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

Objective To prepare monoclonal antibodies against bovine CD4 and identify their basic biological characteristics. Methods Recombinant bovine CD4 (rHis-BoCD4 and rGST-BoCD4) was successfully expressed and purified by constructing a prokaryotic plasmid of bovine CD4 gene. The bovine CD4 monoclonal antibody was produced using hybridoma technology. The subtype and potency of the monoclonal antibody were identified and analyzed by ELISA, while specificity was analyzed through indirect immunofluorescence assay (IFA) and Western-blot. Results Four hybridoma cell lines, namely, 1H4, 6A10, 3F9 and 4G10, stably secreting monoclonal antibodies against BoCD4 were successfully obtained. The subclasses of the monoclonal antibodies subclass 6A10 was IgG2b and the rest of the monoclonal antibodies were of IgM type. Western-blot results showed that the four anti-bovine CD4 mAb strains were able to specifically bind to the bovine CD4 protein expressed in vitro. Indirect immunofluorescence assay showed that four monoclonal antibodies were able to specifically recognize the natural bovine CD4 protein. Flow cytometry assay showed that 3F9 was best to recognize bovine natural CD4 molecules. Conclusion Four monoclonal antibody strains with high specificity to natural bovine CD4 protein were successfully prepared, which lays the foundation for the subsequent studies on the function of bovine CD4 and diagnosis and treatment of bovine T-lymphocyte diseases.
Animals ; Antibodies, Monoclonal/isolation & purification* ; Cattle ; CD4 Antigens/genetics* ; Hybridomas/immunology* ; Antibody Specificity/immunology* ; Mice ; Mice, Inbred BALB C ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique, Indirect

Objective To investigate prokaryotic expression of the antigen sequence (amino acids 59-145) of mouse leukemia-related protein 16 (LRP16) protein and preparation of rabbit anti-mouse LRP16 polyclonal antibody. Methods The prokaryotic expression plasmid pLS962-LRP16 was constructed by the molecular cloning method and transferred into E.coli Rosetta to express LRP16 protein induced by IPTG. The recombinant protein was purified using Ni-NTA affinity columns followed by gel filtration chromatography. New Zealand white rabbits were immunized with the purified antigen to generate polyclonal antiserum, with antibody titer quantified by ELISA. Antigen-specific IgG was affinity-purified using Sepharose-coupled LRP16 and validated through Western blot and immunofluorescence assays. Results SDS-PAGE analysis confirmed insoluble expression of the LRP16 fusion protein as inclusion bodies. ELISA demonstrated exceptional antiserum titer (1:256 000). Western blot and immunofluorescence verified that the polyclonal antibody could specifically recognize endogenous LRP16 in murine tissues. Conclusion The prokaryotic expression of the LRP16 gene is successfully achieved, and the rabbit anti-mouse LRP16 polyclonal antibody exhibiting high specificity is prepared. This lays the foundation for further studies on the function of the LRP16 gene.
Animals ; Rabbits ; Mice ; Antibodies/immunology* ; Escherichia coli/metabolism* ; Enzyme-Linked Immunosorbent Assay ; Blotting, Western ; Antibody Specificity

Objective To prepare CD318-specific monoclonal antibodies and evaluate their specificity, affinity, and application in immunological detection, laying the foundation for the development of CD318-targeted antibody drugs. MethodsCD318 protein was expressed and purified, and was used as an antigen to immunize mice, then mice with higher antiserum titers were screened. We prepared CD318-specific monoclonal antibodies through cell fusion and monoclonal screening, and the specificity, affinity, and application of the obtained monoclonal antibodies in immunological assays were evaluated. Then we constructed a CD318/CD3-targeting bispecific antibody and assessed its impact on T-cell cytotoxicity. Results Thirteen monoclonal antibodies were successfully generated, with the hybridoma clone 13-8-G2 exhibiting the highest titer, strongest specificity, and broadest applicability. The antibody was identified as an IgG1 isotype with a kappa light chain. The variable region of the light chain measured 318 bp, while the heavy chain variable region was 357 bp, yielding an affinity constant of approximately 7.68×10⁹. The specificity of CD318 was confirmed using flow cytometry and immunofluorescence assays. Additionally, a CD318/CD3-targeting bispecific antibody was constructed using the variable regions of this CD318 monoclonal antibody, which demonstrated enhanced T-cell cytotoxicity. Conclusion High-affinity and highly specific CD318 monoclonal antibodies were successfully prepared, laying a foundation for the development of therapeutic antibodies targeting CD318.
Animals ; Antibodies, Monoclonal/biosynthesis* ; Mice ; Antibodies, Bispecific/immunology* ; Humans ; Mice, Inbred BALB C ; Antibody Specificity/immunology* ; CD3 Complex/immunology* ; Antigens, CD/genetics* ; T-Lymphocytes/immunology* ; Hybridomas/immunology* ; Female

Hemoglobin A1c (HbA1c) has a unique structure that makes monoclonal antibody (mAb) preparation challenging. This study aims to develop a method for preparing HbA1c mAbs and establish a fluorescent immunochromatographic assay (FICA) for rapid detection of HbA1c. Three glycosylated peptides were synthesized and used to prepare complete antigens, which were identified by dot enzyme-linked immunosorbent assay (Dot-ELISA) and ultraviolet absorption spectroscopy. The complete antigens and natural HbA1c were used for cross-immunization of mice, and the optimal complete antigen was selected. The mouse with the highest serum titer was chosen for mAb preparation. The purity and specificity of the mAbs were verified, and a FICA method was developed. The optimal complete antigen, with a titer of 1:512 000, was successfully prepared and selected. Fusion with splenocytes resulted in four specific HbA1c antibodies (purity > 90%). The best antibody exhibited a binding constant (Ka) of 1.67×10¹⁰ L/mol with the antigen. Based on this antibody, a FICA method was successfully established, capable of producing results within 15 min. The method demonstrated a good linear range (3%-13% HbA1c, y=0.071 3x+0.005 6, R²=0.993 7), recovery rates of 98%-102%, precision < 10.00%, and no nonspecific reactions. Clinical testing of 210 samples showed positive agreement of 96.36%, negative agreement of 97.00%, and overall agreement of 96.68%. The receiver operating characteristic (ROC) curve analysis yielded an area under curve (AUC) of 0.980 9 [95% confidence interval (CI): 0.961 0-1.000 0], with high consistency verified in multicenter studies. We successfully developed a key technique for preparing HbA1c monoclonal antibodies and established a FICA method for rapid detection of HbA1c. It will provide an efficient and convenient detection method for the early diagnosis and long-term management of diabetes and its complications.
Antibodies, Monoclonal/biosynthesis* ; Animals ; Mice ; Glycated Hemoglobin/immunology* ; Mice, Inbred BALB C ; Humans ; Antibody Specificity ; Chromatography, Affinity/methods* ; Enzyme-Linked Immunosorbent Assay/methods* ; Female

Objective To make the bioinformatics analysis of Ureaplasma parvum UP3-RS02445 and prepare monoclonal antibody (mAb) against UP3-RS02445. Methods The biological characteristics of UP3-RS02445 protein were predicted by bioinformatics software. The UP3-RS02445 prokaryotic expression plasmid was constructed and the corresponding protein expression was induced by isopropyl-β-D-thiogalactoside (IPTG). Thus the expressed protein was used as immunogen to immunize female BALB/c mice. Hybridoma cell technology was used to prepare the monoclonal antibody against UP3-RS02445. The specificity and titer of monoclonal antibody were detected by Western blot and ELISA respectively. The subclass of heavy chain and subtype of light chain were identified by monoclonal antibody subtype identification test strip. Results Bioinformatics analysis showed that UP3-RS02445 protein was composed of 201 amino acids, without transmembrane domain and signal peptide, and belongs to non-secretory proteins. The recombinant prokaryotic plasmid of UP3-RS02445 was successfully constructed and the recombinant protein could be induced in large amount. After cell fusion, two hybridoma cells (A1H5 and A4E2) secreting UP3-RS02445 mAb were screened by ELISA and Western blot. The results of ELISA showed that the titers of monoclonal antibodies were 1:2560. Western blot and Immunofluorescence technique both indicated that the antibodies could bind specifically to the UP3-RS02445 protein. The heavy chain and light chain of the two mAbs were IgG1 and kappa subtypes respectively. Conclusion We prepared the UP3-RS02445 monoclonal antibodies with well specificity and high titer which might lay foundations for the subsequent development of UP diagnostic reagents and the functional study of protein.
Antibodies, Monoclonal/immunology* ; Animals ; Mice, Inbred BALB C ; Female ; Computational Biology/methods* ; Mice ; Ureaplasma urealyticum/genetics* ; Bacterial Proteins/genetics* ; Antibody Specificity ; Enzyme-Linked Immunosorbent Assay ; Hybridomas/immunology*

c-Myc protein encoded by c-Myc (cellular-myelocytomatosis viral oncogene) gene regulates the related gene expression through the Wnt/β-catenin signaling pathway, and has received extensive attention in recent years. The purpose of this study was to express Helicoverpa armigera c-Myc gene (Ha-c-Myc) by using prokaryotic expression system, prepare the polyclonal antibody, examine the spatio-temporal expression profile of Ha-c-Myc, and investigate the possible function of Ha-c-Myc in regulating H. armigera sterol carrier protein-2 (SCP-2) gene expression. The Ha-c-Myc gene was amplified by PCR and cloned into a prokaryotic expression plasmid pET-32a(+). The recombinant plasmid pET-32a-Ha-c-Myc was transformed into Escherichia coli BL21. IPTG was used to induce the expression of the recombinant protein. Protein was purified by Ni²⁺-NTA column and used to immunize New Zealand rabbits for preparing the polyclonal antibody. The Ha-c-Myc expression levels in different developmental stages (egg, larva, prepupa, pupa, and adult) of H. armigera and different tissues (midgut, fat body, head, and epidermis) of the prepupa were determined by real-time quantitative reverse transcription PCR (qRT-PCR). Ha-c-Myc siRNA was synthesized and transfected into H. armigera Ha cells. The relative mRNA levels of Ha-c-Myc and HaSCP-2 in Ha cells were detected by qRT-PCR. Results showed that the pET-32a-Ha-c-Myc recombinant plasmid was constructed. The soluble Ha-c-Myc protein of about 65 kDa was expressed in E. coli. The polyclonal antibody was prepared. Western blotting analysis suggested that the antibody had high specificity. Enzyme linked immunosorbent assay (ELISA) showed that the titer of the antibody was high. Ha-c-Myc gene expressed at all developmental stages, with high levels in the early and late instars of larva, and the prepupal stage. Tissue expression profiles revealed that Ha-c-Myc expressed in various tissues of prepupa, with high expression level in the midgut, but low levels in the epidermis and fat body. RNAi results showed that the knockdown of Ha-c-Myc expression significantly affected transcription of HaSCP-2, leading to a 50% reduction in HaSCP-2 mRNA expression level. In conclusion, the Ha-c-Myc was expressed through a prokaryotic expression system, and the polyclonal anti-Ha-c-Myc antibody was obtained. Ha-c-Myc may promote the expression of HaSCP-2 and play an important role in the lipid metabolism of H. armigera. These results may facilitate further study on the potential role and function mechanism of Ha-c-Myc in H. armigera and provide experimental data for exploring new targets of green pesticides.
Animals ; Rabbits ; Escherichia coli/metabolism* ; Enzyme-Linked Immunosorbent Assay ; Moths/genetics* ; Blotting, Western ; Larva/genetics* ; Isoantibodies/metabolism* ; Antibody Specificity

Objective To investigate antigen optimization of Shisa like protein 1 (SHISAL1) for preparing mouse anti-human SHISAL1 polyclonal antibody and to identify the specificity of the prepared antibody. Methods Bioinformatics was employed to predict the antigenic epitope region of SHISAL1 protein, and then a polypeptide composed of amino acid residues from the site of 28 to 97 of SHISAL1, termed SHISAL1-N, was selected as the antigen. The coding region of SHISAL1-N was cloned by molecular cloning technique, and then it was inserted into pET-28a to generate pET28a-SHISAL1-N recombinant plasmid. The two recombinant plasmids pET28a-SHISAL1-N and pET28a-SHISAL1 were transformed into BL21 (DE3) bacteria and induced to express by IPTG. The two proteins were purified and immunized to female Kunming mice, respectively. The specificities and sensitivities of the acquired antibodies were detected by Western blot analysis, immunoprecipitation and immunofluorescent cytochemical staining. Results pET28a-SHISAL1-N recombinant plasmid was successfully constructed, and the two fused proteins, SHISAL1 and SHISAL1-N, were induced to express. Moreover, two types of SHISAL1 mouse polyclonal antibodies, derived from SHISAL1-N and SHISAL1 antigens, were obtained. Western blot results showed that the antibody prepared from SHISAL1 antigen was less specific and sensitive compared with the antibody prepared from SHISAL1-N antigen which could specifically identify different endogenous SHISAL1 protein. Immunoprecipitation results showed that SHISAL1-N antibody could specifically pull down SHIISAL1 protein in hepatocellular carcinoma cells and immunofluorescence results demonstrated that SHISAL1-N antibody could specifically bind to SHISAL1 protein in the cytoplasm. Conclusion We have optimized the SHISAL1 antigen and prepared the mouse anti-human SHISAL1 polyclonal antibodies successfully, which can be used for Western blot analysis, immunoprecipitation and immunofluorescence cytochemical staining.
Animals ; Female ; Humans ; Mice ; Antibodies ; Antibody Specificity ; Blotting, Western ; Cloning, Molecular ; Epitopes/genetics*

Objective To prepare a rabbit anti-mouse coiled-coil domain containing 189 (Ccdc189) polyclonal antibody. Methods The pET-28a-Ccdc189 prokaryotic expression plasmid was constructed and transformed into E.coli BL21. IPTG was used to induce the expression of Ccdc189 prokaryotic protein. Adult male New Zealand rabbits were immunized with purified recombinant protein to obtain rabbit anti-mouse Ccdc189 polyclonal antibody. The specificity of the polyclonal antibody was identified by Western blot analysis, indirect ELISA and immunofluorescence histochemical staining. Results The pET-28a-Ccdc189 recombinant plasmid was successfully constructed and the expression of the Ccdc189 recombinant protein was induced. ELISA revealed that the titer of the polyclonal antibody was 1:1 000 000. Western blot and immunofluorescence staining demonstrated that the Ccdc189 polyclonal antibody could specifically identify the Ccdc189 prokaryotic protein and the Ccdc189 protein in adult wild-type mouse testis. Conclusion A polyclonal antibody with high specificity against mouse Ccdc189 was successfully created.
Rabbits ; Male ; Animals ; Mice ; Antibody Specificity ; Antibodies ; Enzyme-Linked Immunosorbent Assay ; Blotting, Western ; Recombinant Proteins ; Escherichia coli/genetics*

Objective To prepare specific mouse monoclonal antibody (mAb) against human adenovirus type 55 Hexon protein (HAdV55 Hexon). Methods The Hexon genes of HAdV55, 3, 4, 7, 16 and 21 were chemically synthesized as templates for PCR amplification. The prokaryotic expression plasmids pET28a-HAdV55 Hexon and eukaryotic expression plasmids pCAGGS-HAdV3, 4, 7, 16, 21 and 55 Hexon were constructed respectively. The pET28a-HAdV55 Hexon plasmid was transformed into E. coli competent cell BL21 (DE3) and was induced by IPTG. After the purified inclusion body was denatured and renatured, Hexon55 protein was purified by tangential flow filtration system. pCAGGS-HAdV55 Hexon was used to immunize BALB/c mice by cupping, and HAdV55 Hexon protein was used to booster immunization. The anti-HAdV55 Hexon mAb was prepared by hybridoma technique and the titer and subclass were determined. The specificity of antibody was identified by Western blot using HEK293T cells transfected with pCAGGS-HAdV55 Hexon and by immunofluorescence assay (IFA) using BHK cells transfected with pCAGGS-HAdV55 Hexon. Both clones with high titer were selected, and the cross-reactivity of pCAGGS-HAdV3, 4, 7, 16, 21 and 55 Hexon transfected cells were analyzed by Western blot analysis and IFA. Results PET28a-HAdV55 Hexon and pCAGGS-HAdV55 Hexon, 3, 4, 7, 16 and 21 expression plasmids were successfully constructed. BL21 transformed with pET28a-HAdV55 Hexon was induced by IPTG. The HAdV55 Hexon protein was mainly expressed in the form of inclusion body. After denaturation and renaturation, the purified HAdV55 Hexon protein was obtained by ultrafiltration. Six hybridoma cell lines secreting HAdV55 Hexon mAb were obtained. The antibody subclass analysis showed that 2 strains were IgG2a subtypes and 4 strains were IgG2b. Two specific HAdV55 Hexon antibodies with high titer were obtained, and there was no cross-reactivity with HAdV3, 4, 7, 16, 21 Hexon. Conclusion The specific mice mAb against HAdV55 Hexon provides an experimental basis for establishing its antigen detection method.
Animals ; Mice ; Humans ; Adenoviruses, Human/genetics* ; Escherichia coli/genetics* ; HEK293 Cells ; Isopropyl Thiogalactoside ; Blotting, Western ; Immunoglobulin G ; Antibodies, Monoclonal ; Antibody Specificity ; Mice, Inbred BALB C