Animals ; Dependovirus ; genetics ; immunology ; Gene Transfer Techniques ; instrumentation ; Genetic Therapy ; instrumentation ; Genetic Vectors ; genetics ; immunology ; Humans

AIDS Vaccines ; immunology ; China ; Cross Reactions ; Genetic Vectors ; HIV-1 ; immunology ; Humans ; Immunity, Innate ; Immunity, Mucosal

BACKGROUNDThe large phage antibody library is used to obtain high-affinity human antibody, and the Loxp/cre site-specific recombination system is a potential method for constructing a large phage antibody library. In the present study, a phage antibody library vector pDF was reconstructed to construct diabody more quickly and conveniently without injury to homologous recombination and the expression function of the vector and thus to integrate construction of the large phage antibody library with the preparation of diabodies.

METHODSscFv was obtained by overlap polymerase chain reaction (PCR) amplification with the newly designed VL and VH extension primers. loxp511 was flanked by VL and VH and the endonuclease ACC III encoding sequences were introduced on both sides of loxp511. scFv was cloned into the vector pDF to obtain the vector pDscFv. The vector expression function was identified and the feasibility of diabody preparation was evaluated. A large phage antibody library was constructed in pDscFv. Several antigens were used to screen the antibody library and the quality of the antibody library was evaluated.

RESULTSThe phage antibody library expression vector pDscFv was successfully constructed and confirmed to express functional scFv. The large phage antibody library constructed using this vector was of high diversity. Screening of the library on 6 antigens confirmed the generation of specific antibodies to these antigens. Two antibodies were subjected to enzymatic digestion and were prepared into diabody with functional expression.

CONCLUSIONSThe reconstructed vector pDscFv retains its recombination capability and expression function and can be used to construct large phage antibody libraries. It can be used as a convenient and quick method for preparing diabodies after simple enzymatic digestion, which facilitates clinical trials and application of antibody therapy.

Bacteriophages ; genetics ; Digoxin ; immunology ; Enzyme-Linked Immunosorbent Assay ; Genetic Vectors ; Immunoglobulin Fragments ; biosynthesis ; immunology ; Peptide Library

OBJECTIVETo study the feasibility of delivering viral gene vector from a collagen-coated polyurethane (PU) film through a mechanism involving monoclonal antiviral antibody tethering.

METHODSAnti-adenoviral monoclonal antibodies were covalently bound to the collagen-coated PU surface. These antibodies enabled tethering of replication defective adenoviruses through highly specific antigen-antibody affinity. The PU film-based gene delivery using antibody-tethered adenovirus encoding green fluorescent protein (GEP) was tested in rat arterial smooth muscle cell (A10 cell) culture in vitro. The virus binding stability was studied by incubating the collagen-coated PU film in PBS solution at 37 degrees C for 20 days, followed with A10 cell cultures with the incubated films and the corresponding buffer solution.

RESULTSPU films with antibody-tethered adenovirus encoding GFP demonstrated efficient and highly localized gene delivery to A10 cells. Virus binding was stable for at least 10 days at physiological conditions, more than 77% of the originally bound virus remained in the film after 15 day's incubation.

CONCLUSIONGene delivery using PU film-based anti-viral antibody tethering of vectors exhibited potentials of applications in a wide array of single or multiple therapeutic gene strategies, and in further stent-based gene delivery therapeutic strategies.

Adenoviridae ; genetics ; Antibodies, Monoclonal ; immunology ; Antibody Specificity ; immunology ; Gene Transfer Techniques ; Genetic Therapy ; Genetic Vectors ; Humans ; Polyurethanes ; chemistry ; Protein Binding

This study was purposed to construct a fusion DNA vaccine containing WT1 multi-epitope and stimulating epitope of mycobacterium tuberculosis heat shock protein 70 and to detect its expression and immunogenicity. On the basis of published data, a multi-epitope gene (Multi-WT1) containing three HLA *0201-restricted CTL epitopes: one HLA*2402-restricted CTL epitope, two Th epitopes and one universal Th Pan-DR epitope (PADRE) was constructed. DNA-coding sequence was modified by Computer-Aided Design (CAD) to optimize proteasome-mediated epitope processing through the introduction of different amino acid spacer sequences. The synthetic nucleotide sequence was then inserted into an eukaryotic vector to construct the plasmid pcDNA3.1-WT1.For enhancing CTL activity, HSP70 fragment including stimulatory domain P407-426 was amplified by PCR from mycobacterial HSP70 gene and cloned into pcDNA3.1(+). Then Multi-WT1 was fused to the N-terminal of pcDNA3.1-mHSP70(407-426) to make the multi-epitope fusion gene vaccine pcDNA3.1-WT1-mHSP70(407-426). HEK-293T cells were transfected with this vaccine and the expressed product was identified by RT-PCR. Enzyme-linked immunospot assay (ELISPOT) was used to evaluate the immunological responses elicited by vaccine. The results showed that the most of WT1 epitopes could be correctly cleaved which was confirmed by software Net Chop 3.1 and PAPROCIanalysis. RT-PCR showed correct expression of target gene in HEK293T cells and ELISPOT showed specific T-cell responses. It is concluded that the eukaryotic expression vector PcDNA3.1-WT1-mHSP70(407-426) fusion gene has been successfully constructed and the immunity response is also elicited, which is a good candidate for further research of DNA vaccine.
Bacterial Proteins ; genetics ; immunology ; Epitopes ; genetics ; immunology ; Genetic Vectors ; HSP70 Heat-Shock Proteins ; genetics ; immunology ; Humans ; Immunodominant Epitopes ; Vaccines, DNA ; genetics ; immunology ; WT1 Proteins ; genetics ; immunology

B7-1 Antigen ; genetics ; immunology ; Carcinoma, Hepatocellular ; genetics ; immunology ; Enterotoxins ; genetics ; immunology ; Genetic Vectors ; Humans ; Liver Neoplasms ; genetics ; immunology ; T-Lymphocytes ; immunology ; Transfection ; Tumor Cells, Cultured

How to reduce immune response is an unprecedented challenge for rAAV gene medicine. Recent studies suggested that lowering dosage of the vector used could reduce immune response caused by rAAV gene medicine. Nevertheless, it would also decrease the transgene expression, leading to failure of gene treatment. It is therefore important to take appropriate steps to maintain high gene expression level and pharmacodynamic, while the dosage of rAAV used is reduced. Here, steps to enhancing gene therapy, such as optimization of the administration, reconstruction of the viral vector and selection of the promoter, are discussed in order to achieve maximum outcome.
Animals ; Dependovirus ; genetics ; immunology ; Dose-Response Relationship, Drug ; Gene Dosage ; Gene Transfer Techniques ; Genetic Therapy ; Genetic Vectors ; administration & dosage ; genetics ; immunology ; Humans ; Recombination, Genetic ; Transgenes ; genetics

OBJECTIVETo study the feasibility of preparing a therapeutic lung cancer vaccine by transfecting dendritic cells (DCs) with adeno-associated virus vector carrying carcino-embryonic antigen gene (rAAV/CEA).

METHODSAdherent cells (monocytes) isolated from the peripheral blood of a healthy donor were infected with rAAV/CEA virus stock or pulsed with CEA peptide (control). The monocytes in both groups were induced into mature DCs with recombinant human GM-CSF, IL-4 and TNF-α. At day 7 of induction, the mature DCs were harvested and mixed with T lymphocytes. T cell proliferation stimulated by the DCs was assessed with (3)H-thymidine uptake, and the expression of IL-4, IFN-γ, CD8, CD4, CD25 and CD69 in cytotoxic T lymphocytes (CTL) was analyzed with flow cytometry. The cytotoxicity of the CTL against the target CEA-positive lung cancer A549 cells was tested by (51)Cr releasing assay.

RESULTSThe DCs transfected with rAAV/CEA strongly stimulated the proliferation of the T cell populations, and the induced CTL showed high expressions of CD8, CD69 and IFN-γ. The transfected DCs exhibited a high killing ability of CEA-positive lung cancer cells, and the killing showed a CEA antigen specificity and was limited by MHC I. These results suggested the ability of rAAV/CEA-transfected DCs in generating specific cellular immunity in vitro.

CONCLUSIONIt is feasible to prepare therapeutic lung cancer vaccines by transfecting DCs with rAAV/CEA.

Cancer Vaccines ; Carcinoembryonic Antigen ; genetics ; Cell Line ; Dendritic Cells ; immunology ; Dependovirus ; genetics ; Genetic Vectors ; Humans ; Monocytes ; immunology ; Transfection

Wheat peroxidases 1 (WP1) is the major cationic peroxidase of wheat (Triticum aestivum) grain, which is involved in the development of seeds and an important factor to affect the final processing quality of flour. We constructed a prokaryotic expression vector pET28a-WP1, and transformed it into E. coli host strain T7 Expression. His-tag fused WP1 existed as inclusion body, and the recombinant protein was purified by Ni-NTA resin affinity chromatography under denatured condition. The purity of target protein reached 98%. The recombinant WP1 was refolded by gradient urea dialysis, then used as antigen to immune rabbit to prepare polyclonal antibody. The result of ELISA showed that the titer of rabbit anti-WP1 antiserum was higher than 1:625 000. The result of Western blotting demonstrated that the prepared WP1 polyclonal antibody could be used to detect WP1 with high specificity.
Animals ; Antibodies ; immunology ; metabolism ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; Peroxidases ; biosynthesis ; genetics ; Rabbits ; Recombinant Proteins ; biosynthesis ; genetics ; immunology

The biosafety of gene delivery vectors has received much more attention in recent years. In this article, the biosafety of non-viral gene delivery vectors was mainly discussed. Recent developments in researches on toxicity, nano-effect, blood compatibility and immune response of non-viral gene delivery vectors were reviewed.
Cations ; chemistry ; Drug Delivery Systems ; methods ; Gene Transfer Techniques ; Genetic Therapy ; methods ; Genetic Vectors ; immunology ; pharmacokinetics ; toxicity ; Humans ; Nanoparticles ; chemistry