Objective To prepare mouse anti-human lymphocyte activation gene 3 (LAG3) monoclonal antibody (mAb) and perform immunological identification of the antibody. Methods BALB/c mice were immunized with LAG3-mLumin-3T3 cells, which stably express the extracellular and transmembrane regions of human LAG3 in mouse 3T3 cells. The secretion of anti-human LAG3 antibodies in mouse serum was assessed using flow cytometry and immunofluorescence. SP2/0 cells were injected subcutaneously into the mice to elicit solid myelomas, and mouse myeloma cells were subsequently isolated. Spleen cells from the immunized mice were fused with the myeloma cells to establish hybridomas, which were then separated using the limiting dilution method. Flow cytometry was used to detect LAG3 mAbs in the hybridoma culture medium. To map the epitopes recognized by these mAbs, 3T3 cells expressing individual extracellular domains of LAG3(LAG3 domains 1/-2/-3/-4-3T3) were used. Flow cytometry was also applied to analyze LAG3 expression on activated human peripheral blood mononuclear cells (PBMC) before and after co-culture with the LAG3 mAbs. Results Mice immunized with the recombinant eukaryotic cell antigen produced anti-LAG3 antibodies. The generated hybridomas secreted mouse anti-human LAG3 mAbs, with each hybridoma line recognizing different LAG3 antigenic domains. Conclusion Mouse anti-human LAG3 mAbs were successfully generated, with different hybridoma clones secreting antibodies that recognize distinct LAG3 epitopes. These findings lay the groundwork for further studies into the biological properties of LAG3 and the development of diagnostic reagents and therapeutic blocking antibodies for cancer treatment.
Animals ; Humans ; Mice ; Lymphocyte Activation Gene 3 Protein ; Antibodies, Monoclonal/immunology* ; Mice, Inbred BALB C ; Hybridomas/immunology* ; Antigens, CD/genetics* ; Immunization ; Recombinant Proteins/immunology* ; Female ; Eukaryotic Cells/immunology* ; Flow Cytometry ; Epitopes/immunology*

OBJECTIVE: To construct a eukaryotic expression vector encoding human nasopharyngeal carcinoma anti-idiotype antibody single chain fragment (ScFv) gene G22, and to identify its expression in rectal cancer cells (CMT-93). METHODS: The G22 gene was ligated into the sites of EcoRI and NotI of eukaryotic expression vector pcDNA3.1(+). After the identification and DNA sequencing, the recombinant plasmid pc DNA3.1(+)-G22 was stably transfected into CMT-93 cells, and the expression of G22 was detected by Western blot, flow cytometry and immunofluorescence staining. RESULTS: Restriction enzyme digestion and DNA sequencing showed that the recombinant plasmid contained the human nasopharyngeal carcinoma anti-idiotype antibody ScFv gene G22. Transfection experiment verified that G22 gene could be expressed in CMT-93 cells in the right way. CONCLUSION The eukaryotic expression vector containing the human nasopharyngeal carcinoma anti-idiotype antibody ScFv gene G22 is successfully constructed and expressed, which is the basis for further study of its DNA vaccine.
Antibodies, Anti-Idiotypic ; genetics ; Antibodies, Neoplasm ; genetics ; immunology ; Eukaryotic Cells ; metabolism ; Genetic Vectors ; Humans ; Immunoglobulin Variable Region ; genetics ; Nasopharyngeal Neoplasms ; immunology ; Recombinant Proteins ; biosynthesis ; genetics

The purpose of this study was to construct the IgHV and IL-2 coexpressed vector. The IgHV gene fragments were obtained from the peripheral blood of patients with lymphoma, and were cloned into eukaryotic expression vector. Meanwhile, the gene fragments of IgHV linked with gene of IL-2 were inserted into pcDNA3.0 to form a fusion gene of IgHV-IL-2. Then fusion genes were transfected into COS cells by Lipofectin and the expression of IL-2 was detected by ELISA. The results showed that the IgHV/pcDNA3.0 expression vector was successfully constructed. The 3' end of IgHV was linked to IL-2 gene, and IL-2 could be correctly expressed. In conclusion, the expression vector of IgHV-IL-2 can express IL-2 correctly in COS cells.
Cancer Vaccines ; immunology ; Eukaryotic Cells ; metabolism ; Genes, Immunoglobulin ; Genetic Vectors ; Humans ; Immunoglobulin Heavy Chains ; genetics ; Immunoglobulin Variable Region ; genetics ; Interleukin-2 ; biosynthesis ; genetics ; Lymphoma ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Vaccines, DNA ; biosynthesis ; genetics ; immunology

OBJECTIVESTo construct a novel virus-like particulate peptide-nucleic acid vaccine (VPNV) of human telomerase reverse transcriptase (hTERT), and to study its anti-liver cancer immunity.

METHODSA cationic antigenic peptide was synthesized and purified, and then human granulocyte macrophage colony stimulating factor (hGM-CSF) and TERT gene were cloned into the eukaryotic expression vector pTCAE. The peptide was combined with the nucleic acid vaccine to make a VPNV, which was transfected into eukaryotic cell COS-7. The immunogenicity of hGM-CSF and hTERT were detected using ELISA and Western blot. The efficacy of VPNV for inducing antigen specific CTL response was determined using the lactate dehydrogenase release method.

RESULTSVPNV was verified capable to trigger specific CTL responses and has shown a specific cytolytic activity to liver cancer cell HepG2.

CONCLUSIONA VPNV which can stimulate antigen specific CTL response was successfully constructed. This paves the way for our further investigation of anti-liver cancer immunity in mice.

Animals ; Cancer Vaccines ; immunology ; Cloning, Molecular ; Eukaryotic Cells ; metabolism ; Female ; Granulocyte-Macrophage Colony-Stimulating Factor ; genetics ; immunology ; Liver Neoplasms ; immunology ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Peptide Nucleic Acids ; genetics ; immunology ; Telomerase ; genetics ; immunology ; Vaccines, DNA ; immunology

The recombinant PSMA DNA vaccine for active immunotherapy of prostate cancer was investigated. Two DNA vaccine recombinant plasmids, pcDNA3.1/PSMA and pcDNA3.1/hBD-2-PSMA, were constructed by inserting the hBD-2 gene and PSMA gene into an eukarytoic expression vector pcDNA3.1. Expression of the two recombinants was detected in transfected COS-7 cells and inoculated mouse muscular cells by RT-PCR and immunohistochemical method. When immunized with pcDNA3.1/PSMA and pcDNA3.1/hBD-2-PSMA, the immunized BALB/c mice acquired specific antibody and T cell response to PSMA. The quantity of the spleen lymphocytes and their CTL activity against PSMA gene transfected-BALB/3T3 cells significantly increased in the immunized mice, and the CTL activity of lymphocytes from pcDNA3.1/hBD-2-PSMA immunized mice was significantly higher than that of pcDNA3.1/PSMA immunized mice. This result suggests that pcDNA3.1/hBD-2-PSMA would probably be developed as a DNA vaccine for the immunotherapy of prostate cancer.
3T3 Cells ; Animals ; Eukaryotic Cells ; metabolism ; Genetic Vectors ; Humans ; Immunotherapy, Active ; Male ; Mice ; Mice, Inbred BALB C ; Plasmids ; immunology ; Prostate-Specific Antigen ; genetics ; immunology ; Prostatic Neoplasms ; immunology ; pathology ; therapy ; Recombinant Fusion Proteins ; immunology ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection ; Tumor Cells, Cultured ; Vaccines, DNA ; genetics ; immunology ; beta-Defensins ; genetics ; immunology

OBJECTIVETo construct the eukaryotic expression system of L.interrogans lipL32/1-ompL1/1 fusion gene and to identify the immunoreactivity of expression products.

METHODSPCR with linking primer was used to construct the fusion gene lipL32/1-ompL1/1. The P.pastoris eukaryotic expression system of the fusion gene, pPIC9K-lipL32/1-ompL1/1-P. pastorisGS115, was constructed after the fusion gene was cloned and sequenced. Colony with phenotype His(+)Mut(+) was isolated by using MD and MM plates and His(+) Mut(+) transformant with high resistance to G418 was screened out by using YPD plate. Using lysate of His(+) Mut(+) colony with high copies of the target gene digested with yeast lyase as the template and 5'AOX1 and 3'AOX1 as the primers, the target fusion gene in chromosome DNA of the constructed P. pastoris engineering strain was detected by PCR. Methanol in BMMY medium was used to induce the target recombinant protein rLipL32/1-rOmpL1/1 expression. rLipL32/1-rOmpL1/1 in the medium supernatant was extracted by using ammonium sulfate precipitation and Ni-NTA affinity chromatography. Output and immunoreactivity of rLipL32/1-rOmpL1/1 were measured by SDS-PAGE and Western blot methods, respectively.

RESULTSAmplification fragments of the obtained fusion gene lipL32/1-ompL1/1 was 1794 bp in size. The homogeneity of nucleotide and putative amino acid sequences of the fusion gene were as high as 99.94 % and 100 %, respectively, compared with the sequences of original lipL32/1 and ompL1/1 genotypes. The constructed eukaryotic expression system was able to secrete rLipL32/1-rOmpL1/1 with an output of 10 % of the total proteins in the supernatant, which located the expected position after SDS-PAGE. The rabbit anti-rLipL32/1 and anti-rOmpL1/1 sera could combine the expressed rLipL32/1-rOmpL1/1.

CONCLUSIONAn eukaryotic expression system with high efficiency in P.pastoris of L.interrogans lipL32/1-ompL1/1 fusion gene was successfully constructed in this study. The expressed fusion protein shows specific immunoreactivity, which can be used as a potential antigen for developing a novel vaccine of L.interrogans.

Amino Acid Sequence ; Antigens, Bacterial ; genetics ; immunology ; Bacterial Outer Membrane Proteins ; genetics ; Base Sequence ; Cloning, Molecular ; Eukaryotic Cells ; metabolism ; Gene Expression Regulation, Bacterial ; Genes, Bacterial ; genetics ; Humans ; Leptospira interrogans ; genetics ; Leptospirosis ; immunology ; microbiology ; Lipoproteins ; genetics ; Molecular Sequence Data ; Polymerase Chain Reaction ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Vaccines, Synthetic ; immunology

OBJECTIVEThe purpose of this study was to clone the soluble form of the mouse BlyS (msBlyS) and insert it into a eukaryotic expression vector pSecTag2B in order to further elucidat the antitumor activity induced by msBlyS expressed by the recombined plasmid pSecTag2B-msBlyS.

METHODSFull length cDNA of mouse soluble BlyS (msBlyS) was amplified by reverse transcription-PCR from total RNA of mouse spleen. The PCR product was ligated directly with linearized vector pCR2.1 supplied in the TA cloning kit. The recombined plasmid pCR2.1-msBlyS which was selected and identified using blue-white screening method and restriction map analysis and the purified original plasmid pSecTag2B were both cut by HindIII and EcoR I. The digested fragments were extracted and purified from low-melting temperature agarose and ligated by T4DNA ligase. The recombined plasmid pSecTag2B-msBlyS were isolated and identified by restricted endonuclease cutting and Sanger dideoxy DNA sequencing.

RESULTSThe sequencing data indicated that inserted msBlyS gene had correct DNA sequence and orientation.

CONCLUSIONEukaryotic expression vector pSecTag2B. Expressing mouse BlyS have successfully been cloned. This will provide us an opportunity to do further research work on BlyS.

Animals ; B-Cell Activating Factor ; Cloning, Molecular ; Epitopes, B-Lymphocyte ; genetics ; Eukaryotic Cells ; metabolism ; Genetic Vectors ; Membrane Proteins ; biosynthesis ; genetics ; Mice ; Mice, Inbred BALB C ; Plasmids ; genetics ; Polymerase Chain Reaction ; Receptors, Tumor Necrosis Factor ; biosynthesis ; genetics ; Recombination, Genetic ; Sequence Analysis, DNA ; Spleen ; cytology ; immunology ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics

OBJECTIVETo evaluate the expression of recombinant plasmid pcDNA3.1/GBD of glucan binding protein of Streptococcus mutans in mammalian cells COS-7.

METHODSEukaryotic plasmid carrying encoding gene of GBD of Streptococcus mutans gbpA was constructed and the plasmid was introduced into COS-7 cells by Lipofectamine reagent. The transient expressed protein in COS-7 cells was detected by immunochemistry technique.

RESULTSThe positive expression was detected in plasma of the cells which were transfected with recombinant plasmid pcDNA3.1/GBD. The cells which were transfected with pcDNA3.1 were negative.

CONCLUSIONGBD can translate and express in COS-7 cells after transfected with recombinant plasmid pcDNA3.1/GBD. The expressed protein locates in the plasma and the protein is able to combine with anti-GbpA antibody. The expressed protein has the antigenicity and is a candidate gene vaccine.

Animals ; Antigens, Surface ; biosynthesis ; genetics ; immunology ; Bacterial Proteins ; biosynthesis ; genetics ; immunology ; COS Cells ; Carrier Proteins ; biosynthesis ; genetics ; immunology ; Dental Caries ; prevention & control ; Eukaryotic Cells ; metabolism ; Gene Expression ; Genetic Vectors ; Humans ; Lectins ; Mammals ; Plasmids ; genetics ; immunology ; Recombinant Proteins ; Streptococcus mutans ; genetics ; metabolism ; Transfection ; Vaccines, DNA

The LACK gene from Leishmania, an analogue of the receptor of activated protein kinase C, was discovered recently. In this study, the LACK gene of Leishmania donovani was obtained from the recombinant plasmid T-LACK by PCR. The gene was cloned into eukaryotic expressed plasmid pcDNA3.1(+) to construct recombinant plasmid. This recombinant plasmid then was transfected into the eukaryotic cell COS-7, and the expression of LACK gene in eukaryotic cell was detected by RT-PCR and immunofluorescent staining. Both RT-PCR and immunofluorescent staining of recombinant plasmid transfected COS-7 showed positive reaction, thus indicating that the recombinant plasmid pcDNA3-LACK can express LACK protein in euka ryotic cell COS-7.
Animals ; Antigens, Protozoan ; biosynthesis ; genetics ; immunology ; COS Cells ; Cloning, Molecular ; DNA, Recombinant ; biosynthesis ; genetics ; Eukaryotic Cells ; metabolism ; Genetic Vectors ; Leishmania donovani ; Plasmids ; genetics ; Protozoan Proteins ; biosynthesis ; genetics ; immunology ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection ; Vaccines, DNA

OBJECTIVEGene vaccine security is of concern because of the possibility of insertion mutagenesis resulting in inactivation of tumor suppressor or activation of oncogene. The purpose of this study was to examine the potential of anti-caries DNA vaccine pcDNA3-gtfB integrating into the host cell genome.

METHODSAnti-caries DNA vaccine pcDNA3-gtfB was constructed by the previous study. The gtfB gene(904-4,578 bp, genebank M17361) was cloned from Streptococcus mutans GS-5. 36 Wistar rats were divided into 2 groups: submandibular gland-targeted injection(SGT) group and control group. Rats in SGT group were injected with 100 micrograms of plasmid pcDNA3-gtfB, rats in control group with PBS solution. Genomes from submandibular gland, kidney, heart, liver, lung, and brain tissues were isolated later in 12 weeks. Genomes from different tissues were purified by low-melting agarose electrophoresis. Using the purified genomes as template, plasmid integration were examined by PCR(upper primer: 5'-ATATGGTACCATGACCGAAGCGACATCTAAGCAAGA-3', lower primer: 5'-ACTACTCGAGTTAGAACCATTGACCCTG AGCATTGC-3'). The sensitivity level of PCR was determined by adding gradient plasmid copies into genomes in control group.

RESULTSThe examination of 6 tissues failed in revealing any evidence of integration at the sensitivity level that could detect 1 copy integration in 10,000 nuclei.

CONCLUSIONThe potential frequency of plasmid pcDNA3-gtfB integration into host cell genome would not exceed that of the spontaneous mutation. It was indicated that pcDNA3-gtfB was genetically safe as a promising anti-carious DNA vaccine.

Animals ; Antibodies, Antinuclear ; genetics ; immunology ; Cloning, Molecular ; Dental Caries ; prevention & control ; Eukaryotic Cells ; metabolism ; Genetic Vectors ; Glucosyltransferases ; genetics ; Plasmids ; genetics ; immunology ; Rats ; Rats, Wistar ; Recombination, Genetic ; Streptococcal Vaccines ; genetics ; Streptococcus mutans ; genetics ; immunology ; Vaccines, DNA ; adverse effects ; genetics ; immunology