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Ilmain JK, Perelman SS, Panepinto MC, Irnov I, Coudray N, Samhadaneh N, Pironti A, Ueberheide B, Ekiert DC, Bhabha G, Torres VJ. Unlatching of the stem domains in the Staphylococcus aureus pore-forming leukocidin LukAB influences toxin oligomerization. J Biol Chem 2023; 299:105321. [PMID: 37802313 PMCID: PMC10665946 DOI: 10.1016/j.jbc.2023.105321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 09/22/2023] [Accepted: 09/27/2023] [Indexed: 10/08/2023] Open
Abstract
Staphylococcus aureus (S. aureus) is a serious global pathogen that causes a diverse range of invasive diseases. S. aureus utilizes a family of pore-forming toxins, known as bi-component leukocidins, to evade the host immune response and promote infection. Among these is LukAB (leukocidin A/leukocidin B), a toxin that assembles into an octameric β-barrel pore in the target cell membrane, resulting in host cell death. The established cellular receptor for LukAB is CD11b of the Mac-1 complex. Here, we show that hydrogen voltage-gated channel 1 is also required for the cytotoxicity of all major LukAB variants. We demonstrate that while each receptor is sufficient to recruit LukAB to the plasma membrane, both receptors are required for maximal lytic activity. Why LukAB requires two receptors, and how each of these receptors contributes to pore-formation remains unknown. To begin to resolve this, we performed an alanine scanning mutagenesis screen to identify mutations that allow LukAB to maintain cytotoxicity without CD11b. We discovered 30 mutations primarily localized in the stem domains of LukA and LukB that enable LukAB to exhibit full cytotoxicity in the absence of CD11b. Using crosslinking, electron microscopy, and hydroxyl radical protein footprinting, we show these mutations increase the solvent accessibility of the stem domain, priming LukAB for oligomerization. Together, our data support a model in which CD11b binding unlatches the membrane penetrating stem domains of LukAB, and this change in flexibility promotes toxin oligomerization.
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Affiliation(s)
- Juliana K Ilmain
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Sofya S Perelman
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Maria C Panepinto
- Proteomics Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, New York, USA
| | - Irnov Irnov
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Nicolas Coudray
- Applied Bioinformatics Laboratories, New York University Grossman School of Medicine, New York, New York, USA; Department of Cell Biology, New York University Grossman School of Medicine, New York, New York, USA
| | - Nora Samhadaneh
- Antimicrobial-Resistant Pathogens Program, New York University Langone Health, New York, New York, USA
| | - Alejandro Pironti
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA; Antimicrobial-Resistant Pathogens Program, New York University Langone Health, New York, New York, USA
| | - Beatrix Ueberheide
- Proteomics Laboratory, Division of Advanced Research Technologies, New York University Grossman School of Medicine, New York, New York, USA; Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, New York, USA; Department of Neurology, Center for Cognitive Neurology, New York University Grossman School of Medicine, New York, New York, USA
| | - Damian C Ekiert
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA; Department of Cell Biology, New York University Grossman School of Medicine, New York, New York, USA; Antimicrobial-Resistant Pathogens Program, New York University Langone Health, New York, New York, USA
| | - Gira Bhabha
- Department of Cell Biology, New York University Grossman School of Medicine, New York, New York, USA; Antimicrobial-Resistant Pathogens Program, New York University Langone Health, New York, New York, USA
| | - Victor J Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA; Department of Host-Microbe Interactions, St Jude Children's Research Hospital, Memphis, Tennessee, USA.
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Das Mitra S, Kumar B, Rajegowda S, Bandopadhyay S, Karunakar P, Pais R. Reverse vaccinology & immunoinformatics approach to design a multiepitope vaccine (CV3Ag-antiMRSA) against methicillin resistant Staphylococcus aureus (MRSA) - a pathogen affecting both human and animal health. J Biomol Struct Dyn 2023:1-20. [PMID: 37798927 DOI: 10.1080/07391102.2023.2265471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 09/24/2023] [Indexed: 10/07/2023]
Abstract
Infections caused by drug resistant bacteria is a silent detrimental pandemic affecting the global health care profoundly. Methicillin resistant Staphylococcus aureus (MRSA) is a pathogen that causes serious infections in different settings (community, hospital & veterinary) whose treatment remains highly challenging due to its powerful characteristics (antibiotic resistance strategies, virulence factors). In this study, we used reverse vaccinology (RV) approach and designed an immunogenic multi epitope vaccine (CV3Ag-antiMRSA) targeting three potential antigen candidates viz., mecA encoding transpeptidase (PBP2a) protein responsible for conferring methicillin resistance and two virulence determinants - hlgA encoding gamma-hemolysin component A (a pore forming toxin) and isdB encoding iron regulated surface determinant B (heme transport component that allows S. aureus to scavenge iron from host hemoglobin and myoglobin). We employed an array of immunoinformatic tools/server to identify and use immunogenic epitopes (B cell and MHC class) to develop the chimeric subunit vaccine V4 (CV3Ag-antiMRSA) with immune modulating adjuvant and linkers. Based on different parameters, the vaccine construct V4 (CV3Ag-antiMRSA) was determined to be suitable vaccine (antigenic and non-allergen). Molecular docking and simulation of CV3Ag-antiMRSA with Toll Like Receptor (TLR2) predicted its immuno-stimulating potential. Finally, in silico cloning of CV3Ag-antiMRSA construct into pet28a and pet30 vector displayed its feasibility for the heterologous expression in the E. coli expression system. This vaccine candidate (CV3Ag-antiMRSA) designed based on the MRSA genomes obtained from both animal and human hosts can be experimentally validated and thereby contribute to vaccine development to impart protection to both animal and human health.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Susweta Das Mitra
- Department of Biotechnology, School of Basic & Applied Sciences, Dayananda Sagar University, Bangalore, Karnataka, India
| | - Bharat Kumar
- Department of Biotechnology, School of Basic & Applied Sciences, Dayananda Sagar University, Bangalore, Karnataka, India
| | - Sushmitha Rajegowda
- Department of Biotechnology, School of Basic & Applied Sciences, Dayananda Sagar University, Bangalore, Karnataka, India
| | - Satarupa Bandopadhyay
- Department of Biotechnology, School of Basic & Applied Sciences, Dayananda Sagar University, Bangalore, Karnataka, India
| | - Prashantha Karunakar
- Department of Biotechnology, Dayananda Sagar College of Engineering (Affiliated to Visvesvaraya Technological University, Belagavi), Bangalore, Karnataka, India
| | - Roshan Pais
- Department of Biotechnology, School of Basic & Applied Sciences, Dayananda Sagar University, Bangalore, Karnataka, India
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He J, Yang X, Yang K, Xu H, Chen C, Wang J, Zeng J. TPST2-mediated receptor tyrosine sulfation enhances leukocidin cytotoxicity and S. aureus infection. Front Immunol 2023; 14:1242330. [PMID: 37671153 PMCID: PMC10476081 DOI: 10.3389/fimmu.2023.1242330] [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: 06/19/2023] [Accepted: 07/31/2023] [Indexed: 09/07/2023] Open
Abstract
Background An essential fact underlying the severity of Staphylococcus aureus (S. aureus) infection is the bicomponent leukocidins released by the pathogen to target and lyse host phagocytes through specific binding cell membrane receptors. However, little is known about the impact of post-transcriptional modification of receptors on the leukocidin binding. Method In this study, we used small interfering RNA library (Horizon/Dharmacon) to screen potential genes that affect leukocidin binding on receptors. The cell permeability was investigated through flow cytometry measuring the internalization of 4',6-diamidino-2-phenylindole. Expression of C5a anaphylatoxin chemotactic receptor 1 (C5aR1), sulfated C5aR1 in, and binding of 6x-His-tagged Hemolysin C (HlgC) and Panton-Valentine leukocidin (PVL) slow-component to THP-1 cell lines was detected and analyzed via flow cytometry. Bacterial burden and Survival analysis experiment was conducted in WT and myeloid TPST-cko C57BL/6N mice. Results After short hairpin RNA (shRNA) knockdown of TPST2 gene in THP-1, HL-60, and RAW264.7, the cytotoxicity of HlgAB, HlgCB, and Panton-Valentine leukocidin on THP-1 or HL-60 cells was decreased significantly, and the cytotoxicity of HlgAB on RAW264.7 cells was also decreased significantly. Knockdown of TPST2 did not affect the C5aR1 expression but downregulated cell surface C5aR1 tyrosine sulfation on THP-1. In addition, we found that the binding of HlgC and LukS-PV on cell surface receptor C5aR1 was impaired in C5aR1+TPST2- and C5aR1-TPST2- cells. Phagocyte knockout of TPST2 protects mice from S. aureus infection and improves the survival of mice infected with S. aureus. Conclusion These results indicate that phagocyte TPST2 mediates the bicomponent leukocidin cytotoxicity by promoting cell membrane receptor sulfation modification that facilitates its binding to leukocidin S component.
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Affiliation(s)
- Jie He
- Division of Pulmonary and Critical Care Medicine, Clinical Medical College and The First Affiliated Hospital of Chengdu Medical College, Chengdu, China
| | - Xianggui Yang
- Department of Laboratory Medicine, Clinical Medical College and The First Affiliated Hospital of Chengdu Medical College, Chengdu, China
| | - Kai Yang
- Division of Pulmonary and Critical Care Medicine, Clinical Medical College and The First Affiliated Hospital of Chengdu Medical College, Chengdu, China
| | | | | | | | - Jun Zeng
- Division of Pulmonary and Critical Care Medicine, Clinical Medical College and The First Affiliated Hospital of Chengdu Medical College, Chengdu, China
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Qerqez AN, Silva RP, Maynard JA. Outsmarting Pathogens with Antibody Engineering. Annu Rev Chem Biomol Eng 2023; 14:217-241. [PMID: 36917814 PMCID: PMC10330301 DOI: 10.1146/annurev-chembioeng-101121-084508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
There is growing interest in identifying antibodies that protect against infectious diseases, especially for high-risk individuals and pathogens for which no vaccine is yet available. However, pathogens that manifest as opportunistic or latent infections express complex arrays of virulence-associated proteins and are adept at avoiding immune responses. Some pathogens have developed strategies to selectively destroy antibodies, whereas others create decoy epitopes that trick the host immune system into generating antibodies that are at best nonprotective and at worst enhance pathogenesis. Antibody engineering strategies can thwart these efforts by accessing conserved neutralizing epitopes, generating Fc domains that resist capture or degradation and even accessing pathogens hidden inside cells. Design of pathogen-resistant antibodies can enhance protection and guide development of vaccine immunogens against these complex pathogens. Here, we discuss general strategies for design of antibodies resistant to specific pathogen defense mechanisms.
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Affiliation(s)
- Ahlam N Qerqez
- Department of Chemical Engineering, The University of Texas, Austin, Texas, USA;
| | - Rui P Silva
- Department of Molecular Biosciences, The University of Texas, Austin, Texas, USA
| | - Jennifer A Maynard
- Department of Chemical Engineering, The University of Texas, Austin, Texas, USA;
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Francis D, Bhairaddy A, Joy A, Hari GV, Francis A. Secretory proteins in the orchestration of microbial virulence: The curious case of Staphylococcus aureus. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 133:271-350. [PMID: 36707204 DOI: 10.1016/bs.apcsb.2022.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Microbial virulence showcases an excellent model for adaptive changes that enable an organism to survive and proliferate in a hostile environment and exploit host resources to its own benefit. In Staphylococcus aureus, an opportunistic pathogen of the human host, known for the diversity of the disease conditions it inflicts and the rapid evolution of antibiotic resistance, virulence is a consequence of having a highly plastic genome that is amenable to quick reprogramming and the ability to express a diverse arsenal of virulence factors. Virulence factors that are secreted to the host milieu effectively manipulate the host conditions to favor bacterial survival and growth. They assist in colonization, nutrient acquisition, immune evasion, and systemic spread. The structural and functional characteristics of the secreted virulence proteins have been shaped to assist S. aureus in thriving and disseminating effectively within the host environment and exploiting the host resources to its best benefit. With the aim of highlighting the importance of secreted virulence proteins in bacterial virulence, the present chapter provides a comprehensive account of the role of the major secreted proteins of S. aureus in orchestrating its virulence in the human host.
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Affiliation(s)
- Dileep Francis
- Department of Life Sciences, Kristu Jayanti College, Autonomous, Bengaluru, Karnataka, India.
| | - Anusha Bhairaddy
- Department of Life Sciences, Kristu Jayanti College, Autonomous, Bengaluru, Karnataka, India
| | - Atheene Joy
- Department of Life Sciences, Kristu Jayanti College, Autonomous, Bengaluru, Karnataka, India
| | | | - Ashik Francis
- Rajiv Gandhi Centre for Biotechnology, Trivandrum, Kerala, India
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6
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Howden BP, Giulieri SG, Wong Fok Lung T, Baines SL, Sharkey LK, Lee JYH, Hachani A, Monk IR, Stinear TP. Staphylococcus aureus host interactions and adaptation. Nat Rev Microbiol 2023; 21:380-395. [PMID: 36707725 PMCID: PMC9882747 DOI: 10.1038/s41579-023-00852-y] [Citation(s) in RCA: 96] [Impact Index Per Article: 96.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2023] [Indexed: 01/28/2023]
Abstract
Invasive Staphylococcus aureus infections are common, causing high mortality, compounded by the propensity of the bacterium to develop drug resistance. S. aureus is an excellent case study of the potential for a bacterium to be commensal, colonizing, latent or disease-causing; these states defined by the interplay between S. aureus and host. This interplay is multidimensional and evolving, exemplified by the spread of S. aureus between humans and other animal reservoirs and the lack of success in vaccine development. In this Review, we examine recent advances in understanding the S. aureus-host interactions that lead to infections. We revisit the primary role of neutrophils in controlling infection, summarizing the discovery of new immune evasion molecules and the discovery of new functions ascribed to well-known virulence factors. We explore the intriguing intersection of bacterial and host metabolism, where crosstalk in both directions can influence immune responses and infection outcomes. This Review also assesses the surprising genomic plasticity of S. aureus, its dualism as a multi-mammalian species commensal and opportunistic pathogen and our developing understanding of the roles of other bacteria in shaping S. aureus colonization.
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Affiliation(s)
- Benjamin P. Howden
- grid.1008.90000 0001 2179 088XCentre for Pathogen Genomics, The University of Melbourne, Melbourne, Victoria Australia ,grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia ,grid.410678.c0000 0000 9374 3516Department of Infectious Diseases, Austin Health, Heidelberg, Victoria Australia ,grid.416153.40000 0004 0624 1200Microbiology Department, Royal Melbourne Hospital, Melbourne, Victoria Australia
| | - Stefano G. Giulieri
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia ,grid.416153.40000 0004 0624 1200Victorian Infectious Diseases Service, Royal Melbourne Hospital, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Tania Wong Fok Lung
- grid.21729.3f0000000419368729Department of Paediatrics, Columbia University, New York, NY USA
| | - Sarah L. Baines
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Liam K. Sharkey
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Jean Y. H. Lee
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia ,grid.419789.a0000 0000 9295 3933Department of Infectious Diseases, Monash Health, Clayton, Victoria Australia
| | - Abderrahman Hachani
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Ian R. Monk
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
| | - Timothy P. Stinear
- grid.1008.90000 0001 2179 088XCentre for Pathogen Genomics, The University of Melbourne, Melbourne, Victoria Australia ,grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria Australia
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Hu H, Liu M, Sun S. Pore-Forming Toxins During Bacterial Infection: Molecular Mechanisms and Potential Therapeutic Targets. DRUG DESIGN DEVELOPMENT AND THERAPY 2021; 15:3773-3781. [PMID: 34522083 PMCID: PMC8434828 DOI: 10.2147/dddt.s322393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/19/2021] [Indexed: 12/17/2022]
Abstract
Bacterial infections are predominantly treated with antibiotics, and resistance to antibiotics is becoming an increasing threat to our health. Pore-forming toxins (PFTs) are virulence factors secreted by many pathogenic bacterial strains, both in acute and chronic infections. They are special membrane-targeting proteins that exert toxic effects by forming pores in the cell membrane. Recent studies have elucidated the structure of PFTs and the detailed molecular mechanisms of their pathogenicity. Here, we discuss recent findings that highlight the regulatory mechanisms and important roles of two types of PFTs, α-PFTs and β-PFTs, in mediating the virulence of bacteria, and the therapeutic potential of targeting PFTs for antibacterial treatment. Therapeutic strategies based on PFTs are highly specific and may alleviate the issue of increasing resistance to antibiotics.
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Affiliation(s)
- Haijie Hu
- Institute of Biomedical Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, 250014, People's Republic of China
| | - Min Liu
- Institute of Biomedical Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, 250014, People's Republic of China
| | - Shuang Sun
- Institute of Biomedical Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, 250014, People's Republic of China
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8
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Perelman SS, James DBA, Boguslawski KM, Nelson CW, Ilmain JK, Zwack EE, Prescott RA, Mohamed A, Tam K, Chan R, Narechania A, Pawline MB, Vozhilla N, Moustafa AM, Kim SY, Dittmann M, Ekiert DC, Bhabha G, Shopsin B, Planet PJ, Koralov SB, Torres VJ. Genetic variation of staphylococcal LukAB toxin determines receptor tropism. Nat Microbiol 2021; 6:731-745. [PMID: 33875847 PMCID: PMC8597016 DOI: 10.1038/s41564-021-00890-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 03/11/2021] [Indexed: 02/02/2023]
Abstract
Staphylococcus aureus has evolved into diverse lineages, known as clonal complexes (CCs), which exhibit differences in the coding sequences of core virulence factors. Whether these alterations affect functionality is poorly understood. Here, we studied the highly polymorphic pore-forming toxin LukAB. We discovered that the LukAB toxin variants produced by S. aureus CC30 and CC45 kill human phagocytes regardless of whether CD11b, the previously established LukAB receptor, is present, and instead target the human hydrogen voltage-gated channel 1 (HVCN1). Biochemical studies identified the domain within human HVCN1 that drives LukAB species specificity, enabling the generation of humanized HVCN1 mice with enhanced susceptibility to CC30 LukAB and to bloodstream infection caused by CC30 S. aureus strains. Together, this work advances our understanding of an important S. aureus toxin and underscores the importance of considering genetic variation in characterizing virulence factors and understanding the tug of war between pathogens and the host.
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Affiliation(s)
- Sofya S Perelman
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - David B A James
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Kristina M Boguslawski
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Chase W Nelson
- Institute for Comparative Genomics, American Museum of Natural History, New York, NY, USA
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Juliana K Ilmain
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Erin E Zwack
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Rachel A Prescott
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Adil Mohamed
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Kayan Tam
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Rita Chan
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Apurva Narechania
- Institute for Comparative Genomics, American Museum of Natural History, New York, NY, USA
| | - Miranda B Pawline
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
- Department of Medicine, Division of Infectious Diseases, New York University Grossman School of Medicine, New York, NY, USA
| | - Nikollaq Vozhilla
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Ahmed M Moustafa
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Sang Y Kim
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
- Office of Collaborative Sciences, NYU Grossman School of Medicine, New York, NY, USA
| | - Meike Dittmann
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Damian C Ekiert
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, USA
| | - Gira Bhabha
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, USA
| | - Bo Shopsin
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
- Department of Medicine, Division of Infectious Diseases, New York University Grossman School of Medicine, New York, NY, USA
| | - Paul J Planet
- Institute for Comparative Genomics, American Museum of Natural History, New York, NY, USA
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sergei B Koralov
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
| | - Victor J Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA.
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Convergent Evolution of Neutralizing Antibodies to Staphylococcus aureus γ-Hemolysin C That Recognize an Immunodominant Primary Sequence-Dependent B-Cell Epitope. mBio 2020; 11:mBio.00460-20. [PMID: 32546616 PMCID: PMC7298706 DOI: 10.1128/mbio.00460-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Staphylococcus aureus infection is a major public health threat in part due to the spread of antibiotic resistance and repeated failures to develop a protective vaccine. Infection is associated with production of virulence factors that include exotoxins that attack host barriers and cellular defenses, such as the leukocidin (Luk) family of bicomponent pore-forming toxins. To investigate the structural basis of antibody-mediated functional inactivation of Luk toxins, we generated a panel of murine monoclonal antibodies (MAbs) that neutralize host cell killing by the γ-hemolysin HlgCB. Staphylococcus aureus infection is a major public health threat in part due to the spread of antibiotic resistance and repeated failures to develop a protective vaccine. Infection is associated with production of virulence factors that include exotoxins that attack host barriers and cellular defenses, such as the leukocidin (Luk) family of bicomponent pore-forming toxins. To investigate the structural basis of antibody-mediated functional inactivation of Luk toxins, we generated a panel of murine monoclonal antibodies (MAbs) that neutralize host cell killing by the γ-hemolysin HlgCB. By biopanning these MAbs against a phage-display library of random Luk peptide fragments, we identified a small subregion within the rim domain of HlgC as the epitope for all the MAbs. Within the native holotoxin, this subregion folds into a conserved β-hairpin structure, with exposed key residues, His252 and Tyr253, required for antibody binding. On the basis of the phage-display results and molecular modeling, a 15-amino-acid synthetic peptide representing the minimal epitope on HlgC (HlgC241-255) was designed, and preincubation with this peptide blocked antibody-mediated HIgCB neutralization. Immunization of mice with HlgC241-255 or the homologous LukS246-260 subregion peptide elicited serum antibodies that specifically recognized the native holotoxin subunits. Furthermore, serum IgG from patients who were convalescent for invasive S. aureus infection showed neutralization of HlgCB toxin activity ex vivo, which recognized the immunodominant HlgC241-255 peptide and was dependent on His252 and Tyr253 residues. We have thus validated an efficient, rapid, and scalable experimental workflow for identification of immunodominant and immunogenic leukotoxin-neutralizing B-cell epitopes that can be exploited for new S. aureus-protective vaccines and immunotherapies.
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10
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Unbiased Identification of Immunogenic Staphylococcus aureus Leukotoxin B-Cell Epitopes. Infect Immun 2020; 88:IAI.00785-19. [PMID: 32014894 DOI: 10.1128/iai.00785-19] [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] [Received: 10/07/2019] [Accepted: 01/26/2020] [Indexed: 12/26/2022] Open
Abstract
Unbiased identification of individual immunogenic B-cell epitopes in major antigens of a pathogen remains a technology challenge for vaccine discovery. We therefore developed a platform for rapid phage display screening of deep recombinant libraries consisting of as few as one major pathogen antigen. Using the bicomponent pore-forming leukocidin (Luk) exotoxins of the major pathogen Staphylococcus aureus as a prototype, we randomly fragmented and separately ligated the hemolysin gamma A (HlgA) and LukS genes into a custom-built phage display system, termed pComb-Opti8. Deep sequence analysis of barcoded amplimers of the HlgA and LukS gene fragment libraries demonstrated that biopannng against a cross-reactive anti-Luk monoclonal antibody (MAb) recovered convergent molecular clones with short overlapping homologous sequences. We thereby identified an 11-amino-acid sequence that is highly conserved in four Luk toxin subunits and is ubiquitous in representation within S. aureus clinical isolates. The isolated 11-amino-acid peptide probe was predicted to retain the native three-dimensional (3D) conformation seen within the Luk holotoxin. Indeed, this peptide was recognized by the selecting anti-Luk MAb, and, using mutated peptides, we showed that a particular amino acid side chain was essential for these interactions. Furthermore, murine immunization with this peptide elicited IgG responses that were highly reactive with both the autologous synthetic peptide and the full-length Luk toxin homologues. Thus, using a gene fragment- and phage display-based pipeline, we have identified and validated immunogenic B-cell epitopes that are cross-reactive between members of the pore-forming leukocidin family. This approach could be harnessed to identify novel epitopes for a much-needed S. aureus-protective subunit vaccine.
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Chan R, Buckley PT, O'Malley A, Sause WE, Alonzo F, Lubkin A, Boguslawski KM, Payne A, Fernandez J, Strohl WR, Whitaker B, Lynch AS, Torres VJ. Identification of biologic agents to neutralize the bicomponent leukocidins of Staphylococcus aureus. Sci Transl Med 2020; 11:11/475/eaat0882. [PMID: 30651319 DOI: 10.1126/scitranslmed.aat0882] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 01/22/2018] [Accepted: 12/17/2018] [Indexed: 12/12/2022]
Abstract
A key aspect underlying the severity of infections caused by Staphylococcus aureus is the abundance of virulence factors that the pathogen uses to thwart critical components of the human immune response. One such mechanism involves the destruction of host immune cells by cytolytic toxins secreted by S. aureus, including five bicomponent leukocidins: PVL, HlgAB, HlgCB, LukED, and LukAB. Purified leukocidins can lyse immune cells ex vivo, and systemic injections of purified LukED or HlgAB can acutely kill mice. Here, we describe the generation and characterization of centyrins that bind S. aureus leukocidins with high affinity and protect primary human immune cells from toxin-mediated cytolysis. Centyrins are small protein scaffolds derived from the fibronectin type III-binding domain of the human protein tenascin-C. Although centyrins are potent in tissue culture assays, their short serum half-lives limit their efficacies in vivo. By extending the serum half-lives of centyrins through their fusion to an albumin-binding consensus domain, we demonstrate the in vivo efficacy of these biologics in a murine intoxication model and in models of both prophylactic and therapeutic treatment of live S. aureus systemic infections. These biologics that target S. aureus virulence factors have potential for treating and preventing serious staphylococcal infections.
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Affiliation(s)
- Rita Chan
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Peter T Buckley
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Aidan O'Malley
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - William E Sause
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Francis Alonzo
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Ashira Lubkin
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Kristina M Boguslawski
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Angela Payne
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Jeffrey Fernandez
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, 19477, USA
| | - William R Strohl
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Brian Whitaker
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, 19477, USA
| | - Anthony Simon Lynch
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, 19477, USA.
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA.
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12
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Molecular mechanism of leukocidin GH-integrin CD11b/CD18 recognition and species specificity. Proc Natl Acad Sci U S A 2019; 117:317-327. [PMID: 31852826 PMCID: PMC6955338 DOI: 10.1073/pnas.1913690116] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Staphylococcus aureus is one of the most virulent bacterial pathogens and, in particular, has the richest repertoire of cytotoxins: A single bacterium can secrete 6 different β-barrel pore-forming toxins, with different cell type and species specificities. Each toxin engages specific receptors on target cells, but the role the receptor plays in the pore-formation process is poorly understood. Here, we determine the crystal structures of a very potent S. aureus leukocidin (LukGH) in complex with its receptor (CD11b) from a sensitive (human) and an insensitive (murine) host, and track the receptor involvement in different steps on the pore-formation pathway. These results advance the knowledge of receptor-mediated leukocidin pore formation and open ways for antileukocidin and anti-S. aureus approaches. Host–pathogen interactions are central to understanding microbial pathogenesis. The staphylococcal pore-forming cytotoxins hijack important immune molecules but little is known about the underlying molecular mechanisms of cytotoxin–receptor interaction and host specificity. Here we report the structures of a staphylococcal pore-forming cytotoxin, leukocidin GH (LukGH), in complex with its receptor (the α-I domain of complement receptor 3, CD11b-I), both for the human and murine homologs. We observe 2 binding interfaces, on the LukG and the LukH protomers, and show that human CD11b-I induces LukGH oligomerization in solution. LukGH binds murine CD11b-I weakly and is inactive toward murine neutrophils. Using a LukGH variant engineered to bind mouse CD11b-I, we demonstrate that cytolytic activity does not only require binding but also receptor-dependent oligomerization. Our studies provide an unprecedented insight into bicomponent leukocidin–host receptor interaction, enabling the development of antitoxin approaches and improved animal models to explore these approaches.
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13
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Rogolevich VV, Glushkova TV, Ponasenko AV, Ovcharenko EA. [Infective Endocarditis Causing Native and Prosthetic Heart Valve Dysfunction]. ACTA ACUST UNITED AC 2019; 59:68-77. [PMID: 30990144 DOI: 10.18087/cardio.2019.3.10245] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Accepted: 04/13/2019] [Indexed: 11/18/2022]
Abstract
Infective endocarditis (IE) is the disease that has high inhospital mortality. Heart valves dysfunction - both native and prosthetic - is the primary IE complication requiring a surgical intervention. The IE causes and its course have been discussed in this review. In particular, the role of concomitant infectious foci in the formation and development of IE have been considered, the mechanisms of mutual transition of subacute and acute clinical forms have been described. Modern diagnostic principles and methods based on the Duke criteria system have been mentioned, as well as the difficulties that follow the patient's clinical status evaluation. The normobiotic microbiota participation, as well as the possibilities for their identification using blood culture and PCR technique, have been closely reviewed. According to modern researches and publications, there have been made the conclusion about the contribution of obligate anaerobic bacteria, fungi and viruses to the development of endocarditis. There have been described the hypothesis about the presumptive strategy for the cardiac dysfunction formation as a result of the IE causative agents cells metabolic activity based on a literature data analysis in the article: vegetation formed by Staphylococcus aureus can lead to the heart valve stenosis, and the influence of hyaluronidases, collagenases on a heart valve structure can lead to regurgitation. The pathogens cells ability to avoid the human immune system response is caused by the biofilms, fibrin vegetations formation and the enzymes production - cytotoxins (streptolysins, leukocidin, etc.). It has been suggested that the mediators of inflammation and leukocyte cells participate in the destruction of native and prosthetic tissues due to an IE pathogens inaccessibility for immunocompetent cells.
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Affiliation(s)
- V V Rogolevich
- Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo
| | - T V Glushkova
- Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo
| | - A V Ponasenko
- Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo
| | - E A Ovcharenko
- Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo
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14
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Preventing lung pathology and mortality in rabbit Staphylococcus aureus pneumonia models with cytotoxin-neutralizing monoclonal IgGs penetrating the epithelial lining fluid. Sci Rep 2019; 9:5339. [PMID: 30926865 PMCID: PMC6441091 DOI: 10.1038/s41598-019-41826-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 03/19/2019] [Indexed: 12/23/2022] Open
Abstract
Staphylococcus aureus pneumonia is associated with high mortality irrespective of antibiotic susceptibility. Both MRSA and MSSA strains produce powerful cytotoxins: alpha-hemolysin(Hla) and up to five leukocidins - LukSF-PV, HlgAB, HlgCB, LukED and LukGH (LukAB) - to evade host innate defense mechanisms. Neutralizing cytotoxins has been shown to provide survival benefit in rabbit S. aureus pneumonia models. We studied the mechanisms of protection of ASN100, a combination of two human monoclonal antibodies (mAbs), ASN-1 and ASN-2, that together neutralize Hla and the five leukocidins, in rabbit MRSA and MSSA pneumonia models. Upon prophylactic passive immunization, ASN100 displayed dose-dependent increase in survival and was fully protective against all S. aureus strains tested at 5 or 20 mg/kg doses. Macroscopic and microscopic lung pathology, edema rate, and bacterial burden were evaluated 12 hours post infection and reduced by ASN100. Pharmacokinetic analysis of ASN100 in bronchoalveolar-lavage fluid from uninfected animals detected efficient penetration to lung epithelial lining fluid reaching peak levels between 24 and 48 hours post dosing that were comparable to the mAb concentration measured in serum. These data confirm that the ASN100 mAbs neutralize the powerful cytotoxins of S. aureus in the lung and prevent damage to the mucosal barrier and innate immune cells.
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15
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Nagy E, Nagy G, Power CA, Badarau A, Szijártó V. Anti-bacterial Monoclonal Antibodies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1053:119-153. [PMID: 29549638 DOI: 10.1007/978-3-319-72077-7_7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The failing efficacy of antibiotics and the high mortality rate among high-risk patients calls for new treatment modalities for bacterial infections. Due to the vastly divergent pathogenesis of human pathogens, each microbe requires a tailored approach. The main modes of action of anti-bacterial antibodies are virulence factor neutralization, complement-mediated bacterial lysis and enhancement of opsonophagocytic uptake and killing (OPK). Gram-positive bacteria cannot be lysed by complement and their pathogenesis often involves secreted toxins, therefore typically toxin-neutralization and OPK activity are required to prevent and ameliorate disease. In fact, the success stories in terms of approved products, in the anti-bacterial mAb field are based on toxin neutralization (Bacillus anthracis, Clostridium difficile). In contrast, Gram-negative bacteria are vulnerable to antibody-dependent complement-mediated lysis, while their pathogenesis rarely relies on secreted exotoxins, and involves the pro-inflammatory endotoxin (lipopolysaccharide). Given the complexity of bacterial pathogenesis, antibody therapeutics are expected to be most efficient upon targeting more than one virulence factor and/or combining different modes of action. The improved understanding of bacterial pathogenesis combined with the versatility and maturity of antibody discovery technologies available today are pivotal for the design of novel anti-bacterial therapeutics. The intensified research generating promising proof-of-concept data, and the increasing number of clinical programs with anti-bacterial mAbs, indicate that the field is ready to fulfill its promise in the coming years.
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Affiliation(s)
- Eszter Nagy
- Arsanis Biosciences GmbH/Arsanis, Inc, Vienna, Austria.
| | - Gábor Nagy
- Arsanis Biosciences GmbH/Arsanis, Inc, Vienna, Austria
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16
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Rello J, van Engelen TSR, Alp E, Calandra T, Cattoir V, Kern WV, Netea MG, Nseir S, Opal SM, van de Veerdonk FL, Wilcox MH, Wiersinga WJ. Towards precision medicine in sepsis: a position paper from the European Society of Clinical Microbiology and Infectious Diseases. Clin Microbiol Infect 2018; 24:1264-1272. [PMID: 29581049 DOI: 10.1016/j.cmi.2018.03.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 03/06/2018] [Accepted: 03/10/2018] [Indexed: 12/30/2022]
Abstract
BACKGROUND Our current understanding of the pathophysiology and management of sepsis is associated with a lack of progress in clinical trials, which partly reflects insufficient appreciation of the heterogeneity of this syndrome. Consequently, more patient-specific approaches to treatment should be explored. AIMS To summarize the current evidence on precision medicine in sepsis, with an emphasis on translation from theory to clinical practice. A secondary objective is to develop a framework enclosing recommendations on management and priorities for further research. SOURCES A global search strategy was performed in the MEDLINE database through the PubMed search engine (last search December 2017). No restrictions of study design, time, or language were imposed. CONTENT The focus of this Position Paper is on the interplay between therapies, pathogens, and the host. Regarding the pathogen, microbiologic diagnostic approaches (such as blood cultures (BCs) and rapid diagnostic tests (RDTs)) are discussed, as well as targeted antibiotic treatment. Other topics include the disruption of host immune system and the use of biomarkers in sepsis management, patient stratification, and future clinical trial design. Lastly, personalized antibiotic treatment and stewardship are addressed (Fig. 1). IMPLICATIONS A road map provides recommendations and future perspectives. RDTs and identifying drug-response phenotypes are clear challenges. The next step will be the implementation of precision medicine to sepsis management, based on theranostic methodology. This highly individualized approach will be essential for the design of novel clinical trials and improvement of care pathways.
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Affiliation(s)
- J Rello
- CIBERES, Vall d'Hebron Barcelona Campus Hospital, European Study Group of Infections in Critically Ill Patients (ESGCIP), Barcelona, Spain.
| | - T S R van Engelen
- Centre for Experimental Molecular Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands
| | - E Alp
- Department of Infectious Diseases, Infection Control Committee, Faculty of Medicine, Erciyes University, Kayseri, Turkey
| | - T Calandra
- Infectious Diseases Service, Department of Medicine, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - V Cattoir
- University Hospital of Rennes, Department of Clinical Microbiology, Rennes, France and National Reference Center for Antimicrobial Resistance (lab Enterococci), Rennes, France
| | - W V Kern
- Division of Infectious Diseases, Department of Medicine, University Hospital and Medical Centre, Albert-Ludwigs-University Faculty of Medicine, Freiburg, Germany; Executive Committee of ESCMID Study Group for Bloodstream Infections and Sepsis (ESGBIS), The Netherlands
| | - M G Netea
- Department of Internal Medicine and Radboud Centre for Infectious Diseases (RCI), Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands; Human Genomics Laboratory, Craiova University of Medicine and Pharmacy, Craiova, Romania
| | - S Nseir
- Faculté de Médecine, University of Lille and Centre de Réanimation, CHU Lille, Lille, France
| | - S M Opal
- Brown University, Infectious Diseases, Providence, RI, USA
| | - F L van de Veerdonk
- Department of Internal Medicine and Radboud Centre for Infectious Diseases (RCI), Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - M H Wilcox
- Department of Microbiology, Leeds Teaching Hospitals NHS Trust, University of Leeds, Leeds, UK
| | - W J Wiersinga
- Centre for Experimental Molecular Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands; Department of Medicine, Division of Infectious Diseases, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands; Executive Committee of ESCMID Study Group for Bloodstream Infections and Sepsis (ESGBIS), The Netherlands.
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