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Otto M. Critical Assessment of the Prospects of Quorum-Quenching Therapy for Staphylococcus aureus Infection. Int J Mol Sci 2023; 24:ijms24044025. [PMID: 36835436 PMCID: PMC9958572 DOI: 10.3390/ijms24044025] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/04/2023] [Accepted: 02/08/2023] [Indexed: 02/19/2023] Open
Abstract
Staphylococcus aureus is an important pathogen that causes a high number of infections and is one of the leading causes of death in hospitalized patients. Widespread antibiotic resistance such as in methicillin-resistant S. aureus (MRSA) has prompted research into potential anti-virulence-targeted approaches. Targeting the S. aureus accessory gene regulator (Agr) quorum-sensing system, a master regulator of virulence, is the most frequently proposed anti-virulence strategy for S. aureus. While much effort has been put into the discovery and screening for Agr inhibitory compounds, in vivo analysis of their efficacy in animal infection models is still rare and reveals various shortcomings and problems. These include (i) an almost exclusive focus on topical skin infection models, (ii) technical problems that leave doubt as to whether observed in vivo effects are due to quorum-quenching, and (iii) the discovery of counterproductive biofilm-increasing effects. Furthermore, potentially because of the latter, invasive S. aureus infection is associated with Agr dysfunctionality. Altogether, the potential of Agr inhibitory drugs is nowadays seen with low enthusiasm given the failure to provide sufficient in vivo evidence for their potential after more than two decades since the initiation of such efforts. However, current Agr inhibition-based probiotic approaches may lead to a new application of Agr inhibition strategies in preventing S. aureus infections by targeting colonization or for otherwise difficult-to-treat skin infections such as atopic dermatitis.
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Affiliation(s)
- Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20814, USA
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2
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Epitope-Based Vaccines against the Chlamydia trachomatis Major Outer Membrane Protein Variable Domain 4 Elicit Protection in Mice. Vaccines (Basel) 2022; 10:vaccines10060875. [PMID: 35746483 PMCID: PMC9227494 DOI: 10.3390/vaccines10060875] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 12/21/2022] Open
Abstract
Chlamydia trachomatis (Ct) is the most common bacterial sexual transmitted pathogen, yet a vaccine is not currently available. Here, we used the immunogenic bacteriophage MS2 virus-like particle (VLP) technology to engineer vaccines against the Ct major outer membrane protein variable domain 4 (MOMP-VD4), which contains a conserved neutralizing epitope (TTLNPTIAG). A previously described monoclonal antibody to the MOMP-VD4 (E4 mAb) is capable of neutralizing all urogenital Ct serovars and binds this core epitope, as well as several non-contiguous amino acids. This suggests that this core epitope may require conformational context in order to elicit neutralizing antibodies to Ct. In order to identify immunogens that could elicit neutralizing antibodies to the TTLNPTIAG epitope, we used two approaches. First, we used affinity selection with a bacteriophage MS2-VLP library displaying random peptides in a constrained, surface-exposed loop to identify potential E4 mAb mimotopes. After four rounds of affinity selection, we identified a VLP-displayed peptide (HMVGSTKWTN) that could bind to the E4 mAb and elicited serum IgG that bound weakly to Ct elementary bodies by ELISA. Second, two versions of the core conserved TTLNPTIAG epitope (TTLNPTIAG and TTLNPTIAGA) were recombinantly expressed on the coat protein of the MS2 VLP in a constrained, surface-exposed loop. Mouse immune sera IgG bound to Ct elementary bodies by ELISA. Immunization with these MS2 VLPs provided protection from vaginal Chlamydia infection in a murine challenge model. These data suggest that short peptide epitopes targeting the MOMP-VD4 could be appropriate for Ct vaccine design when displayed on an immunogenic bacteriophage VLP vaccine platform.
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Recent Strategies to Combat Biofilms Using Antimicrobial Agents and Therapeutic Approaches. Pathogens 2022; 11:pathogens11030292. [PMID: 35335616 PMCID: PMC8955104 DOI: 10.3390/pathogens11030292] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 02/01/2023] Open
Abstract
Biofilms are intricate bacterial assemblages that attach to diverse surfaces using an extracellular polymeric substance that protects them from the host immune system and conventional antibiotics. Biofilms cause chronic infections that result in millions of deaths around the world every year. Since the antibiotic tolerance mechanism in biofilm is different than that of the planktonic cells due to its multicellular structure, the currently available antibiotics are inadequate to treat biofilm-associated infections which have led to an immense need to find newer treatment options. Over the years, various novel antibiofilm compounds able to fight biofilms have been discovered. In this review, we have focused on the recent and intensively researched therapeutic techniques and antibiofilm agents used for biofilm treatment and grouped them according to their type and mode of action. We also discuss some therapeutic approaches that have the potential for future advancement.
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Ronsard L, Yousif AS, Peabody J, Okonkwo V, Devant P, Mogus AT, Barnes RM, Rohrer D, Lonberg N, Peabody D, Chackerian B, Lingwood D. Engineering an Antibody V Gene-Selective Vaccine. Front Immunol 2021; 12:730471. [PMID: 34566992 PMCID: PMC8459710 DOI: 10.3389/fimmu.2021.730471] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 08/25/2021] [Indexed: 11/24/2022] Open
Abstract
The ligand-binding surface of the B cell receptor (BCR) is formed by encoded and non-encoded antigen complementarity determining regions (CDRs). Genetically reproducible or ‘public’ antibodies can arise when the encoded CDRs play deterministic roles in antigen recognition, notably within human broadly neutralizing antibodies against HIV and influenza virus. We sought to exploit this by engineering virus-like-particle (VLP) vaccines that harbor multivalent affinity against gene-encoded moieties of the BCR antigen binding site. As proof of concept, we deployed a library of RNA bacteriophage VLPs displaying random peptides to identify a multivalent antigen that selectively triggered germline BCRs using the human VH gene IGVH1-2*02. This VLP selectively primed IGHV1-2*02 BCRs that were present within a highly diversified germline antibody repertoire within humanized mice. Our approach thus provides methodology to generate antigens that engage specific BCR configurations of interest, in the absence of structure-based information.
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Affiliation(s)
- Larance Ronsard
- The Ragon Institute of Massachusetts General Hospital, The Massachusetts Institute of Technology and Harvard University, Cambridge, MA, United States
| | - Ashraf S Yousif
- The Ragon Institute of Massachusetts General Hospital, The Massachusetts Institute of Technology and Harvard University, Cambridge, MA, United States
| | - Julianne Peabody
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Vintus Okonkwo
- The Ragon Institute of Massachusetts General Hospital, The Massachusetts Institute of Technology and Harvard University, Cambridge, MA, United States
| | - Pascal Devant
- The Ragon Institute of Massachusetts General Hospital, The Massachusetts Institute of Technology and Harvard University, Cambridge, MA, United States
| | - Alemu Tekewe Mogus
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | | | - Daniel Rohrer
- Bristol-Myers Squibb, Redwood City, CA, United States
| | - Nils Lonberg
- Bristol-Myers Squibb, Redwood City, CA, United States
| | - David Peabody
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Bryce Chackerian
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Daniel Lingwood
- The Ragon Institute of Massachusetts General Hospital, The Massachusetts Institute of Technology and Harvard University, Cambridge, MA, United States
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5
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Wu X, Yin J, Liu J, Gu Y, Wang S, Wang J. Colorimetric detection of glucose based on the binding specificity of a synthetic cyclic peptide. Analyst 2020; 145:7234-7241. [PMID: 32893268 DOI: 10.1039/d0an00211a] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel colorimetric sensing method for glucose was developed based on the catalytic activity of Au nanoparticles (NPs) and a synthetic cyclic peptide that specifically binds with glucose. It is the first time that a cyclic peptide was used as a recognition element for glucose sensing. In the absence of glucose, the monolayers of cyclic peptide on the Au NP surfaces interfered little with the adsorption of 4-nitrophenol, and the Au NPs catalyze the reduction of bright yellow 4-nitrophenol to colorless 4-aminophenol in the presence of NaBH4. Added glucose was preferentially bound by the cyclic peptides and impeded the adsorption of 4-nitrophenol. Therefore, the color of the solution presented varying shades of yellow depending on the concentration of glucose. The method had a short response time of 10 min and demonstrated a linear response over a range of glucose concentrations from 0.1 mM to 20 mM, with a lower limit of detection of 0.04 mM. Meanwhile, it also provided results readily observable by the naked eye. The method was successfully applied for the detection of glucose in spiked food samples (Chinese cabbage, pear, and wheat flour) and spiked rabbit blood, and a good recovery rate of 88.04-103.28% and 94.27-101.53% was obtained, respectively.
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Affiliation(s)
- Xuemei Wu
- State Key Laboratory of Food Nutrition and Safety, Tianjin Engineering Research Center of Safety Control Technology in Food Processing, Tianjin University of Science and Technology, Tianjin, 300457, China.
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7
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He B, Chen H, Li N, Huang J. SAROTUP: a suite of tools for finding potential target-unrelated peptides from phage display data. Int J Biol Sci 2019; 15:1452-1459. [PMID: 31337975 PMCID: PMC6643146 DOI: 10.7150/ijbs.31957] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 04/09/2019] [Indexed: 01/13/2023] Open
Abstract
SAROTUP (Scanner And Reporter Of Target-Unrelated Peptides) 3.1 is a significant upgrade to the widely used SAROTUP web server for the rapid identification of target-unrelated peptides (TUPs) in phage display data. At present, SAROTUP has gathered a suite of tools for finding potential TUPs and other purposes. Besides the TUPScan, the motif-based tool, and three tools based on the BDB database, i.e., MimoScan, MimoSearch, and MimoBlast, three predictors based on support vector machine, i.e., PhD7Faster, SABinder and PSBinder, are integrated into SAROTUP. The current version of SAROTUP contains 27 TUP motifs and 823 TUP sequences. We also developed the standalone SAROTUP application with graphical user interface (GUI) and command line versions for processing deep sequencing phage display data and distributed it as an open source package, which can perform perfectly locally on almost all systems that support C++ with little or no modification. The web interfaces of SAROTUP have also been redesigned to be more self-evident and user-friendly. The latest version of SAROTUP is freely available at http://i.uestc.edu.cn/sarotup3.
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Affiliation(s)
- Bifang He
- School of Medicine, Guizhou University, Guiyang 550025, China.,Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Heng Chen
- School of Medicine, Guizhou University, Guiyang 550025, China
| | - Ning Li
- Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Jian Huang
- Center for Informational Biology, University of Electronic Science and Technology of China, Chengdu 611731, China
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8
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Quorum Sensing as Antivirulence Target in Cystic Fibrosis Pathogens. Int J Mol Sci 2019; 20:ijms20081838. [PMID: 31013936 PMCID: PMC6515091 DOI: 10.3390/ijms20081838] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/11/2019] [Accepted: 04/11/2019] [Indexed: 12/17/2022] Open
Abstract
Cystic fibrosis (CF) is an autosomal recessive genetic disorder which leads to the secretion of a viscous mucus layer on the respiratory epithelium that facilitates colonization by various bacterial pathogens. The problem of drug resistance has been reported for all the species able to colonize the lung of CF patients, so alternative treatments are urgently needed. In this context, a valid approach is to investigate new natural and synthetic molecules for their ability to counteract alternative pathways, such as virulence regulating quorum sensing (QS). In this review we describe the pathogens most commonly associated with CF lung infections: Staphylococcus aureus, Pseudomonas aeruginosa, species of the Burkholderia cepacia complex and the emerging pathogens Stenotrophomonas maltophilia, Haemophilus influenzae and non-tuberculous Mycobacteria. For each bacterium, the QS system(s) and the molecules targeting the different components of this pathway are described. The amount of investigations published in the last five years clearly indicate the interest and the expectations on antivirulence therapy as an alternative to classical antibiotics.
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9
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Fleitas Martínez O, Cardoso MH, Ribeiro SM, Franco OL. Recent Advances in Anti-virulence Therapeutic Strategies With a Focus on Dismantling Bacterial Membrane Microdomains, Toxin Neutralization, Quorum-Sensing Interference and Biofilm Inhibition. Front Cell Infect Microbiol 2019; 9:74. [PMID: 31001485 PMCID: PMC6454102 DOI: 10.3389/fcimb.2019.00074] [Citation(s) in RCA: 152] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 03/05/2019] [Indexed: 12/11/2022] Open
Abstract
Antimicrobial resistance constitutes one of the major challenges facing humanity in the Twenty-First century. The spread of resistant pathogens has been such that the possibility of returning to a pre-antibiotic era is real. In this scenario, innovative therapeutic strategies must be employed to restrict resistance. Among the innovative proposed strategies, anti-virulence therapy has been envisioned as a promising alternative for effective control of the emergence and spread of resistant pathogens. This review presents some of the anti-virulence strategies that are currently being developed, it will cover strategies focused on quench pathogen quorum sensing (QS) systems, disassemble of bacterial functional membrane microdomains (FMMs), disruption of biofilm formation and bacterial toxin neutralization.
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Affiliation(s)
- Osmel Fleitas Martínez
- Programa de Pós-Graduação em Patologia Molecular, Faculdade de Medicina, Universidade de Brasília, Brasília, Brazil.,Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, Brazil
| | - Marlon Henrique Cardoso
- Programa de Pós-Graduação em Patologia Molecular, Faculdade de Medicina, Universidade de Brasília, Brasília, Brazil.,Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, Brazil.,S-inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil
| | - Suzana Meira Ribeiro
- Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal da Grande Dourados, Dourados, Brazil
| | - Octavio Luiz Franco
- Programa de Pós-Graduação em Patologia Molecular, Faculdade de Medicina, Universidade de Brasília, Brasília, Brazil.,Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, Brazil.,S-inova Biotech, Programa de Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, Brazil
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10
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Computational B-cell epitope identification and production of neutralizing murine antibodies against Atroxlysin-I. Sci Rep 2018; 8:14904. [PMID: 30297733 PMCID: PMC6175905 DOI: 10.1038/s41598-018-33298-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 09/03/2018] [Indexed: 11/08/2022] Open
Abstract
Epitope identification is essential for developing effective antibodies that can detect and neutralize bioactive proteins. Computational prediction is a valuable and time-saving alternative for experimental identification. Current computational methods for epitope prediction are underused and undervalued due to their high false positive rate. In this work, we targeted common properties of linear B-cell epitopes identified in an individual protein class (metalloendopeptidases) and introduced an alternative method to reduce the false positive rate and increase accuracy, proposing to restrict predictive models to a single specific protein class. For this purpose, curated epitope sequences from metalloendopeptidases were transformed into frame-shifted Kmers (3 to 15 amino acid residues long). These Kmers were decomposed into a matrix of biochemical attributes and used to train a decision tree classifier. The resulting prediction model showed a lower false positive rate and greater area under the curve when compared to state-of-the-art methods. Our predictions were used for synthesizing peptides mimicking the predicted epitopes for immunization of mice. A predicted linear epitope that was previously undetected by an experimental immunoassay was able to induce neutralizing-antibody production in mice. Therefore, we present an improved prediction alternative and show that computationally identified epitopes can go undetected during experimental mapping.
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11
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Bolli E, O'Rourke JP, Conti L, Lanzardo S, Rolih V, Christen JM, Barutello G, Forni M, Pericle F, Cavallo F. A Virus-Like-Particle immunotherapy targeting Epitope-Specific anti-xCT expressed on cancer stem cell inhibits the progression of metastatic cancer in vivo. Oncoimmunology 2017; 7:e1408746. [PMID: 29399412 PMCID: PMC5790338 DOI: 10.1080/2162402x.2017.1408746] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 11/17/2017] [Accepted: 11/18/2017] [Indexed: 01/17/2023] Open
Abstract
Aggressive forms of breast cancer, such as Her2+ and triple negative breast cancer (TNBC), are enriched in breast cancer stem cells (BCSC) and have limited therapeutic options. BCSC represent a key cellular reservoir for relapse, metastatic progression and therapeutic resistance. Their ability to resist common cytotoxic therapies relies on different mechanisms, including improved detoxification. The cystine-glutamate antiporter protein xCT (SLC7A11) regulates cystine intake, conversion to cysteine and subsequent glutathione synthesis, protecting cells against oxidative and chemical insults. Our previous work showed that xCT is highly expressed in tumorspheres derived from breast cancer cell lines and downregulation of xCT altered BCSC function in vitro and inhibited pulmonary metastases in vivo. We further strengthened these observations by developing a virus-like-particle (VLP; AX09-0M6) immunotherapy targeting the xCT protein. AX09-0M6 elicited a strong antibody response against xCT including high levels of IgG2a antibody. IgG isolated from AX09-0M6 treated mice bound to tumorspheres, inhibited xCT function as assessed by reactive oxygen species generation and decreased BCSC growth and self-renewal. To assess if AX09-0M6 impacts BCSC in vivo seeding, Her2+ TUBO-derived tumorspheres were injected into the tail vein of AX09-0M6 or control treated female BALB/c mice. AX09-0M6 significantly inhibited formation of pulmonary nodules. To evaluate its ability to impact metastases, AX09-0M6 was administered to mice with established subcutaneous 4T1 tumors. AX09-0M6 administration significantly hampered tumor growth and development of pulmonary metastases. These data show that a VLP-based immunization approach inhibits xCT activity, impacts BCSC biology and significantly reduces metastatic progression in preclinical models.
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Affiliation(s)
- Elisabetta Bolli
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Torino, Italy
| | | | - Laura Conti
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Torino, Italy
| | - Stefania Lanzardo
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Torino, Italy
| | - Valeria Rolih
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Torino, Italy
| | | | - Giuseppina Barutello
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Torino, Italy
| | - Marco Forni
- EuroClone S.p.A Research Laboratory, Molecular Biotechnology Center, University of Torino, Torino, Italy
| | | | - Federica Cavallo
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Torino, Italy
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12
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VLP-based vaccine induces immune control of Staphylococcus aureus virulence regulation. Sci Rep 2017; 7:637. [PMID: 28377579 PMCID: PMC5429642 DOI: 10.1038/s41598-017-00753-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 03/09/2017] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus is the leading cause of skin and soft tissue infections (SSTIs) and mounting antibiotic resistance requires innovative treatment strategies. S. aureus uses secreted cyclic autoinducing peptides (AIPs) and the accessory gene regulator (agr) operon to coordinate expression of virulence factors required for invasive infection. Of the four agr alleles (agr types I-IV and corresponding AIPs1-4), agr type I isolates are most frequently associated with invasive infection. Cyclization via a thiolactone bond is essential for AIP function; therefore, recognition of the cyclic form of AIP1 may be necessary for antibody-mediated neutralization. However, the small sizes of AIPs and labile thiolactone bond have hindered vaccine development. To overcome this, we used a virus-like particle (VLP) vaccine platform (PP7) for conformationally-restricted presentation of a modified AIP1 amino acid sequence (AIP1S). Vaccination with PP7-AIP1S elicited AIP1-specific antibodies and limited agr-activation in vivo. Importantly, in a murine SSTI challenge model with a highly virulent agr type I S. aureus isolate, PP7-AIP1S vaccination reduced pathogenesis and increased bacterial clearance compared to controls, demonstrating vaccine efficacy. Given the contribution of MRSA agr type I isolates to human disease, vaccine targeting of AIP1-regulated virulence could have a major clinical impact in the fight against antibiotic resistance.
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13
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Frietze KM, Pascale JM, Moreno B, Chackerian B, Peabody DS. Pathogen-specific deep sequence-coupled biopanning: A method for surveying human antibody responses. PLoS One 2017; 12:e0171511. [PMID: 28152075 PMCID: PMC5289605 DOI: 10.1371/journal.pone.0171511] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 01/20/2017] [Indexed: 12/05/2022] Open
Abstract
Identifying the targets of antibody responses during infection is important for designing vaccines, developing diagnostic and prognostic tools, and understanding pathogenesis. We developed a novel deep sequence-coupled biopanning approach capable of identifying the protein epitopes of antibodies present in human polyclonal serum. Here, we report the adaptation of this approach for the identification of pathogen-specific epitopes recognized by antibodies elicited during acute infection. As a proof-of-principle, we applied this approach to assessing antibodies to Dengue virus (DENV). Using a panel of sera from patients with acute secondary DENV infection, we panned a DENV antigen fragment library displayed on the surface of bacteriophage MS2 virus-like particles and characterized the population of affinity-selected peptide epitopes by deep sequence analysis. Although there was considerable variation in the responses of individuals, we found several epitopes within the Envelope glycoprotein and Non-Structural Protein 1 that were commonly enriched. This report establishes a novel approach for characterizing pathogen-specific antibody responses in human sera, and has future utility in identifying novel diagnostic and vaccine targets.
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Affiliation(s)
- Kathryn M. Frietze
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, MSC08 4660, 1 University of New Mexico, Albuquerque, NM, United States of America
- * E-mail:
| | - Juan M. Pascale
- Gorgas Memorial Institute for Health Studies, Ave. Justo Arosemena y Calle 35, Panamá, Panamá
| | - Brechla Moreno
- Gorgas Memorial Institute for Health Studies, Ave. Justo Arosemena y Calle 35, Panamá, Panamá
| | - Bryce Chackerian
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, MSC08 4660, 1 University of New Mexico, Albuquerque, NM, United States of America
| | - David S. Peabody
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, MSC08 4660, 1 University of New Mexico, Albuquerque, NM, United States of America
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14
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Reuter K, Steinbach A, Helms V. Interfering with Bacterial Quorum Sensing. PERSPECTIVES IN MEDICINAL CHEMISTRY 2016; 8:1-15. [PMID: 26819549 PMCID: PMC4718088 DOI: 10.4137/pmc.s13209] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 01/22/2023]
Abstract
Quorum sensing (QS) describes the exchange of chemical signals in bacterial populations to adjust the bacterial phenotypes according to the density of bacterial cells. This serves to express phenotypes that are advantageous for the group and ensure bacterial survival. To do so, bacterial cells synthesize autoinducer (AI) molecules, release them to the environment, and take them up. Thereby, the AI concentration reflects the cell density. When the AI concentration exceeds a critical threshold in the cells, the AI may activate the expression of virulence-associated genes or of luminescent proteins. It has been argued that targeting the QS system puts less selective pressure on these pathogens and should avoid the development of resistant bacteria. Therefore, the molecular components of QS systems have been suggested as promising targets for developing new anti-infective compounds. Here, we review the QS systems of selected gram-negative and gram-positive bacteria, namely, Vibrio fischeri, Pseudomonas aeruginosa, and Staphylococcus aureus, and discuss various antivirulence strategies based on blocking different components of the QS machinery.
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Affiliation(s)
- Kerstin Reuter
- Center for Bioinformatics, Saarland University, Saarbrücken, Germany.; Saarbrücken Graduate School of Computer Science, Saarland University, Saarbrücken, Germany
| | - Anke Steinbach
- Department of Drug Design and Optimization, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, Saarbrücken, Germany
| | - Volkhard Helms
- Center for Bioinformatics, Saarland University, Saarbrücken, Germany
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15
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Leo N, Shang Y, Yu JJ, Zeng X. Characterization of Self-Assembled Monolayers of Peptide Mimotopes of CD20 Antigen and Their Binding with Rituximab. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:13764-13772. [PMID: 26609837 DOI: 10.1021/acs.langmuir.5b02605] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
CD20, expressed in greater than 90% of B-lymphocytic lymphomas, is a target for antibody therapy. Rituximab is a chimeric therapeutic monoclonal antibody (mAb) against the protein CD20, allowing it to destroy B cells and to treat lymphoma, leukemia, transplant rejection, and autoimmune disorder. In this work, the binding of rituximab to self-assembled monolayers (SAMs) of peptide mimotopes of CD20 antigen was systematically characterized. Four peptide mimotopes of CD 20 antigen were selected from the literature and redesigned to allow their SAM immobilizations on gold electrodes through a peptide linker with cysteine. The bindings of these peptides with rituximab and control mAbs (trastuzumab and bevacizumab) were characterized by quartz crystal microbalance (QCM). Among the four peptide mimotopes initially selected, the peptide designated as CN-14 (CGSGSGSWPRWLEN) was the most selective and sensitive for rituximab binding. The CN-14 SAM was further characterized by ellipsometry and atomic force microscopy. The thickness of the CN-14 SAM film was approximately 32 Å, and the CN-14 SAM is suggested to be stabilized by a salt bridge of Arg-10 and Glu-13 between CN-14 peptides. The CN-14 salt bridge was evaluated by a series of modifications to the CN-14 peptide sequence and characterized by QCM. The CN-14 amide variant produced a better affinity to rituximab than CN-14 without a significant impact on selectivity. As the pKa of the Glu residue of CN-14 increased, the affinity of the SAM to rituximab increased, whereas the selectivity decreased. This was attributed to the weakening of the salt bridge between the CN-14 Arg-10 and Glu-13 at higher pKa values for Glu-13. Our study shows that peptide mimotopes have potential benefits in sensor applications, as the peptide-peptide interactions in the SAMs can be manipulated by the addition of functional groups to the peptide to influence the binding of target proteins.
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Affiliation(s)
- Norman Leo
- Chemistry Department, Oakland University , Rochester, Michigan 48309, United States
| | - Yuqin Shang
- Chemistry Department, Oakland University , Rochester, Michigan 48309, United States
| | - Jing-jiang Yu
- Nanotechnology Measurements Division, Agilent Technologies, Inc. , Chandler, Arizona 85226, United States
- Nanotechnology Systems Division, Hitachi High Technologies America, Inc. , Clarksburg, Maryland 20871, United States
| | - Xiangqun Zeng
- Chemistry Department, Oakland University , Rochester, Michigan 48309, United States
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Frietze KM, Roden RBS, Lee JH, Shi Y, Peabody DS, Chackerian B. Identification of Anti-CA125 Antibody Responses in Ovarian Cancer Patients by a Novel Deep Sequence-Coupled Biopanning Platform. Cancer Immunol Res 2015; 4:157-64. [PMID: 26589767 DOI: 10.1158/2326-6066.cir-15-0165] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 10/06/2015] [Indexed: 01/22/2023]
Abstract
High-grade epithelial ovarian cancer kills more women than any other gynecologic cancer and is rarely diagnosed at an early stage. We sought to identify tumor-associated antigens (TAA) as candidate diagnostic and/or immunotherapeutic targets by taking advantage of tumor autoantibody responses in individuals with ovarian cancer. Plasma-derived IgG from a pool of five patients with advanced ovarian cancer was subjected to iterative biopanning using a library of bacteriophage MS2 virus-like particles (MS2-VLPs) displaying diverse short random peptides. After two rounds of biopanning, we analyzed the selectant population of MS2-VLPs by Ion Torrent deep sequencing. One of the top 25 most abundant peptides identified (DISGTNTSRA) had sequence similarity to cancer antigen 125 (CA125/MUC16), a well-known ovarian cancer-associated antigen. Mice immunized with MS2-DISGTNTSRA generated antibodies that cross-reacted with purified soluble CA125 from ovarian cancer cells but not membrane-bound CA125, indicating that the DISGTNTSRA peptide was a CA125/MUC16 peptide mimic of soluble CA125. Preoperative ovarian cancer patient plasma (n = 100) was assessed for anti-DISGTNTSRA, anti-CA125, and CA125. Patients with normal CA125 (<35 IU/mL) at the time of diagnosis had significantly more antibodies to DISGTNTSRA and to CA125 than those patients who had high CA125 (>35 IU/mL). A statistically significant survival advantage was observed for patients who had either normal CA125 and/or higher concentrations of antibodies to CA125 at the time of diagnosis. These data show the feasibility of using deep sequence-coupled biopanning to identify TAA autoantibody responses from cancer patient plasma and suggest a possible antibody-mediated mechanism for low CA125 plasma concentrations in some ovarian cancer patients.
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Affiliation(s)
- Kathryn M Frietze
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, New Mexico
| | - Richard B S Roden
- Department of Pathology, The Johns Hopkins University, Baltimore, Maryland
| | - Ji-Hyun Lee
- Biostatistics Shared Resource, University of New Mexico Cancer Center, Albuquerque, New Mexico
| | - Yang Shi
- Biostatistics Shared Resource, University of New Mexico Cancer Center, Albuquerque, New Mexico
| | - David S Peabody
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, New Mexico
| | - Bryce Chackerian
- Department of Molecular Genetics and Microbiology, University of New Mexico, Albuquerque, New Mexico.
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Affinity selection of epitope-based vaccines using a bacteriophage virus-like particle platform. Curr Opin Virol 2015; 11:76-82. [PMID: 25829254 DOI: 10.1016/j.coviro.2015.03.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 03/06/2015] [Accepted: 03/10/2015] [Indexed: 11/21/2022]
Abstract
Display of epitopes on virus-like particles (VLPs) is a highly effective technique for enhancing the immunogenicity of antigens that are poorly immunogenic in their native context. VLP-based vaccines can be used to elicit long-lasting, high-titer antibody responses against diverse target antigens, even self-antigens. Most VLP platform-based vaccines are rationally engineered; specific target epitopes or domains are arrayed so that they are displayed at high-valency on the surface of VLPs. In this review, we describe an alternate technique for vaccine discovery using VLPs. This strategy, analogous to filamentous phage display, allows bacteriophage VLP-based vaccines to be identified from a vast library of potential vaccines by affinity selection. This technology integrates epitope discovery and immunization functions into a single platform.
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Khan BA, Yeh AJ, Cheung GYC, Otto M. Investigational therapies targeting quorum-sensing for the treatment of Staphylococcus aureus infections. Expert Opin Investig Drugs 2015; 24:689-704. [PMID: 25704585 DOI: 10.1517/13543784.2015.1019062] [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] [Indexed: 01/07/2023]
Abstract
INTRODUCTION Antibiotic resistance is a serious global health concern for developed and developing nations. MRSA represents a particularly severe public health threat that is associated with high morbidity and mortality. The lack of novel antibiotics has led scientists to explore therapies targeting bacterial virulence mechanisms and virulence regulators, including those controlling cell-cell communication. AREAS COVERED The authors discuss the role of quorum-sensing in Staphylococcus aureus infections and components of the system that are being targeted using novel investigational drugs. In particular, the authors examine the role of the accessory gene regulator (Agr) system in virulence regulation of S. aureus pathogenesis. Finally, the authors present and compare natural and synthetic compounds that have been found to interfere with Agr functionality. EXPERT OPINION There is a great need to develop new therapeutic methods to combat S. aureus infections. These include anti-virulence therapies that target key global regulators involved with the establishment and propagation of infection. Several molecules have been found to interfere with S. aureus virulence regulation, especially those targeting the Agr quorum-sensing signaling molecule. These preliminary findings warrant further investigation and validation, with the goal of refining a compound that has broad-spectrum inhibitory effects on most S. aureus strains and Agr subtypes.
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Affiliation(s)
- Burhan A Khan
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories , 903 S. 4th St, 1/1110, Hamilton, MT 59840 , USA
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Correction: Development of a Mimotope Vaccine Targeting the Staphylococcus aureus Quorum Sensing Pathway. PLoS One 2015; 10:e0118160. [PMID: 25658426 PMCID: PMC4319946 DOI: 10.1371/journal.pone.0118160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
[This corrects the article DOI: 10.1371/journal.pone.0111198.].
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