected with SET gene recombinant adenovirus vector.On the contrast, SET protein was significantly down-regulated in the GC-2spd(ts) cells infected with Ad-H1-SiRNA/SET (P<0.05) and the knockdown efficiency was approximately 50%-70%. Conclusion:The recombinant adenovirus vector Ad-CMV-SET and Ad-H1-SiRNA/SET were successfully constructed and effectively expressed in germ cells and somatic cells.It provides an experimental tool for further study of SET gene in the physiological and pathophysiological mechanism of reproduction-related diseases.

Construction of the recombinant adenovirus vectors of CALB_2 gene and small interfering RNA,and application in testicular Leydig cells

Objective:To construct the recombinant adenovirus vectors of calretinin(CALB_2) gene and small interfering RNA(siRNA),for over-expression or knock-down of CALB_2,as the basis of functional investigation of CALB_2 in testicular Leydig cells. Methods:The cDNA sequence of CALB_2 was cloned by the reverse transcriptive polymerase chain reaction (RT-PCR).A CALB_2 gene fragment was sub-cloned into adenovirus shuttle plasmid pAdTrack-CMV to construct the shuttle plasmid pAdTrack-CALB_2.Then it was transformed into BJ5183 cells with the adenoviral backbone pAdEasy-1 to obtain the homologous recombinant AdCMV-CALB_2.The recombinant AdCMV-CALB_2 was further packaged and amplificated in AD293 cells.The expression of CALB_2 protein in AD293 cells was detected by Western blotting.CALB_2 protein was over-expressed in mouse Leydig cell line(MLTC-1 cells) by the constructed AdCMV-CALB_2. CALB_2 gene siRNA recombinant adenovirus vector(Ad-H1-siRNA/CALB_2 was also constructed simultaneously. Its efficacy was detected in AD293 cells by Western blotting. Results:The CALB_2 gene recombinant adenovirus vector AdCMV-CALB_2 and the CALB_2 gene siRNA recombinant adenovirus vector Ad-H1-siRNA/CALB_2 were constructed successfully by endonulease digestion and sequencing. AD293 cells infected with AdCMV-CALB_2 or Ad-H1-SiRNA/CALB_2 significantly expressed GFP protein. The expression of CALB_2 protein was significantly up-regulated in AD293 cells infected with AdCMV-CALB_2 plasmids, while the expression of CALB_2 protein was down-regulated by 60%in the CALB_2 cells infected with Ad-H1-SiRNA/CALB_2. MLTC-1 cells did not markedly express CALB_2 protein,while MLTC-1 cells infected with AdCMV-CALB_2 expressed CALB_2 protein at a high level. Conclusions:The recombinant adenovirus vectors of AdCMV-CALB_2 and Ad-H1-SiRNA/CALB_2 were successfully constructed.Both vectors effectively expressed in AD293.CALB_2 protein was over-expressed in the cultured MLTC-1 cells by AdCMV-CALB_2.These vectors of CALB_2 gene and Leydig cell line are useful tools for investigating the testicular function.

腺病毒介导的VEGF-B基因促血管内皮细胞增殖作用的研究

为观察腺病毒介导的血管内皮细胞生长因子B(VEGF B)基因体外转染对血管内皮细胞的促增殖作用 ,构建编码人VEGF B基因的复制缺陷的重组腺病毒载体 ,体外转染鼠主动脉血管内皮细胞 (RAECs) ,应用RT PCR和Westernblot检测外源VEGF B的表达 ,应用四唑盐 (MTT)观察转染后RAECs的增殖。结果发现 ,RAECs可有效地被重组腺病毒载体感染 ,并能成功转录和表达VEGF B基因和蛋白 ,在转染后细胞培养上清中检测到VEGF B蛋白的表达 ,对RAECs有显著促增殖作用。提示重组腺病毒载体介导的人VEGF B基因有血管新生作用 ,可用于缺血性心脏病的治疗。

Antiapoptotic Effect of Gene Therapy with Recombinant Adenovirus Vector Containing Hypoxia-inducible Factor-1α after Cerebral Ischemia and Reperfusion in Rats

Background：Mounting evidence has demonstrated that hypoxia-inducible factor-1α （HIF-1α） could attenuate brain injuries after cerebral ischemia and reperfusion （CIR）.However,few reports have addressed the therapeutic efficacies of a recombinant adenovirus vector containing HIF-1o （AdHIF-1o） gene after ischemia and reperfusion.The aim of this study was to examine the antiapoptotic and neuroprotective effects ofAdHIF-1o gene for cerebral injuries after ischemia and reperfusion in rats.Methods：From February to December 2016,male Sprague-Dawley rats were randomly divided into normal,sham,CIR,AdHIF-1α,and recombinant adenovirus （Ad） groups.Middle cerebral artery occlusion model was established by Longa＇s method and reperfusion resumed at 2 h postocclusion.AdHIF-1α solution,Ad solution,and phosphate-buffered saline were injected into the right lateral ventricle of rats in AdHIF-lα,Ad,and CIR groups.Brain tissue sections were observed under fluorescent microscope to confirm the definite expression of recombinant adenovirus in Ad and AdHIF-1o groups.The expressions of HIF-lα protein were analyzed by immunohistochemical staining at 6 h,24 h,and 72 h postreperfusion.Brain water content and neurological deficit scores were evaluated at 6 h,24 h,and 72 h postreperfusion.Pathological brain injuries were examined after hematoxylin and eosin stain and nerve cell apoptosis was measured after terminal-deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling （TUNEL） stain at 72 h postreperfusion.Comparisons were conducted with one-way analysis of variance by post hoc Scheffe＇s test among different experimental groups.Results：Green fluorescent protein was successfully expressed in brain tissue ofAd andAdHIF-1α groups from 24 h to 21 days postinjection.As detected by immunohistochemical staining,the expressions of HIF-lα protein were obviously enhanced in AdHIF-1o group than those in CIR and Ad groups at 24 h and 72 h postreperfusion,respectively.There were significant reductions of brain water content （78.83% ± 0.34% vs.83.21% ± 0.50% and 83.35% ± 0.32%;84.13% ± 0.24% vs.89.76% ± 0.34% and 89.70% ± 0.18%;respectively;all P 〈 0.05） and neurological deficit scores （2.90 ± 0.74 vs.3.50 ± 0.52 and 3.60 ± 0.53 at 24 h;2.40 ± 0.84 vs.3.60 ± 0.52 and 3.50 ± 0.53 at 72 h;respectively;all P 〈 0.05） in AdHIF-1 α group versus CIR and Ad groups at 24 h and 72 h postreperfusion,respectively.The pathologic changes ofAdHIF-1 α group were milder than those in CIR and Ad groups at 72 h postreperfusion.The percentage of TUNEL-positive cells in cerebral subcortex decreased significantly in AdHIF-1α group versus CIR and Ad groups at 72 h postreperfusion （P 〈 0.05）.Conclusion：AdHIF-1α has an obvious neuroprotective effect on ischemia and reperfusion in rat brains possibly through inhibiting the apoptosis of nerve cells.

Adenovirus vector expressing mda-7 selectively kills hepatocellular carcinoma cell line Hep3B

BACKGROUND: Melanoma differentiation associated gene-7 (mda-7) is a novel tumor suppressor gene, which has suppressor activity in a broad spectrum of human cancer cells both in vitro and in vivo through activation of various intracellular signaling pathways. In this study, we investigated the potential effect of mda-7 on human hepatocellular carcinoma (HCC) in vitro. METHODS: Cells from the human HCC cell line Hep3B and the human liver cell line L-02 were assigned to three groups. One was cultured in Dulbecco's modified Eagle's medium without serum (control). The others were transfected with adenovirus expressing the mda-7 gene (Ad.mda-7) or adenovirus vector serving as negative control (Ad.vec). The expression of MDA-7 and Bcl-2 proteins in Hep3B and L-02 cells was confirmed by the reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay. The methyl thiazolyl tetrazolium colorimetric assay and flow cytometry were used to assess tumor cell proliferation and the cell cycle. Hoechst and Annexin-V/propidium iodide staining were used to study mda-7 gene expression in Hep3B and L-02 cells. The expression of MDA-7, Bcl-2 and Bax proteins were detected by Western blotting. RESULT S: The mda-7 gene was expressed in Hep3B and L-02 cells. The protein concentrations of MDA-7 in supernatants were 790 and 810 pg/ml, respectively. mda-7 induced Hep3B growth suppression and apoptosis, compared with Ad.mda-7 and control (P<0.01). In addition, cell block in G2/M was identified by exposure of HCC cells to secreted MDA-7 protein, but this was not found in L-02. The gene expression of Bcl-2 was markedly decreased in Hep3B but not in L-02. CONCLUSIONS: mda-7 selectively induces growth inhibition and apoptosis in the HCC cell line Hep3B but not in the normal liver cell line L-02 via downregulating the antiapoptosis protein Bcl-2. It could be an ideal gene for gene therapy in HCC.

Construction and Characterization of a Novel Recombinant Attenuated and Replication-Deficient Candidate Human Adenovirus Type 3 Vaccine:"Adenovirus Vaccine Within an Adenovirus Vector"

Human adenoviruses(HAd Vs)are highly contagious and result in large number of acute respiratory disease(ARD)cases with severe morbidity and mortality.Human adenovirus type 3(HAd V-3)is the most common type that causes ARD outbreaks in Asia,Europe,and the Americas.However,there is currently no vaccine approved for its general use.The hexon protein contains the main neutralizing epitopes,provoking strong and lasting immunogenicity.In this study,a novel recombinant and attenuated adenovirus vaccine candidate against HAd V-3 was constructed based on a commercially-available replication-defective HAd V-5 gene therapy and vaccine vector.The entire HAd V-3 hexon gene was integrated into the E1 region of the vector by homologous recombination using a bacterial system.The resultant recombinants expressing the HAd V-3 hexon protein were rescued in AD293 cells,identified and characterized by RT-PCR,Western blots,indirect immunofluorescence,and electron microscopy.This potential vaccine candidate had a similar replicative efficacy as the wild-type HAd V-3 strain.However,and importantly,the vaccine strain had been rendered replication-defective and was incapable of replication in A549 cells after more than twentygeneration passages in AD293 cells.This represents a significant safety feature.The mice immunized both intranasally and intramuscularly by this vaccine candidate raised significant neutralizing antibodies against HAd V-3.Therefore,this recombinant,attenuated,and safe adenovirus vaccine is a promising HAd V-3 vaccine candidate.The strategy of using a clinically approved and replication-defective HAd V-5 vector provides a novel approach to develop universal adenovirus vaccine candidates against all the other types of adenoviruses causing ARDs and perhaps other adenovirus-associated diseases.

Inhibition of vascular smooth muscle cell proliferation by in troduction of retinoblastoma gene via a recombinant adenovirus vector

This study was supported in part by grant from National Natural Science Foundation of China (No. 39570775). Objective To investigate the vascular smooth muscle cell (SMC) growth suppression by recombinant adenovirus vector expressing a retinoblastoma (Rb) protein and to explore a gene therapy approach for vascular proliferative disorders including atherosclerosis and artery restenosis. Methods A replication deficient adenovirus vector encoding a wild type Rb and AdCMVRb, was constructed and transfected into cultured rabbit aortic SMC. The efficiency of gene transfection and expression was detected by immunochemical staining and polymerase chain reaction. The role of Rb in regulating vascular SMC proliferation was observed by cell counting, thymidine incorporation, and flow cytometry. Results Wild type Rb gene transfected effectively into the cultured SMC with AdCMVRb can suppress growth factor stimulated cell proliferation through regulation of DNA synthesis and cell cycle progression. Conclusion The results demonstrate the potential of adenovirus mediated Rb gene therapy for atherosclerosis and artery restenosis after balloon angioplasty.

Recombinant chimpanzee adenovirus vector vaccine expressing the spike protein provides effective and lasting protection against SARS-CoV-2 infection in mice

SARS-CoV-2 infection is a global public health threat.Vaccines are considered amongst the most important tools to control the SARS-CoV-2 pandemic.As expected,deaths from SARS-CoV-2 infection have dropped dramatically with widespread vaccination.However,there are concerns over the duration of vaccine-induced protection,as well as their effectiveness against emerging variants of concern.Here,we constructed a recombinant chimpanzee adenovirus vectored vaccine expressing the full-length spike of SARS-CoV-2(Ad C68-S).Rapid and high levels of humoral and cellular immune responses were observed after immunization of C57BL/6J mice with one or two doses of Ad C68-S.Notably,neutralizing antibodies were observed up to at least six months after vaccination,without substantial decline.Single or double doses Ad C68-S immunization resulted in lower viral loads in lungs of mice against SARS-CoV-2 challenge both in the short term(21 days)and long-term(6 months).Histopathological examination of Ad C68-S immunized mice lungs showed mild histological abnormalities after SARS-CoV-2 infection.Taken together,this study demonstrates the efficacy and durability of the Ad C68-S vaccine and constitutes a promising candidate for clinical evaluation.

A Self-Biomineralized Novel Adenovirus Vectored COVID-19 Vaccine for Boosting Immunization of Mice

SARS-CoV-2 has caused more than 3.8 million deaths worldwide,and several types of COVID-19 vaccines are urgently approved for use,including adenovirus vectored vaccines.However,the thermal instability and pre-existing immunity have limited its wide applications.To circumvent these obstacles,we constructed a self-biomineralized adenovirus vectored COVID-19 vaccine(Sad23L-n Co V-S-Ca P)by generating a calcium phosphate mineral exterior(Ca P)based on Sad23L vector carrying the full-length gene of SARS-Co V-2 spike protein(S)under physiological condition.This Sad23L-n Co V-S-Ca P vaccine was examined for its characteristics of structure,thermostability,immunogenicity and avoiding the problem of preexisting immunity.In thermostability test,Sad23L-n Co V-S-Ca P could be stored at 4°C for over 45 days,26°C for more than 8 days and 37°C for approximately 2 days.Furthermore,Sad23L-n Co V-S-Ca P induced higher level of S-specific antibody and T cell responses,and was not affected by the pre-existing anti-Sad23L immunity,suggesting it could be used as boosting immunization on Sad23L-n Co V-S priming vaccination.The boosting with Sad23L-n Co V-S-Ca P vaccine induced high titers of 10^(5.01)anti-S1,10^(4.77)anti-S2 binding antibody,10^(3.04) pseudovirus neutralizing antibody(IC_(50)),and robust T-cell response of IFN-c(1466.16 SFCs/10^(6)cells)to S peptides,respectively.In summary,the selfbiomineralization of the COVID-19 vaccine Sad23L-n Co V-S-Ca P improved vaccine efficacy,which could be used in prime-boost regimen for prevention of SARS-Co V-2 infection in humans.