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

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

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

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

We developed vectors expressing two antigen of H5N1 influenza virus. Based on the human H5N1 avian influenza virus strain A/Anhui/1/2005 isolated in China, we amplified the matrix protein 2 (M2) and Hemagglutinin (HA) genes by PCR and subcloned them into pStar vector to construct two genes co-expressing recombinant DNA vaccine pStar-M2/HA. After transfection of 293 cells with the plasmid, we confirmed with indirect immunofluorescence assay (IFA) that M2 and HA genes cloned on plasmid pStar co-expressed successfully. Using Ad-Easy adenovirus vector system, by homologous recombination in bacteria and packaging in 293 cells, we constructed two recombinant adenoviruses, namely Ad-M2 and Ad-HA. After infection of 293 cells with the recombinant adenoviruses, we confirmed with IFA that M2 and HA genes cloned into adenoviruses expressed successfully. We then combined the recombinant DNA vaccine and adenoviral vector vaccines in immunization of BALB/c mice with a prime-boost regime. On day 0 and day 28, we immunized the mice with DNA vaccine and on day 14 and day 42, with recombinant adenovirus vaccines. We took blood samples before each injection and 14 days after the final injection. On day 56, we collected splenocytes from the mice. ELISA and hemagglutination inhibition (HI) assay showed that the vaccines successfully induced specific IgG antibodies against HA protein in serum of the immunized mice. ELISPOT confirmed that the vaccines successfully induced the special cellular immune response to M2 and HA protein of H5N1 influenza virus. The study on combined immunization with M2 and HA genes provided basis for development of novel influenza vaccine.
Adenoviridae ; genetics ; metabolism ; Animals ; Female ; Genetic Vectors ; genetics ; Hemagglutinin Glycoproteins, Influenza Virus ; biosynthesis ; genetics ; Influenza A Virus, H5N1 Subtype ; genetics ; immunology ; Influenza Vaccines ; immunology ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Vaccination ; Vaccines, DNA ; immunology ; Viral Matrix Proteins ; biosynthesis ; genetics

Mammalian zona pellucida 3(ZP3) plays an important role in the induction of capacitating sperm acrosome reaction. In this study, we obtained the soluble mZP3 fusion protein and identified its immunoreactivity. mZP3 cDNA was cloned into plasmid pMAL-p2x, and the recombinant plasmid was transformed into Escherichia coli BL21. To get the soluble mZP3 fusion protein, we tried to optimize the expression conditions, including additives, IPTG concentrations, temperatures and induction duration. Then, Western blotting and ELISA were used to identify the immunoreactivity of the purified protein. Based on the optimization experiments, we concluded that the best soluble expression conditions for the mZP3 fusion protein involved incubation to an A600 of 0.6, addition of glucose to a final concentration of 0.02 mol/L, addition of IPTG to a final concentration of 0.6 mmol/L and then further incubation for 4 h at 25 degrees C. Western blotting and ELISA showed that the mZP3 fusion protein retained immunoreactivity. The fusion protein can be used as solubility antigens for developing the immunocontraception vaccines of mZP3 and detecting the immune effects of the vaccine.
Animals ; Egg Proteins ; biosynthesis ; genetics ; immunology ; Escherichia coli ; genetics ; metabolism ; Female ; Membrane Glycoproteins ; biosynthesis ; genetics ; immunology ; Mice ; Receptors, Cell Surface ; biosynthesis ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Solubility ; Vaccines, Contraceptive ; immunology ; Zona Pellucida Glycoproteins

Replication-incompetent adenoviruses expressing three major glycoproteins (gB, gC, and gD) of pseudorabies virus (PrV) were constructed and used to examine the ability of these glycoproteins to induce protective immunity against a lethal challenge. Among three constructs, recombinant adenovirus expressing gB (rAd-gB) was found to induce the most potent immunity biased to Th1-type, as determined by the IgG isotype ratio and the profile of the Th1/Th2 cytokine production. Conversely, the gC-expressing adenovirus (rAd-gC) revealed Th2-type immunity and the gD-expressing adenovirus (rAd-gD) induced lower levels of IFN-gamma and IL-4 production than other constructs, except IL-2 production. Mucosal delivery of rAd-gB induced mucosal IgA and serum IgG responses and biased toward Th2-type immune responses. However, these effects were not observed in response to systemic delivery of rAd-gB. In addition, rAd-gB appeared to induce effective protective immunity against a virulent viral infection, regardless of whether it was administered via the muscular or systemic route. These results suggest that administration of replication-incompetent adenoviruses can induce different types of immunity depending on the expressed antigen and that recombinant adenoviruses expressing gB induced the most potent Th1-biased humoral and cellular immunity and provided effective protection against PrV infection.
Adenoviridae/genetics/*immunology/metabolism ; Animals ; Antibody Formation ; Cell Line ; Cytokines/immunology ; Female ; Glycoproteins/biosynthesis/genetics/*immunology ; Herpesvirus 1, Suid/genetics/*immunology/physiology ; Immunity, Cellular ; Immunoglobulin G/immunology ; Mice ; Mice, Inbred C57BL ; Pseudorabies/*immunology/prevention & control ; Pseudorabies Vaccines/administration & dosage/*immunology ; Swine ; Th1 Cells/immunology ; Th2 Cells/immunology ; *Virus Replication

OBJECTIVETo clone and express avian influenza A virus [A/Hong Kong/482/97(H5N1)] H5 subtype hemagglutinin in baculovirus-insect cell expression system and investigate the antigenicity and bioactivity of the recombinant protein.

METHODSH5 gene of influenza A virus was amplified by PCR. The recombinant bacmid was obtained by cloning the gene to the donor plasmid of pFastBacHTB and transformed into DH10Bac competent cells. The recombinant baculovirus stock was prepared by transfecting the recombinant bacmid DNA into the insect cell line for protein expression after amplification. Immunofluorescene assay (IFA) and Western blotting were performed to identify the antigenicity of the recombinant protein, and hemagglutination assay was used to identify its bioactivity.

RESULTSThe recombinant his-H5 protein was expressed in the insect cells with a relative molecular mass of 64,000, which showed erythrocyte-agglutinating activities with the red blood cells of guinea pig. Western blotting and IFA demonstrated that the recombinant his-H5 could be recognized and bound by standard anti-H5 sera.

CONCLUSIONThe recombinant his-H5 with a post-translation modification is successfully obtained in insect cells, which may provide a potential source for further study of the antigen's biological function and for production of the subunit vaccine or monoclonal antibodies.

Animals ; Baculoviridae ; genetics ; Cell Line ; Erythrocytes ; cytology ; immunology ; Genetic Vectors ; genetics ; Guinea Pigs ; Hemagglutination Tests ; Hemagglutinin Glycoproteins, Influenza Virus ; biosynthesis ; genetics ; immunology ; Influenza A Virus, H5N1 Subtype ; genetics ; immunology ; Recombinant Proteins ; biosynthesis ; immunology ; Spodoptera ; Transfection

To construct a scFv antibody mini-library by phage display technique from the spleen cells of BALB/c mice immunized with extracellular domain of N-cadherin (N-cad), CD34 and AC133, the extracellular domain genes of N-cad, CD34 and AC133 were cloned into a phagemid pSEX81 respectively, and were then displayed on the phagemid in the form of fusion protein with p III protein. After being effectively immunized with the fusion protein, the spleen of the mice were harvested, and total RNA were extracted from the spleen. The cDNA of VH and VL genes were amplified by RT-PCR, and a scFv-phage display antibody library was constructed with the amplified V-genes. The content, multiplicity and expressing potential of the library were examined. As a result, we had produced a scFv library containing 1.4 x 10(6) individual clones which showed different patterns after being digested with restriction endoneuclease Mua I. The surface display expression of the library was also verified. It indicated that the capacity and diversity of the library was sufficient for screening specific scFv antibody against N-cad, CD34 and AC133. The library will be useful for isolating corresponding specific scFv antibodies.
AC133 Antigen ; Animals ; Antibodies ; genetics ; Antigens, CD ; immunology ; Antigens, CD34 ; immunology ; Base Sequence ; Cadherins ; immunology ; Female ; Glycoproteins ; immunology ; Immunoglobulin Fragments ; biosynthesis ; genetics ; Immunoglobulin Variable Region ; biosynthesis ; genetics ; Mice ; Mice, Inbred BALB C ; Molecular Sequence Data ; Peptide Library ; Peptides ; immunology