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Cai Y, Yin G, Huang X, Hu J, Gao Z, Guo X, Qiu Y, Sun H, Feng X. Identification of B-cell epitopes located on the surface in the PB2 protein of the H9N2 subtype avian influenza virus. Avian Pathol 2024; 53:390-399. [PMID: 38563198 DOI: 10.1080/03079457.2024.2338816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 04/04/2024]
Abstract
Avian influenza (AI), caused by H9N2 subtype avian influenza virus (AIV), poses a serious threat to poultry farming and public health due to its transmissibility and pathogenicity. The PB2 protein is a major component of the viral RNA polymerase complex. It is of great importance to identify the antigenic determinants of the PB2 protein to explore the function of the PB2 protein. In this study, the PB2 sequence of H9N2 subtype AIV, from 1090 to 1689 bp, was cloned and expressed. The recombinant PB2 protein with cutting gel was used to immunize BALB/c mice. After cell fusion, the hybridoma cell lines secreting monoclonal antibodies (mAbs) targeting the PB2 protein were screened by indirect ELISA and western blotting, and the antigenic epitopes of mAbs were identified by constructing truncated overlapping fragments in the PB2 protein of H9N2 subtype AIV. The results showed that three hybridoma cell lines (4B7, 4D10, and 5H1) that stably secreted mAbs specific to the PB2 protein were screened; the heavy chain of 4B7 was IgG2α, those of 4D10 and 5H1 were IgG1, and all three mAbs had kappa light chain. Also, the minimum B-cell epitope recognized was 475LRGVRVSK482 and 528TITYSSPMMW537. Homology analysis showed that these two epitopes were conserved among the different subtypes of AIV strains and located on the surface of the PB2 protein. The above findings provide an experimental foundation for further investigation of the function of the PB2 protein and developing monoclonal antibody-based diagnostic kits.
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Affiliation(s)
- Yiqin Cai
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Guihu Yin
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Xiangyu Huang
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Jianing Hu
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Zichen Gao
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Xinyu Guo
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Yawei Qiu
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Haifeng Sun
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Xiuli Feng
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China
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Cai Y, Yin G, Hu J, Liu Y, Huang X, Gao Z, Guo X, Jiang T, Sun H, Feng X. Preparation and Antigenic Site Identification of Monoclonal Antibodies against PB1 Protein of H9N2 Subtype AIV. Vet Sci 2024; 11:412. [PMID: 39330791 PMCID: PMC11435642 DOI: 10.3390/vetsci11090412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 09/02/2024] [Accepted: 09/02/2024] [Indexed: 09/28/2024] Open
Abstract
Recently, low pathogenic avian influenza virus (LPAIV), including H9N2 subtype, has been common clinical epidemic strains, and is widely distributed globally. The PB1 protein is a key component of the viral RNA polymerase complex (vRNP), and is vital to viral transcription and translation. In this study, to investigate the antigenic determinants in the PB1 protein, the truncated PB1 sequence (1bp-735bp) from H9N2 subtype AIV was amplified with PCR, and expressed in plasmid pET-28a (+). After purification, the recombinant PB1 protein was used to immunize BALB/c mice. Following immunization, hybridoma cells producing PB1-specific monoclonal antibodies were generated through the fusion of splenic lymphocytes with SP2/0 cells. Then, four stable hybridoma cell lines (5F12, 5B3, 2H9, and 3E6) were screened using indirect ELISA and Western blotting. Furthermore, two antigenic sites, 67NPIDGPLPED76 and 97ESHPGIFENS106, were identified through the construction of truncated overlapping fragments of the PB1 protein. These sites were conserved among 28 AIV strains, and were located on the PB1 protein surface. The findings offer a theoretical reference for the development and improvement of H9N2 vaccines and offer biological materials for virus detection during AIV infection mechanisms.
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Affiliation(s)
- Yiqin Cai
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Guihu Yin
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Jianing Hu
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Ye Liu
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiangyu Huang
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Zichen Gao
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Xinyu Guo
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Ting Jiang
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Haifeng Sun
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiuli Feng
- Key Laboratory of Animal Microbiology of China's Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
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Duan M, Li B, Zhao Y, Liu Y, Liu Y, Dai R, Li X, Jia F. A CRISPR/Cas12a-mediated, DNA extraction and amplification-free, highly direct and rapid biosensor for Salmonella Typhimurium. Biosens Bioelectron 2023; 219:114823. [PMID: 36308834 DOI: 10.1016/j.bios.2022.114823] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 11/19/2022]
Abstract
CRISPR/Cas-based biosensors were typically used for nucleic-acid targets detection and complex DNA extraction and amplification procedures were usually inevitable. Here, we report a CRISPR/Cas12a-mediated, DNA extraction and amplification-free, highly direct and rapid biosensor (abbreviated as "CATCHER") for Salmonella Typhimurium (S. Typhimurium) with a simple (3 steps) and fast (∼2 h) sensing workflow. Magnetic nanoparticle immobilized anti-S. Typhimurium antibody was worked as capture probe to capture the target and provide movable reaction interface. Colloidal gold labeled with anti-S. Typhimurium antibody and DNase I was used as detection probe to bridge the input target and output signal. First, in the presence of S. Typhimurium, an immuno-sandwich structure was formed. Second, DNase I in sandwich structure degraded the valid, complete activator DNA to invalid DNA fragments which can't trigger the trans-cleavage activity of Cas12a. Finally, the integrity of reporter DNA was preserved presenting a low fluorescence signal. Conversely, in the absence of S. Typhimurium, strong fluorescence recovery appeared owing to the cutting of reporter by activated Cas12a. Significantly, the proposed "CATCHER" showed satisfactory detection performance for S. Typhimurium with the limit of detection (LOD) of 7.9 × 101 CFU/mL in 0.01 M PBS and 6.31 × 103 CFU/mL in spiked chicken samples, providing a general platform for non-nucleic acid targets.
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Affiliation(s)
- Miaolin Duan
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Bingyan Li
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Yijie Zhao
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Yana Liu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Yi Liu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Ruitong Dai
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Xingmin Li
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
| | - Fei Jia
- Department of Biological and Agricultural Engineering, University of Arkansas, Fayetteville, AR, 72701, USA.
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Rosário-Ferreira N, Preto AJ, Melo R, Moreira IS, Brito RMM. The Central Role of Non-Structural Protein 1 (NS1) in Influenza Biology and Infection. Int J Mol Sci 2020; 21:E1511. [PMID: 32098424 PMCID: PMC7073157 DOI: 10.3390/ijms21041511] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 01/23/2020] [Accepted: 01/24/2020] [Indexed: 01/07/2023] Open
Abstract
Influenza (flu) is a contagious viral disease, which targets the human respiratory tract and spreads throughout the world each year. Every year, influenza infects around 10% of the world population and between 290,000 and 650,000 people die from it according to the World Health Organization (WHO). Influenza viruses belong to the Orthomyxoviridae family and have a negative sense eight-segment single-stranded RNA genome that encodes 11 different proteins. The only control over influenza seasonal epidemic outbreaks around the world are vaccines, annually updated according to viral strains in circulation, but, because of high rates of mutation and recurrent genetic assortment, new viral strains of influenza are constantly emerging, increasing the likelihood of pandemics. Vaccination effectiveness is limited, calling for new preventive and therapeutic approaches and a better understanding of the virus-host interactions. In particular, grasping the role of influenza non-structural protein 1 (NS1) and related known interactions in the host cell is pivotal to better understand the mechanisms of virus infection and replication, and thus propose more effective antiviral approaches. In this review, we assess the structure of NS1, its dynamics, and multiple functions and interactions, to highlight the central role of this protein in viral biology and its potential use as an effective therapeutic target to tackle seasonal and pandemic influenza.
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Affiliation(s)
- Nícia Rosário-Ferreira
- Coimbra Chemistry Center, Chemistry Department, Faculty of Science and Technology, University of Coimbra, 3004-535 Coimbra, Portugal
- CNC—Center for Neuroscience and Cell Biology. University of Coimbra, UC Biotech Building, 3060-197 Cantanhede, Portugal
| | - António J. Preto
- CNC—Center for Neuroscience and Cell Biology. University of Coimbra, UC Biotech Building, 3060-197 Cantanhede, Portugal
| | - Rita Melo
- CNC—Center for Neuroscience and Cell Biology. University of Coimbra, UC Biotech Building, 3060-197 Cantanhede, Portugal
- Centro de Ciências e Tecnologias Nucleares and Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066 Bobadela LRS, Portugal
| | - Irina S. Moreira
- CNC—Center for Neuroscience and Cell Biology. University of Coimbra, UC Biotech Building, 3060-197 Cantanhede, Portugal
- Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal
| | - Rui M. M. Brito
- Coimbra Chemistry Center, Chemistry Department, Faculty of Science and Technology, University of Coimbra, 3004-535 Coimbra, Portugal
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Teo SHC, Wu JP, Mok CK, Tan YJ. A NS1-binding monoclonal antibody interacts with two residues that are highly conserved in seasonal as well as newly emerged influenza A virus. Pathog Dis 2019; 77:5370084. [PMID: 30839053 PMCID: PMC7273928 DOI: 10.1093/femspd/ftz012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 03/05/2019] [Indexed: 11/22/2022] Open
Abstract
The non-structural protein 1 (NS1) of influenza A virus (IAV) is a multifunctional protein that antagonizes host antiviral responses, modulating virus pathogenesis. As such, it serves as a good target for research and diagnostic assay development. In this study, we have generated a novel monoclonal antibody (mAb) 19H9 and epitope mapping revealed that two residues, P85 and Y89, of NS1 are essential for interacting with this mAb. Furthermore, residues P85 and Y89 are found to be highly conserved across different IAV subtypes, namely seasonal H1N1 and H3N2, as well as the highly pathogenic H5N1 and H5N6 avian strains. Indeed, mAb 19H9 exhibits broad cross-reactivity with IAV strains of different subtypes. The binding of mAb 19H9 to residue Y89 was further confirmed by the abrogation of interaction between NS1 and p85β. Additionally, mAb 19H9 also detected NS1 proteins expressed in IAV-infected cells, showing NS1 intracellular localization in the cytoplasm and nucleolus. To our knowledge, mAb 19H9 is the first murine mAb to bind at the juxtaposition between the N-terminal RNA-binding domain and C-terminal effector domain of NS1. It could serve as a useful research tool for studying the conformational plasticity and dynamic changes in NS1.
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Affiliation(s)
- Su Hui Catherine Teo
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, MD4, 5 Science Drive 2, Singapore 117545
| | - Jian-Ping Wu
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, MD4, 5 Science Drive 2, Singapore 117545
| | - Chee-Keng Mok
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, MD4, 5 Science Drive 2, Singapore 117545
| | - Yee-Joo Tan
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, MD4, 5 Science Drive 2, Singapore 117545
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), 61 Biopolis Dr, Singapore 138673
- Correspondence author: Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, MD4, 5 Science Drive 2, Singapore 117545. Tel: +65 65163692; E-mail:
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Takahashi H, Nagata S, Odagiri T, Kageyama T. Establishment of the cross-clade antigen detection system for H5 subtype influenza viruses using peptide monoclonal antibodies specific for influenza virus H5 hemagglutinin. Biochem Biophys Res Commun 2018. [PMID: 29524417 DOI: 10.1016/j.bbrc.2018.03.054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The H5 subtype of highly pathogenic avian influenza (H5 HPAI) viruses is a threat to both animal and human public health and has the potential to cause a serious future pandemic in humans. Thus, specific and rapid detection of H5 HPAI viruses is required for infection control in humans. To develop a simple and rapid diagnostic system to detect H5 HPAI viruses with high specificity and sensitivity, we attempted to prepare monoclonal antibodies (mAbs) that specifically recognize linear epitopes in hemagglutinin (HA) of H5 subtype viruses. Nine mAb clones were obtained from mice immunized with a synthetic partial peptide of H5 HA molecules conserved among various H5 HPAI viruses. The antigen-capture enzyme-linked immunosorbent assay using the most suitable combination of these mAbs, which bound specifically to lysed H5 HA under an optimized detergent condition, was specific for H5 viruses and could broadly detect H5 viruses in multiple different clades. Taken together, these peptide mAbs, which recognize linear epitopes in a highly conserved region of H5 HA, may be useful for specific and highly sensitive detection of H5 HPAI viruses and can help in the rapid diagnosis of human, avian, and animal H5 virus infections.
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MESH Headings
- Animals
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/immunology
- Enzyme-Linked Immunosorbent Assay/methods
- Hemagglutinin Glycoproteins, Influenza Virus/analysis
- Hemagglutinin Glycoproteins, Influenza Virus/immunology
- Humans
- Influenza A Virus, H5N1 Subtype/immunology
- Influenza A Virus, H5N1 Subtype/isolation & purification
- Influenza A Virus, H5N2 Subtype/immunology
- Influenza A Virus, H5N2 Subtype/isolation & purification
- Influenza A Virus, H5N8 Subtype/immunology
- Influenza A Virus, H5N8 Subtype/isolation & purification
- Influenza, Human/diagnosis
- Influenza, Human/immunology
- Influenza, Human/virology
- Mice, Inbred BALB C
- Orthomyxoviridae Infections/diagnosis
- Orthomyxoviridae Infections/immunology
- Orthomyxoviridae Infections/virology
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Affiliation(s)
- Hitoshi Takahashi
- Influenza Virus Research Center, National Institute of Infectious Diseases, Tokyo, Japan.
| | - Shiho Nagata
- Influenza Virus Research Center, National Institute of Infectious Diseases, Tokyo, Japan.
| | - Takato Odagiri
- Influenza Virus Research Center, National Institute of Infectious Diseases, Tokyo, Japan.
| | - Tsutomu Kageyama
- Influenza Virus Research Center, National Institute of Infectious Diseases, Tokyo, Japan.
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Li Y, Qiu SS, Shao Y, Song HH, Li GL, Lu W, Zhu LM. Dickkopf-1 has an Inhibitory Effect on Mesenchymal Stem Cells to Fibroblast Differentiation. Chin Med J (Engl) 2017; 129:1200-7. [PMID: 27174329 PMCID: PMC4878166 DOI: 10.4103/0366-6999.181974] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Background: Mesenchymal stem cells (MSCs) are bone marrow stem cells which play an important role in tissue repair. The treatment with MSCs will be likely to aggravate the degree of fibrosis. The Wnt/β-catenin signaling pathway is involved in developmental and physiological processes, such as fibrosis. Dickkopfs (DKKs) are considered as an antagonist to block Wnt/β-catenin signaling pathway by binding the receptor of receptor-related protein (LRP5/6). DKK1 was chosen in attempt to inhibit fibrosis of MSCs by lowering activity of Wnt/β-catenin signaling pathway. Methods: Stable MSCs were randomly divided into four groups: MSCs control, MSCs + transforming growth factor-β (TGF-β), MSCs + DKK1, and MSCs + TGF-β + DKK1. Flow cytometry was used to identify MSCs. Cell viability was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide test. Immunofluorescence was used to detect protein expression in the Wnt/β-catenin signaling pathways. Western blotting analysis was employed to test expression of fibroblast surface markers and, finally, real-time reverse transcription polymerase chain reaction was employed to test mRNA expression of fibroblast surface markers and Wnt/β-catenin signaling proteins. Results: Cultivated MSCs were found to conform to the characteristics of standard MSCs: expression of cluster of differentiation (CD) 73, 90, and 105, not expression of 34, 45, and 79. We found that DKK1 could maintain the normal cell morphology of MSCs. Western blotting analysis showed that fibroblast surface markers were expressed in high quantities in the group MSCs + TGF-β. However, the expression was lower in the MSCs + TGF-β + DKK1. Immunofluorescence showed high expression of all Wnt/β-catnin molecules in the MSCs + TGF-β group but expressed in lower quantities in MSCs + TGF-β + DKK1 group. Finally, mRNA expression of fibroblast markers vimentin, α-smooth muscle actin and Wnt/β-catenin signaling proteins β-catenin, T-cell factor, and glycogen synthase kinase-3β was significantly increased in MSCs + TGF-β group compared to control (P < 0.05). Expression of the same fibroblast markers and Wnt/β-catenin was decreased to regular quantities in the MSCs + TGF-β + DKK1 group. Conclusions: DKK1, Wnt/β-catenin inhibitors, blocks the Wnt/β-catenin signaling pathway to inhibit the process of MSCs fibrosis. It might provide some new ways for clinical treatment of certain diseases.
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Affiliation(s)
- Yan Li
- Department of Chronic Communicable Disease, Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, Jiangsu 210009, China
| | - Sang-Sang Qiu
- Department of Infection Management, Affiliated Wuxi People's Hospital to Nanjing Medical University, Wuxi, Jiangsu 214023, China
| | - Yan Shao
- Department of Chronic Communicable Disease, Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, Jiangsu 210009, China
| | - Hong-Huan Song
- Department of Chronic Communicable Disease, Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, Jiangsu 210009, China
| | - Gu-Li Li
- Department of Chronic Communicable Disease, Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, Jiangsu 210009, China
| | - Wei Lu
- Department of Chronic Communicable Disease, Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, Jiangsu 210009, China
| | - Li-Mei Zhu
- Department of Chronic Communicable Disease, Jiangsu Provincial Center for Disease Prevention and Control, Nanjing, Jiangsu 210009, China
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Identification of a Highly Conserved Epitope on Avian Influenza Virus Non-Structural Protein 1 Using a Peptide Microarray. PLoS One 2016; 11:e0149868. [PMID: 26938453 PMCID: PMC4777286 DOI: 10.1371/journal.pone.0149868] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/05/2016] [Indexed: 11/20/2022] Open
Abstract
Avian influenza virus (AIV) non-structural protein 1 (NS1) is a multifunctional protein. It is present at high levels in infected cells and can be used for AIV detection and diagnosis. In this study, we generated monoclonal antibody (MAb) D7 against AIV NS1 protein by immunization of BALB/c mice with purified recombinant NS1 protein expressed in Escherichia coli. Isotype determination revealed that the MAb was IgG1/κ-type subclass. To identify the epitope of the MAb D7, the NS1 protein was truncated into a total of 225 15-mer peptides with 14 amino acid overlaps, which were spotted for a peptide microarray. The results revealed that the MAb D7 recognized the consensus DAPF motif. Furthermore, the AIV NS1 protein with the DAPF motif deletion was transiently expressed in 293T cells and failed to react with MAb D7. Subsequently, the DAPF motif was synthesized with an elongated GSGS linker at both the C- and N-termini. The MAb D7 reacted with the synthesized peptide both in enzyme-linked immunosorbent assay (ELISA) and dot-blot assays. From these results, we concluded that DAPF motif is the epitope of MAb D7. To our knowledge, this is the first report of a 4-mer epitope on the NS1 protein of AIV that can be recognized by MAb using a peptide microarray, which is able to simplify epitope identification, and that could serve as the basis for immune responses against avian influenza.
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9
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He JL, Wang DS, Fan SK. Opto-Microfluidic Immunosensors: From Colorimetric to Plasmonic. MICROMACHINES 2016; 7:E29. [PMID: 30407402 PMCID: PMC6189923 DOI: 10.3390/mi7020029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 01/25/2016] [Accepted: 02/04/2016] [Indexed: 02/06/2023]
Abstract
Optical detection has long been the most popular technique in immunosensing. Recent developments in the synthesis of luminescent probes and the fabrication of novel nanostructures enable more sensitive and efficient optical detection, which can be miniaturized and integrated with microfluidics to realize compact lab-on-a-chip immunosensors. These immunosensors are portable, economical and automated, but their sensitivity is not compromised. This review focuses on the incorporation and implementation of optical detection and microfluidics in immunosensors; it introduces the working principles of each optical detection technique and how it can be exploited in immunosensing. The recent progress in various opto-microfluidic immunosensor designs is described. Instead of being comprehensive to include all opto-microfluidic platforms, the report centers on the designs that are promising for point-of-care immunosensing diagnostics, in which ease of use, stability and cost-effective fabrication are emphasized.
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Affiliation(s)
- Jie-Long He
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan.
| | - Da-Shin Wang
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan.
| | - Shih-Kang Fan
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan.
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10
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Wen X, Sun J, Wang X, Bao H, Zhao Y, Zeng X, Xu X, Ma Y, Gu L, Chen H. Identification of a novel linear epitope on the NS1 protein of avian influenza virus. BMC Microbiol 2015; 15:168. [PMID: 26289074 PMCID: PMC4545905 DOI: 10.1186/s12866-015-0507-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Accepted: 08/12/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The NS1 protein of avian influenza virus (AIV) is an important virulent factor of AIV. It has been shown to counteract host type I interferon response, to mediate host cell apoptosis, and to regulate the process of protein synthesis. The identification of AIV epitopes on NS1 protein is important for understanding influenza virus pathogenesis. RESULTS In this paper, we describe the generation, identification, and epitope mapping of a NS1 protein-specific monoclonal antibody (MAb) D9. First, to induce the production of MAbs, BALB/c mice were immunized with a purified recombinant NS1 expressed in E. coli. The spleen cells from the immunized mice were fused with myeloma cells SP2/0, and through screening via indirect ELISAs, a MAb, named D9, was identified. Western blot assay results showed that MAb D9 reacted strongly with the recombinant NS1. Confocal laser scanning microscopy showed that this MAb also reacts with NS1 expressed in 293T cells that had been transfected with eukaryotic recombinant plasmids. Results from screening a phage display random 7-mer peptide library with MAb D9 demonstrated that it recognizes phages displaying peptides with the consensus peptide WNLNTV--VS, which closely matches the (182)WNDNTVRVS(190) of AIV NS1. Further identification of the displayed epitope was performed with a set of truncated polypeptides expressed as glutathione S-transferase fusion proteins, and the motif (182)WNDNT(186) was defined as the minimal unit of the linear B cell epitope recognized by MAb D9 in western blot assays. Moreover, homology analysis showed that this epitope is a conserved motif among AIV. CONCLUSIONS We identified a conserved linear epitope, WNDNT, on the AIV NS1 protein that is recognized by MAb D9. This MAb and its epitope may facilitate future studies on NS1 function and aid the development of new diagnostic methods for AIV detection.
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Affiliation(s)
- Xuexia Wen
- Animal Influenza Laboratory of the Ministry of Agriculture and State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China. .,College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China.
| | - Jiashan Sun
- Animal Influenza Laboratory of the Ministry of Agriculture and State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.
| | - Xiurong Wang
- Animal Influenza Laboratory of the Ministry of Agriculture and State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.
| | - Hongmei Bao
- Animal Influenza Laboratory of the Ministry of Agriculture and State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.
| | - Yuhui Zhao
- Animal Influenza Laboratory of the Ministry of Agriculture and State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.
| | - Xianying Zeng
- Animal Influenza Laboratory of the Ministry of Agriculture and State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.
| | - Xiaolong Xu
- Animal Influenza Laboratory of the Ministry of Agriculture and State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.
| | - Yong Ma
- Animal Influenza Laboratory of the Ministry of Agriculture and State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.
| | - Linlin Gu
- Animal Influenza Laboratory of the Ministry of Agriculture and State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.
| | - Hualan Chen
- Animal Influenza Laboratory of the Ministry of Agriculture and State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.
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Glycosylation at hemagglutinin Asn-167 protects the H6N1 avian influenza virus from tryptic cleavage at Arg-201 and maintains the viral infectivity. Virus Res 2014; 197:101-7. [PMID: 25527464 DOI: 10.1016/j.virusres.2014.12.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 11/20/2014] [Accepted: 12/09/2014] [Indexed: 11/23/2022]
Abstract
Cleavage of the hemagglutinin (HA) precursor (HA0) by trypsin, which produces the active HA1 and HA2 complex, is a critical step for activating the avian influenza virus (AIV). However, other tryptic cleavage sites on HA might also cause HA degradation and affect the virulence. Otherwise, HA is modified by glycosylation in the host cell. The conjugated glycans on HA may hinder the antigenic epitopes, and thus prevent the virus from being recognized and attacked by the antibodies. In this study, we observed that glycosylation at the Asn-167 (N167) site on the HA1 of the H6N1 AIV strain A/chicken/Taiwan/2838V/00 (2838V) protected Arg-201 (R201) from tryptic cleavage. The 2838V HA protein became sensitive to tryptic cleavage, whereas the glycans at N167 were removed by N-glycosidase F (PNGase-F). Furthermore, the infectivity of 2838V decreased when pretreated with PNGase-F and trypsin. Our observations suggest that the inaccessibility of the R201 residue of HA1 for tryptic cleavage, which is sterically hindered by glycosylation at N167, is a crucial factor for determining the infectivity of the AIV.
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12
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He JL, Hsieh MS, Juang RH, Wang CH. A monoclonal antibody recognizes a highly conserved neutralizing epitope on hemagglutinin of H6N1 avian influenza virus. Vet Microbiol 2014; 174:333-341. [PMID: 25465660 DOI: 10.1016/j.vetmic.2014.10.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 09/30/2014] [Accepted: 10/14/2014] [Indexed: 10/24/2022]
Abstract
Neutralizing antibodies on the globular head of the hemagglutinin (HA) of avian influenza virus (AIV) are crucial for controlling this disease. However, most neutralizing antibodies lack cross reaction. This report describes the identification of a hemagglutinin epitope on the globular head near the receptor binding site of the H6N1 AIV. A monoclonal antibody named EB2 was prepared against the H6N1 AIV HA. Flow cytometry of AIV-infected chicken embryo fibroblast, DF-1 cells and specific-pathogen-free embryonated eggs were used to verify the neutralizing activity of this mAb. To narrow down the binding region, partially overlapping HA fragments and synthetic peptides were used to map the epitope by immune-blotting. The linear motif RYVRMGTESMN, located on the surface on the globular head of the HA protein, was identified as the epitope bound by EB2 mAb. Alignment of the EB2-defined epitope with other H6 AIVs showed that this epitope was conserved and specific to H6. We propose that this motif is a linear B-cell epitope of the HA protein and is near the receptor binding site. The identified epitope might be useful for clinical applications and as a tool for further study of the structure and function of the AIV HA protein.
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Affiliation(s)
- Jie-Long He
- Department of Biochemical Science and Technology, Institute of Microbiology and Biochemistry, National Taiwan University, Taipei, Taiwan
| | - Ming-Shou Hsieh
- Department of Biochemical Science and Technology, Institute of Microbiology and Biochemistry, National Taiwan University, Taipei, Taiwan
| | - Rong-Huay Juang
- Department of Biochemical Science and Technology, Institute of Microbiology and Biochemistry, National Taiwan University, Taipei, Taiwan.
| | - Ching-Ho Wang
- School of Veterinary Medicine, National Taiwan University, No. 1, Sec 4, Roosevelt Road, Taipei 10617, Taiwan.
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13
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Liu K, Luo HL, Zuo ZY, Jia HN, Zhang YW, Chang YF, Jiao LJ. Regulation of sheep α-TTP by dietary vitamin E and preparation of monoclonal antibody for sheep α-TTP. Gene 2014; 540:110-6. [DOI: 10.1016/j.gene.2014.02.048] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 01/31/2014] [Accepted: 02/25/2014] [Indexed: 01/05/2023]
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