Full-length coxsackie adenovirus receptor (CAR) eukaryotic expression plasmid was transfected into an ovarian cell line, SKOV3, and its effect on the change of malignant metastasis phenotype was explored. CAR mRNA and protein expression levels among 4 ovarian cancer cell lines (A2780, SKOV3, SW626, CAOV3) and the positive control 293 (a transformed human embryo kidney cell line) was detected by using semi-quantitative RT-RCR and Western blot and compared. CAR-negative SKOV3 was transfected with the eukaryotic expression plasmid containing a full-length CAR cDNA and mock-vector respectively. The positive clones were screened by G418. The biological behavior changes of positive transfected cells were gauged by colony formation in soft agar assay and cell adhesion assay. Among the cell lines, there were obviously different CAR expression levels. CAR could not be detected in SKOV3. In transfected cell group, CAR expression was enhanced obviously as compared with non-transfected or mock-transfected groups. Cell adhesion in the transfected group was promoted. The number of colony formation was reduced significantly in transfected groups (25.32 +/- 8.91) as compared with that in non-transfected group (88.75 +/- 13. 98) and mock-transfected group (82.53 +/- 19.37). Among the 4 ovarian cancer cell lines, CAR expression level was variable. Exogenous CAR expression had a potential role in inhibiting the malignant metastasis phenotype of ovary cancer cells.
Cell Line, Tumor ; Lymphatic Metastasis ; Neoplasm Invasiveness ; Ovarian Neoplasms/metabolism ; Ovarian Neoplasms/*pathology ; Phenotype ; Receptors, Virus/*biosynthesis ; Receptors, Virus/genetics ; Transfection

BACKGROUNDTo express and purify human alpha3-integrin to serve as the antigen to prepare its antibody and to separate the Vero cell clones without expression of alpha3-integrin.

METHODSThe human alpha3-integrin gene was amplified by using RT-PCR, then subcloned into a pQE30 expression vector and expressed in E. coli. The gene expression was confirmed by Western blot assay. Rabbit was inoculated with purified antigen to stimulate the antibody generation. The target Vero cells were separated by negative selection using antibody plus complement mediated cytolysis. The separated cell clones were confirmed by immunofluorescence and Western blot assay.

RESULTSThe alpha3- integrin gene was cloned and expressed effetively, Western blot assay revealed that the expressed protein held good immune reactivity. High titer antibody was generated. However the expression of alpha3-integrin was not detected on Vero, VeroE6, Hep-2, 2BS and 293 cells.

CONCLUSIONSThe results of the study suggested that hantavirus has other receptors on Vero cells beside alpha 3-integrin.

Animals ; Cercopithecus aethiops ; Cloning, Molecular ; Gene Expression ; Hantavirus ; Integrin beta3 ; biosynthesis ; genetics ; immunology ; Rabbits ; Receptors, Virus ; Vero Cells ; metabolism

We produced beta1 gene which is about 2400 bp by reverse transcription polymerase chain reaction (RT-PCR) from bovine trachea, reclaimed and purified, then cloned the amplified fragment to pGEM-T easy vector, confirmed by sequencing. The immune-dominant epitope of beta1 gene was chosen by computer analysis and then syncretized ligand-binding domain from 346 bp to 843 bp of ecytoplasm with six histidine, expressed LBD protein massly in E. coli BL21 (DE3), and identified by SDS-PAGE. The fusion protein was purified with Ni-NTA affinity chromatography and immunized New Zealand rabbits preparing of its polyclonal antibody, the specific antibody titer was above 1:12,800 detected by indirect ELISA, the result of Western blot showed that this antibody could be recognized by LBD fusion protein.
Animals ; Antibodies, Monoclonal ; biosynthesis ; Cattle ; Escherichia coli ; genetics ; metabolism ; Foot-and-Mouth Disease Virus ; physiology ; Integrin alpha1beta1 ; biosynthesis ; genetics ; immunology ; Ligands ; Protein Binding ; Protein Interaction Domains and Motifs ; Rabbits ; Receptors, Virus ; genetics ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology

Human hepatitis B virus surface antigen (HBsAg) binding protein(SBP) shows a specific binding ability to HBV surface antigen HBsAg. Previous work proved an ability of SBP to enhance the immune response of HBsAg vaccine. To investigate the function and mechanism of this protein, we constructed SBP-expression strains with Pichia pastoris expression system. We screened these strains and have got an expression strain with high protein expression quantity. Fermentation product was collected and purified to gain a large amount of purified protein. Identification of purified SBP with SDS-PAGE, High performance liquid chromatography, Western blotting and mass spectrometry suggested that the protein was highly purified and with a good integrity. ELISA test of purified SBP showed a significant binding ability to HBsAg, suggesting a good protein activity. This work offers a solid foundation to the research of SBP function and mechanism of immune enhancement.
Binding Sites ; Genetic Vectors ; genetics ; metabolism ; Hepatitis B Surface Antigens ; metabolism ; Humans ; Pichia ; genetics ; metabolism ; Receptors, Virus ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; isolation & purification

OBJECTIVETo investigate the mRNA expression of severe acute respiratory syndrome-associated coronavirus (SARS-COV) functional receptor, angiotensin-converting enzyme 2 (ACE2), in human femoral head and conjunctiva, and explore the possible entry route of SARS-COV in human femoral head.

METHODSACE2 mRNA in human femoral head was detected by nested RT-PCR with human beta actin gene as the positive control.

RESULTSThe mRNA of human beta actin gene could be amplified efficiently in all the tissue samples. The mRNA of human ACE2 was expressed efficiently in the normal lung tissue, but not in the cartilage and cancellous bone under the weight-bearing area of the femoral head.

CONCLUSIONSARS-COV can not infect the femoral head tissue and lead to avascular necrosis of the femoral head directly by the spike glycoprotein, and mechanism of the virus for causing avascular necrosis needs further investigation.

Femoral Neck Fractures ; metabolism ; Femur Head ; metabolism ; Gene Expression ; Humans ; Peptidyl-Dipeptidase A ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Receptors, Virus ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; SARS Virus ; metabolism

Sef (similar expression to fgf genes) was identified as a feedback antagonist of FGF signaling in zerbrafish, mouse and human. To construct recombinant adenoviral vectors expressing hSef-L and hSef-S, the coding sequences of the two isoforms were amplified and ligated into pAdTrack-CMV, forming shuttle vectors pAdTrack-CMV/hSef-L-Myc and pAdTrack-CMV/hSef-S-Myc. After sequence confirmation, these two shuttle vector plasmids were linearized by Pme I and then co-transformed respectively with the adenoviral genome vector pAdEasy-1 into E. coli BJ5183. The successful recombinants were selected by Kanamycin and confirmed by Pac I digestion. The recombinant vectors Ad-hSef-L-Myc and Ad-hSef-S-Myc were finally digested with Pac I and transfected into HEK293 cells to pack into viral particles. The virus were amplified in 293 cells and used to infect MEF cells. Western blotting analysis was used to demonstrate the expression of hSef-L-Myc and hSef-S-Myc proteins. The inhibitory effects of the adenovirus mediated Sef expression on FGF signaling was further evaluated by Elk luciferase reporter assay. Our results indicated the constructed virus could produce effectively the proteins and then inhibit FGF signaling in MEF cells.
Adenoviridae ; genetics ; metabolism ; Cell Line ; Cloning, Molecular ; Defective Viruses ; genetics ; metabolism ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Humans ; Protein Isoforms ; biosynthesis ; genetics ; Receptors, Interleukin ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Transfection ; Virus Cultivation ; methods

OBJECTIVETo construct a yeast expression vector of hepatitis B virus (HBV) PreS1 gene using the Sos-recruitment system (SRS), and evaluate the effect of the expression product on the growth of the yeast cells and activation of the reporter gene.

METHODSThe coding sequence of HBV preS1 was amplified by PCR and cloned into the yeast expression plasmid pSos. The recombinant bait plasmid pSos- PreS1 was verified by sequencing before transformation into competent yeast cells. The effects of the expression product on the yeast cell growth and activation of the reporter gene were evaluated.

RESULTSThe yeast expression vector of HBV PreS1 gene was constructed successfully. The recombinant bait plasmid showed no toxic effect on yeast cdc25H cells without a self-activation of the reporter gene.

CONCLUSIONThe SRS can be used to study the proteins interacting with HBV PreS1 protein and provides a means for obtaining insight into the pathogenic mechanism of HBV.

Cloning, Molecular ; Genetic Vectors ; genetics ; Hepatitis B Surface Antigens ; biosynthesis ; genetics ; Humans ; Plasmids ; genetics ; Protein Precursors ; biosynthesis ; genetics ; Receptors, Virus ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Two-Hybrid System Techniques ; Yeasts ; genetics ; metabolism

OBJECTIVETo study the effects of HIV Tat protein on CCR5 expression of monocytes and HIV infection in monocytes.

METHODSMembrane expression of CCR5 on monocytes was analyzed by flow cytometry. Stimulated with HIV Tat protein, monocytes were infected with monocyte-tropic HIV(Ba-L) and HIV gag p24 level in the supernatant was measured by ELISA methods.

RESULTSHIV Tat protein increased CCR5 expression in human monocytes,which was inhibited by rabbit anti-Tat polyclonal antibody. Tat protein also increased p24 level after monocyte-tropic HIV-1(Ba-L) infected monocytes.

CONCLUSIONTat increases CCR5 expression and HIV-1 infection in monocytes, which indicates that HIV Tat might be a key protein in HIV-1 infection.

Flow Cytometry ; Gene Products, tat ; pharmacology ; HIV ; HIV Infections ; metabolism ; Humans ; Monocytes ; metabolism ; Receptors, CCR5 ; biosynthesis ; genetics ; tat Gene Products, Human Immunodeficiency Virus

To improve the targeting of adenovirus vector for gene therapy, a fusion gene sCAR-EGF, in which epidermal growth factor gene was fused to the 3' end of extracellular Coxsackie virus-adenovirus receptor gene, was constructed and cloned into shuttle plasmid pDC315 to obtain a recombinant plasmid pDC315-sCAR-EGF. With the AdMax system, AD-293 cells were co-transfected with pDC315-sCAR-EGF and adenovirus genomic plasmid pBHGloxdeltaE13cre. Through high efficiency site specific recombination, a replication-defective adenovirus Ad5-CMV-sCAR-EGF was constructed. The recombinant adenovirus was analyzed by PCR and Western blotting, the results indicated that Ad5-CMV-sCAR-EGF contained the fusion gene sCAR-EGF, and the adenovirus infected cells was induced to produce and secrete the fusion protein into the supernatant. We have demonstrated that the fusion protein sCAR-EGF is helpful for elevating the infection efficiency of Ad5-CMV-luc with the reporter gene in vitro, which providing a new approach to the gene therapy for tumors overexpressing EGFR.
Adenoviridae ; genetics ; Cell Line ; Coxsackie and Adenovirus Receptor-Like Membrane Protein ; Enzyme-Linked Immunosorbent Assay ; Epidermal Growth Factor ; analysis ; genetics ; Genetic Therapy ; Humans ; Neoplasms ; therapy ; Polymerase Chain Reaction ; Receptors, Virus ; analysis ; genetics ; Recombinant Fusion Proteins ; biosynthesis