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Caldera JR, Tsai CM, Trieu D, Gonzalez C, Hajam IA, Du X, Lin B, Liu GY. The characteristics of pre-existing humoral imprint determine efficacy of S. aureus vaccines and support alternative vaccine approaches. Cell Rep Med 2024; 5:101360. [PMID: 38232694 PMCID: PMC10829788 DOI: 10.1016/j.xcrm.2023.101360] [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: 01/15/2023] [Revised: 08/15/2023] [Accepted: 12/10/2023] [Indexed: 01/19/2024]
Abstract
The failure of the Staphylococcus aureus (SA) IsdB vaccine trial can be explained by the recall of non-protective immune imprints from prior SA exposure. Here, we investigate natural human SA humoral imprints to understand their broader impact on SA immunizations. We show that antibody responses against SA cell-wall-associated antigens (CWAs) are non-opsonic, while antibodies against SA toxins are neutralizing. Importantly, the protective characteristics of the antibody imprints accurately predict the failure of corresponding vaccines against CWAs and support vaccination against toxins. In passive immunization platforms, natural anti-SA human antibodies reduce the efficacy of the human monoclonal antibodies suvratoxumab and tefibazumab, consistent with the results of their respective clinical trials. Strikingly, in the absence of specific humoral memory responses, active immunizations are efficacious in both naive and SA-experienced mice. Overall, our study points to a practical and predictive approach to evaluate and develop SA vaccines based on pre-existing humoral imprint characteristics.
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Affiliation(s)
- J R Caldera
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA; Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Chih-Ming Tsai
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Desmond Trieu
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Cesia Gonzalez
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Irshad A Hajam
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Xin Du
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - Brian Lin
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA
| | - George Y Liu
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093, USA; Division of Infectious Diseases, Rady Children's Hospital, San Diego, CA 92123, USA.
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2
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Bhattacharya M, Horswill AR. The role of human extracellular matrix proteins in defining Staphylococcus aureus biofilm infections. FEMS Microbiol Rev 2024; 48:fuae002. [PMID: 38337187 PMCID: PMC10873506 DOI: 10.1093/femsre/fuae002] [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: 07/19/2023] [Revised: 01/26/2024] [Accepted: 02/07/2024] [Indexed: 02/12/2024] Open
Abstract
Twenty to forty one percent of the world's population is either transiently or permanently colonized by the Gram-positive bacterium, Staphylococcus aureus. In 2017, the CDC designated methicillin-resistant S. aureus (MRSA) as a serious threat, reporting ∼300 000 cases of MRSA-associated hospitalizations annually, resulting in over 19 000 deaths, surpassing that of HIV in the USA. S. aureus is a proficient biofilm-forming organism that rapidly acquires resistance to antibiotics, most commonly methicillin (MRSA). This review focuses on a large group of (>30) S. aureus adhesins, either surface-associated or secreted that are designed to specifically bind to 15 or more of the proteins that form key components of the human extracellular matrix (hECM). Importantly, this includes hECM proteins that are pivotal to the homeostasis of almost every tissue environment [collagen (skin), proteoglycans (lung), hemoglobin (blood), elastin, laminin, fibrinogen, fibronectin, and fibrin (multiple organs)]. These adhesins offer S. aureus the potential to establish an infection in every sterile tissue niche. These infections often endure repeated immune onslaught, developing into chronic, biofilm-associated conditions that are tolerant to ∼1000 times the clinically prescribed dose of antibiotics. Depending on the infection and the immune response, this allows S. aureus to seamlessly transition from colonizer to pathogen by subtly manipulating the host against itself while providing the time and stealth that it requires to establish and persist as a biofilm. This is a comprehensive discussion of the interaction between S. aureus biofilms and the hECM. We provide particular focus on the role of these interactions in pathogenesis and, consequently, the clinical implications for the prevention and treatment of S. aureus biofilm infections.
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Affiliation(s)
- Mohini Bhattacharya
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, United States
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, United States
- Department of Veterans Affairs, Eastern Colorado Health Care System, Aurora, CO 80045, United States
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3
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Buckley PT, Chan R, Fernandez J, Luo J, Lacey KA, DuMont AL, O'Malley A, Brezski RJ, Zheng S, Malia T, Whitaker B, Zwolak A, Payne A, Clark D, Sigg M, Lacy ER, Kornilova A, Kwok D, McCarthy S, Wu B, Morrow B, Nemeth-Seay J, Petley T, Wu S, Strohl WR, Lynch AS, Torres VJ. Multivalent human antibody-centyrin fusion protein to prevent and treat Staphylococcus aureus infections. Cell Host Microbe 2023; 31:751-765.e11. [PMID: 37098341 DOI: 10.1016/j.chom.2023.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 02/12/2023] [Accepted: 04/03/2023] [Indexed: 04/27/2023]
Abstract
Treating and preventing infections by antimicrobial-resistant bacterial pathogens is a worldwide problem. Pathogens such as Staphylococcus aureus produce an array of virulence determinants, making it difficult to identify single targets for the development of vaccines or monoclonal therapies. We described a human-derived anti-S. aureus monoclonal antibody (mAb)-centyrin fusion protein ("mAbtyrin") that simultaneously targets multiple bacterial adhesins, resists proteolysis by bacterial protease GluV8, avoids Fc engagement by S. aureus IgG-binding proteins SpA and Sbi, and neutralizes pore-forming leukocidins via fusion with anti-toxin centyrins, while maintaining Fc- and complement-mediated functions. Compared with the parental mAb, mAbtyrin protected human phagocytes and boosted phagocyte-mediated killing. The mAbtyrin also reduced pathology, reduced bacterial burden, and protected from different types of infections in preclinical animal models. Finally, mAbtyrin synergized with vancomycin, enhancing pathogen clearance in an animal model of bacteremia. Altogether, these data establish the potential of multivalent mAbs for treating and preventing S. aureus diseases.
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Affiliation(s)
- Peter T Buckley
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA.
| | - Rita Chan
- Department of Microbiology, New York University Grossman School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Jeffrey Fernandez
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Jinquan Luo
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Keenan A Lacey
- Department of Microbiology, New York University Grossman School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Ashley L DuMont
- Department of Microbiology, New York University Grossman School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Aidan O'Malley
- Department of Microbiology, New York University Grossman School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA
| | - Randall J Brezski
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Songmao Zheng
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Thomas Malia
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Brian Whitaker
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Adam Zwolak
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Angela Payne
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Desmond Clark
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Martin Sigg
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Eilyn R Lacy
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Anna Kornilova
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Debra Kwok
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Steve McCarthy
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Bingyuan Wu
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Brian Morrow
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | | | - Ted Petley
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - Sam Wu
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | - William R Strohl
- Janssen Research & Development, 1400 McKean Road, Spring House, PA, USA
| | | | - Victor J Torres
- Department of Microbiology, New York University Grossman School of Medicine, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA; Antimicrobial-Resistant Pathogens Program, New York University Langone Health, Alexandria Center for Life Science, 430 East 29th Street, New York, NY 10016, USA.
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4
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Xiao J, Huang J, Xue X, Wang C, Sun Y, Zheng L, Zhao X, Wang X, Zhao X, Xue H. Novel cassette chromosome recombinases CcrA8B9 catalyse the excision and integration of the staphylococcal cassette chromosome mec element. J Antimicrob Chemother 2023; 78:440-444. [PMID: 36480296 DOI: 10.1093/jac/dkac410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 11/15/2022] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES A defining feature of MRSA is the SCCmec element. The excision and integration of SCCmec elements are catalysed by Ccr recombinases. Currently, seven ccrA, eight ccrB and two ccrC allotypes have been described. However, there have been no recent reports of a novel Ccr recombinase and thus this area should be explored. METHODS According to the proposed criteria of the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC) committee, novel ccr genes were explored by searching the genome of our laboratory staphylococcal strains, which were isolated from bovine mastitis in Northwest China. The biological activity of the novel Ccr recombinases to excise and integrate SCCmec elements was determined. The distribution of the novel ccr genes in staphylococci was conducted by querying the NCBI nr/nt database. RESULTS We report a set of novel Ccr recombinases CcrA8B9, which share nucleotide identities of 46.6%-50.2% and 47.4%-52.8% with the ccrA and ccrB alleles, respectively. We used PCR to show that CcrA8B9 can excise and integrate the SCCmec element. Furthermore, using NCBI BLAST we showed that the ccrA8B9 genes exist in other staphylococcal strains. Unlike the common ccr genes, ccrA8B9 is located outside the SCCmec/SCC element. CONCLUSIONS The novel Ccr recombinases CcrA8B9 can help excise and integrate SCCmec/SCC from the genome and provide a new way to facilitate the transmission of SCCmec/SCC elements among staphylococci.
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Affiliation(s)
- Jinhe Xiao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Jianguo Huang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Xuemei Xue
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Chen Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Yanting Sun
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Liangjun Zheng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Xu Zhao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Xiaokun Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Xin Zhao
- Department of Animal Science, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Huping Xue
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
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5
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Yarawsky AE, Ori AL, English LR, Whitten ST, Herr AB. Convergent behavior of extended stalk regions from staphylococcal surface proteins with widely divergent sequence patterns. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.06.523059. [PMID: 36711672 PMCID: PMC9881980 DOI: 10.1101/2023.01.06.523059] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Staphylococcus epidermidis and S. aureus are highly problematic bacteria in hospital settings. This stems, at least in part, from strong abilities to form biofilms on abiotic or biotic surfaces. Biofilms are well-organized multicellular aggregates of bacteria, which, when formed on indwelling medical devices, lead to infections that are difficult to treat. Cell wall-anchored (CWA) proteins are known to be important players in biofilm formation and infection. Many of these proteins have putative stalk-like regions or regions of low complexity near the cell wall-anchoring motif. Recent work demonstrated the strong propensity of the stalk region of the S. epidermidis accumulation-associated protein (Aap) to remain highly extended under solution conditions that typically induce compaction or other significant conformational changes. This behavior is consistent with the expected function of a stalk-like region that is covalently attached to the cell wall peptidoglycan and projects the adhesive domains of Aap away from the cell surface. In this study, we evaluate whether the ability to resist compaction is a common theme among stalk regions from various staphylococcal CWA proteins. Circular dichroism spectroscopy was used to examine secondary structure changes as a function of temperature and cosolvents along with sedimentation velocity analytical ultracentrifugation and SAXS to characterize structural characteristics in solution. All stalk regions tested are intrinsically disordered, lacking secondary structure beyond random coil and polyproline type II helix, and they all sample highly extended conformations. Remarkably, the Ser-Asp dipeptide repeat region of SdrC exhibited nearly identical behavior in solution when compared to the Aap Pro/Gly-rich region, despite highly divergent sequence patterns, indicating conservation of function by various distinct staphylococcal CWA protein stalk regions.
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Affiliation(s)
- Alexander E. Yarawsky
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Andrea L. Ori
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA,Medical Sciences Baccalaureate Program, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Lance R. English
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Steven T. Whitten
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Andrew B. Herr
- Division of Immunobiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA,Division of Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA,Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
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6
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Dolma KG, Khati R, Paul AK, Rahmatullah M, de Lourdes Pereira M, Wilairatana P, Khandelwal B, Gupta C, Gautam D, Gupta M, Goyal RK, Wiart C, Nissapatorn V. Virulence Characteristics and Emerging Therapies for Biofilm-Forming Acinetobacter baumannii: A Review. BIOLOGY 2022; 11:biology11091343. [PMID: 36138822 PMCID: PMC9495682 DOI: 10.3390/biology11091343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/04/2022] [Accepted: 09/08/2022] [Indexed: 11/20/2022]
Abstract
Simple Summary Acinetobacter baumannii (A. baumannii) is one of the ESKAPE organisms and has the competency to build biofilms. These biofilms account for the most nosocomial infections all over the world. This review reflects on the various physicochemical and environmental factors such as adhesion, pili expression, growth surfaces, drug-resistant genes, and virulence factors that profoundly affect its resistant forte. Emerging drug-resistant issues and limitations to newer drugs are other factors affecting the hospital environment. Here, we discuss newer and alternative methods that can significantly enhance the susceptibility to Acinetobacter spp. Many new antibiotics are under trials, such as GSK-3342830, The Cefiderocol (S-649266), Fimsbactin, and similar. On the other hand, we can also see the impact of traditional medicine and the secondary metabolites of these natural products’ application in searching for new treatments. The field of nanoparticles has demonstrated effective antimicrobial actions and has exhibited encouraging results in the field of nanomedicine. The use of various phages such as vWUPSU and phage ISTD as an alternative treatment for its specificity and effectiveness is being investigated. Cathelicidins obtained synthetically or from natural sources can effectively produce antimicrobial activity in the micromolar range. Radioimmunotherapy and photodynamic therapy have boundless prospects if explored as a therapeutic antimicrobial strategy. Abstract Acinetobacter species is one of the most prevailing nosocomial pathogens with a potent ability to develop antimicrobial resistance. It commonly causes infections where there is a prolonged utilization of medical devices such as CSF shunts, catheters, endotracheal tubes, and similar. There are several strains of Acinetobacter (A) species (spp), among which the majority are pathogenic to humans, but A. baumannii are entirely resistant to several clinically available antibiotics. The crucial mechanism that renders them a multidrug-resistant strain is their potent ability to synthesize biofilms. Biofilms provide ample opportunity for the microorganisms to withstand the harsh environment and further cause chronic infections. Several studies have enumerated multiple physiological and virulence factors responsible for the production and maintenance of biofilms. To further enhance our understanding of this pathogen, in this review, we discuss its taxonomy, pathogenesis, current treatment options, global resistance rates, mechanisms of its resistance against various groups of antimicrobials, and future therapeutics.
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Affiliation(s)
- Karma G. Dolma
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Rachana Khati
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Alok K. Paul
- School of Pharmacy and Pharmacology, University of Tasmania, Hobart, TAS 7001, Australia
| | - Mohammed Rahmatullah
- Department of Biotechnology & Genetic Engineering, University of Development Alternative, Lalmatia, Dhaka 1207, Bangladesh
| | - Maria de Lourdes Pereira
- CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
- Department of Medical Sciences, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
- Correspondence: (P.W.); (V.N.)
| | - Bidita Khandelwal
- Department of Medicine, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Chamma Gupta
- Department of Biotechnology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Deepan Gautam
- Department of Microbiology, Sikkim Manipal Institute of Medical Sciences, Sikkim Manipal University, Gangtok 737102, Sikkim, India
| | - Madhu Gupta
- Department of Pharmaceutics, Delhi Pharmaceutical Sciences and Research University, New Delhi 110017, India
| | - Ramesh K. Goyal
- Department of Pharmaceutics, Delhi Pharmaceutical Sciences and Research University, New Delhi 110017, India
| | - Christophe Wiart
- Institute for Tropical Biology and Conservation, Universiti Malaysia Sabah, Kota Kinabalu 88400, Malaysia
| | - Veeranoot Nissapatorn
- School of Allied Health Sciences and World Union for Herbal Drug Discovery (WUHeDD), Walailak University, Nakhon Si Thammarat 80160, Thailand
- Correspondence: (P.W.); (V.N.)
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7
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de Vor L, Beudeker CR, Flier A, Scheepmaker LM, Aerts PC, Vijlbrief DC, Bekker MN, Beurskens FJ, van Kessel KPM, de Haas CJC, Rooijakkers SHM, van der Flier M. Monoclonal antibodies effectively potentiate complement activation and phagocytosis of Staphylococcus epidermidis in neonatal human plasma. Front Immunol 2022; 13:933251. [PMID: 35967335 PMCID: PMC9372458 DOI: 10.3389/fimmu.2022.933251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 06/29/2022] [Indexed: 12/12/2022] Open
Abstract
Central line associated bloodstream infections (CLABSI) with Staphylococcus epidermidis are a major cause of morbidity in neonates, who have an increased risk of infection because of their immature immune system. As especially preterm neonates suffer from antibody deficiency, clinical studies into preventive therapies have thus far focused on antibody supplementation with pooled intravenous immunoglobulins from healthy donors (IVIG) but with little success. Here we study the potential of monoclonal antibodies (mAbs) against S. epidermidis to induce phagocytic killing by human neutrophils. Nine different mAbs recognizing Staphylococcal surface components were cloned and expressed as human IgG1s. In binding assays, clones rF1, CR5133 and CR6453 showed the strongest binding to S. epidermidis ATCC14990 and CR5133 and CR6453 bound the majority of clinical isolates from neonatal sepsis (19 out of 20). To study the immune-activating potential of rF1, CR5133 and CR6453, bacteria were opsonized with mAbs in the presence or absence of complement. We observed that activation of the complement system is essential to induce efficient phagocytosis of S. epidermidis. Complement activation and phagocytic killing could be enhanced by Fc-mutations that improve IgG1 hexamerization on cellular surfaces. Finally, we studied the ability of the mAbs to activate complement in r-Hirudin neonatal plasma conditions. We show that classical pathway complement activity in plasma isolated from neonatal cord blood is comparable to adult levels. Furthermore, mAbs could greatly enhance phagocytosis of S. epidermidis in neonatal plasma. Altogether, our findings provide insights that are crucial for optimizing anti-S. epidermidis mAbs as prophylactic agents for neonatal CLABSI.
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Affiliation(s)
- Lisanne de Vor
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Coco R. Beudeker
- Department of Paediatric Infectious Diseases and Immunology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Anne Flier
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Lisette M. Scheepmaker
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Piet C. Aerts
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Daniel C. Vijlbrief
- Department of Neonatology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Mireille N. Bekker
- Department of Obstetrics, University Medical Center Utrecht, Utrecht, Netherlands
| | | | - Kok P. M. van Kessel
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Carla J. C. de Haas
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | | | - Michiel van der Flier
- Department of Paediatric Infectious Diseases and Immunology, University Medical Center Utrecht, Utrecht, Netherlands
- *Correspondence: Michiel van der Flier,
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8
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The expression of glycosyltransferases sdgA and sdgB in Staphylococcus epidermidis depends on the conditions of biofilm formation. Arch Microbiol 2022; 204:274. [PMID: 35449342 DOI: 10.1007/s00203-022-02891-0] [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: 12/16/2021] [Revised: 03/02/2022] [Accepted: 04/01/2022] [Indexed: 11/02/2022]
Abstract
The Staphylococcus aureus SdrG protein is glycosylated by SdgA and SdgB for protection against its degradation by the neutrophil cathepsin G. So far, there is no information about the role of Staphylococcus epidermidis SdgA or SdgB in biofilm-forming; therefore, the focus of this work was to determine the distribution and expression of the sdrG, sdgA and sdgB genes in S. epidermidis under in vitro and in vivo biofilm conditions. The frequencies of the sdrG, sdgA and sdgB genes were evaluated by PCR in a collection of 75 isolates. Isolates were grown in dynamic (non-biofilm-forming) or static (biofilm-forming) conditions. The expression of sdrG, sdgA and sdgB was determined by RT-qPCR in cells grown under dynamic conditions (CGDC), as well as in planktonic and sessile cells from a biofilm and cells adhered to a catheter implanted in Balb/c mice. The sdrG and sdgB genes were detected in 100% of isolates, while the sdgA gene was detected in 71% of the sample (p < 0.001). CGDC did not express sdrG, sdgA and sdgB mRNAs. Planktonic and sessile cells expressed sdrG and sdgB, and the same was observed in cells adhered to the catheter. In particular, one isolate, capable of inducing a biofilm under treatment with cathepsin G, expressed sdrG and sdgB in planktonic and sessile cells and cells adhering to the catheter. This suggests that bacteria require biofilm conditions as an important factor for the transcription of the sdgA, sdgB and sdrG genes.
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Abstract
Post-translational modification with O-linked β-N-acetylglucosamine (O-GlcNAc), a process referred to as O-GlcNAcylation, occurs on a vast variety of proteins. Mounting evidence in the past several decades has clearly demonstrated that O-GlcNAcylation is a unique and ubiquitous modification. Reminiscent of a code, protein O-GlcNAcylation functions as a crucial regulator of nearly all cellular processes studied. The primary aim of this review is to summarize the developments in our understanding of myriad protein substrates modified by O-GlcNAcylation from a systems perspective. Specifically, we provide a comprehensive survey of O-GlcNAcylation in multiple species studied, including eukaryotes (e.g., protists, fungi, plants, Caenorhabditis elegans, Drosophila melanogaster, murine, and human), prokaryotes, and some viruses. We evaluate features (e.g., structural properties and sequence motifs) of O-GlcNAc modification on proteins across species. Given that O-GlcNAcylation functions in a species-, tissue-/cell-, protein-, and site-specific manner, we discuss the functional roles of O-GlcNAcylation on human proteins. We focus particularly on several classes of relatively well-characterized human proteins (including transcription factors, protein kinases, protein phosphatases, and E3 ubiquitin-ligases), with representative O-GlcNAc site-specific functions presented. We hope the systems view of the great endeavor in the past 35 years will help demystify the O-GlcNAc code and lead to more fascinating studies in the years to come.
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Affiliation(s)
- Junfeng Ma
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Georgetown University, Washington, DC 20057, United States
| | - Chunyan Hou
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Georgetown University, Washington, DC 20057, United States
| | - Ci Wu
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Georgetown University, Washington, DC 20057, United States
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10
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de Vor L, van Dijk B, van Kessel K, Kavanaugh JS, de Haas C, Aerts PC, Viveen MC, Boel EC, Fluit AC, Kwiecinski JM, Krijger GC, Ramakers RM, Beekman FJ, Dadachova E, Lam MGEH, Vogely HC, van der Wal BCH, van Strijp JAG, Horswill AR, Weinans H, Rooijakkers SHM. Human monoclonal antibodies against Staphylococcus aureus surface antigens recognize in vitro and in vivo biofilm. eLife 2022; 11:e67301. [PMID: 34989676 PMCID: PMC8751199 DOI: 10.7554/elife.67301] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 12/06/2021] [Indexed: 12/22/2022] Open
Abstract
Implant-associated Staphylococcus aureus infections are difficult to treat because of biofilm formation. Bacteria in a biofilm are often insensitive to antibiotics and host immunity. Monoclonal antibodies (mAbs) could provide an alternative approach to improve the diagnosis and potential treatment of biofilm-related infections. Here, we show that mAbs targeting common surface components of S. aureus can recognize clinically relevant biofilm types. The mAbs were also shown to bind a collection of clinical isolates derived from different biofilm-associated infections (endocarditis, prosthetic joint, catheter). We identify two groups of antibodies: one group that uniquely binds S. aureus in biofilm state and one that recognizes S. aureus in both biofilm and planktonic state. Furthermore, we show that a mAb recognizing wall teichoic acid (clone 4497) specifically localizes to a subcutaneously implanted pre-colonized catheter in mice. In conclusion, we demonstrate the capacity of several human mAbs to detect S. aureus biofilms in vitro and in vivo.
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Affiliation(s)
- Lisanne de Vor
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Bruce van Dijk
- Department of Orthopedics, University Medical Centre UtrechtUtrechtNetherlands
| | - Kok van Kessel
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Jeffrey S Kavanaugh
- Department of Immunology and Microbiology, University of Colorado School of MedicineAuroraUnited States
| | - Carla de Haas
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Piet C Aerts
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Marco C Viveen
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Edwin C Boel
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Ad C Fluit
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Jakub M Kwiecinski
- Department of Immunology and Microbiology, University of Colorado School of MedicineAuroraUnited States
| | - Gerard C Krijger
- Department of Radiology and Nuclear Medicine, University Medical Centre UtrechtUtrechtNetherlands
| | - Ruud M Ramakers
- MILabs B.VUtrechtNetherlands
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical CenterUtrechtNetherlands
- Department of Radiation Science and Technology, Delft University of TechnologyDelftNetherlands
| | - Freek J Beekman
- MILabs B.VUtrechtNetherlands
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical CenterUtrechtNetherlands
- Department of Radiation Science and Technology, Delft University of TechnologyDelftNetherlands
| | - Ekaterina Dadachova
- College of Pharmacy and Nutrition, University of SaskatchewanSaskatoonCanada
| | - Marnix GEH Lam
- Department of Radiology and Nuclear Medicine, University Medical Centre UtrechtUtrechtNetherlands
| | - H Charles Vogely
- Department of Orthopedics, University Medical Centre UtrechtUtrechtNetherlands
| | - Bart CH van der Wal
- Department of Orthopedics, University Medical Centre UtrechtUtrechtNetherlands
| | - Jos AG van Strijp
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of MedicineAuroraUnited States
- Department of Veterans Affairs, Eastern Colorado Health Care SystemDenverUnited States
| | - Harrie Weinans
- Department of Orthopedics, University Medical Centre UtrechtUtrechtNetherlands
- Department of Biomechanical engineering, TU DelftDelftNetherlands
| | - Suzan HM Rooijakkers
- Department of Medical Microbiology, University Medical Centre UtrechtUtrechtNetherlands
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11
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Zacharias N, Podust VN, Kajihara KK, Leipold D, Del Rosario G, Thayer D, Dong E, Paluch M, Fischer D, Zheng K, Lei C, He J, Ng C, Su D, Liu L, Masih S, Sawyer W, Tinianow J, Marik J, Yip V, Li G, Chuh J, Morisaki JH, Park S, Zheng B, Hernandez-Barry H, Loyet KM, Xu M, Kozak KR, Phillips GL, Shen BQ, Wu C, Xu K, Yu SF, Kamath A, Rowntree RK, Reilly D, Pillow T, Polson A, Schellenberger V, Hazenbos WLW, Sadowsky J. A homogeneous high-DAR antibody-drug conjugate platform combining THIOMAB antibodies and XTEN polypeptides. Chem Sci 2022; 13:3147-3160. [PMID: 35414872 PMCID: PMC8926172 DOI: 10.1039/d1sc05243h] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 01/27/2022] [Indexed: 11/21/2022] Open
Abstract
The antibody-drug conjugate (ADC) is a well-validated modality for the cell-specific delivery of small molecules with impact expanding rapidly beyond their originally-intended purpose of treating cancer. However, antibody-mediated delivery (AMD)...
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Affiliation(s)
| | - Vladimir N Podust
- Amunix Pharmaceuticals, Inc. 2 Tower Place South San Francisco CA 94080 USA
| | | | | | | | - Desiree Thayer
- Amunix Pharmaceuticals, Inc. 2 Tower Place South San Francisco CA 94080 USA
| | - Emily Dong
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Maciej Paluch
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - David Fischer
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Kai Zheng
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Corinna Lei
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Jintang He
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Carl Ng
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Dian Su
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Luna Liu
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | | | - William Sawyer
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Jeff Tinianow
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Jan Marik
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Victor Yip
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Guangmin Li
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Josefa Chuh
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | | | - Summer Park
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Bing Zheng
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | | | - Kelly M Loyet
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Min Xu
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | | | | | - Ben-Quan Shen
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Cong Wu
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Keyang Xu
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Shang-Fan Yu
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Amrita Kamath
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | | | | | - Thomas Pillow
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | - Andrew Polson
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
| | | | | | - Jack Sadowsky
- Genentech, Inc. 1 DNA Way South San Francisco CA 94080 USA
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12
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Kim DG, Baek I, Lee Y, Kim H, Kim JY, Bang G, Kim S, Yoon HJ, Han BW, Suh SW, Kim HS. Structural basis for SdgB- and SdgA-mediated glycosylation of staphylococcal adhesive proteins. Acta Crystallogr D Struct Biol 2021; 77:1460-1474. [PMID: 34726173 PMCID: PMC8561734 DOI: 10.1107/s2059798321010068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 09/28/2021] [Indexed: 02/07/2023] Open
Abstract
The initiation of infection of host tissues by Staphylococcus aureus requires a family of staphylococcal adhesive proteins containing serine-aspartate repeat (SDR) domains, such as ClfA. The O-linked glycosylation of the long-chain SDR domain mediated by SdgB and SdgA is a key virulence factor that protects the adhesive SDR proteins against host proteolytic attack in order to promote successful tissue colonization, and has also been implicated in staphylococcal agglutination, which leads to sepsis and an immunodominant epitope for a strong antibody response. Despite the biological significance of these two glycosyltransferases involved in pathogenicity and avoidance of the host innate immune response, their structures and the molecular basis of their activity have not been investigated. This study reports the crystal structures of SdgB and SdgA from S. aureus as well as multiple structures of SdgB in complex with its substrates (for example UDP, N-acetylglucosamine or SDR peptides), products (glycosylated SDR peptides) or phosphate ions. Together with biophysical and biochemical analyses, this structural work uncovered the novel mechanism by which SdgB and SdgA carry out the glycosyl-transfer process to the long SDR region in SDR proteins. SdgB undergoes dynamic changes in its structure such as a transition from an open to a closed conformation upon ligand binding and takes diverse forms, both as a homodimer and as a heterodimer with SdgA. Overall, these findings not only elucidate the putative role of the three domains of SdgB in recognizing donor and acceptor substrates, but also provide new mechanistic insights into glycosylation of the SDR domain, which can serve as a starting point for the development of antibacterial drugs against staphylococcal infections.
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Affiliation(s)
- Dong-Gyun Kim
- Research Institute, National Cancer Center, Goyang, Gyeonggi 10408, Republic of Korea
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Inwha Baek
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Yeon Lee
- Research Institute, National Cancer Center, Goyang, Gyeonggi 10408, Republic of Korea
| | - Hyerry Kim
- Research Institute, National Cancer Center, Goyang, Gyeonggi 10408, Republic of Korea
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
- R&D Center, Voronoi Inc., Incheon 21984, Republic of Korea
| | - Jin Young Kim
- Korea Basic Science Institute, Ochang, Chungbuk 28119, Republic of Korea
| | - Geul Bang
- Korea Basic Science Institute, Ochang, Chungbuk 28119, Republic of Korea
| | - Sunghwan Kim
- R&D Center, Voronoi Inc., Incheon 21984, Republic of Korea
| | - Hye Jin Yoon
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Byung Woo Han
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Se Won Suh
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyoun Sook Kim
- Research Institute, National Cancer Center, Goyang, Gyeonggi 10408, Republic of Korea
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13
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Proteinous Components of Neutrophil Extracellular Traps Are Arrested by the Cell Wall Proteins of Candida albicans during Fungal Infection, and Can Be Used in the Host Invasion. Cells 2021; 10:cells10102736. [PMID: 34685715 PMCID: PMC8534323 DOI: 10.3390/cells10102736] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 01/08/2023] Open
Abstract
One of defense mechanisms of the human immune system to counteract infection by the opportunistic fungal pathogen Candida albicans is the recruitment of neutrophils to the site of invasion, and the subsequent production of neutrophil extracellular traps (NETs) that efficiently capture and kill the invader cells. In the current study, we demonstrate that within these structures composed of chromatin and proteins, the latter play a pivotal role in the entrapment of the fungal pathogen. The proteinous components of NETs, such as the granular enzymes elastase, myeloperoxidase and lactotransferrin, as well as histones and cathelicidin-derived peptide LL-37, are involved in contact with the surface of C. albicans cells. The fungal partners in these interactions are a typical adhesin of the agglutinin-like sequence protein family Als3, and several atypical surface-exposed proteins of cytoplasmic origin, including enolase, triosephosphate isomerase and phosphoglycerate mutase. Importantly, the adhesion of both the elastase itself and the mixture of proteins originating from NETs on the C. albicans cell surface considerably increased the pathogen potency of human epithelial cell destruction compared with fungal cells without human proteins attached. Such an implementation of adsorbed NET-derived proteins by invading C. albicans cells might alter the effectiveness of the fungal pathogen entrapment and affect the further host colonization.
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14
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Kretschmer D, Breitmeyer R, Gekeler C, Lebtig M, Schlatterer K, Nega M, Stahl M, Stapels D, Rooijakkers S, Peschel A. Staphylococcus aureus Depends on Eap Proteins for Preventing Degradation of Its Phenol-Soluble Modulin Toxins by Neutrophil Serine Proteases. Front Immunol 2021; 12:701093. [PMID: 34552584 PMCID: PMC8451722 DOI: 10.3389/fimmu.2021.701093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/18/2021] [Indexed: 11/13/2022] Open
Abstract
Neutrophil granulocytes act as a first line of defense against pathogenic staphylococci. However, Staphylococcus aureus has a remarkable capacity to survive neutrophil killing, which distinguishes it from the less-pathogenic Staphylococcus epidermidis. Both species release phenol-soluble modulin (PSM) toxins, which activate the neutrophil formyl-peptide receptor 2 (FPR2) to promote neutrophil influx and phagocytosis, and which disrupt neutrophils or their phagosomal membranes at high concentrations. We show here that the neutrophil serine proteases (NSPs) neutrophil elastase, cathepsin G and proteinase 3, which are released into the extracellular space or the phagosome upon neutrophil FPR2 stimulation, effectively degrade PSMs thereby preventing their capacity to activate and destroy neutrophils. Notably, S. aureus, but not S. epidermidis, secretes potent NSP-inhibitory proteins, Eap, EapH1, EapH2, which prevented the degradation of PSMs by NSPs. Accordingly, a S. aureus mutant lacking all three NSP inhibitory proteins was less effective in activating and destroying neutrophils and it survived less well in the presence of neutrophils than the parental strain. We show that Eap proteins promote pathology via PSM-mediated FPR2 activation since murine intraperitoneal infection with the S. aureus parental but not with the NSP inhibitors mutant strain, led to a significantly higher bacterial load in the peritoneum and kidneys of mFpr2-/- compared to wild-type mice. These data demonstrate that NSPs can very effectively detoxify some of the most potent staphylococcal toxins and that the prominent human pathogen S. aureus has developed efficient inhibitors to preserve PSM functions. Preventing PSM degradation during infection represents an important survival strategy to ensure FPR2 activation.
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Affiliation(s)
- Dorothee Kretschmer
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Ricarda Breitmeyer
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Cordula Gekeler
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Marco Lebtig
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Katja Schlatterer
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Mulugeta Nega
- Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany.,Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Mark Stahl
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Daphne Stapels
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Suzan Rooijakkers
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Andreas Peschel
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
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15
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Sun Z, Zhang X, Zhou D, Zhou K, Li Q, Lin H, Lu W, Liu H, Lu J, Lin X, Li K, Xu T, Zhu M, Bao Q, Zhang H. Identification of Three Clf-Sdr Subfamily Proteins in Staphylococcus warneri, and Comparative Genomics Analysis of a Locus Encoding CWA Proteins in Staphylococcus Species. Front Microbiol 2021; 12:691087. [PMID: 34394031 PMCID: PMC8360574 DOI: 10.3389/fmicb.2021.691087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/28/2021] [Indexed: 11/13/2022] Open
Abstract
Coagulase-negative Staphylococcus warneri is an opportunistic pathogen that is capable of causing several infections, especially in patients with indwelling medical devices. Here, we determined the complete genome sequence of a clinical S. warneri strain isolated from the blood culture of a 1-year-old nursling patient with acute upper respiratory infection. Genome-wide phylogenetic analysis confirmed the phylogenetic relationships between S. warneri and other Staphylococcus species. Using comparative genomics, we identified three cell wall-anchored (CWA) proteins at the same locus (sdr), named SdrJ, SdrK, and SdrL, on the chromosome sequences of different S. warneri strains. Structural predictions showed that SdrJ/K/L have structural features characteristic of Sdr proteins but exceptionally contained an unusual N-terminal repeat region. However, the C-terminal repetitive (R) region of SdrJ contains a significantly larger proportion of alanine (142/338, 42.01%) than the previously reported SdrI (37.00%). Investigation of the genetic organization revealed that the sdrJ/K/L genes were always followed by one or two glycosyltransferase genes, gtfA and gtfB and were present in an ∼56 kb region bordered by a pair of 8 bp identical direct repeats, named Sw-Sdr. This region was further found to be located on a 160-kb region subtended by a pair of 160-bp direct repeats along with other virulence genes and resistance genes. Sw-Sdr contained a putative integrase that was probably a remnant of a functional integrase. Evidence suggests that Sw-Sdr is improbably an efficient pathogenicity island. A large-scale investigation of Staphylococcus genomes showed that sdr loci were a potential hotspot of insertion sequences (ISs), which could lead to intraspecific diversity at these loci. Our work expanded the repository of Staphylococcus Sdr proteins, and for the first time, we established the connection between sdr loci and phylogenetic relationships and compared the sdr loci in different Staphylococcus species, which provided large insights into the genetic environment of CWA genes in Staphylococcus.
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Affiliation(s)
- Zhewei Sun
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Xueya Zhang
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Danying Zhou
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Kexin Zhou
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Qiaoling Li
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Hailong Lin
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Wei Lu
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Hongmao Liu
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Junwan Lu
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Xi Lin
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Kewei Li
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Teng Xu
- Institute of Translational Medicine, Baotou Central Hospital, Baotou, China
| | - Mei Zhu
- Department of Clinical Laboratory, Zhejiang Hospital, Hangzhou, China
| | - Qiyu Bao
- Key Laboratory of Medical Genetics of Zhejiang Province, Key Laboratory of Laboratory Medicine, Ministry of Education, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
| | - Hailin Zhang
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.,School of Laboratory Medicine and Life Sciences, Institute of Biomedical Informatics, Wenzhou Medical University, Wenzhou, China
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16
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Hendriks A, van Dalen R, Ali S, Gerlach D, van der Marel GA, Fuchsberger FF, Aerts PC, de Haas CJ, Peschel A, Rademacher C, van Strijp JA, Codée JD, van Sorge NM. Impact of Glycan Linkage to Staphylococcus aureus Wall Teichoic Acid on Langerin Recognition and Langerhans Cell Activation. ACS Infect Dis 2021; 7:624-635. [PMID: 33591717 PMCID: PMC8023653 DOI: 10.1021/acsinfecdis.0c00822] [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] [Indexed: 12/18/2022]
Abstract
![]()
Staphylococcus
aureus is the leading cause of
skin and soft tissue infections. It remains incompletely understood
how skin-resident immune cells respond to invading S. aureus and contribute to an effective immune response. Langerhans cells
(LCs), the only professional antigen-presenting cell type in the epidermis,
sense S. aureus through their pattern-recognition
receptor langerin, triggering a proinflammatory response. Langerin
recognizes the β-1,4-linked N-acetylglucosamine
(β1,4-GlcNAc) but not α-1,4-linked GlcNAc (α1,4-GlcNAc)
modifications, which are added by dedicated glycosyltransferases TarS
and TarM, respectively, on the cell wall glycopolymer wall teichoic
acid (WTA). Recently, an alternative WTA glycosyltransferase, TarP,
was identified, which also modifies WTA with β-GlcNAc but at
the C-3 position (β1,3-GlcNAc) of the WTA ribitol phosphate
(RboP) subunit. Here, we aimed to unravel the impact of β-GlcNAc
linkage position for langerin binding and LC activation. Using genetically
modified S. aureus strains, we observed that langerin
similarly recognized bacteria that produce either TarS- or TarP-modified
WTA, yet tarP-expressing S. aureus induced increased cytokine production and maturation of in vitro-generated LCs compared to tarS-expressing S. aureus. Chemically synthesized WTA
molecules, representative of the different S. aureus WTA glycosylation patterns, were used to identify langerin-WTA binding
requirements. We established that β-GlcNAc is sufficient to
confer langerin binding, thereby presenting synthetic WTA molecules
as a novel glycobiology tool for structure-binding studies and for
elucidating S. aureus molecular pathogenesis. Overall,
our data suggest that LCs are able to sense all β-GlcNAc-WTA
producing S. aureus strains, likely performing an
important role as first responders upon S. aureus skin invasion.
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Affiliation(s)
- Astrid Hendriks
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, 3584 CX Utrecht, The Netherlands
- Glaxo-Smith Kline, 53100 Siena, Italy
| | - Rob van Dalen
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Sara Ali
- Leiden Institute of Chemistry, Leiden University, 2311 EZ Leiden, The Netherlands
| | - David Gerlach
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, 72074 Tübingen, Germany
- Partner Site Tübingen, German Centre for Infection Research (DZIF), 72074 Tübingen, Germany
| | | | | | - Piet C. Aerts
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Carla J.C. de Haas
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Andreas Peschel
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, 72074 Tübingen, Germany
- Partner Site Tübingen, German Centre for Infection Research (DZIF), 72074 Tübingen, Germany
| | | | - Jos A.G. van Strijp
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, 3584 CX Utrecht, The Netherlands
| | - Jeroen D.C. Codée
- Leiden Institute of Chemistry, Leiden University, 2311 EZ Leiden, The Netherlands
| | - Nina M. van Sorge
- Medical Microbiology, University Medical Center Utrecht, Utrecht University, 3584 CX Utrecht, The Netherlands
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17
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Valle J, Fang X, Lasa I. Revisiting Bap Multidomain Protein: More Than Sticking Bacteria Together. Front Microbiol 2020; 11:613581. [PMID: 33424817 PMCID: PMC7785521 DOI: 10.3389/fmicb.2020.613581] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/03/2020] [Indexed: 12/21/2022] Open
Abstract
One of the major components of the staphylococcal biofilm is surface proteins that assemble as scaffold components of the biofilm matrix. Among the different surface proteins able to contribute to biofilm formation, this review is dedicated to the Biofilm Associated Protein (Bap). Bap is part of the accessory genome of Staphylococcus aureus but orthologs of Bap in other staphylococcal species belong to the core genome. When present, Bap promotes adhesion to abiotic surfaces and induces strong intercellular adhesion by self-assembling into amyloid like aggregates in response to the levels of calcium and the pH in the environment. During infection, Bap enhances the adhesion to epithelial cells where it binds directly to the host receptor Gp96 and inhibits the entry of the bacteria into the cells. To perform such diverse range of functions, Bap comprises several domains, and some of them include several motifs associated to distinct functions. Based on the knowledge accumulated with the Bap protein of S. aureus, this review aims to summarize the current knowledge of the structure and properties of each domain of Bap and their contribution to Bap functionality.
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Affiliation(s)
- Jaione Valle
- Instituto de Agrobiotecnología, CSIC-Gobierno de Navarra, Mutilva, Spain
| | - Xianyang Fang
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Iñigo Lasa
- Laboratory of Microbial Pathogenesis, Navarrabiomed-Universidad Pública de Navarra-Departamento de Salud, IDISNA, Pamplona, Spain
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18
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Chan JM, Gori A, Nobbs AH, Heyderman RS. Streptococcal Serine-Rich Repeat Proteins in Colonization and Disease. Front Microbiol 2020; 11:593356. [PMID: 33193266 PMCID: PMC7661464 DOI: 10.3389/fmicb.2020.593356] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/12/2020] [Indexed: 01/10/2023] Open
Abstract
Glycosylation of proteins, previously thought to be absent in prokaryotes, is increasingly recognized as important for both bacterial colonization and pathogenesis. For mucosal pathobionts, glycoproteins that function as cell wall-associated adhesins facilitate interactions with mucosal surfaces, permitting persistent adherence, invasion of deeper tissues and transition to disease. This is exemplified by Streptococcus pneumoniae and Streptococcus agalactiae, which can switch from being relatively harmless members of the mucosal tract microbiota to bona fide pathogens that cause life-threatening diseases. As part of their armamentarium of virulence factors, streptococci encode a family of large, glycosylated serine-rich repeat proteins (SRRPs) that facilitate binding to various tissue types and extracellular matrix proteins. This minireview focuses on the roles of S. pneumoniae and S. agalactiae SRRPs in persistent colonization and the transition to disease. The potential of utilizing SRRPs as vaccine targets will also be discussed.
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Affiliation(s)
- Jia Mun Chan
- NIHR Mucosal Pathogens Research Unit, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Andrea Gori
- NIHR Mucosal Pathogens Research Unit, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Angela H. Nobbs
- Bristol Dental School, University of Bristol, Bristol, United Kingdom
| | - Robert S. Heyderman
- NIHR Mucosal Pathogens Research Unit, Division of Infection and Immunity, University College London, London, United Kingdom
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19
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Choudhary P, Badmalia MD, Rao A. Shape-function insights into bifunctional O-GlcNActransferase of Listeria monocytogenes EGD-e. Glycobiology 2020; 31:275-287. [PMID: 32776104 DOI: 10.1093/glycob/cwaa076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 08/04/2020] [Accepted: 08/04/2020] [Indexed: 12/13/2022] Open
Abstract
O-GlcNAcylation is an important post-translational modification of proteins. O-GlcNAcylated proteins have crucial roles in several cellular contexts both in eukaryotes and bacteria. O-GlcNActransferase (OGT) is the enzyme instrumental in O-GlcNAcylation of proteins. OGT is conserved across eukaryotes. The first bacterial OGT discovered is GmaR in Listeria monocytogenes. GmaR is a GT-2 family bifunctional protein that catalyzes glycosylation of the flagellin protein FlaA and controls transcription of flagellar motility genes in a temperature-dependent manner. Here, we provide methods for heterologous expression and purification of recombinant GmaR and FlaA, in vivo/in vitro glycosylation assays, analysis of the molecular form of recombinant GmaR and detailed enzyme kinetics. We study the structure and functional dynamics of GmaR. Using solution small-angle X-ray scattering and molecular modeling, we show that GmaR adopts an extended shape with two distinctly spaced structural units in the presence of cofactor Mg2+ and with donor UDP-GlcNAc and cofactor combined. Comparisons of restored structures revealed that in-solution binding of Mg2+ ions brings about shape rearrangements and induces structural-rigidity in hyper-variable regions at the N-terminus of GmaR protein. Taking function and shape data together, we describe that Mg2+ binding enables GmaR to adopt a shape that can bind the substrate. The manuscript provides the first 3D solution structure of a bacterial OGT of GT-2 family and detailed biochemical characterization of GmaR to facilitate its future applications.
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Affiliation(s)
| | - Maulik D Badmalia
- CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India
| | | | - Alka Rao
- CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh 160036, India.,Academy of Scientific and Innovation Research (AcSIR), Sector 19, Kamla Nehru Nagar, Ghaziabad 201002, India
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20
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Arora S, Li X, Hillhouse A, Konganti K, Little SV, Lawhon SD, Threadgill D, Shelburne S, Hook M. Staphylococcus epidermidis MSCRAMM SesJ Is Encoded in Composite Islands. mBio 2020; 11:e02911-19. [PMID: 32071265 PMCID: PMC7029136 DOI: 10.1128/mbio.02911-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/08/2020] [Indexed: 01/18/2023] Open
Abstract
Staphylococcus epidermidis is a leading cause of nosocomial infections in patients with a compromised immune system and/or an implanted medical device. Seventy to 90% of S. epidermidis clinical isolates are methicillin resistant and carry the mecA gene, present in a mobile genetic element (MGE) called the staphylococcal cassette chromosome mec (SCCmec) element. Along with the presence of antibiotic and heavy metal resistance genes, MGEs can also contain genes encoding secreted or cell wall-anchored virulence factors. In our earlier studies of S. epidermidis clinical isolates, we discovered S. epidermidis surface protein J (SesJ), a prototype of a recently discovered subfamily of the microbial surface component recognizing adhesive matrix molecule (MSCRAMM) group. MSCRAMMs are major virulence factors of pathogenic Gram-positive bacteria. Here, we report that the sesJ gene is always accompanied by two glycosyltransferase genes, gtfA and gtfB, and is present in two MGEs, called the arginine catabolic mobile element (ACME) and the staphylococcal cassette chromosome (SCC) element. The presence of the sesJ gene was associated with the left-hand direct repeat DR_B or DR_E. When inserted via DR_E, the sesJ gene was encoded in the SCC element. When inserted via DR_B, the sesJ gene was accompanied by the genes for the type 1 restriction modification system and was encoded in the ACME. Additionally, the SCC element and ACME carry different isoforms of the SesJ protein. To date, the genes encoding MSCRAMMs have been seen to be located in the bacterial core genome. Here, we report the presence of an MSCRAMM in an MGE in S. epidermidis clinical isolates.IMPORTANCES. epidermidis is an opportunistic bacterium that has established itself as a successful nosocomial pathogen. The modern era of novel therapeutics and medical devices has extended the longevity of human life, but at the same time, we also witness the evolution of pathogens to adapt to newly available niches in the host. Increasing antibiotic resistance among pathogens provides an example of such pathogen adaptation. With limited opportunities to modify the core genome, most of the adaptation occurs by acquiring new genes, such as virulence factors and antibiotic resistance determinants present in MGEs. In this study, we describe that the sesJ gene, encoding a recently discovered cell wall-anchored protein in S. epidermidis, is present in both ACME and the SCC element. The presence of virulence factors in MGEs can influence the virulence potential of a specific strain. Therefore, it is critical to study the virulence factors found in MGEs in emerging pathogenic bacteria or strains to understand the mechanisms used by these bacteria to cause infections.
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Affiliation(s)
- Srishtee Arora
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas, USA
| | - Xiqi Li
- Department of Infectious Diseases, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Andrew Hillhouse
- Institute for Genome Sciences and Society, Texas A&M University, College Station, Texas, USA
| | - Kranti Konganti
- Institute for Genome Sciences and Society, Texas A&M University, College Station, Texas, USA
| | - Sara V Little
- Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Sara D Lawhon
- Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - David Threadgill
- Institute for Genome Sciences and Society, Texas A&M University, College Station, Texas, USA
| | - Samuel Shelburne
- Department of Infectious Diseases, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Magnus Hook
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas, USA
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21
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Abstract
Extracellular polysaccharides and glycoproteins of pathogenic bacteria assist in adherence, autoaggregation, biofilm formation, and host immune system evasion. As a result, considerable research in the field of glycobiology is dedicated to study the composition and function of glycans associated with virulence, as well as the enzymes involved in their biosynthesis with the aim to identify novel antibiotic targets. Especially, insights into the enzyme mechanism, substrate binding, and transition-state structures are valuable as a starting point for rational inhibitor design. An intriguing aspect of enzymes that generate or process polysaccharides and glycoproteins is the level of processivity. The existence of enzymatic processivity reflects the need for regulation of the final glycan/glycoprotein length and structure, depending on the role they perform. In this Review, we describe the currently reported examples of various processive enzymes involved in polymerization and transfer of sugar moieties, predominantly in bacterial pathogens, with a focus on the biochemical methods, to showcase the importance of studying processivity for understanding the mechanism.
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Affiliation(s)
- Liubov Yakovlieva
- Stratingh Institute for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Marthe T. C. Walvoort
- Stratingh Institute for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
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22
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Overview of Staphylococcus epidermidis cell wall-anchored proteins: potential targets to inhibit biofilm formation. Mol Biol Rep 2019; 47:771-784. [DOI: 10.1007/s11033-019-05139-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 10/11/2019] [Indexed: 12/18/2022]
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23
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Leonard AC, Petrie LE, Cox G. Bacterial Anti-adhesives: Inhibition of Staphylococcus aureus Nasal Colonization. ACS Infect Dis 2019; 5:1668-1681. [PMID: 31374164 DOI: 10.1021/acsinfecdis.9b00193] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Bacterial adhesion to the skin and mucosa is often a fundamental and early step in host colonization, the establishment of bacterial infections, and pathology. This process is facilitated by adhesins on the surface of the bacterial cell that recognize host cell molecules. Interfering with bacterial host cell adhesion, so-called anti-adhesive therapeutics, offers promise for the development of novel approaches to control bacterial infections. In this review, we focus on the discovery of anti-adhesives targeting the high priority pathogen Staphylococcus aureus. This organism remains a major clinical burden, and S. aureus nasal colonization is associated with poor clinical outcomes. We describe the molecular basis of nasal colonization and highlight potentially efficacious targets for the development of novel nasal decolonization strategies.
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Affiliation(s)
- Allison C. Leonard
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph, Ontario N1G 2W1, Canada
| | - Laurenne E. Petrie
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph, Ontario N1G 2W1, Canada
| | - Georgina Cox
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph, Ontario N1G 2W1, Canada
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24
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Foster TJ. Surface Proteins of Staphylococcus aureus. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0046-2018. [PMID: 31267926 PMCID: PMC10957221 DOI: 10.1128/microbiolspec.gpp3-0046-2018] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Indexed: 12/20/2022] Open
Abstract
The surface of Staphylococcus aureus is decorated with over 20 proteins that are covalently anchored to peptidoglycan by the action of sortase A. These cell wall-anchored (CWA) proteins can be classified into several structural and functional groups. The largest is the MSCRAMM family, which is characterized by tandemly repeated IgG-like folded domains that bind peptide ligands by the dock lock latch mechanism or the collagen triple helix by the collagen hug. Several CWA proteins comprise modules that have different functions, and some individual domains can bind different ligands, sometimes by different mechanisms. For example, the N-terminus of the fibronectin binding proteins comprises an MSCRAMM domain which binds several ligands, while the C-terminus is composed of tandem fibronectin binding repeats. Surface proteins promote adhesion to host cells and tissue, including components of the extracellular matrix, contribute to biofilm formation by stimulating attachment to the host or indwelling medical devices followed by cell-cell accumulation via homophilic interactions between proteins on neighboring cells, help bacteria evade host innate immune responses, participate in iron acquisition from host hemoglobin, and trigger invasion of bacteria into cells that are not normally phagocytic. The study of genetically manipulated strains using animal infection models has shown that many CWA proteins contribute to pathogenesis. Fragments of CWA proteins have the potential to be used in multicomponent vaccines to prevent S. aureus infections.
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25
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Goldeck D, Perry DM, Hayes JWP, Johnson LPM, Young JE, Roychoudhury P, McLuskey EL, Moffat K, Bakker AQ, Kwakkenbos MJ, Frossard JP, Rowland RRR, Murtaugh MP, Graham SP. Establishment of Systems to Enable Isolation of Porcine Monoclonal Antibodies Broadly Neutralizing the Porcine Reproductive and Respiratory Syndrome Virus. Front Immunol 2019; 10:572. [PMID: 30972067 PMCID: PMC6445960 DOI: 10.3389/fimmu.2019.00572] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/04/2019] [Indexed: 02/01/2023] Open
Abstract
The rapid evolution of porcine reproductive and respiratory syndrome viruses (PRRSV) poses a major challenge to effective disease control since available vaccines show variable efficacy against divergent strains. Knowledge of the antigenic targets of virus-neutralizing antibodies that confer protection against heterologous PRRSV strains would be a catalyst for the development of next-generation vaccines. Key to discovering these epitopes is the isolation of neutralizing monoclonal antibodies (mAbs) from immune pigs. To address this need, we sought to establish systems to enable the isolation of PRRSV neutralizing porcine mAbs. We experimentally produced a cohort of immune pigs by sequential challenge infection with four heterologous PRRSV strains spanning PRRSV-1 subtypes and PRRSV species. Whilst priming with PRRSV-1 subtype 1 did not confer full protection against a subsequent infection with a PRRSV-1 subtype 3 strain, animals were protected against a subsequent PRRSV-2 infection. The infection protocol resulted in high serum neutralizing antibody titers against PRRSV-1 Olot/91 and significant neutralization of heterologous PRRSV-1/-2 strains. Enriched memory B cells isolated at the termination of the study were genetically programmed by transduction with a retroviral vector expressing the Bcl-6 transcription factor and the anti-apoptotic Bcl-xL protein, a technology we demonstrated efficiently converts porcine memory B cells into proliferating antibody-secreting cells. Pools of transduced memory B cells were cultured and supernatants containing PRRSV-specific antibodies identified by flow cytometric staining of infected MARC-145 cells and in vitro neutralization of PRRSV-1. Collectively, these data suggest that this experimental system may be further exploited to produce a panel of PRRSV-specific mAbs, which will contribute both to our understanding of the antibody response to PRRSV and allow epitopes to be resolved that may ultimately guide the design of immunogens to induce cross-protective immunity.
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Affiliation(s)
| | - Dana M Perry
- The Pirbright Institute, Pirbright, United Kingdom.,School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Jack W P Hayes
- The Pirbright Institute, Pirbright, United Kingdom.,School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Luke P M Johnson
- The Pirbright Institute, Pirbright, United Kingdom.,School of Veterinary Science, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Jordan E Young
- College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Parimal Roychoudhury
- The Pirbright Institute, Pirbright, United Kingdom.,College of Veterinary Science and Animal Husbandry, Central Agricultural University, Aizawl, India
| | - Elle L McLuskey
- The Pirbright Institute, Pirbright, United Kingdom.,Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Katy Moffat
- The Pirbright Institute, Pirbright, United Kingdom
| | | | | | - Jean-Pierre Frossard
- Department of Virology, Animal and Plant Health Agency, Addlestone, United Kingdom
| | - Raymond R R Rowland
- College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| | - Michael P Murtaugh
- College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Simon P Graham
- The Pirbright Institute, Pirbright, United Kingdom.,School of Veterinary Science, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
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26
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PepN is a non-essential, cell wall-localized protein that contributes to neutrophil elastase-mediated killing of Streptococcus pneumoniae. PLoS One 2019; 14:e0211632. [PMID: 30707714 PMCID: PMC6358159 DOI: 10.1371/journal.pone.0211632] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 01/17/2019] [Indexed: 12/23/2022] Open
Abstract
Streptococcus pneumoniae (Spn) is an asymptomatic colonizer of the human nasopharynx but can also cause disease in the inner ear, meninges, lung and blood. Although various mechanisms contribute to the effective clearance of Spn, opsonophagocytosis by neutrophils is perhaps most critical. Upon phagocytosis, Spn is exposed to various degradative molecules, including a family of neutrophil serine proteases (NSPs) that are stored within intracellular granules. Despite the critical importance of NSPs in killing Spn, the bacterial proteins that are degraded by NSPs leading to Spn death are still unknown. In this report, we identify a 90kDa protein in a purified cell wall (CW) preparation, aminopeptidase N (PepN) that is degraded by the NSP neutrophil elastase (NE). Since PepN lacked a canonical signal sequence or LPxTG motif, we created a mutant expressing a FLAG tagged version of the protein and confirmed its localization to the CW compartment. We determined that not only is PepN a CW-localized protein, but also is a substrate of NE in the context of intact Spn cells. Furthermore, in comparison to wild-type TIGR4 Spn, a mutant strain lacking PepN demonstrated a significant hyper-resistance phenotype in vitro in the presence of purified NE as well as in opsonophagocytic assays with purified human neutrophils ex vivo. Taken together, this is the first study to demonstrate that PepN is a CW-localized protein and a substrate of NE that contributes to the effective killing of Spn by NSPs and human neutrophils.
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27
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Singh V, Phukan UJ. Interaction of host and Staphylococcus aureus protease-system regulates virulence and pathogenicity. Med Microbiol Immunol 2018; 208:585-607. [PMID: 30483863 DOI: 10.1007/s00430-018-0573-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 11/22/2018] [Indexed: 02/06/2023]
Abstract
Staphylococcus aureus causes various health care- and community-associated infections as well as certain chronic TH2 driven inflammatory diseases. It is a potent pathogen with serious virulence and associated high morbidity. Severe pathogenicity is accredited to the S. aureus secreted virulence factors such as proteases and host protease modulators. These virulence factors promote adhesion and invasion of bacteria through damage of tight junction barrier and keratinocytes. They inhibit activation and transmigration of various immune cells such as neutrophils (and neutrophil proteases) to evade opsono-phagocytosis and intracellular bacterial killing. Additionally, they protect the bacteria from extracellular killing by disrupting integrity of extracellular matrix. Platelet activation and agglutination is also impaired by these factors. They also block the classical as well as alternative pathways of complement activation and assist in spread of infection through blood and tissue. As these factors are exquisite factors of S. aureus mediated disease development, we have focused on review of diversification of various protease-system associated virulence factors, their structural building, diverse role in disease development and available therapeutic counter measures. This review summarises the role of protease-associated virulence factors during invasion and progression of disease.
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Affiliation(s)
- Vigyasa Singh
- Molecular Bioprospection Department, CSIR-Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow, 226015, India
| | - Ujjal Jyoti Phukan
- School of Life Science, Jawaharlal Nehru University, New Delhi, 110067, India.
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28
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SssP1, a Streptococcus suis Fimbria-Like Protein Transported by the SecY2/A2 System, Contributes to Bacterial Virulence. Appl Environ Microbiol 2018; 84:AEM.01385-18. [PMID: 30030221 DOI: 10.1128/aem.01385-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 07/10/2018] [Indexed: 12/20/2022] Open
Abstract
Streptococcus suis is an important Gram-positive pathogen in the swine industry and is an emerging zoonotic pathogen for humans. In our previous work, we found a virulent S. suis strain, CZ130302, belonging to a novel serotype, Chz, to be associated with acute meningitis in piglets. However, its underlying mechanisms of pathogenesis remain poorly understood. In this study, we sequenced and analyzed the complete genomes of three Chz serotype strains, including strain CZ130302 and two avirulent strains, HN136 and AH681. By genome comparison, we found two putative genomic islands (GIs) uniquely encoded in strain CZ130302 and designated them 50K GI and 58K GI. In mouse infection model, the deletion of 50K and 58K GIs caused 270-fold and 3-fold attenuation of virulence, respectively. Notably, we identified a complete SecY2/A2 system, coupled with its secretory protein SssP1 encoded in the 50K GI, which contributed to the pathogenicity of strain CZ130302. Immunogold electron microscopy and immunofluorescence analyses indicated that SssP1 could form fimbria-like structures that extend outward from the bacterial cell surface. The sssP1 mutation also attenuated bacterial adherence in human laryngeal epithelial (HEp-2) cells and human brain microvessel endothelial cells (HBMECs) compared with the wild type. Furthermore, we showed that two analogous Ig-like subdomains of SssP1 have sialic acid binding capacities. In conclusion, our results revealed that the 50K GI and the inside SecY2/A2 system gene cluster are related to the virulence of strain CZ130302, and we clarified a new S. suis pathogenesis mechanism mediated by the secretion protein SssP1.IMPORTANCE Streptococcus suis is an important zoonotic pathogen. Here, we managed to identify key factors to clarify the virulence of S. suis strain CZ130302 from a novel serotype, Chz. Notably, it was shown that a fimbria-like structure was significantly connected to the pathogenicity of the CZ130302 strain by comparative genomics analysis and animal infection assays. The mechanisms of how the CZ130302 strain constructs these fimbria-like structures in the cell surface by genes encoding and production transport were subsequently elucidated. Biosynthesis of the fimbria-like structure was achieved by the production of SssP1 glycoproteins, and its construction was dependent on the SecA2/Y2 secretion system. This study identified a visible fimbria-like protein, SssP1, participating in adhesion to host cells and contributing to the virulence in S. suis These findings will promote a better understanding of the pathogenesis of S. suis.
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29
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Fong R, Kajihara K, Chen M, Hotzel I, Mariathasan S, Hazenbos WL, Lupardus PJ. Structural investigation of human S. aureus-targeting antibodies that bind wall teichoic acid. MAbs 2018; 10:979-991. [PMID: 30102105 PMCID: PMC6204806 DOI: 10.1080/19420862.2018.1501252] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a growing health threat worldwide. Efforts to identify novel antibodies that target S. aureus cell surface antigens are a promising direction in the development of antibiotics that can halt MRSA infection. We biochemically and structurally characterized three patient-derived MRSA-targeting antibodies that bind to wall teichoic acid (WTA), which is a polyanionic surface glycopolymer. In S. aureus, WTA exists in both α- and β-forms, based on the stereochemistry of attachment of a N-acetylglucosamine residue to the repeating phosphoribitol sugar unit. We identified a panel of antibodies cloned from human patients that specifically recognize the α or β form of WTA, and can bind with high affinity to pathogenic wild-type strains of S. aureus bacteria. To investigate how the β-WTA specific antibodies interact with their target epitope, we determined the X-ray crystal structures of the three β-WTA specific antibodies, 4462, 4497, and 6078 (Protein Data Bank IDs 6DWI, 6DWA, and 6DW2, respectively), bound to a synthetic WTA epitope. These structures reveal that all three of these antibodies, while utilizing distinct antibody complementarity-determining region sequences and conformations to interact with β-WTA, fulfill two recognition principles: binding to the β-GlcNAc pyranose core and triangulation of WTA phosphate residues with polar contacts. These studies reveal the molecular basis for targeting a unique S. aureus cell surface epitope and highlight the power of human patient-based antibody discovery techniques for finding novel pathogen-targeting therapeutics.
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Affiliation(s)
- Rina Fong
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Kimberly Kajihara
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Matthew Chen
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Isidro Hotzel
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Sanjeev Mariathasan
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Wouter L.W. Hazenbos
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Patrick J. Lupardus
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA,CONTACT Patrick J. Lupardus Department of Structural Biology, Genentech, South San Francisco, CA, USA
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Ajayi C, Åberg E, Askarian F, Sollid JUE, Johannessen M, Hanssen AM. Genetic variability in the sdrD gene in Staphylococcus aureus from healthy nasal carriers. BMC Microbiol 2018; 18:34. [PMID: 29661152 PMCID: PMC5902956 DOI: 10.1186/s12866-018-1179-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 04/08/2018] [Indexed: 11/26/2022] Open
Abstract
Background Staphylococcus aureus cell wall anchored Serine Aspartate repeat containing protein D (SdrD) is a member of the microbial surface component recognising adhesive matrix molecules (MSCRAMMs). It is involved in the bacterial adhesion and virulence. However the extent of genetic variation in S. aureus sdrD gene within isolates from healthy carriers are not known. The aim of this study was to evaluate allelic variation of the sdrD gene among S. aureus from healthy nasal carriers. Results The sdrD A region from 48 S. aureus isolates from healthy carriers were analysed and classified into seven variants. Variations in the sdrD A region were concentrated in the N2 and N3 subdomains. Sequence analysis of the entire sdrD gene of representative isolates revealed variations in the SD repeat and the EF motifs of the B repeat. In silico structural modelling indicates that there are no differences in the SdrD structure of the 7 variants. Variable amino acid residues mapped onto the 3D structure revealed that the variations are surface located, exist within the groove between the N2-N3 subdomains and distributed mainly on the N3 subdomain. Comparison of adhesion to keratinocytes in an in vitro cell adhesion assay, using NCTC 8325–4∆sdrD strains expressing the various sdrD gene variants, indicated a significant difference between only two complements while others showed no major difference in their adhesion. Conclusions This study provides evidence of sequence variations across the different domains of SdrD from S. aureus isolated from healthy nasal carriers. Proper understanding of these variations is necessary in the study of S. aureus pathogenesis. Electronic supplementary material The online version of this article (10.1186/s12866-018-1179-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Clement Ajayi
- Research group of Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037, Tromsø, Norway.
| | - Espen Åberg
- Research group of Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037, Tromsø, Norway
| | - Fatemeh Askarian
- Research group of Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037, Tromsø, Norway
| | - Johanna U E Sollid
- Research group of Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037, Tromsø, Norway
| | - Mona Johannessen
- Research group of Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037, Tromsø, Norway
| | - Anne-Merethe Hanssen
- Research group of Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, 9037, Tromsø, Norway.
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31
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Host-derived fatty acids activate type VII secretion in Staphylococcus aureus. Proc Natl Acad Sci U S A 2017; 114:11223-11228. [PMID: 28973946 DOI: 10.1073/pnas.1700627114] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The type VII secretion system (T7SS) of Staphylococcus aureus is a multiprotein complex dedicated to the export of several virulence factors during host infection. This virulence pathway plays a key role in promoting bacterial survival and the long-term persistence of staphylococcal abscess communities. The expression of the T7SS is activated by bacterial interaction with host tissues including blood serum, nasal secretions, and pulmonary surfactant. In this work we identify the major stimulatory factors as host-specific cis-unsaturated fatty acids. Increased T7SS expression requires host fatty acid incorporation into bacterial biosynthetic pathways by the Saureus fatty acid kinase (FAK) complex, and FakA is required for virulence. The incorporated cis-unsaturated fatty acids decrease Saureus membrane fluidity, and these altered membrane dynamics are partially responsible for T7SS activation. These data define a molecular mechanism by which Saureus cells sense the host environment and implement appropriate virulence pathways.
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32
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Sabaté Brescó M, Harris LG, Thompson K, Stanic B, Morgenstern M, O'Mahony L, Richards RG, Moriarty TF. Pathogenic Mechanisms and Host Interactions in Staphylococcus epidermidis Device-Related Infection. Front Microbiol 2017; 8:1401. [PMID: 28824556 PMCID: PMC5539136 DOI: 10.3389/fmicb.2017.01401] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/11/2017] [Indexed: 12/25/2022] Open
Abstract
Staphylococcus epidermidis is a permanent member of the normal human microbiota, commonly found on skin and mucous membranes. By adhering to tissue surface moieties of the host via specific adhesins, S. epidermidis is capable of establishing a lifelong commensal relationship with humans that begins early in life. In its role as a commensal organism, S. epidermidis is thought to provide benefits to human host, including out-competing more virulent pathogens. However, largely due to its capacity to form biofilm on implanted foreign bodies, S. epidermidis has emerged as an important opportunistic pathogen in patients receiving medical devices. S. epidermidis causes approximately 20% of all orthopedic device-related infections (ODRIs), increasing up to 50% in late-developing infections. Despite this prevalence, it remains underrepresented in the scientific literature, in particular lagging behind the study of the S. aureus. This review aims to provide an overview of the interactions of S. epidermidis with the human host, both as a commensal and as a pathogen. The mechanisms retained by S. epidermidis that enable colonization of human skin as well as invasive infection, will be described, with a particular focus upon biofilm formation. The host immune responses to these infections are also described, including how S. epidermidis seems to trigger low levels of pro-inflammatory cytokines and high levels of interleukin-10, which may contribute to the sub-acute and persistent nature often associated with these infections. The adaptive immune response to S. epidermidis remains poorly described, and represents an area which may provide significant new discoveries in the coming years.
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Affiliation(s)
- Marina Sabaté Brescó
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland.,Molecular Immunology, Swiss Institute of Allergy and Asthma Research, University of ZurichDavos, Switzerland
| | - Llinos G Harris
- Microbiology and Infectious Diseases, Institute of Life Science, Swansea University Medical SchoolSwansea, United Kingdom
| | - Keith Thompson
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland
| | - Barbara Stanic
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland
| | - Mario Morgenstern
- Department of Orthopedic and Trauma Surgery, University Hospital BaselBasel, Switzerland
| | - Liam O'Mahony
- Molecular Immunology, Swiss Institute of Allergy and Asthma Research, University of ZurichDavos, Switzerland
| | - R Geoff Richards
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland
| | - T Fintan Moriarty
- Musculoskeletal Infection, AO Research Institute DavosDavos, Switzerland
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Multimechanistic Monoclonal Antibodies (MAbs) Targeting Staphylococcus aureus Alpha-Toxin and Clumping Factor A: Activity and Efficacy Comparisons of a MAb Combination and an Engineered Bispecific Antibody Approach. Antimicrob Agents Chemother 2017; 61:AAC.00629-17. [PMID: 28584141 PMCID: PMC5527613 DOI: 10.1128/aac.00629-17] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 05/28/2017] [Indexed: 12/23/2022] Open
Abstract
Secreted alpha-toxin and surface-localized clumping factor A (ClfA) are key virulence determinants in Staphylococcus aureus bloodstream infections. We previously demonstrated that prophylaxis with a multimechanistic monoclonal antibody (MAb) combination against alpha-toxin (MEDI4893*) and ClfA (11H10) provided greater strain coverage and improved efficacy in an S. aureus lethal bacteremia model. Subsequently, 11H10 was found to exhibit reduced affinity and impaired inhibition of fibrinogen binding to ClfA002 expressed by members of a predominant hospital-associated methicillin-resistant S. aureus (MRSA) clone, ST5. Consequently, we identified another anti-ClfA MAb (SAR114) from human tonsillar B cells with >100-fold increased affinity for three prominent ClfA variants, including ClfA002, and potent inhibition of bacterial agglutination by 112 diverse clinical isolates. We next constructed bispecific Abs (BiSAbs) comprised of 11H10 or SAR114 as IgG scaffolds and grafted anti-alpha-toxin (MEDI4893*) single-chain variable fragment to the amino or carboxy terminus of the anti-ClfA heavy chains. Although the BiSAbs exhibited in vitro potencies similar to those of the parental MAbs, only 11H10-BiSAb, but not SAR114-BiSAb, showed protective activity in murine infection models comparable to the respective MAb combination. In vivo activity with SAR114-BiSAb was observed in infection models with S. aureus lacking ClfA. Our data suggest that high-affinity binding to ClfA sequesters the SAR114-BiSAb to the bacterial surface, thereby reducing both alpha-toxin neutralization and protection in vivo These results indicate that a MAb combination targeting ClfA and alpha-toxin is more promising for future development than the corresponding BiSAb.
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Pietrocola G, Nobile G, Rindi S, Speziale P. Staphylococcus aureus Manipulates Innate Immunity through Own and Host-Expressed Proteases. Front Cell Infect Microbiol 2017; 7:166. [PMID: 28529927 PMCID: PMC5418230 DOI: 10.3389/fcimb.2017.00166] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 04/18/2017] [Indexed: 01/29/2023] Open
Abstract
Neutrophils, complement system and skin collectively represent the main elements of the innate immune system, the first line of defense of the host against many common microorganisms. Bacterial pathogens have evolved strategies to counteract all these defense activities. Specifically, Staphylococcus aureus, a major human pathogen, secretes a variety of immune evasion molecules including proteases, which cleave components of the innate immune system or disrupt the integrity of extracellular matrix and intercellular connections of tissues. Additionally, S. aureus secretes proteins that can activate host zymogens which, in turn, target specific defense components. Secreted proteins can also inhibit the anti-bacterial function of neutrophils or complement system proteases, potentiating S. aureus chances of survival. Here, we review the current understanding of these proteases and modulators of host proteases in the functioning of innate immunity and describe the importance of these mechanisms in the pathology of staphylococcal diseases.
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Affiliation(s)
- Giampiero Pietrocola
- Unit of Biochemistry, Department of Molecular Medicine, University of PaviaPavia, Italy
| | - Giulia Nobile
- Unit of Biochemistry, Department of Molecular Medicine, University of PaviaPavia, Italy
| | - Simonetta Rindi
- Unit of Biochemistry, Department of Molecular Medicine, University of PaviaPavia, Italy
| | - Pietro Speziale
- Unit of Biochemistry, Department of Molecular Medicine, University of PaviaPavia, Italy
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Bleiziffer I, Eikmeier J, Pohlentz G, McAulay K, Xia G, Hussain M, Peschel A, Foster S, Peters G, Heilmann C. The Plasmin-Sensitive Protein Pls in Methicillin-Resistant Staphylococcus aureus (MRSA) Is a Glycoprotein. PLoS Pathog 2017; 13:e1006110. [PMID: 28081265 PMCID: PMC5230774 DOI: 10.1371/journal.ppat.1006110] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 12/02/2016] [Indexed: 01/16/2023] Open
Abstract
Most bacterial glycoproteins identified to date are virulence factors of pathogenic bacteria, i.e. adhesins and invasins. However, the impact of protein glycosylation on the major human pathogen Staphylococcus aureus remains incompletely understood. To study protein glycosylation in staphylococci, we analyzed lysostaphin lysates of methicillin-resistant Staphylococcus aureus (MRSA) strains by SDS-PAGE and subsequent periodic acid-Schiff’s staining. We detected four (>300, ∼250, ∼165, and ∼120 kDa) and two (>300 and ∼175 kDa) glycosylated surface proteins with strain COL and strain 1061, respectively. The ∼250, ∼165, and ∼175 kDa proteins were identified as plasmin-sensitive protein (Pls) by mass spectrometry. Previously, Pls has been demonstrated to be a virulence factor in a mouse septic arthritis model. The pls gene is encoded by the staphylococcal cassette chromosome (SCC)mec type I in MRSA that also encodes the methicillin resistance-conferring mecA and further genes. In a search for glycosyltransferases, we identified two open reading frames encoded downstream of pls on the SCCmec element, which we termed gtfC and gtfD. Expression and deletion analysis revealed that both gtfC and gtfD mediate glycosylation of Pls. Additionally, the recently reported glycosyltransferases SdgA and SdgB are involved in Pls glycosylation. Glycosylation occurs at serine residues in the Pls SD-repeat region and modifying carbohydrates are N-acetylhexosaminyl residues. Functional characterization revealed that Pls can confer increased biofilm formation, which seems to involve two distinct mechanisms. The first mechanism depends on glycosylation of the SD-repeat region by GtfC/GtfD and probably also involves eDNA, while the second seems to be independent of glycosylation as well as eDNA and may involve the centrally located G5 domains. Other previously known Pls properties are not related to the sugar modifications. In conclusion, Pls is a glycoprotein and Pls glycosyl residues can stimulate biofilm formation. Thus, sugar modifications may represent promising new targets for novel therapeutic or prophylactic measures against life-threatening S. aureus infections. Staphylococcus aureus is a serious pathogen that causes life-threatening infections due to its ability to attach to surfaces, form biofilms, and persist inside the host. One of previously identified virulence factors in S. aureus pathogenesis is the plasmin-sensitive surface protein Pls. We here identified Pls as a posttranslationally modified glycoprotein and characterized the domain within Pls that becomes glycosylated as well as the modifying sugars. Moreover, we found that the glycosyltransferases GtfC and GtfD carry out the glycosylation reactions. In a search for a role for the modifying sugars, we found that Pls can stimulate biofilm formation apparently via two distinct mechanisms, one being dependent on glycosylation by GtfC and GtfD the other being independent of glycosylation as well as eDNA. Moreover, we found that none of the already known Pls functions is mediated by the sugar moieties. Thus, we conclude that GtfC/GtfD-glycosylated Pls may contribute to MRSA pathogenicity via stimulation of biofilm formation and may serve as future target to combat or prevent infections with this serious pathogen.
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Affiliation(s)
- Isabelle Bleiziffer
- Institute of Medical Microbiology, University of Münster, Münster, Germany
- Interdisciplinary Center for Clinical Research (IZKF), University of Münster, Münster, Germany
| | - Julian Eikmeier
- Institute of Medical Microbiology, University of Münster, Münster, Germany
- Interdisciplinary Center for Clinical Research (IZKF), University of Münster, Münster, Germany
| | | | - Kathryn McAulay
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Guoqing Xia
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Muzaffar Hussain
- Institute of Medical Microbiology, University of Münster, Münster, Germany
| | - Andreas Peschel
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, University of Tübingen, Tübingen, Germany
| | - Simon Foster
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Georg Peters
- Institute of Medical Microbiology, University of Münster, Münster, Germany
- Interdisciplinary Center for Clinical Research (IZKF), University of Münster, Münster, Germany
- Cluster of Excellence EXC 1003, Cells in Motion, University of Münster, Münster, Germany
| | - Christine Heilmann
- Institute of Medical Microbiology, University of Münster, Münster, Germany
- Interdisciplinary Center for Clinical Research (IZKF), University of Münster, Münster, Germany
- * E-mail:
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36
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Ganesh VK, Liang X, Geoghegan JA, Cohen ALV, Venugopalan N, Foster TJ, Hook M. Lessons from the Crystal Structure of the S. aureus Surface Protein Clumping Factor A in Complex With Tefibazumab, an Inhibiting Monoclonal Antibody. EBioMedicine 2016; 13:328-338. [PMID: 27789272 PMCID: PMC5264652 DOI: 10.1016/j.ebiom.2016.09.027] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 09/13/2016] [Accepted: 09/29/2016] [Indexed: 01/07/2023] Open
Abstract
The Staphylococcus aureus fibrinogen binding MSCRAMM (Microbial Surface Components Recognizing Adhesive Matrix Molecules), ClfA (clumping factor A) is an important virulence factor in staphylococcal infections and a component of several vaccines currently under clinical evaluation. The mouse monoclonal antibody aurexis (also called 12-9), and the humanized version tefibazumab are therapeutic monoclonal antibodies targeting ClfA that in combination with conventional antibiotics were effective in animal models but showed less impressive efficacy in a limited Phase II clinical trial. We here report the crystal structure and a biochemical characterization of the ClfA/tefibazumab (Fab) complex. The epitope for tefibazumab is located to the "top" of the N3 subdomain of ClfA and partially overlaps with a previously unidentified second binding site for fibrinogen. A high-affinity binding of ClfA to fibrinogen involves both an interaction at the N3 site and the previously identified docking of the C-terminal segment of the fibrinogen γ-chain in the N2N3 trench. Although tefibazumab binds ClfA with high affinity we observe a modest IC50 value for the inhibition of fibrinogen binding to the MSCRAMM. This observation, paired with a common natural occurring variant of ClfA that is not effectively recognized by the mAb, may partly explain the modest effect tefibazumab showed in the initial clinic trail. This information will provide guidance for the design of the next generation of therapeutic anti-staphylococcal mAbs targeting ClfA.
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Affiliation(s)
- Vannakambadi K. Ganesh
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A & M University Health Science Center, 2121 W Holcombe Blvd., Houston, TX 77030, USA,Corresponding authors.
| | - Xiaowen Liang
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A & M University Health Science Center, 2121 W Holcombe Blvd., Houston, TX 77030, USA
| | - Joan A. Geoghegan
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Ana Luisa V. Cohen
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A & M University Health Science Center, 2121 W Holcombe Blvd., Houston, TX 77030, USA
| | - Nagarajan Venugopalan
- GM/CA@APS, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | - Timothy J Foster
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Magnus Hook
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A & M University Health Science Center, 2121 W Holcombe Blvd., Houston, TX 77030, USA,Corresponding authors.
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Abstract
The type I signal peptidase of Staphylococcus aureus, SpsB, is an attractive antibacterial target because it is essential for viability and extracellularly accessible. We synthesized compound 103, a novel arylomycin-derived inhibitor of SpsB with significant potency against various clinical S. aureus strains (MIC of ~1 µg/ml). The predominant clinical strain USA300 developed spontaneous resistance to compound 103 with high frequency, resulting from single point mutations inside or immediately upstream of cro/cI, a homolog of the lambda phage transcriptional repressor cro. These cro/cI mutations led to marked (>50-fold) overexpression of three genes encoding a putative ABC transporter. Overexpression of this ABC transporter was both necessary and sufficient for resistance and, notably, circumvented the essentiality of SpsB during in vitro culture. Mutation of its predicted ATPase gene abolished resistance, suggesting a possible role for active transport; in these bacteria, resistance to compound 103 occurred with low frequency and through mutations in spsB. Bacteria overexpressing the ABC transporter and lacking SpsB were capable of secreting a subset of proteins that are normally cleaved by SpsB and instead were cleaved at a site distinct from the canonical signal peptide. These bacteria secreted reduced levels of virulence-associated proteins and were unable to establish infection in mice. This study reveals the mechanism of resistance to a novel arylomycin derivative and demonstrates that the nominal essentiality of the S. aureus signal peptidase can be circumvented by the upregulation of a putative ABC transporter in vitro but not in vivo. The type I signal peptidase of Staphylococcus aureus (SpsB) enables the secretion of numerous proteins by cleavage of the signal peptide. We synthesized an SpsB inhibitor with potent activity against various clinical S. aureus strains. The predominant S. aureus strain USA300 develops resistance to this inhibitor by mutations in a novel transcriptional repressor (cro/cI), causing overexpression of a putative ABC transporter. This mechanism promotes the cleavage and secretion of various proteins independently of SpsB and compensates for the requirement of SpsB for viability in vitro. However, bacteria overexpressing the ABC transporter and lacking SpsB secrete reduced levels of virulence-associated proteins and are unable to infect mice. This study describes a bacterial resistance mechanism that provides novel insights into the biology of bacterial secretion.
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Crosby HA, Kwiecinski J, Horswill AR. Staphylococcus aureus Aggregation and Coagulation Mechanisms, and Their Function in Host-Pathogen Interactions. ADVANCES IN APPLIED MICROBIOLOGY 2016; 96:1-41. [PMID: 27565579 DOI: 10.1016/bs.aambs.2016.07.018] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human commensal bacterium Staphylococcus aureus can cause a wide range of infections ranging from skin and soft tissue infections to invasive diseases like septicemia, endocarditis, and pneumonia. Muticellular organization almost certainly contributes to S. aureus pathogenesis mechanisms. While there has been considerable focus on biofilm formation and its role in colonizing prosthetic joints and indwelling devices, less attention has been paid to nonsurface-attached group behavior like aggregation and clumping. S. aureus is unique in its ability to coagulate blood, and it also produces multiple fibrinogen-binding proteins that facilitate clumping. Formation of clumps, which are large, tightly packed groups of cells held together by fibrin(ogen), has been demonstrated to be important for S. aureus virulence and immune evasion. Clumps of cells are able to avoid detection by the host's immune system due to a fibrin(ogen) coat that acts as a shield, and the size of the clumps facilitates evasion of phagocytosis. In addition, clumping could be an important early step in establishing infections that involve tight clusters of cells embedded in host matrix proteins, such as soft tissue abscesses and endocarditis. In this review, we discuss clumping mechanisms and regulation, as well as what is known about how clumping contributes to immune evasion.
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Affiliation(s)
- H A Crosby
- University of Iowa, Iowa City, IA, United States
| | - J Kwiecinski
- University of Iowa, Iowa City, IA, United States
| | - A R Horswill
- University of Iowa, Iowa City, IA, United States
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Sugimoto S, Okuda KI, Miyakawa R, Sato M, Arita-Morioka KI, Chiba A, Yamanaka K, Ogura T, Mizunoe Y, Sato C. Imaging of bacterial multicellular behaviour in biofilms in liquid by atmospheric scanning electron microscopy. Sci Rep 2016; 6:25889. [PMID: 27180609 PMCID: PMC4867632 DOI: 10.1038/srep25889] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 04/25/2016] [Indexed: 02/04/2023] Open
Abstract
Biofilms are complex communities of microbes that attach to biotic or abiotic surfaces causing chronic infectious diseases. Within a biofilm, microbes are embedded in a self-produced soft extracellular matrix (ECM), which protects them from the host immune system and antibiotics. The nanoscale visualisation of delicate biofilms in liquid is challenging. Here, we develop atmospheric scanning electron microscopy (ASEM) to visualise Gram-positive and -negative bacterial biofilms immersed in aqueous solution. Biofilms cultured on electron-transparent film were directly imaged from below using the inverted SEM, allowing the formation of the region near the substrate to be studied at high resolution. We visualised intercellular nanostructures and the exocytosis of membrane vesicles, and linked the latter to the trafficking of cargos, including cytoplasmic proteins and the toxins hemolysin and coagulase. A thick dendritic nanotube network was observed between microbes, suggesting multicellular communication in biofilms. A universal immuno-labelling system was developed for biofilms and tested on various examples, including S. aureus biofilms. In the ECM, fine DNA and protein networks were visualised and the precise distribution of protein complexes was determined (e.g., straight curli, flagella, and excreted cytoplasmic molecular chaperones). Our observations provide structural insights into bacteria-substratum interactions, biofilm development and the internal microbe community.
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Affiliation(s)
- Shinya Sugimoto
- Department of Bacteriology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan.,Jikei Center for Biofilm Science and Technology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Ken-Ichi Okuda
- Department of Bacteriology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan.,Jikei Center for Biofilm Science and Technology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Reina Miyakawa
- Department of Bacteriology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Mari Sato
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8566, Japan
| | - Ken-Ichi Arita-Morioka
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Chuo-Ku, Kumamoto, 860-0811, Japan
| | - Akio Chiba
- Department of Bacteriology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Kunitoshi Yamanaka
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Chuo-Ku, Kumamoto, 860-0811, Japan
| | - Teru Ogura
- Department of Molecular Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Chuo-Ku, Kumamoto, 860-0811, Japan
| | - Yoshimitsu Mizunoe
- Department of Bacteriology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan.,Jikei Center for Biofilm Science and Technology, The Jikei University School of Medicine, 3-25-8 Nishi-Shimbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Chikara Sato
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Higashi 1-1-1, Tsukuba, Ibaraki 305-8566, Japan
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40
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Kwakkenbos MJ, van Helden PM, Beaumont T, Spits H. Stable long-term cultures of self-renewing B cells and their applications. Immunol Rev 2016; 270:65-77. [PMID: 26864105 PMCID: PMC4755196 DOI: 10.1111/imr.12395] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Monoclonal antibodies are essential therapeutics and diagnostics in a large number of diseases. Moreover, they are essential tools in all sectors of life sciences. Although the great majority of monoclonal antibodies currently in use are of mouse origin, the use of human B cells to generate monoclonal antibodies is increasing as new techniques to tap the human B cell repertoire are rapidly emerging. Cloned lines of immortalized human B cells are ideal sources of monoclonal antibodies. In this review, we summarize our studies to the regulation of the replicative life span, differentiation, and maturation of B cells that led to the development of a platform that uses immortalization of human B cells by in vitro genetic modification for antibody development. We describe a number of human antibodies that were isolated using this platform and the application of the technique in other species. We also discuss the use of immortalized B cells as antigen-presenting cells for the discovery of tumor neoantigens.
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Affiliation(s)
| | | | - Tim Beaumont
- AIMM TherapeuticsAcademic Medical CenterAmsterdamThe Netherlands
| | - Hergen Spits
- AIMM TherapeuticsAcademic Medical CenterAmsterdamThe Netherlands
- Department of Cell Biology and HistologyAcademic Medical CenterUniversity of AmsterdamAmsterdamThe Netherlands
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41
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Abstract
UNLABELLED Treatment of Staphylococcus aureus infections has become increasingly difficult because of the emergence of multidrug-resistant isolates. Development of a vaccine to prevent staphylococcal infections remains a priority. To determine whether clumping factor A (ClfA) is a good target protein for inclusion in a multivalent vaccine, we evaluated its efficacy in a variety of relevant staphylococcal infection models, challenging with different S. aureus strains. ClfA adsorbed to Alhydrogel and mixed with Sigma Adjuvant System was more immunogenic and stimulated a more robust Th17 response than ClfA administered with alum alone. ClfA immunization induced the production of functional antibodies in rabbits and mice that blocked S. aureus binding to fibrinogen and were opsonic for S. aureus strains that produced little or no capsular polysaccharide. Mice immunized with ClfA showed a modest reduction in the bacterial burden recovered from subcutaneous abscesses provoked by S. aureus USA300 strain LAC. In addition, the ClfA vaccine reduced lethality in a sepsis model following challenge with strain Newman, but not ST80. Vaccination with ClfA did not protect against surgical wound infection, renal abscess formation, or bacteremia. Passive immunization with antibodies to ClfA did not protect against staphylococcal bacteremia in mice or catheter-induced endocarditis in rats. Some enhancement of bacteremia was observed by ClfA immunization or passive administration of ClfA antibodies when mice were challenged by the intraperitoneal route. Although rodent models of staphylococcal infection have their limitations, our data do not support the inclusion of ClfA in an S. aureus multivalent vaccine. IMPORTANCE Antibiotics are often ineffective in eradicating Staphylococcus aureus infections, and thus, a preventative vaccine is sorely needed. Two single-component vaccines and two immunoglobulin preparations failed to meet their designated endpoints in phase III clinical trials. Importantly, recipients of an S. aureus surface protein (iron surface determinant B) vaccine who developed a staphylococcal infection experienced a higher rate of multiorgan failure and mortality than placebo controls, raising safety concerns. Multicomponent S. aureus vaccines have now been generated, and several include surface protein clumping factor A (ClfA). We immunized mice with ClfA and generated a robust T cell response and serum antibodies that were functional in vitro. Nonetheless, ClfA was not protective in a number of relevant animal models of S. aureus infection, and high levels of ClfA antibodies enhanced bacteremia when mice were challenged with community-acquired methicillin-resistant S. aureus strains. Evidence supporting ClfA as a vaccine component is lacking.
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Arora S, Uhlemann AC, Lowy FD, Hook M. A Novel MSCRAMM Subfamily in Coagulase Negative Staphylococcal Species. Front Microbiol 2016; 7:540. [PMID: 27199900 PMCID: PMC4850167 DOI: 10.3389/fmicb.2016.00540] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 04/01/2016] [Indexed: 12/14/2022] Open
Abstract
Coagulase negative staphylococci (CoNS) are important opportunistic pathogens. Staphylococcus epidermidis, a coagulase negative staphylococcus, is the third leading cause of nosocomial infections in the US. Surface proteins like Microbial Surface Components Recognizing Adhesive Matrix Molecules (MSCRAMMs) are major virulence factors of pathogenic gram positive bacteria. Here, we identified a new chimeric protein in S. epidermidis, that we call SesJ. SesJ represents a prototype of a new subfamily of MSCRAMMs. Structural predictions show that SesJ has structural features characteristic of a MSCRAMM along with a N-terminal repeat region and an aspartic acid containing C-terminal repeat region, features that have not been previously observed in staphylococcal MSCRAMMs but have been found in other surface proteins from gram positive bacteria. We identified and analyzed structural homologs of SesJ in three other CoNS. These homologs of SesJ have an identical structural organization but varying sequence identities within the domains. Using flow cytometry, we also show that SesJ is expressed constitutively on the surface of a representative S. epidermidis strain, from early exponential to stationary growth phase. Thus, SesJ is positioned to interact with protein targets in the environment and plays a role in S. epidermidis virulence.
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Affiliation(s)
- Srishtee Arora
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, HoustonTX, USA
| | - Anne-Catrin Uhlemann
- Division of Infectious Diseases, Department of Medicine, College of Physicians and Surgeons, Columbia University in the City of New York, New YorkNY, USA
| | - Franklin D. Lowy
- Division of Infectious Diseases, Department of Medicine, College of Physicians and Surgeons, Columbia University in the City of New York, New YorkNY, USA
| | - Magnus Hook
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, HoustonTX, USA
- *Correspondence: Magnus Hook,
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43
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Zhu F, Wu H. Insights into bacterial protein glycosylation in human microbiota. SCIENCE CHINA. LIFE SCIENCES 2016; 59:11-8. [PMID: 26712033 PMCID: PMC5298937 DOI: 10.1007/s11427-015-4980-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Accepted: 11/05/2015] [Indexed: 01/14/2023]
Abstract
The study of human microbiota is an emerging research topic. The past efforts have mainly centered on studying the composition and genomic landscape of bacterial species within the targeted communities. The interaction between bacteria and hosts is the pivotal event in the initiation and progression of infectious diseases. There is a great need to identify and characterize the molecules that mediate the bacteria-host interaction. Bacterial surface exposed proteins play an important role in the bacteria- host interaction. Numerous surface proteins are glycosylated, and the glycosylation is crucial for their function in mediating the bacterial interaction with hosts. Here we present an overview of surface glycoproteins from bacteria that inhabit three major mucosal environments across human body: oral, gut and skin. We describe the important enzymes involved in the process of protein glycosylation, and discuss how the process impacts the bacteria-host interaction. Emerging molecular details underlying glycosylation of bacterial surface proteins may lead to new opportunities for designing anti-infective small molecules, and developing novel vaccines in order to treat or prevent bacterial infection.
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Affiliation(s)
- Fan Zhu
- Departments of Microbiology and Pediatric Dentistry, Schools of Dentistry and Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Hui Wu
- Departments of Microbiology and Pediatric Dentistry, Schools of Dentistry and Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
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44
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Lehar SM, Pillow T, Xu M, Staben L, Kajihara KK, Vandlen R, DePalatis L, Raab H, Hazenbos WL, Morisaki JH, Kim J, Park S, Darwish M, Lee BC, Hernandez H, Loyet KM, Lupardus P, Fong R, Yan D, Chalouni C, Luis E, Khalfin Y, Plise E, Cheong J, Lyssikatos JP, Strandh M, Koefoed K, Andersen PS, Flygare JA, Wah Tan M, Brown EJ, Mariathasan S. Novel antibody-antibiotic conjugate eliminates intracellular S. aureus. Nature 2015. [PMID: 26536114 DOI: 10.1038/nature16057.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Staphylococcus aureus is considered to be an extracellular pathogen. However, survival of S. aureus within host cells may provide a reservoir relatively protected from antibiotics, thus enabling long-term colonization of the host and explaining clinical failures and relapses after antibiotic therapy. Here we confirm that intracellular reservoirs of S. aureus in mice comprise a virulent subset of bacteria that can establish infection even in the presence of vancomycin, and we introduce a novel therapeutic that effectively kills intracellular S. aureus. This antibody-antibiotic conjugate consists of an anti-S. aureus antibody conjugated to a highly efficacious antibiotic that is activated only after it is released in the proteolytic environment of the phagolysosome. The antibody-antibiotic conjugate is superior to vancomycin for treatment of bacteraemia and provides direct evidence that intracellular S. aureus represents an important component of invasive infections.
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Affiliation(s)
- Sophie M Lehar
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Thomas Pillow
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Min Xu
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Leanna Staben
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Kimberly K Kajihara
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Richard Vandlen
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Laura DePalatis
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Helga Raab
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Wouter L Hazenbos
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - J Hiroshi Morisaki
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Janice Kim
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Summer Park
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Martine Darwish
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Byoung-Chul Lee
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Hilda Hernandez
- Biochemical and Cellular Pharmacology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Kelly M Loyet
- Biochemical and Cellular Pharmacology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Patrick Lupardus
- Structural Biology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Rina Fong
- Structural Biology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Donghong Yan
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Cecile Chalouni
- Pathology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Elizabeth Luis
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Yana Khalfin
- Biochemical and Cellular Pharmacology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Emile Plise
- Drug metabolism and Pharmacokinetics Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Jonathan Cheong
- Drug metabolism and Pharmacokinetics Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Joseph P Lyssikatos
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Magnus Strandh
- Symphogen A/S, Pederstrupvej 93, DK-2750 Ballerup, Denmark
| | - Klaus Koefoed
- Symphogen A/S, Pederstrupvej 93, DK-2750 Ballerup, Denmark
| | | | - John A Flygare
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Man Wah Tan
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Eric J Brown
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Sanjeev Mariathasan
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
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45
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De Gregorio E, Del Franco M, Martinucci M, Roscetto E, Zarrilli R, Di Nocera PP. Biofilm-associated proteins: news from Acinetobacter. BMC Genomics 2015; 16:933. [PMID: 26572057 PMCID: PMC4647330 DOI: 10.1186/s12864-015-2136-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 10/23/2015] [Indexed: 11/10/2022] Open
Abstract
Background A giant protein called BAP (biofilm-associated protein) plays a role in biofilm formation and adhesion to host cells in A. baumannii. Most of the protein is made by arrays of 80–110 aa modules featuring immunoglobulin-like (Ig-like) motifs. Results The survey of 541 A. baumannii sequenced strains belonging to 108 STs (sequence types) revealed that BAP is highly polymorphic, distinguishable in three main types for changes both in the repetitive and the COOH region. Analyzing the different STs, we found that 29 % feature type-1, 40 % type-2 BAP, 11 % type-3 BAP, 20 % lack BAP. The type-3 variant is restricted to A. baumannii, type-1 and type-2 BAP have been identified also in other species of the Acinetobacter calcoaceticus-baumannii (ACB) complex. A. calcoaceticus and A. pittii also encode BAP-like proteins in which Ig-like repeats are replaced by long tracts of alternating serine and aspartic acid residues. We have identified in species of the ACB complex two additional proteins, BLP1 and BLP2 (BAP-like proteins 1 and 2) which feature Ig-like repeats, share with BAP a sequence motif at the NH2 terminus, and are similarly expressed in stationary growth phase. The knock-out of either BLP1 or BLP2 genes of the A. baumannii ST1 AYE strain severely affected biofilm formation, as measured by comparing biofilm biomass and thickness, and adherence to epithelial cells. BLP1 is missing in the majority of type-3 BAP strains. BLP2 is largely conserved, but is frequently missing in BAP-negative cells. Conclusions Multiple proteins sharing Ig-like repeats seem to be involved in biofilm formation. The uneven distribution of the different BAP types, BLP1, and BLP2 is highly indicative that alternative protein complexes involved in biofilm formation are assembled in different A. baumannii strains. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2136-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Eliana De Gregorio
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università Federico II, Via Sergio Pansini 5, Naples, 80131, Italy.
| | - Mariateresa Del Franco
- Dipartimento di Sanità Pubblica, Università Federico II, Via Sergio Pansini 5, 80131, Naples, Italy.
| | - Marianna Martinucci
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università Federico II, Via Sergio Pansini 5, Naples, 80131, Italy.
| | - Emanuela Roscetto
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università Federico II, Via Sergio Pansini 5, Naples, 80131, Italy.
| | - Raffaele Zarrilli
- Dipartimento di Sanità Pubblica, Università Federico II, Via Sergio Pansini 5, 80131, Naples, Italy.
| | - Pier Paolo Di Nocera
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università Federico II, Via Sergio Pansini 5, Naples, 80131, Italy.
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46
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Lehar SM, Pillow T, Xu M, Staben L, Kajihara KK, Vandlen R, DePalatis L, Raab H, Hazenbos WL, Morisaki JH, Kim J, Park S, Darwish M, Lee BC, Hernandez H, Loyet KM, Lupardus P, Fong R, Yan D, Chalouni C, Luis E, Khalfin Y, Plise E, Cheong J, Lyssikatos JP, Strandh M, Koefoed K, Andersen PS, Flygare JA, Wah Tan M, Brown EJ, Mariathasan S. Novel antibody-antibiotic conjugate eliminates intracellular S. aureus. Nature 2015; 527:323-8. [PMID: 26536114 DOI: 10.1038/nature16057] [Citation(s) in RCA: 542] [Impact Index Per Article: 60.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 10/06/2015] [Indexed: 11/09/2022]
Abstract
Staphylococcus aureus is considered to be an extracellular pathogen. However, survival of S. aureus within host cells may provide a reservoir relatively protected from antibiotics, thus enabling long-term colonization of the host and explaining clinical failures and relapses after antibiotic therapy. Here we confirm that intracellular reservoirs of S. aureus in mice comprise a virulent subset of bacteria that can establish infection even in the presence of vancomycin, and we introduce a novel therapeutic that effectively kills intracellular S. aureus. This antibody-antibiotic conjugate consists of an anti-S. aureus antibody conjugated to a highly efficacious antibiotic that is activated only after it is released in the proteolytic environment of the phagolysosome. The antibody-antibiotic conjugate is superior to vancomycin for treatment of bacteraemia and provides direct evidence that intracellular S. aureus represents an important component of invasive infections.
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Affiliation(s)
- Sophie M Lehar
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Thomas Pillow
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Min Xu
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Leanna Staben
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Kimberly K Kajihara
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Richard Vandlen
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Laura DePalatis
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Helga Raab
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Wouter L Hazenbos
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - J Hiroshi Morisaki
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Janice Kim
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Summer Park
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Martine Darwish
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Byoung-Chul Lee
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Hilda Hernandez
- Biochemical and Cellular Pharmacology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Kelly M Loyet
- Biochemical and Cellular Pharmacology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Patrick Lupardus
- Structural Biology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Rina Fong
- Structural Biology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Donghong Yan
- Translational Immunology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Cecile Chalouni
- Pathology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Elizabeth Luis
- Protein Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Yana Khalfin
- Biochemical and Cellular Pharmacology Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Emile Plise
- Drug metabolism and Pharmacokinetics Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Jonathan Cheong
- Drug metabolism and Pharmacokinetics Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Joseph P Lyssikatos
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Magnus Strandh
- Symphogen A/S, Pederstrupvej 93, DK-2750 Ballerup, Denmark
| | - Klaus Koefoed
- Symphogen A/S, Pederstrupvej 93, DK-2750 Ballerup, Denmark
| | | | - John A Flygare
- Medicinal Chemistry Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Man Wah Tan
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Eric J Brown
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
| | - Sanjeev Mariathasan
- Infectious Diseases Department, Genentech Inc., South San Francisco, California 94080, USA
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47
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Antibacterial monoclonal antibodies: the next generation? Curr Opin Microbiol 2015; 27:78-85. [PMID: 26302478 DOI: 10.1016/j.mib.2015.07.014] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 07/28/2015] [Accepted: 07/30/2015] [Indexed: 12/21/2022]
Abstract
There is a clear need for renewed efforts to combat the increasing incidence of antibiotic resistance. While the antibiotic resistance epidemic is due in part to the misuse of antibiotics, even proper empiric antibiotic therapy increases the selective pressure and potential for drug-resistance and spread of resistance mechanisms between bacteria. Antibiotic resistance coupled with the detrimental effects of broad-spectrum antibiotics on the healthy microbiome, have led the field to explore pathogen specific antibacterials such as monoclonal antibodies (mAbs). Medical need along with advances in mAb discovery, engineering, and production have driven significant effort developing mAb-based antibacterials. If successful, they will provide physicians with precision weapons to combat bacterial infections and can help prevent a return to a pre-antibiotic era.
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48
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Lannergård J, Kristensen BM, Gustafsson MCU, Persson JJ, Norrby-Teglund A, Stålhammar-Carlemalm M, Lindahl G. Sequence variability is correlated with weak immunogenicity in Streptococcus pyogenes M protein. Microbiologyopen 2015; 4:774-89. [PMID: 26175306 PMCID: PMC4618610 DOI: 10.1002/mbo3.278] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 06/18/2015] [Indexed: 11/06/2022] Open
Abstract
The M protein of Streptococcus pyogenes, a major bacterial virulence factor, has an amino-terminal hypervariable region (HVR) that is a target for type-specific protective antibodies. Intriguingly, the HVR elicits a weak antibody response, indicating that it escapes host immunity by two mechanisms, sequence variability and weak immunogenicity. However, the properties influencing the immunogenicity of regions in an M protein remain poorly understood. Here, we studied the antibody response to different regions of the classical M1 and M5 proteins, in which not only the HVR but also the adjacent fibrinogen-binding B repeat region exhibits extensive sequence divergence. Analysis of antisera from S. pyogenes-infected patients, infected mice, and immunized mice showed that both the HVR and the B repeat region elicited weak antibody responses, while the conserved carboxy-terminal part was immunodominant. Thus, we identified a correlation between sequence variability and weak immunogenicity for M protein regions. A potential explanation for the weak immunogenicity was provided by the demonstration that protease digestion selectively eliminated the HVR-B part from whole M protein-expressing bacteria. These data support a coherent model, in which the entire variable HVR-B part evades antibody attack, not only by sequence variability but also by weak immunogenicity resulting from protease attack.
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Affiliation(s)
- Jonas Lannergård
- Department of Laboratory Medicine, Lund University, Lund, Sweden.,Department of Veterinary Disease Biology, University of Copenhagen, Frederiksberg C, Denmark
| | | | | | - Jenny J Persson
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Anna Norrby-Teglund
- Center for Infectious Medicine, Karolinska Institutet, Huddinge University Hospital, Stockholm, Sweden
| | | | - Gunnar Lindahl
- Department of Laboratory Medicine, Lund University, Lund, Sweden.,Department of Veterinary Disease Biology, University of Copenhagen, Frederiksberg C, Denmark
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49
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Li H, Chen Q, Zhao J, Urmila K. Enhancing the antimicrobial activity of natural extraction using the synthetic ultrasmall metal nanoparticles. Sci Rep 2015; 5:11033. [PMID: 26046938 PMCID: PMC4457014 DOI: 10.1038/srep11033] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 05/13/2015] [Indexed: 12/18/2022] Open
Abstract
The use of Catechin as an antibacterial agent is becoming ever-more common, whereas unstable and easy oxidation, have limited its application. A simple and low-energy-consuming approach to synthesize highly stable and dispersive Catechin-Cu nanoparticles(NPs) has been developed, in which the stability and dispersivity of the NPs are varied greatly with the pH value and temperature of the reaction. The results demonstrate that the optimal reaction conditions are pH 11 at room temperature. As-synthesized NPs display excellent antimicrobial activity, the survival rates of bacterial cells exposed to the NPs were evaluated using live/dead Bacterial Viability Kit. The results showed that NPs at the concentration of 10 ppm and 20 ppm provided rapid and effective killing of up to 90% and 85% of S. aureus and E. coli within 3 h, respectively. After treatment with 20 ppm and 40 ppm NPs, the bacteria are killed completely. Furthermore, on the basis of assessing the antibacterial effects by SEM, TEM, and AFM, it was found the cell membrane damage of the bacteria caused by direct contact of the bacteria with the NPs was the effective mechanism in the bacterial inactivation.
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Affiliation(s)
- Huanhuan Li
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
| | - Quansheng Chen
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
| | - Jiewen Zhao
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
| | - Khulal Urmila
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China
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50
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Cell Wall-Anchored Surface Proteins of Staphylococcus aureus: Many Proteins, Multiple Functions. Curr Top Microbiol Immunol 2015; 409:95-120. [PMID: 26667044 DOI: 10.1007/82_2015_5002] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Staphylococcus aureus persistently colonizes about 20 % of the population and is intermittently associated with the remainder. The organism can cause superficial skin infections and life-threatening invasive diseases. The surface of the bacterial cell displays a variety of proteins that are covalently anchored to peptidoglycan. They perform many functions including adhesion to host cells and tissues, invasion of non-phagocytic cells, and evasion of innate immune responses. The proteins have been categorized into distinct classes based on structural and functional analysis. Many surface proteins are multifunctional. Cell wall-anchored proteins perform essential functions supporting survival and proliferation during the commensal state and during invasive infections. The ability of cell wall-anchored proteins to bind to desquamated epithelial cells is important during colonization, and the binding to fibrinogen is of particular significance in pathogenesis.
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