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Zong X, Liu P, Wang Z, Zhu H, Zhong C, Zhong P, Jiang H, Liu J, Ma Z, Liu X, Liu R, Ding Y. Structural insights into the binding of nanobodies to the Staphylococcal enterotoxin B. Int J Biol Macromol 2024; 276:133957. [PMID: 39029852 DOI: 10.1016/j.ijbiomac.2024.133957] [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: 04/16/2024] [Revised: 05/21/2024] [Accepted: 07/16/2024] [Indexed: 07/21/2024]
Abstract
Staphylococcal Enterotoxin Type B (SEB), produced by Staphylococcus aureus bacteria, is notorious for inducing severe food poisoning and toxic shock syndrome. While nanobody-based treatments hold promises for combating SEB-induced diseases, the lack of structural information between SEB and nanobodies has hindered the development of nanobody-based therapeutics. Here, we present crystal structures of SEB-Nb3, SEB-Nb6, SEB-Nb8, SEB-Nb11, and SEB-Nb20 at resolutions ranging from 1.59 Å to 2.33 Å. Crystallographic analysis revealed that Nb3, Nb8, Nb11, and Nb20 bind to SEB at the T-cell receptor (TCR) interface, while Nb6 binds at the major histocompatibility complex (MHC) interface, suggesting their potential to inhibit SEB function by disrupting interactions with TCR or MHC molecules. Molecular biological analyses confirmed the thermodynamic and kinetic parameters of Nb3, Nb5, Nb6, Nb8, Nb11, Nb15, Nb18, and Nb20 to SEB. The competitive inhibition was further confirmed by cell-based experiments demonstrating nanobody neutralization. These findings elucidate the structural basis for developing specific nanobodies to neutralize SEB threats, providing crucial insights into the underlying mechanisms and offering significant assistance for further optimization towards future therapeutic strategies.
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Affiliation(s)
- Xin Zong
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Peng Liu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Ziying Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Haoran Zhu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Chao Zhong
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Peiyu Zhong
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - He Jiang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Jiayuan Liu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Zhiqiang Ma
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Xihuan Liu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Rui Liu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China; Quzhou Fudan Institute, Quzhou, Zhejiang 324002, China.
| | - Yu Ding
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China; Quzhou Fudan Institute, Quzhou, Zhejiang 324002, China.
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Mei M, Lu M, Li S, Ren X, Xing B, Hu Y, Wu Y, Chen H, Wang L, Yi L, Ming K, Wei Z. Development of nanobodies specific to clumping factors A of Staphylococcus aureus by yeast surface display. Int J Biol Macromol 2024; 259:129208. [PMID: 38185298 DOI: 10.1016/j.ijbiomac.2024.129208] [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: 11/06/2023] [Revised: 12/25/2023] [Accepted: 01/01/2024] [Indexed: 01/09/2024]
Abstract
The Staphylococcus aureus clumping factor A (ClfA) is a fibrinogen (Fg) binding protein that plays an important role in the clumping of S. aureus in blood plasma. The current anti-infective approaches targeting ClfA are mainly based on monoclonal antibodies but showed less impressive efficacy for clinical applications. Nanobodies offer advantages in enhanced tissue penetration and a propensity to bind small epitopes. However, there is no report on generating specific nanobodies for ClfA. Here, we constructed a synthetic nanobody library based on yeast surface display to isolate nanobodies against the Fg binding domain ClfA221-550. We firstly obtained a primary nanobody directed to ClfA221-550, and then employed error-prone mutagenesis to enhance its binding affinity. Finally, 18 variants were isolated with high affinities (EC50, 1.1 ± 0.1 nM to 4.8 ± 0.3 nM), in which CNb1 presented the highest inhibition efficiency in the adhesion of S. aureus to fibrinogen. Moreover, structural simulation analysis indicated that the epitope for CNb1 partially overlapped with the binding sites for fibrinogen, thus inhibiting ClfA binding to Fg. Overall, these results indicated that the specific nanobodies generated here could prevent the adhesion of S. aureus to fibrinogen, suggesting their potential capacities in the control of S. aureus infections.
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Affiliation(s)
- Meng Mei
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China; Hubei Jiangxia Laboratory, Wuhan, Hubei, China
| | - Mengqing Lu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Shiqi Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Xinyi Ren
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Banbin Xing
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Yang Hu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Yuqi Wu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Huan Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Longhao Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Li Yi
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China
| | - Ke Ming
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China; Hubei Jiangxia Laboratory, Wuhan, Hubei, China
| | - Zigong Wei
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei, China; Hubei Jiangxia Laboratory, Wuhan, Hubei, China; Hubei Province Key Laboratory of Biotechnology of Chinese Traditional Medicine, National & Local Joint Engineering Research Center of High-throughput Drug Screening Technology, School of life sciences, Hubei University, Wuhan, Hubei, PR China.
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3
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Escamilla-Gutiérrez A, Córdova-Espinoza MG, Sánchez-Monciváis A, Tecuatzi-Cadena B, Regalado-García AG, Medina-Quero K. In silico selection of aptamers for bacterial toxins detection. J Biomol Struct Dyn 2023; 41:10909-10918. [PMID: 36546716 DOI: 10.1080/07391102.2022.2159529] [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: 08/17/2022] [Accepted: 12/10/2022] [Indexed: 12/24/2022]
Abstract
The most commonly used toxins in biological warfare are staphylococcal enterotoxin B (3SEB), cholera toxin (1XTC), and botulinum toxin (3BTA). Uncovering novel strategies for identifying these toxins is paramount; therefore, aptamers are used for this purpose. Aptamers are single-stranded DNA or RNA oligonucleotides selected via Systematic Evolution of Ligands by Exponential Enrichment (SELEX) with high binding affinity and specificity against target molecules. However, SELEX in vitro is tedious; hence, adopting alternative in silico molecular docking approaches is necessary. We aimed to conduct molecular docking with accessible tools and obtain RNA aptamers. First, 4,820,095 sequences obtained from an initial library of 9.5 × 109 Python script sequences were used. The GraphClust program was used to create representative groups or clusters, and the DoGSiteScorer (https://proteins.plus/) was used to conduct binding site detection of the proteins: 5DO4 (thrombin), 3SEB, 1XTC, and 3BTA. rDock, HDock, and PatchDock were adopted, combining different docking program results (consensus scoring), to improve receptor-ligand prediction. An analysis of the poses and root mean square deviation (RMSD) was performed, and 468 structurally different aptamers were obtained. The DoGSiteScorer program predicted the binding site of each protein to direct the interaction with the aptamer. Candidate aptamers for 3SEB, 1XTC, and 3BTA were selected according to the pose value considering the closeness of the interaction with a lower mean of 45.923 Å, 45.854 Å, and 72.490 Å, respectively.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Alejandro Escamilla-Gutiérrez
- Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
- Hospital General, Instituto Mexicano del Seguro Social IMSS, Ciudad de México, México
| | - María Guadalupe Córdova-Espinoza
- Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, México
- Laboratorio de Inmunología, Escuela Militar de Graduados de Sanidad, Secretaría de la Defensa Nacional, Ciudad de México, México
| | - Anahí Sánchez-Monciváis
- Laboratorio de Inmunología, Escuela Militar de Graduados de Sanidad, Secretaría de la Defensa Nacional, Ciudad de México, México
| | - Brenda Tecuatzi-Cadena
- Laboratorio de Inmunología, Escuela Militar de Graduados de Sanidad, Secretaría de la Defensa Nacional, Ciudad de México, México
| | - Ana Gabriela Regalado-García
- Laboratorio de Inmunología, Escuela Militar de Graduados de Sanidad, Secretaría de la Defensa Nacional, Ciudad de México, México
| | - Karen Medina-Quero
- Laboratorio de Inmunología, Escuela Militar de Graduados de Sanidad, Secretaría de la Defensa Nacional, Ciudad de México, México
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Tian L, Jackson K, Chan M, Saif A, He L, Didar TF, Hosseinidoust Z. Phage display for the detection, analysis, disinfection, and prevention of Staphylococcus aureus. SMART MEDICINE 2022; 1:e20220015. [PMID: 39188734 PMCID: PMC11235639 DOI: 10.1002/smmd.20220015] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 09/25/2022] [Indexed: 08/28/2024]
Abstract
The World Health Organization has designated Staphylococcus aureus as a global health concern. This designation stems from the emergence of multiple drug-resistant strains that already account for hundreds of thousands of deaths globally. The development of novel treatment strategies to eradicate S. aureus or mitigate its pathogenic potential is desperately needed. In the effort to develop emerging strategies to combat S. aureus, phage display is uniquely positioned to assist in this endeavor. Leveraging bacteriophages, phage display enables researchers to better understand interactions between proteins and their antagonists. In doing so, researchers have the capacity to design novel inhibitors, biosensors, disinfectants, and immune modulators that can target specific S. aureus strains. In this review, we highlight how phage display can be leveraged to design novel solutions to combat S. aureus. We further discuss existing uses of phage display as a detection, intervention, and prevention platform against S. aureus and provide outlooks on how this technology can be optimized for future applications.
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Affiliation(s)
- Lei Tian
- Department of Chemical EngineeringMcMaster UniversityHamiltonOntarioCanada
| | - Kyle Jackson
- Department of Chemical EngineeringMcMaster UniversityHamiltonOntarioCanada
| | - Michael Chan
- Department of Chemical EngineeringMcMaster UniversityHamiltonOntarioCanada
| | - Ahmed Saif
- Department of Chemical EngineeringMcMaster UniversityHamiltonOntarioCanada
| | - Leon He
- Department of Chemical EngineeringMcMaster UniversityHamiltonOntarioCanada
| | - Tohid F. Didar
- School of Biomedical EngineeringMcMaster UniversityHamiltonOntarioCanada
- Michael DeGroote Institute for Infectious Disease ResearchMcMaster UniversityHamiltonOntarioCanada
- Department of Mechanical EngineeringMcMaster UniversityHamiltonOntarioCanada
| | - Zeinab Hosseinidoust
- Department of Chemical EngineeringMcMaster UniversityHamiltonOntarioCanada
- School of Biomedical EngineeringMcMaster UniversityHamiltonOntarioCanada
- Michael DeGroote Institute for Infectious Disease ResearchMcMaster UniversityHamiltonOntarioCanada
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5
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Han X, Ortines R, Mukherjee I, Kanipakala T, Kort T, Sherchand SP, Liao G, Mednikov M, Chenine AL, Aman MJ, Nykiforuk CL, Adhikari RP. Hyperimmune Targeting Staphylococcal Toxins Effectively Protect Against USA 300 MRSA Infection in Mouse Bacteremia and Pneumonia Models. Front Immunol 2022; 13:893921. [PMID: 35655774 PMCID: PMC9152286 DOI: 10.3389/fimmu.2022.893921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 04/07/2022] [Indexed: 11/13/2022] Open
Abstract
Staphylococcus aureus has been acquiring multiple drug resistance and has evolved into superbugs such as Methicillin/Vancomycin-resistant S. aureus (MRSA/VRSA) and, consequently, is a major cause of nosocomial and community infections associated with high morbidity and mortality for which no FDA-approved vaccines or biotherapeutics are available. Previous efforts targeting the surface-associated antigens have failed in clinical testing. Here, we generated hyperimmune products from sera in rabbits against six major S. aureus toxins targeted by an experimental vaccine (IBT-V02) and demonstrated significant efficacy for an anti-virulence passive immunization strategy. Extensive in vitro binding and neutralizing titers were analyzed against six extracellular toxins from individual animal sera. All IBT-V02 immunized animals elicited the maximum immune response upon the first boost dose against all pore-forming vaccine components, while for superantigen (SAgs) components of the vaccine, second and third doses of a boost were needed to reach a plateau in binding and toxin neutralizing titers. Importantly, both anti-staphylococcus hyperimmune products consisting of full-length IgG (IBT-V02-IgG) purified from the pooled sera and de-speciated F(ab')2 (IBT-V02-F(ab')2) retained the binding and neutralizing titers against IBT-V02 target toxins. F(ab')2 also exhibited cross-neutralization titers against three leukotoxins (HlgAB, HlgCB, and LukED) and four SAgs (SEC1, SED, SEK, and SEQ) which were not part of IBT-V02. F(ab')2 also neutralized toxins in bacterial culture supernatant from major clinical strains of S. aureus. In vivo efficacy data generated in bacteremia and pneumonia models using USA300 S. aureus strain demonstrated dose-dependent protection by F(ab')2. These efficacy data confirmed the staphylococcal toxins as viable targets and support the further development effort of hyperimmune products as a potential adjunctive therapy for emergency uses against life-threatening S. aureus infections.
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Affiliation(s)
- Xiaobing Han
- Research and Development, Emergent BioSolutions Canada Inc., Winnipeg, MB, Canada.,Department of Immunology, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - Roger Ortines
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | - Ipsita Mukherjee
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | | | - Thomas Kort
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | | | - Grant Liao
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | - Mark Mednikov
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | - Agnes L Chenine
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | - M Javad Aman
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | - Cory L Nykiforuk
- Research and Development, Emergent BioSolutions Canada Inc., Winnipeg, MB, Canada
| | - Rajan P Adhikari
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
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6
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Xiong Z, Mai J, Li F, Liang B, Yao S, Liang Z, Zhang C, Gao F, Ai X, Wang J, Long Y, Yang M, Gong S, Zhou Z. Oral administration of recombinant Bacillus subtilis spores expressing mutant staphylococcal enterotoxin B provides potent protection against lethal enterotoxin challenge. AMB Express 2020; 10:215. [PMID: 33315153 PMCID: PMC7734462 DOI: 10.1186/s13568-020-01152-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Accepted: 11/25/2020] [Indexed: 01/01/2023] Open
Abstract
Pathogenicity of Staphylococcus aureus is induced by staphylococcal enterotoxin B (SEB). A mutant form of SEB (mSEB) is immunogenic as well as less toxic. Recombinant mSEB and SEB were expressed in pET28a prokaryotic plasmids. Tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels in mSEB-stimulated macrophages were lower than those in SEB-stimulated macrophages (p < 0.001, p < 0.01 respectively). Using CotC as a fusion protein, we constructed recombinant Bacillus subtilis spores expressing mSEB on the spore surface and evaluated their safety and protective efficacy via mouse models. Oral administration of mSEB-expressing spores increased SEB-specific IgA in feces and SEB-specific IgG1 and IgG2a in the sera, compared with mice in naïve and CotC spore-treated groups (p < 0.001, p < 0.01, p < 0.001 respectively). Six weeks following oral dosing of recombinant spores, significant differences were not found in the serum biochemical indices between the mSEB group and the naïve and CotC groups. Furthermore, oral administration of mSEB spores increased the survival rate by 33.3% in mice intraperitoneally injected with 5 µg of wild-type SEB plus 25 µg lipopolysaccharide (LPS). In summation, recombinant spores stably expressing mSEB were developed, and oral administration of such recombinant spores induced a humoral immune response and provided protection against SEB challenge in mice.
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7
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Kong R, Lee YS, Kang DH, Wang S, Li Q, Kwon DY, Kang OH. The antibacterial activity and toxin production control of bee venom in mouse MRSA pneumonia model. BMC Complement Med Ther 2020; 20:238. [PMID: 32718325 PMCID: PMC7385961 DOI: 10.1186/s12906-020-02991-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 06/16/2020] [Indexed: 01/02/2023] Open
Abstract
Background The current antimicrobial therapy is still important for the treatment of pneumonia due to MRSA infection, but there are some limitations, including the route of administration, side effect profile, and increased microbial resistance patterns. Therefore, we investigated whether BV, which shows a strong antimicrobial effect against MRSA, would be effective in a pneumonia model. Methods In vitro, we checked MIC, qRT-PCR, western blot, ELISA, LDH-assay. In vivo, we checked survival rate, gross pathological change, histopathology, lung bacterial clearance assay, and the expression of inflammatory related gene. Results The minimum inhibitory concentration of BV against MRSA is 15.6 μg/ml by broth dilution method. The production of toxins and related gene were reduced by BV in MRSA. The secretion of cytokines were decreased by treatment with BV in 264.7 RAW macrophages stimulated by MRSA Also, BV protected A549 from pathogenicity of MRSA. Bee venom reduced the number of bacteria in the lungs and alleviated the symptoms of MRSA-induced pneumonia in mouse. Conclusion BV inhibited the virulence of the bacterium and the number of bacterial cells present in lung tissue, thereby alleviating the symptoms of pneumonia in mice. This study suggested that BV may be a candidate substance for the treatment of pneumonia caused by MRSA infection.
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Affiliation(s)
- Ryong Kong
- Department of Oriental Pharmacy, College of Pharmacy and Wonkwang-Oriental Medicines Research Institute, Wonkwang University, Iksan, Jeonbuk, 54538, Republic of Korea
| | - Young-Seob Lee
- Department of Herbal Crop Research, National Institute of Horticultural & Herbal Science, RDA, 92 Bisanro, Eumsung, Chungbuk, 27709, Republic of Korea
| | - Dam-Hee Kang
- Department of Oriental Pharmacy, College of Pharmacy and Wonkwang-Oriental Medicines Research Institute, Wonkwang University, Iksan, Jeonbuk, 54538, Republic of Korea
| | - Shu Wang
- Department of Oriental Pharmacy, College of Pharmacy and Wonkwang-Oriental Medicines Research Institute, Wonkwang University, Iksan, Jeonbuk, 54538, Republic of Korea
| | - Qianqian Li
- Department of Oriental Pharmacy, College of Pharmacy and Wonkwang-Oriental Medicines Research Institute, Wonkwang University, Iksan, Jeonbuk, 54538, Republic of Korea
| | - Dong-Yeul Kwon
- Department of Oriental Pharmacy, College of Pharmacy and Wonkwang-Oriental Medicines Research Institute, Wonkwang University, Iksan, Jeonbuk, 54538, Republic of Korea
| | - Ok-Hwa Kang
- Department of Oriental Pharmacy, College of Pharmacy and Wonkwang-Oriental Medicines Research Institute, Wonkwang University, Iksan, Jeonbuk, 54538, Republic of Korea.
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8
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Liu Y, Song Z, Ge S, Zhang J, Xu L, Yang F, Lu D, Luo P, Gu J, Zou Q, Zeng H. Determining the immunological characteristics of a novel human monoclonal antibody developed against staphylococcal enterotoxin B. Hum Vaccin Immunother 2020; 16:1708-1718. [PMID: 32275466 DOI: 10.1080/21645515.2020.1744362] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Staphylococci are the main cause of nosocomial infections globally. The exotoxin staphylococcal enterotoxin B (SEB) produced by methicillin-resistant Staphylococcus aureus is a major cause of pathology after a staphylococcal infection. We previously isolated an anti-SEB human monoclonal antibody designated as M0313. Here we further characterize this antibody in vitro and in vivo. Immunoblotting analysis and ELISA results indicated that M0313 accurately recognized and bound to SEB. Its binding affinity to native SEB was measured at the low nM level. M0313 effectively inhibited SEB from inducing mouse splenic lymphocyte and human peripheral blood mononuclear cell proliferation and cytokine release in cell culture. M0313 also neutralized SEB toxicity in BALB/c female mice. Most importantly, M0313 promoted the survival of mice treated with SEB-expressing bacteria. In-vivo imaging revealed that M0313 treatment significantly reduced the replication of SEB-expressing bacteria in mice. The neutralization capacity of M0313 correlated with its ability to block SEB from binding to major histocompatibility complex II and T-cell receptor by binding to the SEB residues 85-102 and 90-92. Thus, the monoclonal antibody M0313 may be developed into a therapeutic agent.
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Affiliation(s)
- Yuanyuan Liu
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy and Laboratory Medicine, Third Military Medical University , Chongqing, PR China
| | - Zhen Song
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy and Laboratory Medicine, Third Military Medical University , Chongqing, PR China.,Clinical Laboratory Department, Army 954th Hospital, General Hospital of Tibet Military Region , Tibet, PR China
| | - Shuang Ge
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy and Laboratory Medicine, Third Military Medical University , Chongqing, PR China
| | - Jinyong Zhang
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy and Laboratory Medicine, Third Military Medical University , Chongqing, PR China
| | - Limin Xu
- Research and Development Department, Chengdu Olymvax Biotechnology Co., Ltd ., Chengdu, Sichuan, PR China
| | - Feng Yang
- Research and Development Department, Chengdu Olymvax Biotechnology Co., Ltd ., Chengdu, Sichuan, PR China
| | - Dongshui Lu
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy and Laboratory Medicine, Third Military Medical University , Chongqing, PR China
| | - Ping Luo
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy and Laboratory Medicine, Third Military Medical University , Chongqing, PR China
| | - Jiang Gu
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy and Laboratory Medicine, Third Military Medical University , Chongqing, PR China
| | - Quanming Zou
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy and Laboratory Medicine, Third Military Medical University , Chongqing, PR China
| | - Hao Zeng
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy and Laboratory Medicine, Third Military Medical University , Chongqing, PR China
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9
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Masters EA, Trombetta RP, de Mesy Bentley KL, Boyce BF, Gill AL, Gill SR, Nishitani K, Ishikawa M, Morita Y, Ito H, Bello-Irizarry SN, Ninomiya M, Brodell JD, Lee CC, Hao SP, Oh I, Xie C, Awad HA, Daiss JL, Owen JR, Kates SL, Schwarz EM, Muthukrishnan G. Evolving concepts in bone infection: redefining "biofilm", "acute vs. chronic osteomyelitis", "the immune proteome" and "local antibiotic therapy". Bone Res 2019; 7:20. [PMID: 31646012 PMCID: PMC6804538 DOI: 10.1038/s41413-019-0061-z] [Citation(s) in RCA: 273] [Impact Index Per Article: 54.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/17/2019] [Accepted: 06/21/2019] [Indexed: 02/08/2023] Open
Abstract
Osteomyelitis is a devastating disease caused by microbial infection of bone. While the frequency of infection following elective orthopedic surgery is low, rates of reinfection are disturbingly high. Staphylococcus aureus is responsible for the majority of chronic osteomyelitis cases and is often considered to be incurable due to bacterial persistence deep within bone. Unfortunately, there is no consensus on clinical classifications of osteomyelitis and the ensuing treatment algorithm. Given the high patient morbidity, mortality, and economic burden caused by osteomyelitis, it is important to elucidate mechanisms of bone infection to inform novel strategies for prevention and curative treatment. Recent discoveries in this field have identified three distinct reservoirs of bacterial biofilm including: Staphylococcal abscess communities in the local soft tissue and bone marrow, glycocalyx formation on implant hardware and necrotic tissue, and colonization of the osteocyte-lacuno canalicular network (OLCN) of cortical bone. In contrast, S. aureus intracellular persistence in bone cells has not been substantiated in vivo, which challenges this mode of chronic osteomyelitis. There have also been major advances in our understanding of the immune proteome against S. aureus, from clinical studies of serum antibodies and media enriched for newly synthesized antibodies (MENSA), which may provide new opportunities for osteomyelitis diagnosis, prognosis, and vaccine development. Finally, novel therapies such as antimicrobial implant coatings and antibiotic impregnated 3D-printed scaffolds represent promising strategies for preventing and managing this devastating disease. Here, we review these recent advances and highlight translational opportunities towards a cure.
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Affiliation(s)
- Elysia A. Masters
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY USA
| | - Ryan P. Trombetta
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY USA
| | - Karen L. de Mesy Bentley
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
| | - Brendan F Boyce
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY USA
| | - Ann Lindley Gill
- Department of Microbiology & Immunology, University of Rochester Medical Center, Rochester, NY USA
| | - Steven R. Gill
- Department of Microbiology & Immunology, University of Rochester Medical Center, Rochester, NY USA
| | - Kohei Nishitani
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedic Surgery, Kyoto University, Kyoto, Japan
| | - Masahiro Ishikawa
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedic Surgery, Kyoto University, Kyoto, Japan
| | - Yugo Morita
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedic Surgery, Kyoto University, Kyoto, Japan
| | - Hiromu Ito
- Department of Orthopaedic Surgery, Kyoto University, Kyoto, Japan
| | | | - Mark Ninomiya
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
| | - James D. Brodell
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
| | - Charles C. Lee
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
| | - Stephanie P. Hao
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
| | - Irvin Oh
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
| | - Chao Xie
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
| | - Hani A. Awad
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
| | - John L. Daiss
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
| | - John R. Owen
- Department of Orthopaedic Surgery, Virginia Commonwealth University Medical Center, Richmond, VA USA
| | - Stephen L. Kates
- Department of Orthopaedic Surgery, Virginia Commonwealth University Medical Center, Richmond, VA USA
| | - Edward M. Schwarz
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY USA
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
- Department of Microbiology & Immunology, University of Rochester Medical Center, Rochester, NY USA
| | - Gowrishankar Muthukrishnan
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
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10
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Liu S, Zhang S, Duan Y, Niu Y, Gu H, Zhao Z, Zhang S, Yang Y, Wang X, Gao Y, Yang P. Transcutaneous immunization of recombinant Staphylococcal enterotoxin B protein using a dissolving microneedle provides potent protection against lethal enterotoxin challenge. Vaccine 2019; 37:3810-3819. [PMID: 31147275 DOI: 10.1016/j.vaccine.2019.05.055] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 05/16/2019] [Accepted: 05/19/2019] [Indexed: 12/25/2022]
Abstract
Staphylococcal enterotoxin B (SEB) produced by the Staphylococcus aureus bacteriumis most commonly associated with food poisoning and is known to also cause toxic shock syndrome. Currently, no approved vaccine or specific drug is available to treat SEB intoxication. In this study, we fabricated dissolving microneedles (MNs) loaded with recombinant SEB (rSEB) protein, and evaluated its characteristics, including dissolution profile, protein particle size, insertion depth, antigen retention time in vivo, and skin irritation. Our results showed that rSEB protein-loaded dissolving MNs made of chondroitin sulfate (2%) and trehalose (0.8%) could easily penetrate into the mouse skin within 5 min. The rSEB particle size was unchanged before and after MN fabrication. The skin penetration depth of the MNs was 260 µm. Moreover, the MNs also significantly extended the antigen retention time in vivo. rSEB protein-loaded dissolving MNs also triggered slight erythema at the beginning of administration, but this erythema disappeared within a few hours. More importantly, we investigated the immunogenicity and protective efficacy of rSEB protein-loaded dissolving MNs. Challenge studies in mice revealed that mice in full-dose MN group had a high level of SEB specific antibody response thatprovided100% protection against a lethal SEB toxin challenge. However, there was only 60% protection observed in mice that were in the half-dose MN (dose sparing) group. We also determined the pathological alterations in the tissues of the immunized mice. Taken together, these dissolving MNs may present a promising transcutaneous immunization strategy for treating SEB intoxication.
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Affiliation(s)
- Siqi Liu
- Beijing 302 Hospital/5th Medical Center of Chinese PLA General of Hospital, Beijing 100039, China; College of Basic Medicine, Inner Mongolia Medical University, Hohhot 010110, China
| | - Suohui Zhang
- Key Laboratory of Photo Chemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing China
| | - Yueqiang Duan
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Yan Niu
- College of Basic Medicine, Inner Mongolia Medical University, Hohhot 010110, China
| | - Hongjing Gu
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Zhongpeng Zhao
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Shaogeng Zhang
- Beijing 302 Hospital/5th Medical Center of Chinese PLA General of Hospital, Beijing 100039, China
| | - Ying Yang
- College of Basic Medicine, Inner Mongolia Medical University, Hohhot 010110, China
| | - Xiliang Wang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China.
| | - Yunhua Gao
- Key Laboratory of Photo Chemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing China.
| | - Penghui Yang
- Beijing 302 Hospital/5th Medical Center of Chinese PLA General of Hospital, Beijing 100039, China; State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China.
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11
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Effective Treatment of Staphylococcal Enterotoxin B Aerosol Intoxication in Rhesus Macaques by Using Two Parenterally Administered High-Affinity Monoclonal Antibodies. Antimicrob Agents Chemother 2019; 63:AAC.02049-18. [PMID: 30782986 PMCID: PMC6496046 DOI: 10.1128/aac.02049-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 02/13/2019] [Indexed: 11/23/2022] Open
Abstract
Staphylococcal enterotoxin B (SEB) is a protein exotoxin found on the cell surface of Staphylococcus aureus that is the source for multiple pathologies in humans. When purified and concentrated in aerosol form, SEB can cause an acute and often fatal intoxication and thus is considered a biological threat agent. Staphylococcal enterotoxin B (SEB) is a protein exotoxin found on the cell surface of Staphylococcus aureus that is the source for multiple pathologies in humans. When purified and concentrated in aerosol form, SEB can cause an acute and often fatal intoxication and thus is considered a biological threat agent. There are currently no vaccines or treatments approved for human use. Studies with rodent models of SEB intoxication show that antibody therapy may be a promising treatment strategy; however, many have used antibodies only prophylactically or well before any clinical signs of intoxication are apparent. We assessed and compared the protective efficacies of two monoclonal antibodies, Ig121 and c19F1, when administered after aerosol exposure in a uniformly lethal nonhuman primate model of SEB intoxication. Rhesus macaques were challenged using small-particle aerosols of SEB and then were infused intravenously with a single dose of either Ig121 or c19F1 (10 mg/kg of body weight) at either 0.5, 2, or 4 h postexposure. Onset of clinical signs and hematological and cytokine response in untreated controls confirmed the acute onset and potency of the toxin used in the challenge. All animals administered either Ig121 or c19F1 survived SEB challenge, whereas the untreated controls succumbed to SEB intoxication 30 to 48 h postexposure. These results represent the successful therapeutic in vivo protection by two investigational drugs against SEB in a severe nonhuman primate disease model and punctuate the therapeutic value of monoclonal antibodies when faced with treatment options for SEB-induced toxicity in a postexposure setting.
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12
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Chen G, Karauzum H, Long H, Carranza D, Holtsberg FW, Howell KA, Abaandou L, Zhang B, Jarvik N, Ye W, Liao GC, Gross ML, Leung DW, Amarasinghe GK, Aman MJ, Sidhu SS. Potent Neutralization of Staphylococcal Enterotoxin B In Vivo by Antibodies that Block Binding to the T-Cell Receptor. J Mol Biol 2019; 431:4354-4367. [PMID: 30928493 DOI: 10.1016/j.jmb.2019.03.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 03/12/2019] [Accepted: 03/13/2019] [Indexed: 11/15/2022]
Abstract
To develop an antibody (Ab) therapeutic against staphylococcal enterotoxin B (SEB), a potential incapacitating bioterrorism agent and a major cause of food poisoning, we developed a "class T" anti-SEB neutralizing Ab (GC132) targeting an epitope on SEB distinct from that of previously developed "class M" Abs. A systematic engineering approach was applied to affinity-mature Ab GC132 to yield an optimized therapeutic candidate (GC132a) with sub-nanomolar binding affinity. Mapping of the binding interface by hydrogen-deuterium exchange coupled to mass spectrometry revealed that the class T epitope on SEB overlapped with the T-cell receptor binding site, whereas other evidence suggested that the class M epitope overlapped with the binding site for the major histocompatibility complex. In the IgG format, GC132a showed ∼50-fold more potent toxin-neutralizing efficacy than the best class M Ab in vitro, and fully protected mice from lethal challenge in a toxic shock post-exposure model. We also engineered bispecific Abs (bsAbs) that bound tetravalently by utilizing two class M binding sites and two class T binding sites. The bsAbs displayed enhanced toxin neutralization efficacy compared with the respective monospecific Ab subunits as well as a mixture of the two, indicating that enhanced efficacy was due to heterotypic tetravalent binding to two non-overlapping epitopes on SEB. Together, these results suggest that class T anti-SEB Ab GC132a is an excellent candidate for clinical development and for bsAb engineering.
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Affiliation(s)
- Gang Chen
- Banting and Best Department of Medical Research, Department of Molecular Genetics, and the Terrence Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | | | - Hua Long
- Banting and Best Department of Medical Research, Department of Molecular Genetics, and the Terrence Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Danielle Carranza
- Banting and Best Department of Medical Research, Department of Molecular Genetics, and the Terrence Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | | | - Katie A Howell
- Integrated Biotherapeutics, Inc., Rockville, MD 20850, USA
| | - Laura Abaandou
- Integrated Biotherapeutics, Inc., Rockville, MD 20850, USA
| | - Bojie Zhang
- Department of Chemistry, Washington University in St. Louis, St Louis, MO 63130, USA
| | - Nick Jarvik
- Banting and Best Department of Medical Research, Department of Molecular Genetics, and the Terrence Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Wei Ye
- Banting and Best Department of Medical Research, Department of Molecular Genetics, and the Terrence Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Grant C Liao
- Integrated Biotherapeutics, Inc., Rockville, MD 20850, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St Louis, MO 63130, USA; Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Daisy W Leung
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - M Javad Aman
- Integrated Biotherapeutics, Inc., Rockville, MD 20850, USA.
| | - Sachdev S Sidhu
- Banting and Best Department of Medical Research, Department of Molecular Genetics, and the Terrence Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada.
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13
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Kroetsch A, Qiao C, Heavey M, Guo L, Shah DK, Park S. Engineered pH-dependent recycling antibodies enhance elimination of Staphylococcal enterotoxin B superantigen in mice. MAbs 2018; 11:411-421. [PMID: 30526311 DOI: 10.1080/19420862.2018.1545510] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
A new modality in antibody engineering has emerged in which the antigen affinity is designed to be pH dependent (PHD). In particular, combining high affinity binding at neutral pH with low affinity binding at acidic pH leads to a novel antibody that can more effectively neutralize the target antigen while avoiding antibody-mediated antigen accumulation. Here, we studied how the in vivo pharmacokinetics of the superantigen, Staphylococcal enterotoxin B (SEB), is affected by an engineered antibody with pH-dependent binding. PHD anti-SEB antibodies were engineered by introducing mutations into a high affinity anti-SEB antibody, 3E2, by rational design and directed evolution. Three antibody mutants engineered in the study have an affinity at pH 6.0 that is up to 68-fold weaker than the control antibody. The pH dependency of each mutant, measured as the pH-dependent affinity ratio (PAR - ratio of affinity at pH 7.4 and pH 6.0), ranged from 6.7-11.5 compared to 1.5 for the control antibody. The antibodies were characterized in mice by measuring their effects on the pharmacodynamics and pharmacokinetics (PK) of SEB after co-administration. All antibodies were effective in neutralizing the toxin and reducing the toxin-induced cytokine production. However, engineered PHD antibodies led to significantly faster elimination of the toxin from the circulation than wild type 3E2. The area under the curve computed from the SEB PK profile correlated well with the PAR value of antibody, indicating the importance of fine tuning the pH dependency of binding. These results suggest that a PHD recycling antibody may be useful to treat intoxication from a bacterial toxin by accelerating its clearance.
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Affiliation(s)
- Andrew Kroetsch
- a Department of Chemical and Biological Engineering , University at Buffalo , Buffalo , New York , USA
| | - Chunxia Qiao
- b Department of Pharmaceutical Sciences , University at Buffalo , Buffalo , New York , USA
| | - Mairead Heavey
- b Department of Pharmaceutical Sciences , University at Buffalo , Buffalo , New York , USA
| | - Leiming Guo
- b Department of Pharmaceutical Sciences , University at Buffalo , Buffalo , New York , USA
| | - Dhaval K Shah
- b Department of Pharmaceutical Sciences , University at Buffalo , Buffalo , New York , USA
| | - Sheldon Park
- a Department of Chemical and Biological Engineering , University at Buffalo , Buffalo , New York , USA
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14
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Liang B, Mai J, Liu Y, Huang Y, Zhong H, Xie Y, Deng Q, Huang L, Yao S, He Y, Long Y, Yang Y, Gong S, Yang H, Zhou Z. Prevalence and Characterization of Staphylococcus aureus Isolated From Women and Children in Guangzhou, China. Front Microbiol 2018; 9:2790. [PMID: 30505300 PMCID: PMC6250813 DOI: 10.3389/fmicb.2018.02790] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 10/30/2018] [Indexed: 12/18/2022] Open
Abstract
The prevalent Staphylococcus aureus clones and antibiotic susceptibility profiles are known to change dynamically and geographically; however, recent S. aureus strains causing infections in women and children in China have not been characterized. In this study, we analyzed the molecular epidemiology and antimicrobial resistance of S. aureus isolated from patients in four centers for women and children in Guangzhou, China. In total, 131 S. aureus isolates (100 from children and 31 from women) were analyzed by spa typing, multi-locus sequence typing, virulence gene and antimicrobial resistance profiling, staphylococcal chromosomal cassette mec typing, and mutation analyses of rpoB. A total of 58 spa types, 27 sequence types (STs), and 10 clonal complexes (CCs) were identified. While CC59 (ST59-IV, 48.8%; ST338-III, 35.7%) and CC45 (ST45-IV, 100%) were the major clones (84.4%) among MRSA isolates, CC5 (ST188, 24.3%; ST1, 21.6%) and CC398 (ST398, 70%) were the major ones (70.1%) among MSSA isolates. ST338-MRSA-III mostly found in pus but hardly in respiratory tract samples while ST45-MRSA-IV was on the opposite, even though they both found in blood and cerebrospinal fluid sample frequently. Staphylococcal enterotoxin genes seb-seq-sek were strongly associated with ST59 and ST338, while sec was associated with ST45, ST121, ST22, and ST30. All ST338, ST1232, and SCCmec III isolates carried lukF/S-PV genes. A total of 80% of ST338 isolates were resistant to erythromycin, clindamycin, and tetracycline. All ST45 isolates exhibited intermediate or complete resistance to rifampicin. In total, 481 HIS/ASN mutations in rpoB were found in rifampicin-resistant or intermediate-resistant isolates. ST338-III and ST45-IV emerged as two of three major clones in MRSA isolates from women and children in Guangzhou, China, though ST59-MRSA-IV remained the most prevalent MRSA clone. Clonal distribution of S. aureus varied, depending on the specimen source. Virulence genes and antibiograms were closely associated with the clonal lineage. These results clarified the molecular epidemiology of S. aureus from women and children in Guangzhou, China, and provide critical information for the control and treatment of S. aureus infections.
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Affiliation(s)
- Bingshao Liang
- Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Jialiang Mai
- Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yunfeng Liu
- Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yanmei Huang
- Clinical Laboratory, Zengcheng Maternity and Children's Health Care Center, Guangzhou Medical University, Guangzhou, China
| | - Huamin Zhong
- Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yongqiang Xie
- Clinical Laboratory, Guangzhou Maternity and Children's Health Care Center, Guangzhou Medical University, Guangzhou, China
| | - Qiulian Deng
- Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Lianfen Huang
- Clinical Laboratory, Nansha Maternity and Children's Health Care Center, Guangzhou Medical University, Guangzhou, China
| | - Shuwen Yao
- Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yanming He
- Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yan Long
- Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yiyu Yang
- Pediatric Intensive Care Unit, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Sitang Gong
- Department of Gastroenterology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Hongling Yang
- Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Zhenwen Zhou
- Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
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15
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Achuth J, Renuka RM, Jalarama Reddy K, Shivakiran MS, Venkataramana M, Kadirvelu K. Development and evaluation of an IgY based silica matrix immunoassay platform for rapid onsite SEB detection. RSC Adv 2018; 8:25500-25513. [PMID: 35702392 PMCID: PMC9097597 DOI: 10.1039/c8ra03574a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/09/2018] [Indexed: 12/24/2022] Open
Abstract
The present study involves immunoassay platform development based on a surface functionalized silica matrix for rapid onsite detection of Staphylococcal enterotoxin B (SEB). Silica matrix functionalization as well as the immunoassay parameters was experimentally designed and optimized through response surface methodology (RSM). Silica surface functionalization was carried out with hydrofluoric acid (HF), ammonia, 3-aminopropyl triethoxysilane (APTES) and glutaraldehyde (GA). The RSM optimized matrix functionalization parameters for HF, ammonia, APTES and GA were determined to be 10%, 40%, 20% and 10% (V/V), respectively. Antibodies for the study were generated against recombinant SEB toxin in rabbit (anti-SEB IgG) and chicken (anti-SEB IgY). Subsequently, antibodies were immobilized on the functionalized silica matrix and were further characterized by SEM and contact angle measurements to elucidate the surface uniformity and degree of hydrophilicity. The immunoassay platform was developed with anti-SEB IgG (capturing agent) and anti-SEB IgY (revealing partner). The limit of detection (LOD) of the developed platform was determined to be 0.005 μg mL-1 and no cross-reactivity with similar toxins was observed. Upon co-evaluation with a standard ELISA kit (Chondrex, Inc) against various field isolates, the platform was found to be on par and reliable. In conclusion, the developed method may find better utility in onsite detection of SEB from resource-poor settings.
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Affiliation(s)
- J Achuth
- DRDO-BU-CLS, Bharathiar University Campus Coimbatore Tamilnadu-641046 India +0422 2428162
| | - R M Renuka
- DRDO-BU-CLS, Bharathiar University Campus Coimbatore Tamilnadu-641046 India +0422 2428162
| | - K Jalarama Reddy
- Freeze Drying and Animal Product Technology Division, Defence Food Research Laboratory Siddarthanagar Mysore Karnataka- 570011 India
| | - M S Shivakiran
- Department of Biotechnology, Vignan's University Guntur Andhra Pradesh-522213 India
| | - M Venkataramana
- DRDO-BU-CLS, Bharathiar University Campus Coimbatore Tamilnadu-641046 India +0422 2428162
| | - K Kadirvelu
- DRDO-BU-CLS, Bharathiar University Campus Coimbatore Tamilnadu-641046 India +0422 2428162
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16
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Nelson B, Adams J, Kuglstatter A, Li Z, Harris SF, Liu Y, Bohini S, Ma H, Klumpp K, Gao J, Sidhu SS. Structure-Guided Combinatorial Engineering Facilitates Affinity and Specificity Optimization of Anti-CD81 Antibodies. J Mol Biol 2018; 430:2139-2152. [PMID: 29778602 DOI: 10.1016/j.jmb.2018.05.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 05/08/2018] [Accepted: 05/10/2018] [Indexed: 12/12/2022]
Abstract
Hepatitis C viral infection is the major cause of chronic hepatitis that affects as many as 71 million people worldwide. Rather than target the rapidly shifting viruses and their numerous serotypes, four independent antibodies were made to target the host antigen CD81 and were shown to block hepatitis C viral entry. The single-chain variable fragment of each antibody was crystallized in complex with the CD81 large extracellular loop in order to guide affinity maturation of two distinct antibodies by phage display. Affinity maturation of antibodies using phage display has proven to be critical to therapeutic antibody development and typically involves modification of the paratope for increased affinity, improved specificity, enhanced stability or a combination of these traits. One antibody was engineered for increased affinity for human CD81 large extracellular loop that equated to increased efficacy, while the second antibody was engineered for cross-reactivity with cynomolgus CD81 to facilitate animal model testing. The use of structures to guide affinity maturation library design demonstrates the utility of combining structural analysis with phage display technologies.
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Affiliation(s)
- Bryce Nelson
- Banting and Best Department of Medical Research and Department of Medical Genetics, The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Jarrett Adams
- Banting and Best Department of Medical Research and Department of Medical Genetics, The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | | | - Zhijian Li
- Banting and Best Department of Medical Research and Department of Medical Genetics, The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada
| | | | - Yang Liu
- Hoffmann-La Roche Inc., Palo Alto, 94304, CA, USA
| | | | - Han Ma
- Hoffmann-La Roche Inc., Palo Alto, 94304, CA, USA
| | - Klaus Klumpp
- Hoffmann-La Roche Inc., Palo Alto, 94304, CA, USA
| | - Junjun Gao
- Hoffmann-La Roche Inc., Palo Alto, 94304, CA, USA.
| | - Sachdev S Sidhu
- Banting and Best Department of Medical Research and Department of Medical Genetics, The Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada.
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17
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Zhao Y, Tang J. Staphylococcal enterotoxin M causes intestine dysfunction via activating inflammation. J Food Saf 2018. [DOI: 10.1111/jfs.12465] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yanying Zhao
- College of Life Science and Technology; Southwest Minzu University (Southwest University for Nationalities); Chengdu China
| | - Junni Tang
- College of Life Science and Technology; Southwest Minzu University (Southwest University for Nationalities); Chengdu China
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18
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Roychowdhury S, Oh YJ, Kajiura H, Hamorsky KT, Fujiyama K, Matoba N. Hydroponic Treatment of Nicotiana benthamiana with Kifunensine Modifies the N-glycans of Recombinant Glycoprotein Antigens to Predominantly Man9 High-Mannose Type upon Transient Overexpression. FRONTIERS IN PLANT SCIENCE 2018; 9:62. [PMID: 29441088 PMCID: PMC5797603 DOI: 10.3389/fpls.2018.00062] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/12/2018] [Indexed: 05/17/2023]
Abstract
Nicotiana benthamiana transient overexpression systems offer unique advantages for rapid and scalable biopharmaceuticals production, including high scalability and eukaryotic post-translational modifications such as N-glycosylation. High-mannose-type glycans (HMGs) of glycoprotein antigens have been implicated in the effectiveness of some subunit vaccines. In particular, Man9GlcNAc2 (Man9) has high binding affinity to mannose-specific C-type lectin receptors such as the mannose receptor and dendritic cell-specific intracellular adhesion molecule 3-grabbing non-integrin (DC-SIGN). Here, we investigated the effect of kifunensine, an α-mannosidase I inhibitor, supplemented in a hydroponic culture of N. benthamiana for the production of Man9-rich HMG glycoproteins, using N-glycosylated cholera toxin B subunit (gCTB) and human immunodeficiency virus gp120 that are tagged with a H/KDEL endoplasmic reticulum retention signal as model vaccine antigens. Biochemical analysis using anti-fucose and anti-xylose antibodies as well as Endo H and PNGase F digestion showed that kifunensine treatment effectively reduced plant-specific glycoforms while increasing HMGs in the N-glycan compositions of gCTB. Detailed glycan profiling revealed that plant-produced gp120 had a glycan profile bearing mostly HMGs regardless of kifunensine treatment. However, the gp120 produced under kifunensine-treatment conditions showed Man9 being the most prominent glycoform (64.5%), while the protein produced without kifunensine had a substantially lower Man9 composition (20.3%). Our results open up possibilities for efficient production of highly mannosylated recombinant vaccine antigens in plants.
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Affiliation(s)
- Sugata Roychowdhury
- James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY, United States
| | - Young J. Oh
- James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY, United States
| | - Hiroyuki Kajiura
- The International Center for Biotechnology, Osaka University, Suita, Japan
| | - Krystal T. Hamorsky
- James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY, United States
- Department of Medicine, University of Louisville School of Medicine, Louisville, KY, United States
| | - Kazuhito Fujiyama
- The International Center for Biotechnology, Osaka University, Suita, Japan
| | - Nobuyuki Matoba
- James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY, United States
- Center for Predictive Medicine, University of Louisville School of Medicine, Louisville, KY, United States
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, United States
- *Correspondence: Nobuyuki Matoba
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Bernhard W, El-Sayed A, Barreto K, Gonzalez C, Hill W, Parada AC, Fonge H, Geyer CR. Near infrared fluorescence imaging of EGFR expression in vivo using IRDye800CW-nimotuzumab. Oncotarget 2017; 9:6213-6227. [PMID: 29464066 PMCID: PMC5814206 DOI: 10.18632/oncotarget.23557] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 10/27/2017] [Indexed: 01/24/2023] Open
Abstract
Nimotuzumab is a humanized anti-epidermal growth factor receptor (EGFR) monoclonal antibody that is approved in many countries for the treatment of EGFR-positive cancers. Near infrared (NIR) fluorescent dye-labeled antibodies represent an attractive class of image-guided surgical probes because of their high specificity, tumor uptake, and low dissociation from tumor cells that express the antigen. In this study, we developed a NIR fluorescent dye-labeled nimotuzumab immunoconjugate, IRDye800CW-nimotuzumab, and evaluated in vitro binding with EGFR-positive cells, in vivo tumor uptake by NIR fluorescent imaging, and ex vivo biodistribution. There was no difference in binding between nimotuzumab and IRDye800CW-nimotuzumab to EGFR-positive cells. In mice bearing EGFR-positive xenografts, IRDye800CW-nimotuzumab uptake peaked at 4 days post injection and slowly decreased thereafter with high levels of accumulation still observed at 28 days post injection. In EGFR-positive xenografts, IRDye800CW-nimotuzumab showed more than 2-fold higher uptake in tumors compared to IRDye800CW-cetuximab. In addition, liver uptake of IRDye800CW-nimotuzumab was two-fold lower than cetuximab. The lower liver uptake of IRDye800CW-nimotuzumab could have implications on the selected dose for clinical trials of the immunoconjugate. In summary, this study shows that nimotuzumab is a good candidate for NIR fluorescent imaging and image-guided surgery.
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Affiliation(s)
- Wendy Bernhard
- Department of Pathology, University of Saskatchewan, Saskatoon, Canada
| | - Ayman El-Sayed
- Department of Pathology, University of Saskatchewan, Saskatoon, Canada
| | - Kris Barreto
- Department of Pathology, University of Saskatchewan, Saskatoon, Canada
| | - Carolina Gonzalez
- Department of Pathology, University of Saskatchewan, Saskatoon, Canada
| | - Wayne Hill
- Department of Pathology, University of Saskatchewan, Saskatoon, Canada
| | | | - Humphrey Fonge
- Department of Medical Imaging, University of Saskatchewan, Saskatoon, Canada.,Department of Medical Imaging, Royal University Hospital, Saskatoon, Canada.,Saskatchewan Centre for Cyclotron Sciences (SCCS), Fedoruk Centre, Saskatoon, Canada
| | - C Ronald Geyer
- Department of Pathology, University of Saskatchewan, Saskatoon, Canada
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20
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Karau MJ, Tilahun ME, Krogman A, Osborne BA, Goldsby RA, David CS, Mandrekar JN, Patel R, Rajagopalan G. Passive therapy with humanized anti-staphylococcal enterotoxin B antibodies attenuates systemic inflammatory response and protects from lethal pneumonia caused by staphylococcal enterotoxin B-producing Staphylococcus aureus. Virulence 2017; 8:1148-1159. [PMID: 27925510 PMCID: PMC5711449 DOI: 10.1080/21505594.2016.1267894] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 11/21/2016] [Accepted: 11/28/2016] [Indexed: 02/08/2023] Open
Abstract
Drugs such as linezolid that inhibit bacterial protein synthesis may be beneficial in treating infections caused by toxigenic Staphylococcus aureus. As protein synthesis inhibitors have no effect on preformed toxins, neutralization of pathogenic exotoxins with anti-toxin antibodies may be beneficial in conjunction with antibacterial therapy. Herein, we evaluated the efficacy of human-mouse chimeric high-affinity neutralizing anti-staphylococcal enterotoxin B (SEB) antibodies in the treatment of experimental pneumonia caused by SEB-producing S. aureus. Since HLA class II transgenic mice mount a stronger systemic immune response following challenge with SEB and are more susceptible to SEB-induced lethal toxic shock than conventional mice strains, HLA-DR3 transgenic mice were used. Lethal pneumonia caused by SEB-producing S. aureus in HLA-DR3 transgenic mice was characterized by robust T cell activation and elevated systemic levels of several pro-inflammatory cytokines and chemokines. Prophylactic administration of a single dose of linezolid 30 min prior to the onset of infection attenuated the systemic inflammatory response and protected from mortality whereas linezolid administered 60 min after the onset of infection failed to confer significant protection. Human-mouse chimeric high-affinity neutralizing anti-SEB antibodies alone, but not polyclonal human IgG, mitigated this response and protected from death when administered immediately after initiation of infection. Further, anti-SEB antibodies as well as intact polyclonal human IgG, but not its Fab or Fc fragments, protected from lethal pneumonia when followed with linezolid therapy 60 min later. In conclusion, neutralization of superantigens with high-affinity antibodies may have beneficial effects in pneumonia.
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Affiliation(s)
- Melissa J. Karau
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Mulualem E. Tilahun
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA, USA
- Department of Biology, Amherst College, Amherst, MA, USA
| | - Ashton Krogman
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Barbara A. Osborne
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA, USA
| | | | - Chella S. David
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Jayawant N. Mandrekar
- Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Robin Patel
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
- Division of Infectious Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Govindarajan Rajagopalan
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN, USA
- Division of Infectious Diseases, Department of Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA
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Multimechanistic Monoclonal Antibodies (MAbs) Targeting Staphylococcus aureus Alpha-Toxin and Clumping Factor A: Activity and Efficacy Comparisons of a MAb Combination and an Engineered Bispecific Antibody Approach. Antimicrob Agents Chemother 2017; 61:AAC.00629-17. [PMID: 28584141 PMCID: PMC5527613 DOI: 10.1128/aac.00629-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 05/28/2017] [Indexed: 12/23/2022] Open
Abstract
Secreted alpha-toxin and surface-localized clumping factor A (ClfA) are key virulence determinants in Staphylococcus aureus bloodstream infections. We previously demonstrated that prophylaxis with a multimechanistic monoclonal antibody (MAb) combination against alpha-toxin (MEDI4893*) and ClfA (11H10) provided greater strain coverage and improved efficacy in an S. aureus lethal bacteremia model. Subsequently, 11H10 was found to exhibit reduced affinity and impaired inhibition of fibrinogen binding to ClfA002 expressed by members of a predominant hospital-associated methicillin-resistant S. aureus (MRSA) clone, ST5. Consequently, we identified another anti-ClfA MAb (SAR114) from human tonsillar B cells with >100-fold increased affinity for three prominent ClfA variants, including ClfA002, and potent inhibition of bacterial agglutination by 112 diverse clinical isolates. We next constructed bispecific Abs (BiSAbs) comprised of 11H10 or SAR114 as IgG scaffolds and grafted anti-alpha-toxin (MEDI4893*) single-chain variable fragment to the amino or carboxy terminus of the anti-ClfA heavy chains. Although the BiSAbs exhibited in vitro potencies similar to those of the parental MAbs, only 11H10-BiSAb, but not SAR114-BiSAb, showed protective activity in murine infection models comparable to the respective MAb combination. In vivo activity with SAR114-BiSAb was observed in infection models with S. aureus lacking ClfA. Our data suggest that high-affinity binding to ClfA sequesters the SAR114-BiSAb to the bacterial surface, thereby reducing both alpha-toxin neutralization and protection in vivo These results indicate that a MAb combination targeting ClfA and alpha-toxin is more promising for future development than the corresponding BiSAb.
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Reddy PN, Srirama K, Dirisala VR. An Update on Clinical Burden, Diagnostic Tools, and Therapeutic Options of Staphylococcus aureus. Infect Dis (Lond) 2017; 10:1179916117703999. [PMID: 28579798 PMCID: PMC5443039 DOI: 10.1177/1179916117703999] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 03/18/2017] [Indexed: 12/26/2022] Open
Abstract
Staphylococcus aureus is an important pathogen responsible for a variety of diseases ranging from mild skin and soft tissue infections, food poisoning to highly serious diseases such as osteomyelitis, endocarditis, and toxic shock syndrome. Proper diagnosis of pathogen and virulence factors is important for providing timely intervention in the therapy. Owing to the invasive nature of infections and the limited treatment options due to rampant spread of antibiotic-resistant strains, the trend for development of vaccines and antibody therapy is increasing at rapid rate than development of new antibiotics. In this article, we have discussed elaborately about the host-pathogen interactions, clinical burden due to S aureus infections, status of diagnostic tools, and treatment options in terms of prophylaxis and therapy.
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Krakauer T. FDA-approved immunosuppressants targeting staphylococcal superantigens: mechanisms and insights. Immunotargets Ther 2017; 6:17-29. [PMID: 28497030 PMCID: PMC5423536 DOI: 10.2147/itt.s125429] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Immunostimulating staphylococcal enterotoxin B (SEB) and related superantigenic toxins cause diseases in human beings and laboratory animals by hyperactivating cells of the immune system. These protein toxins bind to the major histocompatibility complex class II (MHC II) molecules and specific Vβ regions of T-cell receptors (TCRs), resulting in the stimulation of both monocytes/macrophages and T lymphocytes. The bridging of TCR with MHC II molecules by superantigens triggers intracellular signaling cascades, resulting in excessive release of proinflammatory mediators and massive polyclonal T-cell proliferation. The early induction of tumor necrosis factor α, interleukin 1 (IL-1), interleukin 2 (IL-2), interferon gamma (IFNγ), and macrophage chemoattractant protein 1 promotes fever, inflammation, and multiple organ injury. The signal transduction pathways for staphylococcal superantigen-induced toxicity downstream from TCR/major histocompatibility complex (MHC) ligation and interaction of cell surface co-stimulatory molecules include the mitogen-activated protein kinase cascades and cytokine receptor signaling, activating nuclear factor κB (NFκB) and the phosphoinositide 3-kinase/mammalian target of rapamycin pathways. Knowledge of host regulation within these activated pathways and molecules initiated by SEB and other superantigens enables the selection of US Food and Drug Administration (FDA)-approved drugs to interrupt and prevent superantigen-induced shock in animal models. This review focuses on the use of FDA-approved immunosuppressants in targeting the signaling pathways induced by staphylococcal superantigens.
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Affiliation(s)
- Teresa Krakauer
- Department of Immunology, Molecular Translational Sciences Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD, USA
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24
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A novel method for immobilization of proteins via entrapment of magnetic nanoparticles through epoxy cross-linking. Anal Biochem 2017; 519:42-50. [DOI: 10.1016/j.ab.2016.12.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 12/08/2016] [Accepted: 12/09/2016] [Indexed: 01/19/2023]
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25
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Simulation of the M13 life cycle I: Assembly of a genetically-structured deterministic chemical kinetic simulation. Virology 2016; 500:259-274. [PMID: 27644585 DOI: 10.1016/j.virol.2016.08.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 08/16/2016] [Accepted: 08/18/2016] [Indexed: 11/22/2022]
Abstract
To expand the quantitative, systems level understanding and foster the expansion of the biotechnological applications of the filamentous bacteriophage M13, we have unified the accumulated quantitative information on M13 biology into a genetically-structured, experimentally-based computational simulation of the entire phage life cycle. The deterministic chemical kinetic simulation explicitly includes the molecular details of DNA replication, mRNA transcription, protein translation and particle assembly, as well as the competing protein-protein and protein-nucleic acid interactions that control the timing and extent of phage production. The simulation reproduces the holistic behavior of M13, closely matching experimentally reported values of the intracellular levels of phage species and the timing of events in the M13 life cycle. The computational model provides a quantitative description of phage biology, highlights gaps in the present understanding of M13, and offers a framework for exploring alternative mechanisms of regulation in the context of the complete M13 life cycle.
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26
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Yang HJ, Zhang JY, Wei C, Yang LY, Zuo QF, Zhuang Y, Feng YJ, Srinivas S, Zeng H, Zou QM. Immunisation With Immunodominant Linear B Cell Epitopes Vaccine of Manganese Transport Protein C Confers Protection against Staphylococcus aureus Infection. PLoS One 2016; 11:e0149638. [PMID: 26895191 PMCID: PMC4764517 DOI: 10.1371/journal.pone.0149638] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 02/03/2016] [Indexed: 12/15/2022] Open
Abstract
Vaccination strategies for Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA) infections have attracted much research attention. Recent efforts have been made to select manganese transport protein C, or manganese binding surface lipoprotein C (MntC), which is a metal ion associated with pathogen nutrition uptake, as potential candidates for an S. aureus vaccine. Although protective humoral immune responses to MntC are well-characterised, much less is known about detailed MntC-specific B cell epitope mapping and particularly epitope vaccines, which are less-time consuming and more convenient. In this study, we generated a recombinant protein rMntC which induced strong antibody response when used for immunisation with CFA/IFA adjuvant. On the basis of the results, linear B cell epitopes within MntC were finely mapped using a series of overlapping synthetic peptides. Further studies indicate that MntC113-136, MntC209-232, and MntC263-286 might be the original linear B-cell immune dominant epitope of MntC, furthermore, three-dimensional (3-d) crystal structure results indicate that the three immunodominant epitopes were displayed on the surface of the MntC antigen. On the basis of immunodominant MntC113-136, MntC209-232, and MntC263-286 peptides, the epitope vaccine for S. aureus induces a high antibody level which is biased to TH2 and provides effective immune protection and strong opsonophagocytic killing activity in vitro against MRSA infection. In summary, the study provides strong proof of the optimisation of MRSA B cell epitope vaccine designs and their use, which was based on the MntC antigen in the development of an MRSA vaccine.
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Affiliation(s)
- Hui-Jie Yang
- National Engineering Research Centre for Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
| | - Jin-Yong Zhang
- National Engineering Research Centre for Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
| | - Chao Wei
- National Engineering Research Centre for Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
| | - Liu-Yang Yang
- National Engineering Research Centre for Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
| | - Qian-Fei Zuo
- National Engineering Research Centre for Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
| | - Yuan Zhuang
- National Engineering Research Centre for Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
| | - You-Jun Feng
- School of Basic Medical Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
| | - Swaminath Srinivas
- Department of Biochemistry, University of Illinois, Urbana, IL, 61801, United States of America
| | - Hao Zeng
- National Engineering Research Centre for Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
- * E-mail: (HZ); (QMZ)
| | - Quan-Ming Zou
- National Engineering Research Centre for Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
- * E-mail: (HZ); (QMZ)
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27
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de Souza CSM, Fortaleza CMCB, Witzel CL, Silveira M, Bonesso MF, Marques SA, Cunha MDLRDSD. Toxigenic profile of methicillin-sensitive and resistant Staphylococcus aureus isolated from special groups. Ann Clin Microbiol Antimicrob 2016; 15:9. [PMID: 26880287 PMCID: PMC4754922 DOI: 10.1186/s12941-016-0125-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 02/03/2016] [Indexed: 11/10/2022] Open
Abstract
Background Staphylococcus aureus is characterized by its pathogenicity and high prevalence, causing disease in both healthy and immunocompromised individuals due to its easy dissemination. This fact is aggravated by the widespread dissemination of S. aureus carrying toxigenic genes.
The objective of this study was to determine the toxigenic profile of methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in patients with purulent skin and/or soft tissue infections seen at the Dermatology Department of the University Hospital of the Botucatu Medical School, asymptomatic adults older than 60 years living in nursing homes, and prison inmates of the Avaré Detention Center. Methods PCR was used for the detection of the mecA gene, enterotoxin genes (sea, seb, and sec), exfoliative toxins A and B (eta and etb), toxic shock syndrome toxin 1 (tst), panton–valentine leukocidin (lukS-PV and lukF-PV), and alpha- and delta-hemolysins or cytotoxins (hla and hld). Results The results showed a significant prevalence of toxigenic genes among S. aureus isolates from asymptomatic individuals, with the observation of a higher prevalence of cytotoxin genes. However, the panton–valentine leukocidin gene was only detected in MSSA isolated from patients with skin infections and the tst gene was exclusively found in MSSA isolated from prison inmates. Conclusions The present study demonstrated a significant prevalence of toxigenic genes in MSSA and MRSA strains isolated from asymptomatic S. aureus carriers. There was a higher prevalence of cytotoxin genes.
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Affiliation(s)
- Camila Sena Martins de Souza
- Department of Microbiology and Immunology, Botucatu Biosciences Institute, UNESP-Univ Estadual Paulista, Botucatu, SP, Brazil. .,Department of Tropical Diseases, Botucatu School of Medicine, University Hospital, UNESP-Univ Estadual Paulista, Botucatu, SP, Brazil.
| | | | - Claudia Lima Witzel
- Department of Microbiology and Immunology, Botucatu Biosciences Institute, UNESP-Univ Estadual Paulista, Botucatu, SP, Brazil. .,Department of Tropical Diseases, Botucatu School of Medicine, University Hospital, UNESP-Univ Estadual Paulista, Botucatu, SP, Brazil.
| | - Mônica Silveira
- Department of Tropical Diseases, Botucatu School of Medicine, University Hospital, UNESP-Univ Estadual Paulista, Botucatu, SP, Brazil.
| | - Mariana Fávero Bonesso
- Department of Microbiology and Immunology, Botucatu Biosciences Institute, UNESP-Univ Estadual Paulista, Botucatu, SP, Brazil. .,Department of Tropical Diseases, Botucatu School of Medicine, University Hospital, UNESP-Univ Estadual Paulista, Botucatu, SP, Brazil.
| | - Silvio Alencar Marques
- Department of Dermatology and Radiology, Botucatu School of Medicine, University Hospital, UNESP-Univ Estadual Paulista, Botucatu, SP, Brazil.
| | - Maria de Lourdes Ribeiro de Souza da Cunha
- Department of Microbiology and Immunology, Botucatu Biosciences Institute, UNESP-Univ Estadual Paulista, Botucatu, SP, Brazil. .,Department of Tropical Diseases, Botucatu School of Medicine, University Hospital, UNESP-Univ Estadual Paulista, Botucatu, SP, Brazil.
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28
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Spence JS, Krause TB, Mittler E, Jangra RK, Chandran K. Direct Visualization of Ebola Virus Fusion Triggering in the Endocytic Pathway. mBio 2016; 7:e01857-15. [PMID: 26861015 PMCID: PMC4752599 DOI: 10.1128/mbio.01857-15] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/07/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Ebola virus (EBOV) makes extensive and intricate use of host factors in the cellular endosomal/lysosomal pathway to release its genome into the cytoplasm and initiate infection. Following viral internalization into endosomes, host cysteine proteases cleave the EBOV fusion glycoprotein (GP) to unmask the binding site for its intracellular receptor, the cholesterol transporter Niemann-Pick C1 (NPC1). GP-NPC1 interaction is required for viral entry. Despite these and other recent discoveries, late events in EBOV entry following GP-NPC1 binding and culminating in GP-catalyzed fusion between viral and cellular lipid bilayers remain enigmatic. A mechanistic understanding of EBOV membrane fusion has been hampered by the failure of previous efforts to reconstitute fusion in vitro or at the cell surface. This report describes an assay to monitor initial steps directly in EBOV membrane fusion-triggering of GP and virus-cell lipid mixing-by single virions in live cells. Fusogenic triggering of GP occurs predominantly in Rab7-positive (Rab7(+)) endosomes, absolutely requires interaction between proteolytically primed GP and NPC1, and is blocked by key GP-specific neutralizing antibodies with therapeutic potential. Unexpectedly, cysteine protease inhibitors do not inhibit lipid mixing by virions bearing precleaved GP, even though they completely block cytoplasmic entry by these viruses, as shown previously. These results point to distinct cellular requirements for different steps in EBOV membrane fusion and suggest a model in which host cysteine proteases are dispensable for GP fusion triggering after NPC1 binding but are required for the formation of fusion pores that permit genome delivery. IMPORTANCE Ebola virus (EBOV) causes outbreaks of highly lethal disease for which no approved vaccines or treatments exist. Recent work has elucidated key molecular features of the complex EBOV entry process, including stepwise interactions with multiple host factors. However, there is a critical gap in our understanding of events that surround the final membrane fusion step which persists due to the paucity of direct and extensive investigation of EBOV fusion. Here, we report a real-time assay for EBOV glycoprotein fusion triggering and use it to define its cellular location and requirements. We also uncover an unexpected requirement for host proteases at a step after fusion triggering that may reflect their role in formation of fusion pores for genome delivery.
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Affiliation(s)
- Jennifer S Spence
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Tyler B Krause
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Eva Mittler
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Rohit K Jangra
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Kartik Chandran
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
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29
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Karauzum H, Datta SK. Adaptive Immunity Against Staphylococcus aureus. Curr Top Microbiol Immunol 2016; 409:419-439. [PMID: 26919865 DOI: 10.1007/82_2016_1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A complex interplay between host and bacterial factors allows Staphylococcus aureus to occupy its niche as a human commensal and a major human pathogen. The role of neutrophils as a critical component of the innate immune response against S. aureus, particularly for control of systemic infection, has been established in both animal models and in humans with acquired and congenital neutrophil dysfunction. The role of the adaptive immune system is less clear. Although deficiencies in adaptive immunity do not result in the marked susceptibility to S. aureus infection that neutrophil dysfunction imparts, emerging evidence suggests both T cell- and B cell-mediated adaptive immunity can influence host susceptibility and control of S. aureus. The contribution of adaptive immunity depends on the context and site of infection and can be either beneficial or detrimental to the host. Furthermore, S. aureus has evolved mechanisms to manipulate adaptive immune responses to its advantage. In this chapter, we will review the evidence for the role of adaptive immunity during S. aureus infections. Further elucidation of this role will be important to understand how it influences susceptibility to infection and to appropriately design vaccines that elicit adaptive immune responses to protect against subsequent infections.
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Affiliation(s)
- Hatice Karauzum
- Bacterial Pathogenesis Unit, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, 20892, USA
| | - Sandip K Datta
- Bacterial Pathogenesis Unit, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD, 20892, USA.
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30
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Sause WE, Buckley PT, Strohl WR, Lynch AS, Torres VJ. Antibody-Based Biologics and Their Promise to Combat Staphylococcus aureus Infections. Trends Pharmacol Sci 2015; 37:231-241. [PMID: 26719219 DOI: 10.1016/j.tips.2015.11.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 11/18/2015] [Accepted: 11/19/2015] [Indexed: 11/26/2022]
Abstract
The growing incidence of serious infections mediated by methicillin-resistant Staphylococcus aureus (MRSA) strains poses a significant risk to public health. This risk is exacerbated by a prolonged void in the discovery and development of truly novel antibiotics and the absence of a vaccine. These gaps have created renewed interest in the use of biologics in the prevention and treatment of serious staphylococcal infections. In this review, we focus on efforts towards the discovery and development of antibody-based biologic agents and their potential as clinical agents in the management of serious S. aureus infections. Recent promising data for monoclonal antibodies (mAbs) targeting anthrax and Ebola highlight the potential of antibody-based biologics as therapeutic agents for serious infections.
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Affiliation(s)
- William E Sause
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA
| | - Peter T Buckley
- Janssen Research & Development LLC, 1400 McKean Road, Spring House, PA 19477, USA
| | - William R Strohl
- Janssen Research & Development LLC, 1400 McKean Road, Spring House, PA 19477, USA
| | - A Simon Lynch
- Janssen Research & Development LLC, 1400 McKean Road, Spring House, PA 19477, USA.
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA.
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31
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Plant-Derived Monoclonal Antibodies for Prevention and Treatment of Infectious Disease. Microbiol Spectr 2015; 2:AID-0004-2012. [PMID: 26082108 DOI: 10.1128/microbiolspec.aid-0004-2012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Numerous monoclonal antibodies (MAbs) that recognize and neutralize infectious pathogens have been isolated and developed over the years. The fact that infectious diseases can involve large populations of infected individuals is an important factor that has motivated the search for both cost-effective and scalable methods of antibody production. The current technologies for production of antibodies in plants allow for very rapid expression and evaluation that can also be readily scaled for multikilogram production runs. In addition, recent progress in manipulating glycosylation in plant production systems has allowed for the evaluation of antibodies containing glycans that are nearly homogeneous, are mammalian in structure, and have enhanced neutralizing capabilities. Among the anti-infectious disease antibodies that have been produced in plants are included those intended for prevention or treatment of anthrax, Clostridium perfringens, Ebola virus, human immunodeficiency virus, herpes simplex virus, rabies, respiratory syncytial virus, staphylococcal enterotoxin, West Nile virus, and tooth decay. Animal and human efficacy data for these MAbs are discussed.
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32
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Vuong C, Yeh AJ, Cheung GYC, Otto M. Investigational drugs to treat methicillin-resistant Staphylococcus aureus. Expert Opin Investig Drugs 2015; 25:73-93. [PMID: 26536498 DOI: 10.1517/13543784.2016.1109077] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
INTRODUCTION Staphylococcus aureus remains one of the leading causes of morbidity and mortality worldwide. This is to a large extent due to antibiotic-resistant strains, in particular methicillin-resistant S. aureus (MRSA). While the toll of invasive MRSA infections appears to decrease in U.S. hospitals, the rate of community-associated MRSA infections remains constant and there is a surge of MRSA in many other countries, a situation that calls for continuing if not increased efforts to find novel strategies to combat MRSA infections. AREAS COVERED This review provides an overview of current investigational drugs and therapeutic antibodies against S. aureus in early clinical development (up to phase II clinical development). It includes a short description of the mechanism of action and a presentation of microbiological and clinical data. EXPERT OPINION Increased recent antibiotic development efforts and results from pathogenesis research have led to several new antibiotics and therapies, such as anti-virulence drugs, as well as a more informed selection of targets for vaccination efforts against MRSA. This developing portfolio of novel anti-staphylococcal drugs will hopefully provide us with additional and more efficient ways to combat MRSA infections in the near future and prevent us from running out of treatment options, even if new resistances arise.
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Affiliation(s)
- Cuong Vuong
- a Principal Scientist/Laboratory Head, Bacteriology , AiCuris GmbH & Co. KG, Friedrich-Ebert-Str. 475/Geb. 302, 42117 Wuppertal , Germany
| | - Anthony J Yeh
- b Post-baccalaureate IRTA, Laboratory of Bacteriology , National Institute of Allergy and Infectious Diseases, National Institutes of Health , Bldg. 33, 1W10, 9000 Rockville Pike, Bethesda , MD 20892 , USA
| | - Gordon Y C Cheung
- c Staff Scientist, National Institute of Allergy and Infectious Diseases , National Institutes of Health, Laboratory of Bacteriology , Bldg. 33, 1W10, 9000 Rockville Pike, Bethesda , MD 20892 , USA
| | - Michael Otto
- d Senior Investigator, National Institute of Allergy and Infectious Diseases , National Institutes of Health, Laboratory of Bacteriology , Bldg. 33, 1W10, 9000 Rockville Pike, Bethesda , MD 20892 , USA
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Zhang J, Yang F, Zhang X, Jing H, Ren C, Cai C, Dong Y, Zhang Y, Zou Q, Zeng H. Protective Efficacy and Mechanism of Passive Immunization with Polyclonal Antibodies in a Sepsis Model of Staphylococcus aureus Infection. Sci Rep 2015; 5:15553. [PMID: 26490505 PMCID: PMC4614693 DOI: 10.1038/srep15553] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 09/23/2015] [Indexed: 11/09/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is an opportunistic bacterial pathogen responsible for a diverse spectrum of human diseases, resulting in considerable yearly mortality rates. Due to its rapid acquisition of antibiotic resistance, it becomes increasingly difficult to cure S. aureus infections with conventional antibiotics. Immunotherapy represents a promising alternative strategy to prevent and/or treat the infection. In the present study, passive immunization with polyclonal antibodies targeting three possible S. aureus antigens, Hla, SEB and MntC (termed "SAvac-pcAb") after challenge with lethal dose of S. aureus resulted in reduced bacterial loads, inflammatory cell infiltration and decreased pathology, and was able to provide nearly complete protection in a murine sepsis model. In vitro studies confirmed the direct interaction of SAvac-pcAb with S. aureus bacteria. Additional studies validated that SAvac-pcAb contained both opsonic and neutralizing antibodies that contributed to its protective efficacy. The former mediated opsonophagocytosis in a neutrophil-dependent manner, while the later inhibited the biological functions of Hla and SEB, two major virulence factors secreted by S. aureus. Critically, we demonstrated that SAvac-pcAb was cross-reactive with different clinical strains of S. aureus. These results confirmed the efficacy for treatment of S. aureus infection by passive immunization as an important therapeutic option.
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Affiliation(s)
- Jinyong Zhang
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, 400038, PR China
| | - Feng Yang
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, 400038, PR China.,College of Bioengineering, Chongqing University, Chongqing, 400044, PR China
| | - Xiaoli Zhang
- Department of Clinical Hematology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, PR China
| | - Haiming Jing
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, 400038, PR China
| | - Chunyan Ren
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, 400038, PR China
| | - Changzhi Cai
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, 400038, PR China
| | - Yandong Dong
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, 400038, PR China
| | - Yudong Zhang
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, 400038, PR China
| | - Quanming Zou
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, 400038, PR China
| | - Hao Zeng
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, 400038, PR China
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Abstract
Staphylococcal enterotoxin B is one of the most potent bacterial superantigens that exerts profound toxic effects upon the immune system, leading to stimulation of cytokine release and inflammation. It is associated with food poisoning, nonmenstrual toxic shock, atopic dermatitis, asthma, and nasal polyps in humans. Currently, there is no treatment or vaccine available. Passive immunotherapy using monoclonal antibodies made in several different species has shown significant inhibition in in vitro studies and reduction in staphylococcal enterotoxin B-induced lethal shock in in vivo studies. This should encourage future endeavors to develop these antibodies as therapeutic reagents.
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Antibacterial monoclonal antibodies: the next generation? Curr Opin Microbiol 2015; 27:78-85. [PMID: 26302478 DOI: 10.1016/j.mib.2015.07.014] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 07/28/2015] [Accepted: 07/30/2015] [Indexed: 12/21/2022]
Abstract
There is a clear need for renewed efforts to combat the increasing incidence of antibiotic resistance. While the antibiotic resistance epidemic is due in part to the misuse of antibiotics, even proper empiric antibiotic therapy increases the selective pressure and potential for drug-resistance and spread of resistance mechanisms between bacteria. Antibiotic resistance coupled with the detrimental effects of broad-spectrum antibiotics on the healthy microbiome, have led the field to explore pathogen specific antibacterials such as monoclonal antibodies (mAbs). Medical need along with advances in mAb discovery, engineering, and production have driven significant effort developing mAb-based antibacterials. If successful, they will provide physicians with precision weapons to combat bacterial infections and can help prevent a return to a pre-antibiotic era.
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Zhao Z, Sun HQ, Wei SS, Li B, Feng Q, Zhu J, Zeng H, Zou QM, Wu C. Multiple B-cell epitope vaccine induces a Staphylococcus enterotoxin B-specific IgG1 protective response against MRSA infection. Sci Rep 2015. [PMID: 26201558 PMCID: PMC4511869 DOI: 10.1038/srep12371] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
No vaccine against methicillin-resistant Staphylococcus aureus (MRSA) has been currently approved for use in humans. Staphylococcus enterotoxin B (SEB) is one of the most potent MRSA exotoxins. In the present study, we evaluated the efficacy and immunologic mechanisms of an SEB multiple B-cell epitope vaccine against MRSA infection. Synthetic overlapping peptide ELISA identified three novel B-cell immunodominant SEB epitopes (in addition to those previously known): SEB31–48, SEB133–150, and SEB193–210. Six B-cell immunodominant epitopes (amino acid residues 31–48, 97–114, 133–150, 193–210, 205–222, and 247–261) were sufficient to induce robust IgG1/IgG2b-specific protective responses against MRSA infection. Therefore, we constructed a recombinant MRSA SEB-specific multiple B-cell epitope vaccine Polypeptides by combining the six SEB immunodominant epitopes and demonstrated its ability to induce a robust SEB-specific IgG1 response to MRSA, as well as a Th2-directing isotype response. Moreover, Polypeptides-induced antisera stimulated synergetic opsonophagocytosis killing of MRSA. Most importantly, Polypeptides was more effective at clearing the bacteria in MRSA-infected mice than the whole SEB antigen, and was able to successfully protect mice from infection by various clinical MRSA isolates. Altogether, these results support further evaluation of the SEB multiple B-cell epitope-vaccine to address MRSA infection in humans.
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Affiliation(s)
- Zhuo Zhao
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
| | - He-Qiang Sun
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
| | - Shan-Shan Wei
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing 400038, PR China
| | - Bin Li
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
| | - Qiang Feng
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
| | - Jiang Zhu
- Department of Pathology, Southwest Hospital, Third Military Medical University, Chongqing 400038, PR China
| | - Hao Zeng
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
| | - Quan-Ming Zou
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
| | - Chao Wu
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing 400038, PR China
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Chen G, Gorelik L, Simon KJ, Pavlenco A, Cheung A, Brickelmaier M, Chen LL, Jin P, Weinreb PH, Sidhu SS. Synthetic antibodies and peptides recognizing progressive multifocal leukoencephalopathy-specific point mutations in polyomavirus JC capsid viral protein 1. MAbs 2015; 7:681-92. [PMID: 25879139 PMCID: PMC4623438 DOI: 10.1080/19420862.2015.1038447] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Revised: 03/18/2015] [Accepted: 04/01/2015] [Indexed: 10/23/2022] Open
Abstract
Polyomavirus JC (JCV) is the causative agent of progressive multifocal leukoencephalopathy (PML), a rare and frequently fatal brain disease that afflicts a small fraction of the immune-compromised population, including those affected by AIDS and transplantation recipients on immunosuppressive drug therapy. Currently there is no specific therapy for PML. The major capsid viral protein 1 (VP1) involved in binding to sialic acid cell receptors is believed to be a key player in pathogenesis. PML-specific mutations in JCV VP1 sequences present at the binding pocket of sialic acid cell receptors, such as L55F and S269F, abolish sialic acid recognition and might favor PML onset. Early diagnosis of these PML-specific mutations may help identify patients at high risk of PML, thus reducing the risks associated with immunosuppressive therapy. As a first step in the development of such early diagnostic tools, we report identification and characterization of affinity reagents that specifically recognize PML-specific mutations in VP1 variants using phage display technology. We first identified 2 peptides targeting wild type VP1 with moderate specificity. Fine-tuning via selection of biased libraries designed based on 2 parental peptides yielded peptides with different, yet still moderate, bindinspecificities. In contrast, we had great success in identifying synthetic antibodies that recognize one of the PML-specific mutations (L55F) with high specificity from the phage-displayed libraries. These peptides and synthetic antibodies represent potential candidates for developing tailored immune-based assays for PML risk stratification in addition to complementing affinity reagents currently available for the study of PML and JCV.
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Key Words
- BSA, bovine serum albumin
- CDR, complementarity determining region
- CSF, cerebrospinal fluid
- D66H, Asp to His mutation at position 66
- DHFR, dihydrofolate reductase
- ELISA, enzyme linked immunosorbent assay
- HRP, horseradish peroxidase
- IPTG, isopropyl β-D-1-thiogalactopyranoside
- JC virus
- JCV, polyomavirus JC
- L55F, Leu to Phe mutation at position 55
- P8, M13 major coat protein
- PBS, phosphate-buffered saline
- PCR, polymerase chain reaction
- PML, progressive multifocal leukoencephalopathy
- S269F, Ser to Phe mutation at position 269
- TMB, 3,3',5,5'-tetramethylbenzidine
- VLP, virus-like particle
- VP1, major capsid viral protein 1
- WT: type 3 wild type JCV VP1
- phage display
- protein engineering
- synthetic antibody
- virus-like particle
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Affiliation(s)
- Gang Chen
- Banting and Best Department of Medical Research; Terrence Donnelly Centre for Cellular and Biomolecular Research; University of Toronto; Toronto, Ontario, Canada
| | | | | | - Alevtina Pavlenco
- Banting and Best Department of Medical Research; Terrence Donnelly Centre for Cellular and Biomolecular Research; University of Toronto; Toronto, Ontario, Canada
| | | | | | | | | | | | - Sachdev S Sidhu
- Banting and Best Department of Medical Research; Terrence Donnelly Centre for Cellular and Biomolecular Research; University of Toronto; Toronto, Ontario, Canada
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Dutta K, Varshney AK, Franklin MC, Goger M, Wang X, Fries BC. Mechanisms mediating enhanced neutralization efficacy of staphylococcal enterotoxin B by combinations of monoclonal antibodies. J Biol Chem 2015; 290:6715-30. [PMID: 25572397 DOI: 10.1074/jbc.m114.630715] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Staphylococcal enterotoxin B (SEB) is a superantigen that cross-links the major histocompatibility complex class II and specific V-β chains of the T-cell receptor, thus forming a ternary complex. Developing neutralizing mAb to disrupt the ternary complex and abrogate the resulting toxicity is a major therapeutic challenge because SEB is effective at very low concentrations. We show that combining two SEB-specific mAbs enhances their efficacy, even though one of the two mAbs by itself has no effect on neutralization. Crystallography was employed for fine-mapping conformational epitopes in binary and ternary complexes between SEB and Fab fragments. NMR spectroscopy was used to validate and identify subtle allosteric changes induced by mAbs binding to SEB. The mapping of epitopes established that a combination of different mAbs can enhance efficacy of mAb-mediated protection from SEB induced lethal shock by two different mechanisms: one mAb mixture promoted clearance of the toxin both in vitro and in vivo by FcR-mediated cross-linking and clearance, whereas the other mAb mixture induced subtle allosteric conformational changes in SEB that perturbed formation of the SEB·T-cell receptor·major histocompatibility complex class II trimer. Finally structural information accurately predicted mAb binding to other superantigens that share conformational epitopes with SEB. Fine mapping of conformational epitopes is a powerful tool to establish the mechanism and optimize the action of synergistic mAb combinations.
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Affiliation(s)
- Kaushik Dutta
- From the New York Structural Biology Center, New York, New York 10027,
| | - Avanish K Varshney
- the Department of Medicine and Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York 11790, and the Department of Medicine, Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461
| | | | - Michael Goger
- From the New York Structural Biology Center, New York, New York 10027
| | - Xiaobo Wang
- the Department of Medicine, Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Bettina C Fries
- the Department of Medicine and Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York 11790, and the Department of Medicine, Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461
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Sully EK, Whaley K, Bohorova N, Bohorov O, Goodman C, Kim D, Pauly M, Velasco J, Holtsberg FW, Stavale E, Aman MJ, Tangudu C, Uzal FA, Mantis NJ, Zeitlin L. A tripartite cocktail of chimeric monoclonal antibodies passively protects mice against ricin, staphylococcal enterotoxin B and Clostridium perfringens epsilon toxin. Toxicon 2014; 92:36-41. [PMID: 25260254 PMCID: PMC4248019 DOI: 10.1016/j.toxicon.2014.09.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 09/10/2014] [Accepted: 09/16/2014] [Indexed: 11/25/2022]
Abstract
Due to the fast-acting nature of ricin, staphylococcal enterotoxin B (SEB), and Clostridium perfringens epsilon toxin (ETX), it is necessary that therapeutic interventions following a bioterrorism incident by one of these toxins occur as soon as possible after intoxication. Moreover, because the clinical manifestations of intoxication by these agents are likely to be indistinguishable from each other, especially following aerosol exposure, we have developed a cocktail of chimeric monoclonal antibodies that is capable of neutralizing all three toxins. The efficacy of this cocktail was demonstrated in mouse models of lethal dose toxin challenge.
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Affiliation(s)
- Erin K Sully
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Kevin Whaley
- Mapp Biopharmaceutical, Inc., 92121 San Diego, CA, USA
| | | | | | | | - Do Kim
- Mapp Biopharmaceutical, Inc., 92121 San Diego, CA, USA
| | - Michael Pauly
- Mapp Biopharmaceutical, Inc., 92121 San Diego, CA, USA
| | - Jesus Velasco
- Mapp Biopharmaceutical, Inc., 92121 San Diego, CA, USA
| | | | - Eric Stavale
- Integrated BioTherapeutics, Gaithersburg, MD, USA
| | - M Javad Aman
- Integrated BioTherapeutics, Gaithersburg, MD, USA
| | - Chandra Tangudu
- Department of Veterinary Sciences, Iowa State University, USA
| | | | - Nicholas J Mantis
- Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, NY, USA; Department of Biomedical Sciences, School of Public Health, University at Albany, Albany, NY, USA.
| | - Larry Zeitlin
- Mapp Biopharmaceutical, Inc., 92121 San Diego, CA, USA.
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Parker D, Ryan CL, Alonzo F, Torres VJ, Planet PJ, Prince AS. CD4+ T cells promote the pathogenesis of Staphylococcus aureus pneumonia. J Infect Dis 2014; 211:835-45. [PMID: 25240171 DOI: 10.1093/infdis/jiu525] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We postulated that the activation of proinflammatory signaling by methicillin-resistant Staphylococcus aureus (MRSA) strain USA300 is a major factor in the pathogenesis of severe pneumonia and a target for immunomodulation. Local activation of T cells in the lung was a conserved feature of multiple strains of S. aureus, in addition to USA300. The pattern of Vβ chain activation was consistent with known superantigens, but deletion of SelX or SEK and SEQ was not sufficient to prevent T-cell activation, indicating the participation of multiple genes. Using Rag2(-/-), Cd4(-/-), and Cd28(-/-) mice, we observed significantly improved clearance of MRSA from the airways and decreased lung pathology, compared with findings for wild-type controls. The improved outcome correlated with decreased production of proinflammatory cytokines (tumor necrosis factor, KC, interleukin 6, and interleukin 1β). Our data suggest that T-cell-mediated hypercytokinemia induced by infection with MRSA strain USA300 contributes to pathogenesis and may be a therapeutic target for improving outcomes of this common infection in a clinical setting.
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Affiliation(s)
- Dane Parker
- Department of Pediatrics, Columbia University
| | | | - Francis Alonzo
- Department of Microbiology, New York University School of Medicine, New York, New York
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, New York
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Varshney AK, Wang X, Aguilar JL, Scharff MD, Fries BC. Isotype switching increases efficacy of antibody protection against staphylococcal enterotoxin B-induced lethal shock and Staphylococcus aureus sepsis in mice. mBio 2014; 5:e01007-14. [PMID: 24917594 PMCID: PMC4056548 DOI: 10.1128/mbio.01007-14] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 05/15/2014] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Staphylococcal enterotoxin B (SEB) is a potent toxin that is produced by Staphylococcus aureus strains and is classified as a category B select agent. We have previously shown that monoclonal antibody (MAb) 20B1, a murine anti-SEB IgG1, successfully treats SEB-induced lethal shock (SEBILS) and bacteremia that is caused by SEB-producing S. aureus. In this study, we have generated two isotype switch variants of the original IgG1 MAb 20B1, an IgG2a and IgG2b, both bearing the same variable region sequence, and compared their neutralizing and protective activity in in vitro and in vivo assays, respectively. All 3 isotypes demonstrated comparable affinity to SEB and comparable 50% inhibitory concentrations (IC50s) in T cell proliferation assays. In vivo, however, the IgG2a isotype variant of 20B1 exhibited significantly greater protection than IgG1 or IgG2b in murine SEB intoxication and S. aureus sepsis models. Protection was associated with downmodulation of inflammatory host response. Our data demonstrate that changing the isotype of already protective MAbs, without affecting their antigen specificity or sensitivity, can result in an enhancement of their protective ability. Isotype selection, therefore, should be carefully considered in the development of toxin-neutralizing MAbs and the design of antibody therapeutics. IMPORTANCE The purpose of this study was to enhance the protective efficacy of an existing, protective monoclonal antibody against staphylococcal enterotoxin B. Using two in vivo mouse models, our study demonstrates that the protective efficacy of a monoclonal antibody may be improved by inducing an isotype switch at the Fc region of an antibody, without altering the antigen specificity or sensitivity of the antibody. The development of therapeutic MAbs with higher efficacy may allow for the achievement of equal therapeutic benefit with a lower dosage. In turn, the use of lower doses may reduce the cost of these therapies, while reducing the potential for adverse side effects.
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Affiliation(s)
| | | | - Jorge L Aguilar
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Matthew D Scharff
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA
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Detection and measurement of staphylococcal enterotoxin-like K (SEl-K) secretion by Staphylococcus aureus clinical isolates. J Clin Microbiol 2014; 52:2536-43. [PMID: 24808237 DOI: 10.1128/jcm.00387-14] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Staphylococcal enterotoxin-like K (SEl-K) is a potent mitogen that elicits T-cell proliferation and cytokine production at very low concentrations. However, unlike the classical enterotoxins SEB and toxic shock syndrome toxin 1 (TSST-1), the gene for SEl-K is commonly present in more than half of all Staphylococcus aureus clinical isolates and is present in almost all USA300 community-acquired methicillin-resistant S. aureus (CA-MRSA) isolates. Sequencing of the sel-k gene in over 20 clinical isolates and comparative analysis with all 14 published sel-k sequences indicate that there are at least 6 variants of the sel-k gene, including one that is conserved among all examined USA300 strains. Additionally, we have developed a highly sensitive enzyme-linked immunosorbent assay (ELISA) that specifically detects and measures SEl-K protein in culture supernatants and biological fluids. Quantification of in vitro SEl-K secretion by various S. aureus isolates using this novel capture ELISA revealed detectable amounts of SEl-K secretion by all isolates, with the highest secretion levels being exhibited by MRSA strains that coexpress SEB. In vivo secretion was measured in a murine thigh abscess model, where similar levels of SEl-K accumulation were noted regardless of whether the infecting strain exhibited high or low secretion of SEl-K in vitro. We conclude that SEl-K is commonly expressed in the setting of staphylococcal infection, in significant amounts. SEl-K should be further explored as a target for passive immunotherapy against complicated S. aureus infection.
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Varshney AK, Wang X, MacIntyre J, Zollner RS, Kelleher K, Kovalenko OV, Pechuan X, Byrne FR, Fries BC. Humanized staphylococcal enterotoxin B (SEB)-specific monoclonal antibodies protect from SEB intoxication and Staphylococcus aureus infections alone or as adjunctive therapy with vancomycin. J Infect Dis 2014; 210:973-81. [PMID: 24803533 DOI: 10.1093/infdis/jiu198] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Staphylococcal enterotoxin B (SEB), a potential biological warfare agent, is a potent superantigen that contributes to the virulence of methicillin-resistant Staphylococcus aureus (MRSA), which is a major health threat in the United States. Efforts to develop toxin-neutralizing antibodies as adjunctive therapies are justified, given the high mortality and frequent failure of therapy despite available antibiotics. METHODS Murine SEB-specific mAb 20B1 was humanized, and treatment benefits of Hu-1.6/1.1 and Hu-1.4/1.1 variants were investigated in mice in an SEB intoxication model, as well as in sepsis and deep-tissue infection models. RESULTS Hu-1.6/1.1 and Hu-1.4/1.1 protected mice against SEB-induced lethal shock. Hu-1.6/1.1 also enhanced survival of mice that developed fatal sepsis after challenge with a SEB-producing MRSA strain. Combined treatment of Hu-1.6/1.1 with vancomycin further increased survival and altered cytokine responses, compared with monotherapy with either monoclonal antibody or vancomycin alone. Efficacy was also demonstrated in the deep-tissue infection model, where Hu-1.4/1.1 bound to SEB in vivo and decreased abscess formation, as well as proinflammatory cytokine levels. CONCLUSIONS SEB-neutralizing mAb 20B1 was successfully humanized. The mAb affects outcome by modulating the proinflammatory host response in both the sepsis and the intoxication models, which justifies further development.
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Affiliation(s)
| | - Xiaobo Wang
- Department of Medicine Department of Microbiology and Immunology
| | | | | | | | | | - Ximo Pechuan
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx
| | - Fergus R Byrne
- Pfizer Centers for Therapeutic Innovation, New York, New York
| | - Bettina C Fries
- Department of Medicine Department of Microbiology and Immunology
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Zhao Z, Li B, Sun HQ, Zhang JY, Wang YL, Chen L, Hu J, He YF, Zeng H, Zou QM, Wu C. Fine-mapping of immunodominant linear B-cell epitopes of the Staphylococcus aureus SEB antigen using short overlapping peptides. PLoS One 2014; 9:e90445. [PMID: 24599257 PMCID: PMC3943954 DOI: 10.1371/journal.pone.0090445] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Accepted: 01/31/2014] [Indexed: 01/06/2023] Open
Abstract
Staphylococcal enterotoxin B (SEB) is one of the most potent Staphylococcus aureus exotoxins (SEs). Due to its conserved sequence and stable structure, SEB might be a good candidate antigen for MRSA vaccines. Although cellular immune responses to SEB are well-characterized, much less is known regarding SEB-specific humoral immune responses, particularly regarding detailed epitope mapping. In this study, we utilized a recombinant nontoxic mutant of SEB (rSEB) and an AlPO4 adjuvant to immunize BALB/c mice and confirmed that rSEB can induce a high antibody level and effective immune protection against MRSA infection. Next, the antisera of immunized mice were collected, and linear B cell epitopes within SEB were finely mapped using a series of overlapping synthetic peptides. Three immunodominant B cell epitopes of SEB were screened by ELISA, including a novel epitope, SEB205-222, and two known epitopes, SEB97–114 and SEB247-261. Using truncated peptides, an ELISA was performed with peptide-KLH antisera, and the core sequence of the three immunodominant B cell epitopes were verified as SEB97-112, SEB207-222, and SEB247-257. In vitro, all of the immunodominant epitope-specific antisera (anti-SEB97-112, anti-SEB207-222 and anti-SEB247-257) were observed to inhibit SEB-induced T cell mitogenesis and cytokine production from splenic lymphocytes of BALB/c mice. The homology analysis indicated that SEB97–112 and SEB207-222 were well-conserved among different Staphylococcus aureus strains. The 3D crystal structure of SEB indicated that SEB97–112 was in the loop region inside SEB, whereas SEB207-222 and SEB247-257 were in the β-slice region outside SEB. In summary, the fine-mapping of linear B-cell epitopes of the SEB antigen in this study will be useful to understand anti-SEB immunity against MRSA infection further and will be helpful to optimize MRSA vaccine designs that are based on the SEB antigen.
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Affiliation(s)
- Zhuo Zhao
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Bin Li
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - He-Qiang Sun
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Jin-Yong Zhang
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Yi-Lin Wang
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Li Chen
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Jian Hu
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, PR China
| | - Ya-Fei He
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, PR China
| | - Hao Zeng
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
| | - Quan-Ming Zou
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
- * E-mail: (CW); (Q-MZ)
| | - Chao Wu
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Third Military Medical University, Chongqing, PR China
- * E-mail: (CW); (Q-MZ)
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Abstract
Highly functional synthetic antibody libraries can be used to generate antibodies against a multitude of antigens with affinities and specificities that rival or exceed those of natural antibodies. Current design and generation of synthetic antibody libraries are dependent on our insights from previous studies of simplified synthetic antibody libraries, in addition to our knowledge of antibody structure and function and sequence diversity of natural antibody repertoires. We describe a detailed protocol for the design and generation of phage-displayed synthetic antibody libraries built on a single framework with diversity restricted to four complementarity-determining regions by using precisely designed degenerate oligonucleotides. This general methodology could be applied to generation of large, functional synthetic antibody libraries using standard supplies, equipment, and molecular biology techniques.
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Affiliation(s)
- Gang Chen
- University of Toronto, Toronto, ON, Canada
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46
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YU FENGLING, LIU TINGTING, ZHU XIANG, YANG WENGXUAN, ZHANG TAO, LIN NA, LIU YONG, LIU CONGSEN, JIANG JIU, GUAN JUNCHANG. Staphylococcal enterotoxin B and α-toxin induce the apoptosis of ECV304 cells via similar mechanisms. Mol Med Rep 2013; 8:591-6. [DOI: 10.3892/mmr.2013.1550] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 06/13/2013] [Indexed: 11/06/2022] Open
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47
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Endom EE. Bioterrorism and the Pediatric Patient: An Update. CLINICAL PEDIATRIC EMERGENCY MEDICINE 2013. [DOI: 10.1016/j.cpem.2013.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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48
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Abstract
Staphylococcus aureus plays an important role in numerous human cases of food poisoning, soft tissue, and bone infections, as well as potentially lethal toxic shock. This common bacterium synthesizes various virulence factors that include staphylococcal enterotoxins (SEs). These protein toxins bind directly to major histocompatibility complex class II on antigen-presenting cells and specific Vβ regions of T-cell receptors, resulting in potentially life-threatening stimulation of the immune system. Picomolar concentrations of SEs ultimately elicit proinflammatory cytokines that can induce fever, hypotension, multi-organ failure, and lethal shock. Various in vitro and in vivo models have provided important tools for studying the biological effects of, as well as potential vaccines/therapeutics against, the SEs. This review succinctly presents known physical and biological properties of the SEs, including various intervention strategies. In particular, SEB will often be portrayed as per biodefense concerns dating back to the 1960s.
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Affiliation(s)
- Teresa Krakauer
- Integrated Toxicology Division; United States Army Medical Research Institute of Infectious Diseases; Fort Detrick, MD USA
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49
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Hudson LC, Seabolt BS, Odle J, Bost KL, Stahl CH, Piller KJ. Sublethal staphylococcal enterotoxin B challenge model in pigs to evaluate protection following immunization with a soybean-derived vaccine. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:24-32. [PMID: 23114702 PMCID: PMC3535777 DOI: 10.1128/cvi.00526-12] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 10/24/2012] [Indexed: 11/20/2022]
Abstract
In an effort to develop a sustainable platform for manufacturing protein-based vaccine candidates, we expressed a triple mutant of staphylococcal enterotoxin B carrying the L45R, Y89A, and Y94A modifications in transgenic soybean seeds (soy-mSEB). Soy-mSEB possessed no detectable superantigen activity in vitro. We found that this soybean-derived, nontoxic mutant of SEB could be stably expressed, stored in seeds for extended periods at room temperature without degradation, and easily purified from contaminating soy proteins. Vaccination of pigs with purified soy-mSEB, or the identical triple mutant expressed in Escherichia coli (E. coli-mSEB), resulted in high antibody titers against the native toxin in immunized animals. In fact, titers were indistinguishable regardless of the immunogen used, demonstrating the equivalence of soy-mSEB and E. coli-mSEB vaccinations. Antisera from either immunized group were able to block native SEB superantigen activity in an in vitro neutralization assay. Similar results were obtained when immunized animals were challenged with a sublethal dose of native toxin. Significant reductions in toxin-induced serum cytokine levels were observed in soy-mSEB- and E. coli-mSEB-immunized pigs compared to control animals. The reductions in SEB-induced cytokine responses were similar regardless of the immunogen used for vaccination. Surprisingly, however, some clinical symptoms, such as prostration, lethargy, emesis, and/or diarrhea, were still observed in all immunized animals. These studies demonstrate the potential for soybean-derived proteins as a platform technology for sustainable vaccine manufacturing and the usefulness of a sublethal challenge model in pigs for evaluating the efficacy of potential SEB vaccine candidates.
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Affiliation(s)
- Laura C. Hudson
- Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
- SoyMeds, Inc., Davidson, North Carolina, USA
| | - Brynn S. Seabolt
- Laboratory of Developmental Nutrition, Department of Animal Science, North Carolina State University, Raleigh, North Carolina, USA
| | - Jack Odle
- Laboratory of Developmental Nutrition, Department of Animal Science, North Carolina State University, Raleigh, North Carolina, USA
| | - Kenneth L. Bost
- Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
- SoyMeds, Inc., Davidson, North Carolina, USA
| | - Chad H. Stahl
- Laboratory of Developmental Nutrition, Department of Animal Science, North Carolina State University, Raleigh, North Carolina, USA
| | - Kenneth J. Piller
- Department of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina, USA
- SoyMeds, Inc., Davidson, North Carolina, USA
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50
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Koellhoffer JF, Chen G, Sandesara RG, Bale S, Saphire EO, Chandran K, Sidhu SS, Lai JR. Two synthetic antibodies that recognize and neutralize distinct proteolytic forms of the ebola virus envelope glycoprotein. Chembiochem 2012; 13:2549-57. [PMID: 23111988 DOI: 10.1002/cbic.201200493] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Indexed: 11/06/2022]
Abstract
Ebola virus (EBOV) is a highly pathogenic member of the Filoviridae family of viruses that causes severe hemorrhagic fever. Infection proceeds through fusion of the host cell and viral membranes, a process that is mediated by the viral envelope glycoprotein (GP). Following endosomal uptake, a key step in viral entry is the proteolytic cleavage of GP by host endosomal cysteine proteases. Cleavage exposes a binding site for the host cell receptor Niemann-Pick C1 (NPC1) and may induce conformational changes in GP leading to membrane fusion. However, the precise details of the structural changes in GP associated with proteolysis and the role of these changes in viral entry have not been established. Here, we have employed synthetic antibody technology to identify antibodies targeting EBOV GP prior to and following proteolysis (i.e. in the "uncleaved" [GP(UNCL)] and "cleaved" [GP(CL)] forms). We identified antibodies with distinct recognition profiles: Fab(CL) bound preferentially to GP(CL) (EC(50)=1.7 nM), whereas Fab(UNCL) bound specifically to GP(UNCL) (EC(50)=75 nM). Neutralization assays with GP-containing pseudotyped viruses indicated that these antibodies inhibited GP(CL)- or GP(UNCL)-mediated viral entry with specificity matching their recognition profiles (IC(50): 87 nM for IgG(CL); 1 μM for Fab(UNCL)). Competition ELISAs indicate that Fab(CL) binds an epitope distinct from that of KZ52, a well-characterized EBOV GP antibody, and from that of the luminal domain of NPC1. The binding epitope of Fab(UNCL) was also distinct from that of KZ52, suggesting that Fab(UNCL) binds a novel neutralization epitope on GP(UNCL). Furthermore, the neutralizing ability of Fab(CL) suggests that there are targets on GP(CL) available for neutralization. This work showcases the applicability of synthetic antibody technology to the study of viral membrane fusion, and provides new tools for dissecting intermediates of EBOV entry.
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Affiliation(s)
- Jayne F Koellhoffer
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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