Objective Currently, there is no commercially available quantitative detection kit for the main Felis domestic allergen (Fel d 1) in China. To establish a rapid detection method for Fel d 1, this study aims to prepare monoclonal antibodies against Fel d 1 protein. Methods The codon preference of Escherichia coli was utilized to optimize and synthesize the Fel d 1 gene. The prokaryotic expression plasmid pET-28a-Fel d 1 was constructed and used to express and purify the recombinant Fel d 1 protein. Subsequently, the recombinant protein was immunized into BALB/c mice and monoclonal antibodies (mAbs) were prepared by the hybridoma technique. An indirect ELISA was established using the recombinant Fel d 1 as the coating antigen, and hybridoma cell lines were screened for positive clones. The specificity and antigenic epitopes of the mAbs were confirmed by Western blot analysis. Finally, the selected hybridoma cells were injected into the peritoneal cavities of BALB/c mice for large-scale monoclonal antibody production. Results The recombinant plasmid pET-28a-Fel d 1 was successfully constructed, and soluble Fel d 1 protein was obtained after optimizing the expression conditions. Western blot and antibody titer assays confirmed the successful isolation of two hybridoma cell lines, 7D11 and 5H4, which stably secreted mAbs specific to Fel d 1. Antibody characterization revealed that the 5H4 mAb was of the IgG2a subtype and could recognize the amino acid region 105-163 of Fel d 1, while the 7D11 mAb was the IgG1 subtype and could recognize the amino acid region 1-59. Conclusion The high-purity recombinant Fel d 1 protein produced in this study provides a promising alternative for clinical immunotherapy of cat allergies. Furthermore, the monoclonal antibody prepared in this experiment lays a material foundation for the in-depth study of the biological function of Fel d 1 and the development of ELISA detection.
Animals ; Antibodies, Monoclonal/biosynthesis* ; Mice, Inbred BALB C ; Cats ; Mice ; Allergens/genetics* ; Glycoproteins/genetics* ; Enzyme-Linked Immunosorbent Assay ; Hybridomas/immunology* ; Recombinant Proteins/genetics* ; Female ; Antibody Specificity

Boiled silkworm pupa is a traditional food in Asia, and patients with silkworm pupa food allergy are common in these regions. Still now only one allergen from silkworm, arginine kinase, has been identified. The purpose of this study was to identify novel food allergens in silkworm pupa by analyzing a protein extract after heat treatment. Heat treated extracts were examined by proteomic analysis. A 27-kDa glycoprotein was identified, expressed in Escherichia coli, and purified. IgE reactivity of the recombinant protein was investigated by ELISA. High molecular weight proteins (above 100 kDa) elicited increased IgE binding after heat treatment compared to that before heat treatment. The molecular identities of these proteins, however, could not be determined. IgE reactivity toward a 27-kDa glycoprotein was also increased after heating the protein extract. The recombinant protein was recognized by IgE antibodies from allergic subjects (33.3%). Glycation or aggregation of protein by heating may create new IgE binding epitopes. Heat stable allergens are shown to be important in silkworm allergy. Sensitization to the 27-kDa glycoprotein from silkworm may contribute to elevation of IgE to silkworm.
Adolescent ; Adult ; Allergens/*chemistry/*immunology ; Amino Acid Sequence ; Animals ; Bombyx/*chemistry/genetics/growth & development/*immunology ; Epitopes/immunology ; Female ; Food Hypersensitivity/etiology ; Glycoproteins/*chemistry/genetics/*immunology ; Hot Temperature ; Humans ; Immunoglobulin E/immunology ; Male ; Molecular Sequence Data ; Molecular Weight ; Proteomics ; Pupa/chemistry/immunology ; Recombinant Proteins/biosynthesis/chemistry/immunology ; Sequence Alignment

Pituitary adenomas (PAs) are well known as a common intracranial benign tumor, and a portion of PAs are refractory to current therapeutic methods. ErbB receptors family signaling pathway regulates the expression of PAs activation associated gene. Inhibition of epidermal growth factor receptor (EGFR) can inhibit proliferation of PAs. Leucine-rich repeats and immunoglobulin-like domains protein 1 ( LRIG1), a negative mediated gene of ErbB receptors family, plays a role in many tumors. However, there are seldom researches about the functional role of LRIG1 in PAs. The aim of this study is to explore the potential effect of LRIG1 and its regulating mechanism in PAs. First, we investigated the role of LRIG1 in cell migration, invasion of PAs with transfected LRIG1 or control. Then, we explored its impact on cell proliferation and apoptosis of PAs in vivo. To study the regulating mechanism of LRIG1, we examined the expression of molecular factor of PI3K/AKT and Ras/Raf/ERK pathway using Western blotting in vitro and RT-PCR in vitro and in vivo. It was found that LRIG1 over-expression inhibited cell migration, invasion and proliferation, and promoted apoptosis of PAs in vivo and in vitro. Furthermore, LRIG1 suppressed the expression of signaling of PI3K/AKT and Ras/Raf/ERK pathways in PAs. LRIG1, as a negative mediated gene of tumor, can inhibit biological function of PAs via inhibiting PI3K/AKT and Ras/Raf/ERK pathways, and it might be a new target for gene therapy of PAs.
Animals ; Apoptosis ; genetics ; Brain Neoplasms ; genetics ; pathology ; Cell Line, Tumor ; Cell Movement ; genetics ; Cell Proliferation ; genetics ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; MAP Kinase Signaling System ; genetics ; Membrane Glycoproteins ; biosynthesis ; genetics ; Mice ; Oncogene Protein v-akt ; biosynthesis ; Phosphatidylinositol 3-Kinases ; genetics ; Pituitary Neoplasms ; genetics ; pathology ; Xenograft Model Antitumor Assays ; raf Kinases ; biosynthesis ; genetics

Dendritic cells (DCs) comprise two functionally distinct subsets: plasmacytoid DCs (pDCs) and myeloid DCs (mDCs). pDCs are specialized in rapid and massive secretion of type I interferon (IFN-I) in response to nucleic acids through Toll like receptor (TLR)-7 or TLR-9. In this report, we characterized a CD56(+) DC population that express typical pDC markers including CD123 and BDCA2 but produce much less IFN-I comparing with pDCs. In addition, CD56(+) DCs cluster together with mDCs but not pDCs by genome-wide transcriptional profiling. Accordingly, CD56(+) DCs functionally resemble mDCs by producing IL-12 upon TLR4 stimulation and priming naïve T cells without prior activation. These data suggest that the CD56(+) DCs represent a novel mDC subset mixed with some pDC features. A CD4(+)CD56(+) hematological malignancy was classified as blastic plasmacytoid dendritic cell neoplasm (BPDCN) due to its expression of characteristic molecules of pDCs. However, we demonstrated that BPDCN is closer to CD56(+) DCs than pDCs by global gene-expression profiling. Thus, we propose that the CD4(+)CD56(+) neoplasm may be a tumor counterpart of CD56(+) mDCs but not pDCs.
Biomarkers ; metabolism ; CD56 Antigen ; genetics ; immunology ; Cell Lineage ; genetics ; immunology ; Dendritic Cells ; immunology ; metabolism ; pathology ; Gene Expression ; Hematologic Neoplasms ; genetics ; immunology ; pathology ; Humans ; Immunophenotyping ; Interferon Type I ; biosynthesis ; metabolism ; Interleukin-12 ; biosynthesis ; metabolism ; Interleukin-3 Receptor alpha Subunit ; genetics ; immunology ; Lectins, C-Type ; genetics ; immunology ; Membrane Glycoproteins ; genetics ; immunology ; Myeloid Cells ; immunology ; metabolism ; pathology ; Receptors, Immunologic ; genetics ; immunology ; Terminology as Topic ; Toll-Like Receptor 4 ; genetics ; immunology ; Toll-Like Receptor 7 ; genetics ; immunology ; Toll-Like Receptor 9 ; genetics ; immunology

Glycosylation is vital for activity, higher structure and function of protein. Glycoproteins derived from yeast contain N-glycan of high mannose type and are usually hyperglycosylated, while those from mammalian cells contain N-glycan of hybrid or complex type. We introduced the alpha-1,2-mannosidase I (MDSI) into yeast cells, which catalyzed an essential proceeding of N-glycan structures from Man8GlcNAc2 to Man5GlcNAc2. The plasmids contained MDSI genes from Homo sapiens [HMDSI(delta185)] or Arabidopsis thaliana [ATMDSI(delta48)], and three ER-signals were used to be transformed a mutant Pichia pastoris GJK01, respectively. The reporter protein HSA/GM-CSF (human serum albumin and granulocyte-macrophage colony stimulating factor fusion protein) was expressed and its N-glycans were analyzed by DSA-FACE (DNA sequencer assisted fluorophore-assisted carbohydrate electrophoresis). The plasmid contained ER-ScMnsI-ATMDSI(delta48) was expressed in Pichia pastoris, the Man5GlcNAc2 N-glycan on secreted glycoprotein HSA/GM-CSF was observed. The research reported here provided basic substrate to obtain the hybrid- and complex-type glycans in mammalian cell.
Gene Transfer Techniques ; Genetic Vectors ; genetics ; Glycoproteins ; biosynthesis ; Glycosylation ; Humans ; Mannose ; biosynthesis ; Oligosaccharides ; biosynthesis ; genetics ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; alpha-Mannosidase ; genetics

We tried to construct and identify the recombinant replication-deficient adenovirus vector coding for human tissue factor pathway inhibitor 2 (hTFPI-2) gene by AdMax system in HEK293 cells. Firstly, we obtained hTFPI-2 gene from the recombinant plasmid pIRES2-EGFP-TFPI-2 by PCR using primers with restriction endonuclease site of EcoRI or SacI. After digesting the hTFPI-2 gene and plasmid PDC316-IRES-EGFP shuttle vector, we ligated them with T4 ligase and formed the recombinant shuttle vector PDC316-IRES-EGFP-hTFPI-2. It was confirmed that the ligation product was inserted the gene of hTFPI-2 correctly by sequencing. Then we took cotransfection of HEK293 cells with the recombinant shuttle vector and genomic plasmid pBHGloxdeltaE1,3Cre by liposome lipofectamine2000, and finished the package of recombinant adenovirus Ad-hTFPI-2. The results of the PCR test and restriction endonuclease digestion confirmed the successful construction of the recombinants Ad-hTFPI-2. Furthermore, we measured the titre of Ad-hTFPI-2 with the aid of green fluorescence protein expression after multiplication and purification. The titre was 0.931 x 10(12) pfu/ml. Finally, we infected U937 monocytes by purified Ad-hTFPI-2, and determined the infection efficiency and the TFPI-2's level and activity. The efficiency of Ad-hTFPI-2 infection in U937 cells was 89.33%. After infected by Ad-hTFPI-2, the TFPI-2's level in supernatant increased about 7 fold. Also the TFPI-2 in supernatant had activities of inhibiting trypsin and plasmin. The recombinant adenovirus with the hTFPI-2 gene was constructed successfully. It will be helpful for the further investigation of its potentiality to be applied in antiatherosclerosis.
Adenoviridae ; genetics ; metabolism ; Defective Viruses ; genetics ; metabolism ; Genetic Vectors ; genetics ; Glycoproteins ; biosynthesis ; genetics ; Humans ; Monocytes ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; Transfection ; U937 Cells

In order to detect antibody against swine influenza virus (H1N1), HA1 region of hemagglutinin gene in epidemic swine influenza virus (H1N1) strain was amplified and subcloned into prokaryotic expression vector pET30a. Then recombinant HA1 protein was expressed by Escherichia coli BL21. The purified recombinant HA1 protein was obtained after the treatment of denaturing, refolding and affinity chromatography with immobilized nickel chelating NTA (Ni-NTA). An indirect enzyme-linked immunosorbent assay (ELISA) method was established using the purified protein as antigen. Then 785 swine serum samples collected during 2008-2009 were detected by this method, and the positive ratio was 15.54%. There were diversities among provinces (8%-47%). The diagnostic specificity and diagnostic sensitivity of this method arrived at 91% and 95% respectively, using the results of IDEXX ELISA kit as reference.
Animals ; Antibodies, Viral ; blood ; Enzyme-Linked Immunosorbent Assay ; methods ; Escherichia coli ; genetics ; metabolism ; Hemagglutinin Glycoproteins, Influenza Virus ; biosynthesis ; genetics ; Influenza A Virus, H1N1 Subtype ; immunology ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Swine

The spike (S) glycoprotein of HCoV-NL63 is a major target in the development of diagnostic assays and vaccines, but its antigenic and immunogenic properties remain unclear. Four fragments coding spike proteins (S1, S2, RL and RS) from HCoV-NL63 were amplified and cloned into the expression vector derived from vaccinia virus (Tiantan strain), and recombinant vaccinia viruses expressing four segments of spike proteins were generated (vJSC1175-S1; vJSC1175-S2; vJSC1175-RL; vJSC1175-RS), respectively. Their expression location in cell and level were characterized using indirect immune fluorescence assay (IFA) and Western-Blot, respectively. The expressions of four segments of spike proteins in recombinant vaccinia viruses were showed at appropriate level and with posttranslational modification (glycosylation), and S1, RL and RS were mainly distributed in the cell membrane, while the S2 was mainly distributed in the cytoplasm. Our results provide a basis for further exploring diagnostic role and vaccine development of different spike segments from HCoV-NL63.
Base Sequence ; Blotting, Western ; Coronavirus NL63, Human ; chemistry ; Fluorescent Antibody Technique, Indirect ; Humans ; Membrane Glycoproteins ; biosynthesis ; genetics ; Molecular Sequence Data ; Plasmids ; Recombinant Proteins ; biosynthesis ; Spike Glycoprotein, Coronavirus ; Vaccinia virus ; genetics ; Viral Envelope Proteins ; biosynthesis ; genetics

There is a great need for new vaccine development against influenza A viruses due to the drawbacks of traditional vaccines that are mainly prepared using embryonated eggs. The main component of the current split influenza A virus vaccine is viral hemagglutinin (HA) which induces a strong antibody-mediated immune response. To develop a modern vaccine against influenza A viruses, the current research has been focused on the universal vaccines targeting viral M2, NP and HA proteins. Crystallographic studies have shown that HA forms a trimer embedded on the viral envelope surface, and each monomer consists of a globular head (HA1) and a "rod-like" stalk region (HA2), the latter being more conserved among different HA subtypes and being the primary target for universal vaccines. In this study, we rationally designed the HA head based on the crystal structure of the 2009-pandemic influenza A (H1N1) virus HA as a model, tested its immunogenicity in mice, solved its crystal structure and further examined its immunological characteristics. The results show that the HA globular head can be easily prepared by in vitro refolding in an E. coli expression system, which maintains its intact structure and allows for the stimulation of a strong immune response. Together with recent reports on some similar HA globular head preparations we conclude that structure-based rational design of the HA globular head can be used for subtype-specific vaccines against influenza viruses.
Animals ; Antibodies, Viral ; immunology ; Crystallography, X-Ray ; Drug Design ; Female ; Freund's Adjuvant ; administration & dosage ; Hemagglutinin Glycoproteins, Influenza Virus ; genetics ; immunology ; Humans ; Influenza A Virus, H1N1 Subtype ; genetics ; immunology ; Influenza Vaccines ; administration & dosage ; biosynthesis ; Influenza, Human ; immunology ; prevention & control ; virology ; Mice ; Mice, Inbred BALB C ; Models, Molecular ; Protein Folding ; Recombinant Proteins ; genetics ; immunology ; Structure-Activity Relationship ; Vaccination ; Vaccines, Subunit ; administration & dosage ; biosynthesis

OBJECTIVETo explore whether overexpression of P-selectin glycoprotein ligand-1 (PSGL-1) promotes the adhesive ability of endothelial progenitor cells and functionally facilitates neovascularization in mouse model of hindlimb ischemia.

METHODSRat endothelial progenitor cells were transfected with recombinant adenovirus vector encoding human PSGL-1. The mRNA and protein expression levels of PSGL-1 were measured by RT-PCR and Western blot, respectively. The effect of overexpression of PSGL-1 in endothelial progenitor cells was analyzed by adherence assay. Histological examination of skeletal muscle sections retrieved from the mouse ischemic hindlimbs was performed, and the hindlimb blood flow was measured by laser Doppler flow meter.

RESULTSAdenovirus vector expressing of PSGL-1 gene was successfully constructed with high titer of 3.1 × 10¹¹ pfu/ml. After transfection, PSGL-1 gene was highly expressed in the transfected endothelial progenitor cells. In vitro assay showed that overexpression of PSGL-1 enhanced the adhesive properties of endothelial progenitor cells. When the transfected endothelial progenitor cells were transplanted into the ischemic hindlimb of nude mice, the number of new capillary vessels was (41.0 ± 2.2)/HPF compared to that of (21.0 ± 2.5)/HPF in the negative control group and (10.0 ± 1.6)/HPF in the blank control group (P < 0.01). Furthermore, the blood flow was increased in the experimental group (119.1% ± 7.0%), whereas in the negative control group, it was (93.3% ± 3.0%) and in the blank control group it was (76.3% ± 12.0%), P < 0.01.

CONCLUSIONSOverexpression of PSGL-1 enhances the adhesive and angiogenic properties of endothelial progenitor cells. The approach may provide an effective therapeutic strategy to improve the efficiency of cell-based proangiogenic therapy.

Adenoviridae ; genetics ; Animals ; Cell Adhesion ; Cells, Cultured ; Endothelial Cells ; cytology ; Hindlimb ; blood supply ; Humans ; Ischemia ; therapy ; Male ; Membrane Glycoproteins ; biosynthesis ; genetics ; Mice ; Mice, Nude ; Neovascularization, Physiologic ; physiology ; RNA, Messenger ; metabolism ; Rats ; Rats, Wistar ; Stem Cell Transplantation ; Stem Cells ; cytology ; metabolism ; Transfection