Escherichia coli ; genetics ; Humans ; Recombinant Fusion Proteins ; immunology ; Viral Nonstructural Proteins ; genetics ; immunology

Foot-and-mouth disease virus (FMDV) is the aetiological angent of a highly contagious viral disease. The complete gene encoding the structural protein of FMDV (P1) was subcloned into expression vector pGEX-KG, resulting in the fusion expression plasmid pKG-P1. After transformed into E. coli BL21(DE3) and induced by IPTG, the results of SDS-PAGE showed that the GST-P1 fusion protein was expressed in high level. The molecular weight of the fusion protein wa 110kD and the expressed products were soluble. Western-blotting was performed to confirm that the expressed fusion protein could specifically react with antiserum against FMDV. The fusion proteins were further purified by GST purification kit and an indirect ELISA (P1-ELISA) based on the purified proteins was developed. Comparison between P1-ELISA and the standard indirect haemagglutinin assay showed the two methods had 87 per cent agreement by detecting 864 serum samples, indicating the purified P1 protein was specific as the antigen of indirect P1-ELISA.
Capsid Proteins ; biosynthesis ; genetics ; immunology ; Escherichia coli ; genetics ; metabolism ; Foot-and-Mouth Disease Virus ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology

Cloning, Molecular ; Escherichia coli ; genetics ; Hepacivirus ; genetics ; Humans ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Viral Nonstructural Proteins ; biosynthesis ; genetics ; immunology

In the study, a gene encoding Tat protein N terminal 1- 21 amino acid residues-deleted mutant (Tat22-101) was amplified by PCR from a full length Tat gene of human immunodeficiency virus type 1, and the prokaryotic expression plasmid pET32a-Tat22-101 was constructed. After identification by digestion with endonucleases and sequencing, the recombinant plasmid pET32a-Tat22-101 was transformed into E. coli BL21(DE3) and expressed with IPTG induction. The mutant fusion protein with deleted Tat N terminal was purified by an affinity chromatography column Ni(2+)-NTA and subsequently identified by SDS-PAGE and Western blotting. The results showed that the molecular weight of the mutant protein was approximately 26.9kD. Furthermore, BALB/c mice were immunized with the mutant protein and the anti-sera were collected. ELISA results showed that the mutant protein preserved its immunogenicity, particularly it could improve the production of antibodies to other epitopes in addition to the N terminal epitope of Tat protein, which might provide some valuable information for the study of Tat functions as well as for development of potential novel HIV Tat vaccine.
Animals ; Female ; Gene Products, tat ; biosynthesis ; genetics ; immunology ; HIV-1 ; genetics ; immunology ; Humans ; Mice ; Mice, Inbred BALB C ; Mutant Proteins ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology

OBJECTIVE: To synthesize the specific CagA gene segment of the gastric cancer idiotype Helicobacter pylori (H. pylori), establish the prokaryotic expression system and identify the antigenicity sequence of recombination signals. METHODS: We selected the CagA fragment which was related to gastric cancer in our earlier research. The CagA gene segment was optimized and synthesized. The synthesized CagA gene was cut from the pUC57-CagA plasmid and then was carried by expression vector pET32a to be transformed into the host bacterium BL21 (DE3). The positively cloned pET32a-CagA was selected by receptivity of aniline and colony PCR. The host bacterium with pET32a-CagA was induced by IPTG to express fusion protein. The expression of CagA protein was analyzed by SDS-PAGE gel electrophoresis and the antigenicity of fusion protein was examined by Western blot. RESULTS: CagA gene segment was designed and synthesized. The sequence of synthesis CagA gene segment was the same as the one designed before (AF289435). We successfully constructed the plasmid of prokaryotic expression of the pET32a-CagA. Homology of the target CagA proteinum was 100%, the same as AAG09884. The host bacterium BL21 (DE3) containing pET32a-CagA could express CagA fusion protein after the IPTG induction. SDS-PAGE gel electrophoresis showed that the molecular weight of fusion protein was the same as expected (45 kD). Western blot showed that the fusion protein could be combined with the antibody of the whole bacterium of anti-H. pylori. CONCLUSION The synthesized CagA fusion protein from the prokaryotic expression system has antigenicity. We hope to set the foundation for selecting the strain in H. pylori correlated to gastric cancer and corresponding therapy in clinical practice.
Amino Acid Sequence ; Antigens, Bacterial ; genetics ; immunology ; Bacterial Proteins ; genetics ; immunology ; Base Sequence ; Genetic Vectors ; Helicobacter pylori ; genetics ; immunology ; Molecular Sequence Data ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology

Pseudorabies virus (PRV), an alpha-herpesvirus, has been used as a vector for live-viral animal vaccines. The recombinant PRV TK- / gE- / GP5+, which expressing GP5 of PRRSV, is developed based on the PRV genetic-depleting vaccine-virus strain, TK- / gE- /LacZ+. However, this strain stimulated poorly the vaccinated animals to produce neutralizing antibodies against PRRSV. In order to develop a booster specific immunized response of the PRV recombinant, the ORF5 gene of PRRSV TK- / gE- / LacZ+ was substituted by a modified ORF5 gene, ORF5m. The resultant recombinant PRV, TK- /gE- / GP5m+, was verified by PCR, Southern blotting and Western blotting. TK- / gE- / GP5m+ and TK- / gE- / GP5+ expressed GP5 proteins were inoculated into balb/c mice to evaluate their immunogenicity. The results demonstrated that the amount of neutralization antibodies and cell-immunity responses induced by TK- / gE- /GP5m+ against PRRSV were higher than that of TK- / gE- / GP5+. This study indicated that the new recombinant PRV expressing the modified GP5m protein is a candidate for the development of bivalent genetic engineering vaccines against PRRSV and PRV.
Animals ; Genetic Vectors ; Herpesvirus 1, Suid ; genetics ; immunology ; Mice ; Mice, Inbred BALB C ; Porcine respiratory and reproductive syndrome virus ; genetics ; immunology ; Recombinant Fusion Proteins ; genetics ; immunology ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Swine ; Viral Envelope Proteins ; biosynthesis ; genetics ; Viral Vaccines ; genetics ; immunology

LTB gene fragment was amplified by PCR from plasmid pMDTLT, and a recombinant plasmid pETLTBVP1 was constructed by inserting LTB gene fragment into VP1 gene expression plasmid pETVP1 constructed previously. The recombinant plasmids were transformed into E. coli BL21(DE3) and induced to express by IPTG. The recombinant protein existed in the inclusion body and its molecular weight was about 39 kD proved by SDS-PAGE analysis. Western blotting showed that the fusion protein could be reacted with both anti-FMDV and anti-cholera toxin serum demonstrating the immunoactivity of the fusion protein. Strong immune responses can be induced in mice inoculated with the fusion protein intraperitoneally, and the serum antibody level is higher than that of commercial foot-and-mouth disease vaccines.
Animals ; Antibodies, Viral ; blood ; Bacterial Toxins ; genetics ; immunology ; metabolism ; Capsid Proteins ; genetics ; immunology ; metabolism ; Enterotoxins ; genetics ; immunology ; metabolism ; Escherichia coli ; genetics ; metabolism ; Escherichia coli Proteins ; Female ; Gene Fusion ; genetics ; Mice ; Plasmids ; genetics ; Recombinant Fusion Proteins ; genetics ; immunology ; metabolism

OBJECTIVETo observe the specific cellular and humoral immune responses after immunization with recombinant adenovirus Ad5F35-LMP2 in rhesus monkeys.

METHODSSixteen rhesuses were immunized with Ad5F35-LMP2 through intra-muscular injection in three groups: high dosage group (1.5 x 10(10) TCID(50)/rhesus), medium dosage group (1.5 x 10(9)TCID(50)/rhesus), low dosage group (1.5 x 10(8)TCID50/rhesus) and the last group was control (PBS 4 ml/rhesus). They were totally immunized three times at intervals of one month. The EBV-LMP2 specific cellular immune responses were tested during the 0, 4, 8, 12 weeks by Elispot after immunization respectively. And the titers of anti-LMP2 antibody were tested by EIA at the same time.

RESULTSEBV-LMP2 specific cellular and humoral immune responses which were induced by recombinant adenovirus Ad5F35-LMP2 can be found in all the three dosage groups. The potency of immune responses was related with the dosage of immunization. Higher dosage elicited more potent immune response.

CONCLUSIONThe recombinant adenovirus Ad5F35-LMP2 could elicit LMP2 specific cellular and humoral immune responses in rhesus.

Adenoviruses, Human ; genetics ; Animals ; Cell Differentiation ; Herpesvirus 4, Human ; genetics ; Immunity, Cellular ; immunology ; Immunization ; methods ; Macaca mulatta ; Recombinant Fusion Proteins ; genetics ; immunology ; Viral Matrix Proteins ; genetics ; immunology

Transmembrane protein p185 (the product of Her2/c-erbB-2 gene) is a member of the epidermal growth factor receptor (EGFR) family. Its overexpression was found in about 30% of breast cancer. It is essential to obtain soluble extracellular domain (ECD) of p185, especially disulfide bond rich domains, for identifying the epitopes of anti-p185 antibodies and researching the interrelationship between the antigen and antibody. The disulfide bond rich domain I-II and domain IV of p185 ECD were amplified from plasmid pBabe/erbB-2 by PCR respectively. These two fragments were inserted into pGEX/4T-1 vector, transfected into E. coli Origami B (DE3) pLysS and expressed inductively by low concentration of IPTG and low temperature overnight. After the pressure lysis of cells, the supernatants were analyzed by SDS-PAGE and the result demonstrated that this GST-fusion protein was expressed solubly in the amount of 10-15 mg/L. By the ELISA, Western blot and other immunological assays, the fusion proteins and their GST cut-off derivates both showed binding activities with several anti-p185 antibodies respectively. These results indicated that it was a feasible and effectual method to express disulfide bond rich domain I-II and domain IV of p185 ECD and this method may also be used to express other disulfide bond rich proteins.
Antibodies, Monoclonal ; immunology ; Disulfides ; immunology ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Humans ; Receptor, ErbB-2 ; biosynthesis ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Solubility ; Transfection

OBJECTIVETo construct eukaryotic expression plasmid IRES-gD-IL-2 which contains both HSV-1 glycoprotein D (gD) gene and IL-2 gene and to induce it to express in antigen presenting cell (APC) -- dendritic cells (DCs).

METHODSThe whole sequence of gD and IL-2 were amplified by PCR assay. After confirmation by PCR, double-enzyme digestion and sequencing, these genes were directly cloned into eukaryotic expression vector IRES, then were transfected into DCs. Western blotting was employed to identify the transcription and expression of gD gene.

RESULTSThe results of PCR and enzyme digestion showed that the recombinant expression plasmid contained correct fragments, and the transcription and expression of gD were confirmed by Western blotting.

CONCLUSIONThe recombinant expression vector IRES-gD-IL-2 was constructed, the results of the Western blotting showed that the recombinant protein could be identified by gD- specific antibody, therefore the protein has immunologic competence.

Blotting, Western ; Dendritic Cells ; metabolism ; Herpes Simplex Virus Vaccines ; immunology ; Humans ; Interleukin-2 ; genetics ; Plasmids ; Recombinant Fusion Proteins ; genetics ; immunology ; Vaccines, DNA ; immunology ; Viral Envelope Proteins ; genetics