OBJECTIVETo observe the effects of recombinant fusion protein interleukin (IL)-18 on the expression of immune-inflammatory factors in the mice infected with Staphylococcus aureus (SA), and to investigate the mechanism of action of IL-18 in defense of SA infection in vivo.

METHODSA total of 40 specific pathogen-free female BLAB/c mice were randomly divided into four groups: control, SA infection, immunized, and intervention. A mouse model of SA infection was established by nasal inoculation with SA liquid. The immunized group and the intervention group were intranasally given IL-18 before SA modeling, and then the SA infection group and the intervention group received the nasal inoculation with SA liquid; the control group was treated with phosphate buffered saline instead. The levels of IL-4, interferon (IFN)-γ, tumor necrosis factor (TNF), granulocyte colony-stimulating factor (G-CSF), IgM in the serum and bronchoalveolar lavage fluid (BALF) of mice were measured by enzyme-linked immunosorbent assay. The expression of macrophage inflammatory protein (MIP)-1α mRNA and MIP-2β mRNA in the lung tissue of mice were determined by real-time fluorescent quantitative PCR.

RESULTSCompared with the control group, the SA infection group and the immunized group had significantly higher levels of IL-4, G-CSF, and IgM in the serum and BALF and expression of MIP-1α mRNA and MIP-2β mRNA in the lung tissue (P<0.05); the SA infection group had a significantly lower level of IFN-γ and a significantly higher level of TNF in the serum and BALF (P<0.05); the immunized group had a significantly higher level of IFN-γ in the serum and BALF (P<0.05). Compared with the SA infection group, the intervention group had significantly higher levels of IL-4, IFN-γ, G-CSF, and IgM in the serum and BALF and expression of MIP-1α mRNA in the lung tissue. In contrast, the intervention group showed a significantly lower level of TNF in the serum and BALF and expression of MIP-2β mRNA in the lung tissue (P<0.05). All the above indicators in the intervention group were significantly higher than those in the control group (P<0.05), except the serum level of IFN-γ.

CONCLUSIONSIn the mice infected with SA, the recombinant fusion protein IL-18 by mucosal immunity can affect inflammatory factors in the serum and BALF and the expression of MIP-1α mRNA and MIP-2β mRNA in the lung tissue to promote the anti-infective immune response and enhance the ability to clear pathogens.

Animals ; Chemokine CCL3 ; analysis ; Female ; Granulocyte Colony-Stimulating Factor ; blood ; Interferon-gamma ; blood ; Interleukin-18 ; therapeutic use ; Interleukin-4 ; blood ; Mice ; Mice, Inbred BALB C ; Recombinant Fusion Proteins ; pharmacology ; therapeutic use ; Staphylococcal Infections ; drug therapy ; immunology

Dirofilaria immitis (heartworm) infections affect domestic dogs, cats, and various wild mammals with increasing incidence in temperate and tropical areas. More sensitive antibody detection methodologies are required to diagnose asymptomatic dirofilariasis with low worm burdens. Applying current transcriptomic technologies would be useful to discover potential diagnostic markers for D. immitis infection. A filarial homologue of the mammalian translationally controlled tumor protein (TCTP) was initially identified by screening the assembled transcriptome of D. immitis (DiTCTP). A BLAST analysis suggested that the DiTCTP gene shared the highest similarity with TCTP from Loa loa at protein level (97%). A histidine-tagged recombinant DiTCTP protein (rDiTCTP) of 40 kDa expressed in Escherichia coli BL21 (DE3) showed immunoreactivity with serum from a dog experimentally infected with heartworms. Localization studies illustrated the ubiquitous presence of rDiTCTP protein in the lateral hypodermal chords, dorsal hypodermal chord, muscle, intestine, and uterus in female adult worms. Further studies on D. immitis-derived TCTP are warranted to assess whether this filarial protein could be used for a diagnostic purpose.
Animal Structures/chemistry ; Animals ; Antibodies, Helminth/blood ; Antigens, Helminth/chemistry/*genetics/immunology/*isolation & purification ; Cloning, Molecular ; Dirofilaria immitis/chemistry/*genetics/immunology ; Disease Models, Animal ; Dogs ; Escherichia coli/genetics ; Gene Expression ; Molecular Sequence Data ; Molecular Weight ; Recombinant Fusion Proteins/chemistry/genetics/immunology/isolation & purification ; Sequence Analysis, DNA ; Tumor Markers, Biological/chemistry/*genetics/immunology/*isolation & purification

Cartilage oligomeric matrix protein-angiopoietin-1 (COMP-Ang1) is an angiogenic factor for vascular angiogenesis. The aim was to investigate the effect of an intracavernosal injection of COMP-Ang1 on cavernosal angiogenesis in a diabetic rat model. Male Otsuka Long-Evans Tokushima Fatty (OLETF) rats made up the experimental group (1 yr old) and Long-Evans Tokushima Otsuka (LETO) rats made up the control group. The experimental group was divided into vehicle only, 10 microg COMP-Ang1, and 20 microg COMP-Ang1. COMP-Ang1 was injected into the corpus cavernosum of the penis. After 4 weeks, the penile tissues of the rats were obtained for immunohistochemistry and Western blot analysis. The immunoreactivity of PECAM-1 and VEGF was increased in the COMP-Ang1 group compared with the vehicle only group. Moreover, the expression of PECAM-1 and VEGF was notably augmented in the 20 microg Comp Ang-1 group. In the immunoblotting study, the expression of PECAM-1 and VEGF protein was significantly less in the OLEFT rats than in the control LETO rats. However, this expression was restored to control level after intracavernosal injection of COMP-Ang1. These results show that an intracavernosal injection of COMP-Ang1 enhances cavernous angiogenesis by structurally reinforcing the cavernosal endothelium.
Angiopoietin-1/genetics/*metabolism ; Animals ; Antigens, CD31/metabolism ; Blood Glucose/analysis ; Blotting, Western ; Body Weight ; Cartilage Oligomeric Matrix Protein/genetics/*metabolism ; Diabetes Mellitus, Experimental/*pathology ; Immunohistochemistry ; Male ; Neovascularization, Physiologic/*drug effects ; Penis/metabolism/pathology ; Rats ; Rats, Long-Evans ; Recombinant Fusion Proteins/biosynthesis/genetics/*pharmacology ; Vascular Endothelial Growth Factor A/metabolism

Anti-angiogenesis mechanism plays a vital role in tumor targeting immunotherapy. Based on the amino acid sequence of an anti-VEGFR-2 scFv-Fc fusion antibody (AK404R-Fc), this article is aimed to generate an anti-VEGFR-2 human IgG1-like full length antibody (Mab-04). Firstly, the light chain (L-chain) and heavy chain (H-chain) were obtained by overlap PCR and then linked to eukaryotic expression vector pcDNA3.1, separately. The recombinant plasmids (pcDNA3.1-L-chain and pcDNA3.1-H-chain) were then co-transfected into CHO-k cells using liposome transient transfection. Subsequently, Mab-04 antibody was expressed and purified by Protein A affinity chromatography. Western blotting was applied to identify the expression of Mab-04 and its affinity was detected by ELISA assay. DNA sequencing revealed the successful construction of recombinant plasmids and Western blotting assay proved the successful expression of full-length antibody (1 microg x mL(-1)). Finally, ELISA assay illustrated that the binding of the antibody to its antigen was in a concentration-dependent manner (IC50: 50 nmol x L(-1)). These outcomes above indicated that Mab-04 was successfully expressed and assembled, which laid the foundation for further preparation and antineoplastic activity study.
Animals ; Antibodies, Monoclonal, Humanized ; analysis ; CHO Cells ; Cricetulus ; Genetic Vectors ; Immunoglobulin Fc Fragments ; genetics ; Immunoglobulin G ; genetics ; immunology ; Plasmids ; Recombinant Fusion Proteins ; analysis ; genetics ; Single-Chain Antibodies ; genetics ; Transfection ; Vascular Endothelial Growth Factor Receptor-2 ; genetics ; immunology

PURPOSE: SNF2L belongs to Imitation Switch family and plays an essential role in neural tissues and gonads. In our previous studies, we have demonstrated that the basal transcription of human SNF2L gene is regulated by two cis-elements, cAMP response element (CRE)- and Sp1-binding sites. Recent studies suggested that cyclic adenosine monophosphate (cAMP) stimulation significantly up-regulated SNF2L expression in ovarian granulose cells. These data suggested that protein kinase-mediated signal pathways might also regulate SNF2L expression in neural cells. We therefore investigated the effects of agents that activate protein kinases A on SNF2L gene expression in neural cells. MATERIALS AND METHODS: To increase intracellular cAMP levels, all neural cells were treated with forskolin and dbcAMP, two cAMP response activators. We exmined the effects of cAMP on the promoter activity of human SNF2L gene by luciferase reporter gene assays, and further examined the effects of cAMP on endogenous SNF2L mRNA levels by qPCR. RESULTS: Transient expression of a luciferase fusion gene under the control of the SNF2L promoter was significantly increased by treatment of rat primary neurons with forskolin or dbcAMP, but not PC12, C6 and SH-SY5Y cells. Consistently, treatment with forskolin or dbcAMP could enhance endogenous SNF2L mRNA levels also only in rat primary neurons. CONCLUSION: These results suggest that the CRE consensus sequence in the SNF2L proximal promoter most likely confers constitutive activation and regulation by cAMP in neural cells.
Animals ; Bucladesine/pharmacology ; Cell Line ; Colforsin/pharmacology ; Cyclic AMP/*metabolism ; DNA-Binding Proteins/chemistry/*genetics/metabolism ; *Gene Expression Regulation ; Humans ; Luciferases/analysis ; Neurons/*metabolism ; PC12 Cells ; Promoter Regions, Genetic ; RNA, Messenger/metabolism ; Rats ; Rats, Wistar ; Recombinant Fusion Proteins/analysis ; *Response Elements ; Transcription Factors/chemistry/*genetics/metabolism

The CBD gene from Trichoderma reesei was cloned into the Corynebacterium glutamicum secretion expression vector pXMJ19-sp, in which green fluorescent protein was inserted to obtain pXMJ19-sp-GFP-CBD. After induced by 0.5 mmol/L IPTG, GFP-CBD was expressed in Corynebacterium glutamicum at high level of 200 mg/L. The GFP-CBD could be purified to high purity with cellulose column. The results indicated CBD can be successfully used in Corynebacterium glutamicum expression system and thus offer an extremely simple, effective and scalable way for production of recombinant proteins.
Base Sequence ; Cellulases ; biosynthesis ; genetics ; Cellulose ; chemistry ; genetics ; Cloning, Molecular ; Corynebacterium glutamicum ; genetics ; metabolism ; Cost-Benefit Analysis ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; genetics ; metabolism ; Molecular Sequence Data ; Protein Engineering ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Trichoderma ; genetics

Bartter syndrome (BS) is classified into 5 genotypes according to underlying mutant genes and BS III is caused by loss-of-function mutations in the CLCNKB gene encoding for basolateral ClC-Kb. BS III is the most common genotype in Korean patients with BS and W610X is the most common CLCNKB mutation in Korean BS III. In this study, we tested the hypothesis that the CLCNKB W610X mutation can be rescued in vitro using aminoglycoside antibiotics, which are known to induce translational read-through of a nonsense mutation. The CLCNKB cDNA was cloned into a eukaryotic expression vector and the W610X nonsense mutation was generated by site-directed mutagenesis. Cultured polarized MDCK cells were transfected with the vectors, and the read-through was induced using an aminoglycoside derivative, G418. Cellular expression of the target protein was monitored via immunohistochemistry. While cells transfected with the mutant CLCNKB failed to express ClC-Kb, G418 treatment of the cells induced the full-length protein expression, which was localized to the basolateral plasma membranes. It is demonstrated that the W610X mutation in CLCNKB can be a good candidate for trial of translational read-through induction as a therapeutic modality.
Animals ; Bartter Syndrome/genetics/*pathology ; Chloride Channels/analysis/genetics/*metabolism ; Cloning, Molecular ; Codon, Nonsense ; Dogs ; Humans ; Immunohistochemistry ; Madin Darby Canine Kidney Cells ; Microscopy, Confocal ; Mutagenesis, Site-Directed ; Recombinant Fusion Proteins/analysis/biosynthesis/genetics ; Transfection

When we try to establish the gene recombinant yeast cell to screen the androgenic endocrine disruptors, the key procedure is the androgen receptor (AR) expression in the yeast cell. For this purpose, we obtained the GPD (glyceraldehyde-3-phosphote dehydrogenase) promoter from the yeast genosome of W303-1A using PCR system and inserting it into Swa I and BamH I sites of pYestrp2. The new constructed vector was named pGPD. The V5 epitope tag DNA with a 5'-BamH I and a 3'-EcoR I sticky end was cloned into the corresponding site of the pGPD vector to yield the vector of pGPDV5. The 2 723 bp full length AR ORF amplified by PCR from pcDNA3.1/AR was fused to V5 epitope tag DNA in pGPDV5 to give the AR yeast expression vector of pGPDV5/AR. This fused vector was transformed into the yeast cell (W303-1A). Western blot was used to detect the V5 fused protein of AR, in the protocol of which the primary monoclonal antibody (IgG(2a)) of mouse anti-V5 and the polyclonal secondary antibody of goat anti-mouse (IgG) linked to horseradish peroxidase (HRP) were used to detect the specific protein in the given sample of the transformed yeast extract. The result showed that the fused protein of AR was expressed successfully in the yeast cell.
Base Sequence ; Endocrine Disruptors ; analysis ; Epitopes ; biosynthesis ; genetics ; Genetic Vectors ; genetics ; Glyceraldehyde-3-Phosphate Dehydrogenases ; genetics ; Humans ; Molecular Sequence Data ; Promoter Regions, Genetic ; Receptors, Androgen ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; genetics ; Yeasts ; genetics ; metabolism

This experimental study was aimed to construct the recombinant bisbicistronic eukaryotic expression vector containing endocrine and exocrine protein (EECP) gene associated with breast cancer and enhanced green fluorescent protein (EGFP) gene. And then we transfected it into breast cancer cells MCF-7 to detect the expression of EECP protein and study preliminary biological function of EECP gene. The EECP sequence was cloned to pBluescript II SK (+) plasmid. After restriction endonuclease reaction of pBluescript II SK(+) plasmid, the EECP fragment was cloned to pIRES2-EGFP vector forming a recombinant eukaryotic expression vector named pEECP-IRES2-EGFP. The potential vector was identified by restriction endonuclease digestion and sequencing. Correct plasmid was extracted and transfected into breast cancer cells MCF-7. The expression of EECP protein was detected by western blot analysis. Its biological function was studied by MTT and Flow-cytometry. It turns out that the recombinant eukaryotic expression vector containing EECP gene and EGFP gene was constructed successfully, and it could transfect MCF-7 cells efficiently. It can get higher expression of EECP protein and higher cell proliferation, thus providing an important and convenient tool for studying the function of EECP gene in vitro and in vivo.
Base Sequence ; Breast Neoplasms ; genetics ; pathology ; Female ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; biosynthesis ; genetics ; Humans ; MCF-7 Cells ; Molecular Sequence Data ; Proteins ; analysis ; genetics ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Ribosomes ; chemistry ; metabolism

To verify the reliability of targeted detecting HER2 positive cancer cells and clinical pathological tissue specimens with a recombinant anti HER2 single chain antibody in single chain Fv fragment (scFv) format, we have constructed the fusion variable regions of the ScFv specific for HER2/neu. labeled a green-fluorescent protein(GFP). The humanized recombinant Anti HER2 ScFv-GFP gene was inserted into pFast Bac HT A, and expressed in insect cells sf9. Then the recombinant fusion protein Anti HER2 ScFv-GFP was properly purified with Ni2+-NTA affinity chromatography from the infected sf9 cells used to test the specificity of the fusion antibody for HER2 positive cancer cells. Firstly, the purified antibody incubated with HER2 positive breast cancer cells SKBR3, BT474 and HER2 negative breast cancer cells MCF7 for 12 h/24 h/48 h at 37 degrees C, in order to confirm targeted detecting HER2 positive breast cancer cells by Laser Confocal Microscopy. Furthermore, the same clinical pathological tissue samples were assessed by immunohistochemistry (IHC) and the fusion antibody Anti HER2 ScFv-GFP in the meanwhile. The data obtained indicated that the recombinant eukaryotic expression plasmid pFast Bac HT A/Anti HER2 ScFv-GFP was constructed successfully In addition, obvious green fluorescent was observed in insect cells sf9. When the purified fusion antibody was incubated with different cancer cells, much more green fluorescent was observed on the surface of the HER2 positive cancer cells SKBR3 and BT474. In contrast, no green fluorescent on the surface of the HER2 negative cancer cells MCF7 was detected. The concentration of the purified fusion antibody was 115.5 microg/mL, of which protein relative molecular weight was 60 kDa. The analysis showed the purity was about 97% and the titer was about 1:64. The detection results of IHC and fusion antibody testing indicated the conformity. In summary, the study showed that the new fusion antibody Anti HER2 ScFv-GFP can test HER2 positive cancer cells, indicating a potential candidate method for clinical HER2 positive specimens detection.
Animals ; Breast Neoplasms ; diagnosis ; pathology ; Female ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; genetics ; Humans ; MCF-7 Cells ; Receptor, ErbB-2 ; analysis ; Recombinant Fusion Proteins ; genetics ; Sf9 Cells ; Single-Chain Antibodies ; genetics