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Saha S, Barik D, Biswas D. AMPs as Host-Directed Immunomodulatory Agents against Skin Infections Caused by Opportunistic Bacterial Pathogens. Antibiotics (Basel) 2024; 13:439. [PMID: 38786167 PMCID: PMC11117387 DOI: 10.3390/antibiotics13050439] [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: 12/01/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 05/25/2024] Open
Abstract
Skin is the primary and largest protective organ of the human body. It produces a number of highly evolved arsenal of factors to counter the continuous assault of foreign materials and pathogens from the environment. One such potent factor is the repertoire of Antimicrobial Peptides (AMPs) that not only directly destroys invading pathogens, but also optimally modulate the immune functions of the body to counter the establishment and spread of infections. The canonical direct antimicrobial functions of these AMPs have been in focus for a long time to design principles for enhanced therapeutics, especially against the multi-drug resistant pathogens. However, in recent times the immunomodulatory functions performed by these peptides at sub-microbicidal concentrations have been a point of major focus in the field of host-directed therapeutics. Such strategies have the added benefit of not having the pathogens develop resistance against the immunomodulatory pathways, since the pathogens exploit these signaling pathways to obtain and survive within the host. Thus, this review summarizes the potent immunomodulatory effect of these AMPs on, specifically, the different host immune cells with the view of providing a platform of information that might help in designing studies to exploit and formulate effective host-directed adjunct therapeutic strategies that would synergies with drug regimens to counter the current diversity of drug-resistant skin opportunistic pathogens.
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Affiliation(s)
| | | | - Debabrata Biswas
- Institute of Life Sciences, NALCO Square, Bhubaneswar 751023, Odisha, India; (S.S.); (D.B.)
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2
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Bruserud Ø, Mosevoll KA, Bruserud Ø, Reikvam H, Wendelbo Ø. The Regulation of Neutrophil Migration in Patients with Sepsis: The Complexity of the Molecular Mechanisms and Their Modulation in Sepsis and the Heterogeneity of Sepsis Patients. Cells 2023; 12:cells12071003. [PMID: 37048076 PMCID: PMC10093057 DOI: 10.3390/cells12071003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/21/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023] Open
Abstract
Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Common causes include gram-negative and gram-positive bacteria as well as fungi. Neutrophils are among the first cells to arrive at an infection site where they function as important effector cells of the innate immune system and as regulators of the host immune response. The regulation of neutrophil migration is therefore important both for the infection-directed host response and for the development of organ dysfunctions in sepsis. Downregulation of CXCR4/CXCL12 stimulates neutrophil migration from the bone marrow. This is followed by transmigration/extravasation across the endothelial cell barrier at the infection site; this process is directed by adhesion molecules and various chemotactic gradients created by chemotactic cytokines, lipid mediators, bacterial peptides, and peptides from damaged cells. These mechanisms of neutrophil migration are modulated by sepsis, leading to reduced neutrophil migration and even reversed migration that contributes to distant organ failure. The sepsis-induced modulation seems to differ between neutrophil subsets. Furthermore, sepsis patients should be regarded as heterogeneous because neutrophil migration will possibly be further modulated by the infecting microorganisms, antimicrobial treatment, patient age/frailty/sex, other diseases (e.g., hematological malignancies and stem cell transplantation), and the metabolic status. The present review describes molecular mechanisms involved in the regulation of neutrophil migration; how these mechanisms are altered during sepsis; and how bacteria/fungi, antimicrobial treatment, and aging/frailty/comorbidity influence the regulation of neutrophil migration.
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Affiliation(s)
- Øystein Bruserud
- Leukemia Research Group, Department of Clinical Science, University of Bergen, 5021 Bergen, Norway
- Section for Hematology, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
- Correspondence:
| | - Knut Anders Mosevoll
- Section for Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
- Section for Infectious Diseases, Department of Clinical Research, University of Bergen, 5021 Bergen, Norway
| | - Øyvind Bruserud
- Department for Anesthesiology and Intensive Care, Haukeland University Hospital, 5021 Bergen, Norway
| | - Håkon Reikvam
- Leukemia Research Group, Department of Clinical Science, University of Bergen, 5021 Bergen, Norway
- Section for Hematology, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
| | - Øystein Wendelbo
- Section for Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
- Faculty of Health, VID Specialized University, Ulriksdal 10, 5009 Bergen, Norway
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3
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Alptekin A, Parvin M, Chowdhury HI, Rashid MH, Arbab AS. Engineered exosomes for studies in tumor immunology. Immunol Rev 2022; 312:76-102. [PMID: 35808839 DOI: 10.1111/imr.13107] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 05/27/2022] [Indexed: 12/14/2022]
Abstract
Exosomes are a type of extracellular vesicle (EV) with diameters of 30-150 nm secreted by most of the cells into the extracellular spaces and can alter the microenvironment through cell-to-cell interactions by fusion with the plasma membrane and subsequent endocytosis and release of the cargo. Because of their biocompatibility, low toxicity and immunogenicity, permeability (even through the blood-brain barrier (BBB)), stability in biological fluids, and ability to accumulate in the lesions with higher specificity, investigators have started making designer's exosomes or engineered exosomes to carry biologically active protein on the surface or inside the exosomes as well as using exosomes to carry drugs, micro RNA, and other products to the site of interest. In this review, we have discussed biogenesis, markers, and contents of various exosomes including exosomes of immune cells. We have also discussed the current methods of making engineered and designer's exosomes as well as the use of engineered exosomes targeting different immune cells in the tumors, stroke, as well as at peripheral blood. Genetic engineering and customizing exosomes create an unlimited opportunity to use in diagnosis and treatment. Very little use has been discovered, and we are far away to reach its limits.
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Affiliation(s)
- Ahmet Alptekin
- Georgia Cancer Center, Augusta University, Augusta, Georgia, USA
| | - Mahrima Parvin
- Georgia Cancer Center, Augusta University, Augusta, Georgia, USA
| | | | | | - Ali S Arbab
- Georgia Cancer Center, Augusta University, Augusta, Georgia, USA
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4
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Cieślik M, Bagińska N, Jończyk-Matysiak E, Węgrzyn A, Węgrzyn G, Górski A. Temperate Bacteriophages-The Powerful Indirect Modulators of Eukaryotic Cells and Immune Functions. Viruses 2021; 13:v13061013. [PMID: 34071422 PMCID: PMC8228536 DOI: 10.3390/v13061013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/22/2021] [Accepted: 05/27/2021] [Indexed: 12/11/2022] Open
Abstract
Bacteriophages are natural biological entities that limit the growth and amplification of bacteria. They are important stimulators of evolutionary variability in bacteria, and currently are considered a weapon against antibiotic resistance of bacteria. Nevertheless, apart from their antibacterial activity, phages may act as modulators of mammalian immune responses. In this paper, we focus on temperate phages able to execute the lysogenic development, which may shape animal or human immune response by influencing various processes, including phagocytosis of bacterial invaders and immune modulation of mammalian host cells.
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Affiliation(s)
- Martyna Cieślik
- Bacteriophage Laboratory, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland; (M.C.); (N.B.); (E.J.-M.)
| | - Natalia Bagińska
- Bacteriophage Laboratory, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland; (M.C.); (N.B.); (E.J.-M.)
| | - Ewa Jończyk-Matysiak
- Bacteriophage Laboratory, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland; (M.C.); (N.B.); (E.J.-M.)
| | - Alicja Węgrzyn
- Laboratory of Phage Therapy, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Kładki 24, 80-822 Gdańsk, Poland;
| | - Grzegorz Węgrzyn
- Department of Molecular Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland;
| | - Andrzej Górski
- Bacteriophage Laboratory, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland; (M.C.); (N.B.); (E.J.-M.)
- Phage Therapy Unit, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114 Wrocław, Poland
- Infant Jesus Hospital, The Medical University of Warsaw, 02-006 Warsaw, Poland
- Correspondence:
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5
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Wilden JJ, Jacob JC, Ehrhardt C, Ludwig S, Boergeling Y. Altered Signal Transduction in the Immune Response to Influenza Virus and S. pneumoniae or S. aureus Co-Infections. Int J Mol Sci 2021; 22:5486. [PMID: 34067487 PMCID: PMC8196994 DOI: 10.3390/ijms22115486] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/14/2021] [Accepted: 05/19/2021] [Indexed: 12/23/2022] Open
Abstract
Influenza virus is a well-known respiratory pathogen, which still leads to many severe pulmonary infections in the human population every year. Morbidity and mortality rates are further increased if virus infection coincides with co-infections or superinfections caused by bacteria such as Streptococcus pneumoniae (S. pneumoniae) and Staphylococcus aureus (S. aureus). This enhanced pathogenicity is due to complex interactions between the different pathogens and the host and its immune system and is mainly governed by altered intracellular signaling processes. In this review, we summarize the recent findings regarding the innate and adaptive immune responses during co-infection with influenza virus and S. pneumoniae or S. aureus, describing the signaling pathways involved and how these interactions influence disease outcomes.
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Affiliation(s)
- Janine J. Wilden
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, 48149 Muenster, Germany; (J.J.W.); (J.C.J.); (S.L.)
| | - Jasmin C. Jacob
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, 48149 Muenster, Germany; (J.J.W.); (J.C.J.); (S.L.)
- CiM-IMPRS, The Joined Graduate School of the Cells in Motion Interfaculty Centre, University of Muenster and the International Max Planck Research School—Molecular Biomedicine, 48149 Muenster, Germany
| | - Christina Ehrhardt
- Section of Experimental Virology, Center for Molecular Biomedicine (CMB), Institute of Medical Microbiology, Jena University Hospital, 07745 Jena, Germany;
| | - Stephan Ludwig
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, 48149 Muenster, Germany; (J.J.W.); (J.C.J.); (S.L.)
- “Cells in Motion Interfaculty Center (CIMIC)”, WWU Muenster, 48149 Muenster, Germany
| | - Yvonne Boergeling
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, 48149 Muenster, Germany; (J.J.W.); (J.C.J.); (S.L.)
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6
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Monoclonal Antibodies Targeting Surface-Exposed and Secreted Proteins from Staphylococci. Vaccines (Basel) 2021; 9:vaccines9050459. [PMID: 34064471 PMCID: PMC8147999 DOI: 10.3390/vaccines9050459] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/14/2021] [Accepted: 04/30/2021] [Indexed: 02/01/2023] Open
Abstract
Staphylococci (specifically Staphylococcus aureus and Staphylococcus epidermidis) are the causative agents of diseases ranging from superficial skin and soft tissue infections to severe conditions such as fatal pneumonia, bacteremia, sepsis and endocarditis. The widespread and indiscriminate use of antibiotics has led to serious problems of resistance to staphylococcal disease and has generated a renewed interest in alternative therapeutic agents such as vaccines and antibodies. Staphylococci express a large repertoire of surface and secreted virulence factors, which provide mechanisms (adhesion, invasion and biofilm development among others) for both bacterial survival in the host and evasion from innate and adaptive immunity. Consequently, the development of antibodies that target specific antigens would provide an effective protective strategy against staphylococcal infections. In this review, we report an update on efforts to develop anti-staphylococci monoclonal antibodies (and their derivatives: minibodies, antibody–antibiotic conjugates) and the mechanism by which such antibodies can help fight infections. We also provide an overview of mAbs used in clinical trials and highlight their therapeutic potential in various infectious contexts.
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7
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Maity S, Ambatipudi K. Mammary microbial dysbiosis leads to the zoonosis of bovine mastitis: a One-Health perspective. FEMS Microbiol Ecol 2021; 97:6006870. [PMID: 33242081 DOI: 10.1093/femsec/fiaa241] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 11/24/2020] [Indexed: 12/21/2022] Open
Abstract
Bovine mastitis is a prototypic emerging and reemerging bacterial disease that results in cut-by-cut torture to animals, public health and the global economy. Pathogenic microbes causing mastitis have overcome a series of hierarchical barriers resulting in the zoonotic transmission from bovines to humans either by proximity or remotely through milk and meat. The disease control is challenging and has been attributed to faulty surveillance systems to monitor their emergence at the human-animal interface. The complex interaction between the pathogens, the hidden pathobionts and commensals of the bovine mammary gland that create a menace during mastitis remains unexplored. Here, we review the zoonotic potential of these pathogens with a primary focus on understanding the interplay between the host immunity, mammary ecology and the shift from symbiosis to dysbiosis. We also address the pros and cons of the current management strategies and the extent of the success in implementing the One-Health approach to keep these pathogens at bay.
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Affiliation(s)
- Sudipa Maity
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, , India
| | - Kiran Ambatipudi
- Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, , India
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8
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Buchan KD, van Gent M, Prajsnar TK, Ogryzko NV, de Jong NWM, Kolata J, Foster SJ, van Strijp JAG, Renshaw SA. Human-specific staphylococcal virulence factors enhance pathogenicity in a humanised zebrafish C5a receptor model. J Cell Sci 2021; 134:jcs.252205. [PMID: 33589501 DOI: 10.1242/jcs.252205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 01/12/2021] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus infects ∼30% of the human population and causes a spectrum of pathologies ranging from mild skin infections to life-threatening invasive diseases. The strict host specificity of its virulence factors has severely limited the accuracy of in vivo models for the development of vaccines and therapeutics. To resolve this, we generated a humanised zebrafish model and determined that neutrophil-specific expression of the human C5a receptor conferred susceptibility to the S. aureus toxins PVL and HlgCB, leading to reduced neutrophil numbers at the site of infection and increased infection-associated mortality. These results show that humanised zebrafish provide a valuable platform to study the contribution of human-specific S. aureus virulence factors to infection in vivo that could facilitate the development of novel therapeutic approaches and essential vaccines.
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Affiliation(s)
- Kyle D Buchan
- The Bateson Centre and Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.,The Florey Institute for Host-Pathogen Interactions, Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Michiel van Gent
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Tomasz K Prajsnar
- The Bateson Centre and Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Nikolay V Ogryzko
- The Bateson Centre and Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Nienke W M de Jong
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Julia Kolata
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Simon J Foster
- The Florey Institute for Host-Pathogen Interactions, Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Jos A G van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Stephen A Renshaw
- The Bateson Centre and Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
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9
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Tromp AT, Zhao Y, Jongerius I, Heezius ECJM, Abrial P, Ruyken M, van Strijp JAG, de Haas CJC, Spaan AN, van Kessel KPM, Henry T, Haas PJA. Pre-existing antibody-mediated adverse effects prevent the clinical development of a bacterial anti-inflammatory protein. Dis Model Mech 2020; 13:dmm045534. [PMID: 32471891 PMCID: PMC7541340 DOI: 10.1242/dmm.045534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 05/04/2020] [Indexed: 12/24/2022] Open
Abstract
Bacterial pathogens have evolved to secrete strong anti-inflammatory proteins that target the immune system. It was long speculated whether these virulence factors could serve as therapeutics in diseases in which abnormal immune activation plays a role. We adopted the secreted chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS) as a model virulence factor-based therapeutic agent for diseases in which C5AR1 stimulation plays an important role. We show that the administration of CHIPS in human C5AR1 knock-in mice successfully dampens C5a-mediated neutrophil migration during immune complex-initiated inflammation. Subsequent CHIPS toxicology studies in animal models were promising. However, during a small phase I trial, healthy human volunteers showed adverse effects directly after CHIPS administration. Subjects showed clinical signs of anaphylaxis with mild leukocytopenia and increased C-reactive protein concentrations, which are possibly related to the presence of relatively high circulating anti-CHIPS antibodies and suggest an inflammatory response. Even though our data in mice show CHIPS as a potential anti-inflammatory agent, safety issues in human subjects temper the use of CHIPS in its current form as a therapeutic candidate. The use of staphylococcal proteins, or other bacterial proteins, as therapeutics or immune-modulators in humans is severely hampered by pre-existing circulating antibodies.
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Affiliation(s)
- Angelino T Tromp
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Yuxi Zhao
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Ilse Jongerius
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
- Sanquin Research, Department of Immunopathology, 1006AD Amsterdam, The Netherlands
- Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, 1105AZ Amsterdam, The Netherlands
| | - Erik C J M Heezius
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Pauline Abrial
- Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, Ecole Normale Supérieure de Lyon, Université Lyon, 69007 Lyon, France
| | - Maartje Ruyken
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Jos A G van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Carla J C de Haas
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - András N Spaan
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY 10065, USA
| | - Kok P M van Kessel
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Thomas Henry
- Sanquin Research, Department of Immunopathology, 1006AD Amsterdam, The Netherlands
| | - Pieter-Jan A Haas
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
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10
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Shalapour S, Karin M. Cruel to Be Kind: Epithelial, Microbial, and Immune Cell Interactions in Gastrointestinal Cancers. Annu Rev Immunol 2020; 38:649-671. [PMID: 32040356 DOI: 10.1146/annurev-immunol-082019-081656] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A plethora of experimental and epidemiological evidence supports a critical role for inflammation and adaptive immunity in the onset of cancer and in shaping its response to therapy. These data are particularly robust for gastrointestinal (GI) cancers, such as those affecting the GI tract, liver, and pancreas, on which this review is focused. We propose a unifying hypothesis according to which intestinal barrier disruption is the origin of tumor-promoting inflammation that acts in conjunction with tissue-specific cancer-initiating mutations. The gut microbiota and its products impact tissue-resident and recruited myeloid cells that promote tumorigenesis through secretion of growth- and survival-promoting cytokines that act on epithelial cells, as well as fibrogenic and immunosuppressive cytokines that interfere with the proper function of adaptive antitumor immunity. Understanding these relationships should improve our ability to prevent cancer development and stimulate the immune system to eliminate existing malignancies.
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Affiliation(s)
- Shabnam Shalapour
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA; , .,Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA
| | - Michael Karin
- Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA; , .,Department of Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093, USA.,Moores Cancer Center, University of California, San Diego, La Jolla, California 92093, USA
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11
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Abstract
Staphylococcus aureus has become a serious threat to human health. In addition to having increased antibiotic resistance, the bacterium is a master at adapting to its host by evading almost every facet of the immune system, the so-called immune evasion proteins. Many of these immune evasion proteins target neutrophils, the most important immune cells in clearing S. aureus infections. The neutrophil attacks pathogens via a plethora of strategies. Therefore, it is no surprise that S. aureus has evolved numerous immune evasion strategies at almost every level imaginable. In this review we discuss step by step the aspects of neutrophil-mediated killing of S. aureus, such as neutrophil activation, migration to the site of infection, bacterial opsonization, phagocytosis, and subsequent neutrophil-mediated killing. After each section we discuss how S. aureus evasion molecules are able to resist the neutrophil attack of these different steps. To date, around 40 immune evasion molecules of S. aureus are known, but its repertoire is still expanding due to the discovery of new evasion proteins and the addition of new functions to already identified evasion proteins. Interestingly, because the different parts of neutrophil attack are redundant, the evasion molecules display redundant functions as well. Knowing how and with which proteins S. aureus is evading the immune system is important in understanding the pathophysiology of this pathogen. This knowledge is crucial for the development of therapeutic approaches that aim to clear staphylococcal infections.
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12
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Chen C, Yang C, Barbieri JT. Staphylococcal Superantigen-like protein 11 mediates neutrophil adhesion and motility arrest, a unique bacterial toxin action. Sci Rep 2019; 9:4211. [PMID: 30862940 PMCID: PMC6414612 DOI: 10.1038/s41598-019-40817-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 02/05/2019] [Indexed: 11/09/2022] Open
Abstract
Methicillin resistant Staphylococcus aureus (MRSA) is a major human pathogen, which causes superficial to lethal clinical infections. Neutrophils are the most abundant leukocytes in the blood and are the first defense mechanism against S. aureus infections. Here we show Staphylococcal Superantigen-Like protein 11 (SSL11) from MRSA USA300_FPR3757 mediated differentiated human neutrophil-like cells (dHL60) motility arrest by inducing cell adhesion and “locking” cells in adhesion stage, without inducing oxidative burst. Pre-incubation of SSL11 with the glycan Sialyl Lewis X blocked SSL11 function and de-glycosylation of dHL60 cells by PNGase F abolished SSL11 binding, suggesting that SSL11 functions via interacting with glycans. This is the first description of a bacterial toxin inhibiting neutrophil motility by inducing adhesion and “locking” cells in an adhesion stage. Therefore, this study might provide a new target against S. aureus infections.
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Affiliation(s)
- Chen Chen
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
| | - Chen Yang
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Joseph T Barbieri
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
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13
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Buchan KD, Foster SJ, Renshaw SA. Staphylococcus aureus: setting its sights on the human innate immune system. MICROBIOLOGY-SGM 2019; 165:367-385. [PMID: 30625113 DOI: 10.1099/mic.0.000759] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Staphylococcus aureus has colonized humans for at least 10 000 years, and today inhabits roughly a third of the population. In addition, S. aureus is a major pathogen that is responsible for a significant disease burden, ranging in severity from mild skin and soft-tissue infections to life-threatening endocarditis and necrotizing pneumonia, with treatment often hampered by resistance to commonly available antibiotics. Underpinning its versatility as a pathogen is its ability to evade the innate immune system. S. aureus specifically targets innate immunity to establish and sustain infection, utilizing a large repertoire of virulence factors to do so. Using these factors, S. aureus can resist phagosomal killing, impair complement activity, disrupt cytokine signalling and target phagocytes directly using proteolytic enzymes and cytolytic toxins. Although most of these virulence factors are well characterized, their importance during infection is less clear, as many display species-specific activity against humans or against animal hosts, including cows, horses and chickens. Several staphylococcal virulence factors display species specificity for components of the human innate immune system, with as few as two amino acid changes reducing binding affinity by as much as 100-fold. This represents a major issue for studying their roles during infection, which cannot be examined without the use of humanized infection models. This review summarizes the major factors S. aureus uses to impair the innate immune system, and provides an in-depth look into the host specificity of S. aureus and how this problem is being approached.
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Affiliation(s)
- Kyle D Buchan
- 1The Bateson Centre and Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Simon J Foster
- 2Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Stephen A Renshaw
- 1The Bateson Centre and Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
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14
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Targeting formyl peptide receptors to facilitate the resolution of inflammation. Eur J Pharmacol 2018; 833:339-348. [PMID: 29935171 DOI: 10.1016/j.ejphar.2018.06.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 06/08/2018] [Accepted: 06/19/2018] [Indexed: 12/12/2022]
Abstract
The formyl peptide receptors (FPRs) are G protein coupled receptors that recognize a broad range of structurally distinct pathogen and danger-associated molecular patterns and mediate host defense to infection and tissue injury. It became evident that the cellular distribution and biological functions of FPRs extend beyond myeloid cells and governing their activation and trafficking. In recent years, significant progress has been made to position FPRs at check points that control the resolution of inflammation, tissue repair and return to homeostasis. Accumulating data indicate a role for FPRs in an ever-increasing range of human diseases, including atherosclerosis, chronic obstructive pulmonary disease, asthma, autoimmune diseases and cancer, in which dysregulated or defective resolution are increasingly recognized as critical component of the pathogenesis. This review summarizes recent advances on how FPRs recognize distinct ligands and integrate opposing cues to govern various responses and will discuss how this knowledge could be harnessed for developing novel therapeutic strategies to counter inflammation that underlies many human diseases.
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15
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Bastian OW, Mrozek MH, Raaben M, Leenen LPH, Koenderman L, Blokhuis TJ. Serum from the Human Fracture Hematoma Contains a Potent Inducer of Neutrophil Chemotaxis. Inflammation 2018; 41:1084-1092. [PMID: 29511935 PMCID: PMC5982450 DOI: 10.1007/s10753-018-0760-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A controlled local inflammatory response is essential for adequate fracture healing. However, the current literature suggests that local and systemic hyper-inflammatory conditions after major trauma induce increased influx of neutrophils into the fracture hematoma (FH) and impair bone regeneration. Inhibiting neutrophil chemotaxis towards the FH without compromising the hosts' defense may therefore be a target of future therapies that prevent impairment of fracture healing after major trauma. We investigated whether chemotaxis of neutrophils towards the FH could be studied in vitro. Moreover, we determined whether chemotaxis of neutrophils towards the FH was mediated by the CXCR1, CXCR2, FPR, and C5aR receptors. Human FHs were isolated during an open reduction internal fixation (ORIF) procedure within 3 days after trauma and spun down to obtain the fracture hematoma serum. Neutrophil migration towards the FH was studied using Ibidi™ Chemotaxis3D μ-Slides and image analysis of individual neutrophil tracks was performed. Our study showed that the human FH induces significant neutrophil chemotaxis, which was not affected by blocking CXCR1 and CXCR2. In contrast, neutrophil chemotaxis towards the FH was significantly inhibited by chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS), which blocks FPR and C5aR. Blocking only C5aR with CHIPSΔ1F also significantly inhibited neutrophil chemotaxis towards the FH. Our finding that neutrophil chemotaxis towards the human FH can be blocked in vitro using CHIPS may aid the development of therapies that prevent impairment of fracture healing after major trauma.
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Affiliation(s)
- Okan W. Bastian
- Department of Traumatology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mikolaj H. Mrozek
- Department of Traumatology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marco Raaben
- Department of Traumatology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Luke P. H. Leenen
- Department of Traumatology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Leo Koenderman
- Department of Respiratory Medicine and Laboratory of Translational Immunology (LTI), University Medical Center Utrecht, Utrecht, The Netherlands
| | - Taco J. Blokhuis
- Department of Traumatology, Maastricht University Medical Center, Maastricht, The Netherlands
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16
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Ansari J, Kaur G, Gavins FNE. Therapeutic Potential of Annexin A1 in Ischemia Reperfusion Injury. Int J Mol Sci 2018; 19:ijms19041211. [PMID: 29659553 PMCID: PMC5979321 DOI: 10.3390/ijms19041211] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 01/19/2023] Open
Abstract
Cardiovascular disease (CVD) continues to be the leading cause of death in the world. Increased inflammation and an enhanced thrombotic milieu represent two major complications of CVD, which can culminate into an ischemic event. Treatment for these life-threatening complications remains reperfusion and restoration of blood flow. However, reperfusion strategies may result in ischemia-reperfusion injury (I/RI) secondary to various cardiovascular pathologies, including myocardial infarction and stroke, by furthering the inflammatory and thrombotic responses and delivering inflammatory mediators to the affected tissue. Annexin A1 (AnxA1) and its mimetic peptides are endogenous anti-inflammatory and pro-resolving mediators, known to have significant effects in resolving inflammation in a variety of disease models. Mounting evidence suggests that AnxA1, which interacts with the formyl peptide receptor (FPR) family, may have a significant role in mitigating I/RI associated complications. In this review article, we focus on how AnxA1 plays a protective role in the I/R based vascular pathologies.
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Affiliation(s)
- Junaid Ansari
- Department of Molecular & Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71130, USA.
| | - Gaganpreet Kaur
- Department of Molecular & Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71130, USA.
| | - Felicity N E Gavins
- Department of Molecular & Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71130, USA.
- Department of Neurology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71130, USA.
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17
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Kobayashi SD, Malachowa N, DeLeo FR. Neutrophils and Bacterial Immune Evasion. J Innate Immun 2018; 10:432-441. [PMID: 29642066 DOI: 10.1159/000487756] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 02/14/2018] [Indexed: 12/31/2022] Open
Abstract
Neutrophils are an important component of the innate immune system and provide a front line of defense against bacterial infection. Although most bacteria are killed readily by neutrophils, some bacterial pathogens have the capacity to circumvent destruction by these host leukocytes. The ability of bacterial pathogens to avoid killing by neutrophils often involves multiple attributes or characteristics, including the production of virulence molecules. These molecules are diverse in composition and function, and collectively have the potential to alter or inhibit neutrophil recruitment, phagocytosis, bactericidal activity, and/or apoptosis. Here, we review the ability of bacteria to target these processes.
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18
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Abstract
The microbiota - the collection of microorganisms that live within and on all mammals - provides crucial signals for the development and function of the immune system. Increased availability of technologies that profile microbial communities is facilitating the entry of many immunologists into the evolving field of host-microbiota studies. The microbial communities, their metabolites and components are not only necessary for immune homeostasis, they also influence the susceptibility of the host to many immune-mediated diseases and disorders. In this Review, we discuss technological and computational approaches for investigating the microbiome, as well as recent advances in our understanding of host immunity and microbial mutualism with a focus on specific microbial metabolites, bacterial components and the immune system.
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19
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He HQ, Ye RD. The Formyl Peptide Receptors: Diversity of Ligands and Mechanism for Recognition. Molecules 2017; 22:E455. [PMID: 28335409 PMCID: PMC6155412 DOI: 10.3390/molecules22030455] [Citation(s) in RCA: 165] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 03/09/2017] [Indexed: 12/21/2022] Open
Abstract
The formyl peptide receptors (FPRs) are G protein-coupled receptors that transduce chemotactic signals in phagocytes and mediate host-defense as well as inflammatory responses including cell adhesion, directed migration, granule release and superoxide production. In recent years, the cellular distribution and biological functions of FPRs have expanded to include additional roles in homeostasis of organ functions and modulation of inflammation. In a prototype, FPRs recognize peptides containing N-formylated methionine such as those produced in bacteria and mitochondria, thereby serving as pattern recognition receptors. The repertoire of FPR ligands, however, has expanded rapidly to include not only N-formyl peptides from microbes but also non-formyl peptides of microbial and host origins, synthetic small molecules and an eicosanoid. How these chemically diverse ligands are recognized by the three human FPRs (FPR1, FPR2 and FPR3) and their murine equivalents is largely unclear. In the absence of crystal structures for the FPRs, site-directed mutagenesis, computer-aided ligand docking and structural simulation have led to the identification of amino acids within FPR1 and FPR2 that interact with several formyl peptides. This review article summarizes the progress made in the understanding of FPR ligand diversity as well as ligand recognition mechanisms used by these receptors.
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Affiliation(s)
- Hui-Qiong He
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, China.
- Institute of Chinese Medical Sciences, University of Macau, Macau SAR 999078, China.
| | - Richard D Ye
- Institute of Chinese Medical Sciences, University of Macau, Macau SAR 999078, China.
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20
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Neutrophils and Immunity: From Bactericidal Action to Being Conquered. J Immunol Res 2017; 2017:9671604. [PMID: 28299345 PMCID: PMC5337389 DOI: 10.1155/2017/9671604] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 01/29/2017] [Indexed: 12/19/2022] Open
Abstract
The neutrophil is the major phagocyte and the final effector cell of the innate immunity, with a primary role in the clearance of extracellular pathogens. Using the broad array of cytokines, extracellular traps, and effector molecules as the humoral arm, neutrophils play a crucial role in the host defense against pathogen infections. On the other hand, the pathogen has the capacity to overcome neutrophil-mediated host defense to establish infection causing human disease. Pathogens, such as S. aureus, have the potential to thwart neutrophil chemotaxis and phagocytosis and thereby succeed in evading killing by neutrophils. Furthermore, S. aureus surviving within neutrophils promotes neutrophil cytolysis, resulting in the release of host-derived molecules that promote local inflammation. Here, we provide a detailed overview of the mechanisms by which neutrophils kill the extracellular pathogens and how pathogens evade neutrophils degradation. This review will provide insights that might be useful for the development of novel therapies against infections caused by antibiotic resistant pathogens.
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21
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do Vale A, Cabanes D, Sousa S. Bacterial Toxins as Pathogen Weapons Against Phagocytes. Front Microbiol 2016; 7:42. [PMID: 26870008 PMCID: PMC4734073 DOI: 10.3389/fmicb.2016.00042] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 01/11/2016] [Indexed: 12/31/2022] Open
Abstract
Bacterial toxins are virulence factors that manipulate host cell functions and take over the control of vital processes of living organisms to favor microbial infection. Some toxins directly target innate immune cells, thereby annihilating a major branch of the host immune response. In this review we will focus on bacterial toxins that act from the extracellular milieu and hinder the function of macrophages and neutrophils. In particular, we will concentrate on toxins from Gram-positive and Gram-negative bacteria that manipulate cell signaling or induce cell death by either imposing direct damage to the host cells cytoplasmic membrane or enzymatically modifying key eukaryotic targets. Outcomes regarding pathogen dissemination, host damage and disease progression will be discussed.
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Affiliation(s)
- Ana do Vale
- Host Interaction and Response, Instituto de Investigação e Inovação em Saúde, Universidade do PortoPorto, Portugal; Group of Fish Immunology and Vaccinology, Instituto de Biologia Molecular e Celular, Universidade do PortoPorto, Portugal
| | - Didier Cabanes
- Host Interaction and Response, Instituto de Investigação e Inovação em Saúde, Universidade do PortoPorto, Portugal; Group of Molecular Microbiology, Instituto de Biologia Molecular e Celular, Universidade do PortoPorto, Portugal
| | - Sandra Sousa
- Host Interaction and Response, Instituto de Investigação e Inovação em Saúde, Universidade do PortoPorto, Portugal; Group of Molecular Microbiology, Instituto de Biologia Molecular e Celular, Universidade do PortoPorto, Portugal
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22
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Stapels DAC, Kuipers A, von Köckritz-Blickwede M, Ruyken M, Tromp AT, Horsburgh MJ, de Haas CJC, van Strijp JAG, van Kessel KPM, Rooijakkers SHM. Staphylococcus aureus protects its immune-evasion proteins against degradation by neutrophil serine proteases. Cell Microbiol 2015; 18:536-45. [PMID: 26418545 DOI: 10.1111/cmi.12528] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 09/20/2015] [Indexed: 12/12/2022]
Abstract
Neutrophils store large quantities of neutrophil serine proteases (NSPs) that contribute, via multiple mechanisms, to antibacterial immune defences. Even though neutrophils are indispensable in fighting Staphylococcus aureus infections, the importance of NSPs in anti-staphylococcal defence is yet unknown. However, the fact that S. aureus produces three highly specific inhibitors for NSPs [the extracellular adherence proteins (EAPs) Eap, EapH1 and EapH2], suggests that these proteases are important for host defences against this bacterium. In this study we demonstrate that NSPs can inactivate secreted virulence factors of S. aureus and that EAP proteins function to prevent this degradation. Specifically, we find that a large group of S. aureus immune-evasion proteins is vulnerable to proteolytic inactivation by NSPs. In most cases, NSP cleavage leads to functional inactivation of virulence proteins. Interestingly, proteins with similar immune-escape functions appeared to have differential cleavage sensitivity towards NSPs. Using targeted mutagenesis and complementation analyses in S. aureus, we demonstrate that all EAP proteins can protect other virulence factors from NSP degradation in complex bacterial supernatants. These findings show that NSPs inactivate S. aureus virulence factors. Moreover, the protection by EAP proteins can explain why this antibacterial function of NSPs was masked in previous studies. Furthermore, our results indicate that therapeutic inactivation of EAP proteins can help to restore the natural host immune defences against S. aureus.
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Affiliation(s)
- D A C Stapels
- Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - A Kuipers
- Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - M von Köckritz-Blickwede
- Department of Physiological Chemistry, University of Veterinary Medicine Hannover, Hannover, Germany
| | - M Ruyken
- Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - A T Tromp
- Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - M J Horsburgh
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - C J C de Haas
- Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - J A G van Strijp
- Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - K P M van Kessel
- Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - S H M Rooijakkers
- Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
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23
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Schepetkin IA, Khlebnikov AI, Kirpotina LN, Quinn MT. Antagonism of human formyl peptide receptor 1 with natural compounds and their synthetic derivatives. Int Immunopharmacol 2015; 37:43-58. [PMID: 26382576 DOI: 10.1016/j.intimp.2015.08.036] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 08/25/2015] [Accepted: 08/28/2015] [Indexed: 12/18/2022]
Abstract
Formyl peptide receptor 1 (FPR1) regulates a wide variety of neutrophil functional responses and plays an important role in inflammation and the pathogenesis of various diseases. To date, a variety of natural and synthetic molecules have been identified as FPR1 ligands. Here, we review current knowledge on natural products and natural product-inspired small molecules reported to antagonize and/or inhibit the FPR1-mediated responses. Based on this literature, additional screening of selected commercially available natural compounds for their ability to inhibit fMLF-induced Ca(2+) mobilization in human neutrophils and FPR1 transfected HL-60 cells, and pharmacophore modeling, natural products with potential as FPR1 antagonists are considered and discussed in this review. The identification and characterization of natural products that antagonize FPR1 activity may have potential for the development of novel therapeutics to limit or alter the outcome of inflammatory processes.
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Affiliation(s)
- Igor A Schepetkin
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, United States
| | - Andrei I Khlebnikov
- Department of Biotechnology and Organic Chemistry, Tomsk Polytechnic University, Tomsk 634050, Russia; Department of Chemistry, Altai State Technical University, Barnaul, Russia
| | - Liliya N Kirpotina
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, United States
| | - Mark T Quinn
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, United States.
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24
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Koymans KJ, Vrieling M, Gorham RD, van Strijp JAG. Staphylococcal Immune Evasion Proteins: Structure, Function, and Host Adaptation. Curr Top Microbiol Immunol 2015; 409:441-489. [PMID: 26919864 DOI: 10.1007/82_2015_5017] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Staphylococcus aureus is a successful human and animal pathogen. Its pathogenicity is linked to its ability to secrete a large amount of virulence factors. These secreted proteins interfere with many critical components of the immune system, both innate and adaptive, and hamper proper immune functioning. In recent years, numerous studies have been conducted in order to understand the molecular mechanism underlying the interaction of evasion molecules with the host immune system. Structural studies have fundamentally contributed to our understanding of the mechanisms of action of the individual factors. Furthermore, such studies revealed one of the most striking characteristics of the secreted immune evasion molecules: their conserved structure. Despite high-sequence variability, most immune evasion molecules belong to a small number of structural categories. Another remarkable characteristic is that S. aureus carries most of these virulence factors on mobile genetic elements (MGE) or ex-MGE in its accessory genome. Coevolution of pathogen and host has resulted in immune evasion molecules with a highly host-specific function and prevalence. In this review, we explore how these shared structures and genomic locations relate to function and host specificity. This is discussed in the context of therapeutic options for these immune evasion molecules in infectious as well as in inflammatory diseases.
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Affiliation(s)
- Kirsten J Koymans
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
| | - Manouk Vrieling
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Ronald D Gorham
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Jos A G van Strijp
- Department of Medical Microbiology, University Medical Center Utrecht, G04-614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
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25
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Bloes DA, Kretschmer D, Peschel A. Enemy attraction: bacterial agonists for leukocyte chemotaxis receptors. Nat Rev Microbiol 2014; 13:95-104. [PMID: 25534805 DOI: 10.1038/nrmicro3390] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The innate immune system recognizes conserved microorganism-associated molecular patterns (MAMPs), some of which are sensed by G protein-coupled receptors (GPCRs), and this leads to chemotactic leukocyte influx. Recent studies have indicated that these processes are crucial for host defence and rely on a larger set of chemotactic MAMPs and corresponding GPCRs than was previously thought. Agonists, such as bacterial formyl peptides, enterococcal pheromone peptides, staphylococcal peptide toxins, bacterial fermentation products and the Helicobacter pylori peptide HP(2-20), stimulate specific GPCRs. The importance of leukocyte chemotaxis in host defence is highlighted by the fact that some bacterial pathogens produce chemotaxis inhibitors. How the various chemoattractants, receptors and antagonists shape antibacterial host defence represents an important topic for future research.
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Affiliation(s)
- Dominik Alexander Bloes
- Cellular and Molecular Microbiology Division, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
| | - Dorothee Kretschmer
- Cellular and Molecular Microbiology Division, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
| | - Andreas Peschel
- Cellular and Molecular Microbiology Division, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
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26
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Rongpharpi SR, Duggal S, Kalita H, Duggal AK. Staphylococcus aureus bacteremia: targeting the source. Postgrad Med 2014; 126:167-75. [PMID: 25295661 DOI: 10.3810/pgm.2014.09.2811] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Bacteremia due to Staphylococcus aureus is one of the major causes of morbidity and mortality in India, but studies targeting the source of Staphylococcus aureus bacteremia are lacking. S. aureus has a vivid armamentarium consisting of toxins, adhesins, and other virulence factors by virtue of which it can cause varied types of infections, sometimes of a serious nature. This review highlights the possible causes of S. aureus bacteremia, and discusses the necessity of tracing its source and eliminating it with proper antibiotic therapy to avoid recurrences or relapses.
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Affiliation(s)
- Sharon Rainy Rongpharpi
- Senior Resident, Department of Microbiology, Dr. Baba Saheb Ambedkar Hospital, New Delhi, India
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27
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Qin C, Yang YH, May L, Gao X, Stewart AG, Tu Y, Woodman OL, Ritchie RH. Cardioprotective potential of annexin-A1 mimetics in myocardial infarction. Pharmacol Ther 2014; 148:47-65. [PMID: 25460034 DOI: 10.1016/j.pharmthera.2014.11.012] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 11/14/2014] [Indexed: 12/15/2022]
Abstract
Myocardial infarction (MI) and its resultant heart failure remains a major cause of death in the world. The current treatments for patients with MI are revascularization with thrombolytic agents or interventional procedures. These treatments have focused on restoring blood flow to the ischemic tissue to prevent tissue necrosis and preserve organ function. The restoration of blood flow after a period of ischemia, however, may elicit further myocardial damage, called reperfusion injury. Pharmacological interventions, such as antioxidant and Ca(2+) channel blockers, have shown premises in experimental settings; however, clinical studies have shown limited success. Thus, there is a need for the development of novel therapies to treat reperfusion injury. The therapeutic potential of glucocorticoid-regulated anti-inflammatory mediator annexin-A1 (ANX-A1) has recently been recognized in a range of systemic inflammatory disorders. ANX-A1 binds to and activates the family of formyl peptide receptors (G protein-coupled receptor family) to inhibit neutrophil activation, migration and infiltration. Until recently, studies on the cardioprotective actions of ANX-A1 and its peptide mimetics (Ac2-26, CGEN-855A) have largely focused on its anti-inflammatory effects as a mechanism of preserving myocardial viability following I-R injury. Our laboratory provided the first evidence of the direct protective action of ANX-A1 on myocardium, independent of inflammatory cells in vitro. We now review the potential for ANX-A1 based therapeutics to be seen as a "triple shield" therapy against myocardial I-R injury, limiting neutrophil infiltration and preserving both cardiomyocyte viability and contractile function. This novel therapy may thus represent a valuable clinical approach to improve outcome after MI.
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Affiliation(s)
- Chengxue Qin
- Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia; Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria, Australia
| | - Yuan H Yang
- Centre for Inflammatory Diseases Monash University and Monash Medical Centre, Clayton, Victoria, Australia
| | - Lauren May
- Department of Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, and Department of Pharmacology, Monash University, Parkville, Victoria, Australia
| | - Xiaoming Gao
- Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia
| | - Alastair G Stewart
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria, Australia
| | - Yan Tu
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria, Australia
| | - Owen L Woodman
- School of Medical Sciences, RMIT University, Bundoora 3083, Victoria, Australia
| | - Rebecca H Ritchie
- Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia; Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, Victoria, Australia; Department of Medicine, Monash University, Clayton, Victoria, Australia.
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28
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Fevre C, Bestebroer J, Mebius MM, de Haas CJC, van Strijp JAG, Fitzgerald JR, Haas PJA. Staphylococcus aureus proteins SSL6 and SElX interact with neutrophil receptors as identified using secretome phage display. Cell Microbiol 2014; 16:1646-65. [PMID: 24840181 DOI: 10.1111/cmi.12313] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 05/02/2014] [Accepted: 05/05/2014] [Indexed: 12/20/2022]
Abstract
In order to cause colonization and invasive disease, pathogenic bacteria secrete proteins that modulate host immune defences. Identification and characterization of these proteins leads to a better understanding of the pathological processes underlying infectious and inflammatory diseases and is essential in the development of new strategies for their prevention and treatment. Current techniques to functionally characterize these proteins are laborious and inefficient. Here we describe a high-throughput functional selection strategy using phage display in order to identify immune evasion proteins. Using this technique we identified two previously uncharacterized proteins secreted by Staphylococcus aureus, SElX and SSL6 that bind to neutrophil surface receptors. SElX binds PSGL-1 on neutrophils and thereby inhibits the interaction between PSGL-1 and P-selectin, a crucial step in the recruitment of neutrophils to the site of infection. SSL6 is the first bacterial protein identified that binds CD47, a widely expressed cell surface protein recently described as an interesting target in anti-cancer therapy. Our findings provide new insights into the pathogenesis of S. aureus infections and support phage display as an efficient method to identify bacterial secretome proteins interacting with humoral or cellular immune components.
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Affiliation(s)
- Cindy Fevre
- Department of Medical Microbiology, University Medical Center Utrecht, PO G04.614, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
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29
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Abstract
In this review, we examine the current status of Staphylococcus aureus vaccine development and the prospects for future vaccines. Examination of the clinical trials to date show that murine models have not predicted success in humans for active or passive immunization. A key factor in the failure to develop a vaccine to prevent S. aureus infections comes from our relatively limited knowledge of human protective immunity. More recent reports on the elements of the human immune response to staphylococci are analysed. In addition, there is some controversy concerning the role of antibodies for protecting humans, and these data are reviewed. From a review of the current state of understanding of staphylococcal immunity, a working model is proposed. Some new work has provided some initial candidate biomarker(s) to predict outcomes of invasive infections and to predict the efficacy of antibiotic therapy in humans. We conclude by looking to the future through the perspective of lessons gleaned from the clinical vaccine trials.
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Affiliation(s)
- Vance G. Fowler
- Division of Infectious Diseases Duke University Medical Center Durham, NC 27710
| | - Richard A. Proctor
- University of Wisconsin School of Medicine and Public Health Madison, WI
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30
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Spaan AN, Surewaard BGJ, Nijland R, van Strijp JAG. Neutrophils versus Staphylococcus aureus: a biological tug of war. Annu Rev Microbiol 2013; 67:629-50. [PMID: 23834243 DOI: 10.1146/annurev-micro-092412-155746] [Citation(s) in RCA: 234] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The pathogen Staphylococcus aureus is well adapted to its human host. Neutrophil-mediated killing is a crucial defense system against S. aureus; however, the pathogen has evolved many strategies to resist killing. We first describe the discrete steps of neutrophil activation and migration to the site of infection and the killing of microbes by neutrophils in general. We then highlight the different approaches utilized by S. aureus to resist the different steps of neutrophil attack. Various molecules are discussed in their evolutionary context. Most of the molecules secreted by S. aureus to combat neutrophil attacks at the site of infection show clear human specificity. Many elements of human neutrophil defenses appear redundant, and so the evasion strategies of staphylococci display redundant functions as well. All efforts by S. aureus to resist neutrophil-mediated killing stress the importance of these mechanisms in the pathophysiology of staphylococcal diseases. However, the highly human-specific nature of most host-pathogen interactions hinders the in vivo establishment of their contribution to staphylococcal pathophysiology.
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Affiliation(s)
- András N Spaan
- Department of Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, The Netherlands; , , ,
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Klos A, Wende E, Wareham KJ, Monk PN. International Union of Basic and Clinical Pharmacology. [corrected]. LXXXVII. Complement peptide C5a, C4a, and C3a receptors. Pharmacol Rev 2013; 65:500-43. [PMID: 23383423 DOI: 10.1124/pr.111.005223] [Citation(s) in RCA: 178] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The activation of the complement cascade, a cornerstone of the innate immune response, produces a number of small (74-77 amino acid) fragments, originally termed anaphylatoxins, that are potent chemoattractants and secretagogues that act on a wide variety of cell types. These fragments, C5a, C4a, and C3a, participate at all levels of the immune response and are also involved in other processes such as neural development and organ regeneration. Their primary function, however, is in inflammation, so they are important targets for the development of antiinflammatory therapies. Only three receptors for complement peptides have been found, but there are no satisfactory antagonists as yet, despite intensive investigation. In humans, there is a single receptor for C3a (C3a receptor), no known receptor for C4a, and two receptors for C5a (C5a₁ receptor and C5a₂ receptor). The most recently characterized receptor, the C5a₂ receptor (previously known as C5L2 or GPR77), has been regarded as a passive binding protein, but signaling activities are now ascribed to it, so we propose that it be formally identified as a receptor and be given a name to reflect this. Here, we describe the complex biology of the complement peptides, introduce a new suggested nomenclature, and review our current knowledge of receptor pharmacology.
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Affiliation(s)
- Andreas Klos
- Department for Medical Microbiology, Medical School Hannover, Hannover, Germany
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Boer JC, Domanska UM, Timmer-Bosscha H, Boer IGJ, de Haas CJC, Joseph JV, Kruyt FAE, de Vries EGE, den Dunnen WFA, van Strijp JAG, Walenkamp AME. Inhibition of formyl peptide receptor in high-grade astrocytoma by CHemotaxis Inhibitory Protein of S. aureus. Br J Cancer 2013; 108:587-96. [PMID: 23322202 PMCID: PMC3593554 DOI: 10.1038/bjc.2012.603] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Background: High-grade astrocytomas are malignant brain tumours that infiltrate the surrounding brain tissue and have a poor prognosis. Activation of formyl peptide receptor (FPR1) on the human astrocytoma cell line U87 promotes cell motility, growth and angiogenesis. We therefore investigated the FPR1 inhibitor, Chemotaxis Inhibitory Protein of S. aureus (CHIPS), as a potential anti-astrocytoma drug. Methods and results: FPR1 expression was studied immunohistochemically in astrocytomas WHO grades I–IV. With intracellular calcium mobilisation and migration assays, human ligands were tested for their ability to activate FPR1 on U87 cells and on a cell line derived from primary astrocytoma grade IV patient material. Thereafter, we selectively inhibited these ligand-induced responses of FPR1 with an anti-inflammatory compound called Chemotaxis Inhibitory Protein of S. aureus (CHIPS). U87 xenografts in NOD-SCID mice served to investigate the effects of CHIPS in vivo. FPR1 was expressed in 29 out of 32 (90%) of all grades of astrocytomas. Two human mitochondrial-derived formylated peptides, formyl-methionil-leucine-lysine-isoleucine-valine (fMLKLIV) and formyl-methionil-methionil-tyrosine-alanine-leucine-phenylalanine (fMMYALF), were potent activators of FPR1 on tumour cells. Ligand-induced responses of FPR1-expressing tumour cells could be inhibited with FPR1 inhibitor CHIPS. Treatment of tumour-bearing mice with CHIPS slightly reduced tumour growth and improved survival as compared to non-treated animals (P=0.0019). Conclusion: Targeting FPR1 with CHIPS reduces cell motility and tumour cell activation, and prolongs the survival of tumour-bearing mice. This strategy could be explored in future research to improve treatment results for astrocytoma patients.
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Affiliation(s)
- J C Boer
- Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9700 RB Groningen, The Netherlands
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Lu X, Xia M, Endresz V, Faludi I, Mundkur L, Gonczol E, Chen D, Kakkar VV. Immunization With a Combination of 2 Peptides Derived From the C5a Receptor Significantly Reduces Early Atherosclerotic Lesion in
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J Mice. Arterioscler Thromb Vasc Biol 2012; 32:2358-71. [DOI: 10.1161/atvbaha.112.253179] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Objective—
The goal of this study was to assess whether immunization of
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tm1Her
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J mice with 2 peptides located at the N-terminus of the C5a receptor (C5aR), either alone or in combination, is effective in reducing atherosclerotic lesions.
Methods and Results—
Five- to 6-week-old female
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tm1Her
Apob
tm2Sgy
J mice were immunized using a repetitive immunization multiple sites strategy with keyhole limpet hemocyanin-conjugated peptides derived from the C5aR, either alone (designated as C5aR-P1 [aa 1–21] and C5aR-P2 [aa 19–31]) or in combination (designated as C5aR-P1+C5aR-P2). Mice were fed a high-fat diet for 10 weeks. Lesions were evaluated histologically; local and systemic immune responses were analyzed by immunohistochemistry of aorta samples and cytokine measurements in plasma samples and splenocyte supernatants. Immunization of
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tm1Her
Apob
tm2Sgy
J mice with these peptides elicited high concentrations of antibodies against each peptide. Immunization with the single peptide inhibited plaque development. Combined inoculation with C5aR-P1+C5aR-P2 had an additive effect on reducing the lesion in the aorta sinus and descending aortas when compared with controls. This effect correlated with cellular infiltration and cytokine/chemokine secretion in the serum or in stimulated spleen cells as well as specific cellular immune responses when compared with controls.
Conclusion—
Immunization of mice with C5aR-P1 and C5aR-P2, either alone or in combination, was effective in reducing early atherosclerotic lesion development. The combined peptide is more potential than either epitope alone to reduce atherosclerotic lesion formation through the induction of a specific Treg cell response as well as blockage of monocyte differentiation into macrophages.
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Affiliation(s)
- Xinjie Lu
- From the Mary and Garry Weston Molecular Immunology Laboratory, Thrombosis Research Institute, London, UK (X.L., M.X., D.C., V.V.K.); Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary (V.E., I.F.); Virology, National Center for Epidemiology, Budapest, Hungary (E.G.); MRC Centre for Transplantation, King’s College London, London, UK (D.C.); and the Thrombosis Research Institute, Bangalore, India (L.M., V.V.K.)
| | - Min Xia
- From the Mary and Garry Weston Molecular Immunology Laboratory, Thrombosis Research Institute, London, UK (X.L., M.X., D.C., V.V.K.); Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary (V.E., I.F.); Virology, National Center for Epidemiology, Budapest, Hungary (E.G.); MRC Centre for Transplantation, King’s College London, London, UK (D.C.); and the Thrombosis Research Institute, Bangalore, India (L.M., V.V.K.)
| | - Valeria Endresz
- From the Mary and Garry Weston Molecular Immunology Laboratory, Thrombosis Research Institute, London, UK (X.L., M.X., D.C., V.V.K.); Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary (V.E., I.F.); Virology, National Center for Epidemiology, Budapest, Hungary (E.G.); MRC Centre for Transplantation, King’s College London, London, UK (D.C.); and the Thrombosis Research Institute, Bangalore, India (L.M., V.V.K.)
| | - Ildiko Faludi
- From the Mary and Garry Weston Molecular Immunology Laboratory, Thrombosis Research Institute, London, UK (X.L., M.X., D.C., V.V.K.); Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary (V.E., I.F.); Virology, National Center for Epidemiology, Budapest, Hungary (E.G.); MRC Centre for Transplantation, King’s College London, London, UK (D.C.); and the Thrombosis Research Institute, Bangalore, India (L.M., V.V.K.)
| | - Lakshmi Mundkur
- From the Mary and Garry Weston Molecular Immunology Laboratory, Thrombosis Research Institute, London, UK (X.L., M.X., D.C., V.V.K.); Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary (V.E., I.F.); Virology, National Center for Epidemiology, Budapest, Hungary (E.G.); MRC Centre for Transplantation, King’s College London, London, UK (D.C.); and the Thrombosis Research Institute, Bangalore, India (L.M., V.V.K.)
| | - Eva Gonczol
- From the Mary and Garry Weston Molecular Immunology Laboratory, Thrombosis Research Institute, London, UK (X.L., M.X., D.C., V.V.K.); Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary (V.E., I.F.); Virology, National Center for Epidemiology, Budapest, Hungary (E.G.); MRC Centre for Transplantation, King’s College London, London, UK (D.C.); and the Thrombosis Research Institute, Bangalore, India (L.M., V.V.K.)
| | - Daxin Chen
- From the Mary and Garry Weston Molecular Immunology Laboratory, Thrombosis Research Institute, London, UK (X.L., M.X., D.C., V.V.K.); Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary (V.E., I.F.); Virology, National Center for Epidemiology, Budapest, Hungary (E.G.); MRC Centre for Transplantation, King’s College London, London, UK (D.C.); and the Thrombosis Research Institute, Bangalore, India (L.M., V.V.K.)
| | - Vijay V. Kakkar
- From the Mary and Garry Weston Molecular Immunology Laboratory, Thrombosis Research Institute, London, UK (X.L., M.X., D.C., V.V.K.); Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary (V.E., I.F.); Virology, National Center for Epidemiology, Budapest, Hungary (E.G.); MRC Centre for Transplantation, King’s College London, London, UK (D.C.); and the Thrombosis Research Institute, Bangalore, India (L.M., V.V.K.)
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Bardoel BW, Vos R, Bouman T, Aerts PC, Bestebroer J, Huizinga EG, Brondijk THC, van Strijp JAG, de Haas CJC. Evasion of Toll-like receptor 2 activation by staphylococcal superantigen-like protein 3. J Mol Med (Berl) 2012; 90:1109-20. [PMID: 22714643 DOI: 10.1007/s00109-012-0926-8] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 05/02/2012] [Accepted: 05/31/2012] [Indexed: 12/21/2022]
Abstract
Toll-like receptors (TLRs) are crucial for our host defense against microbial infections. TLR2 is especially important to fight bacterial infections, as it specifically recognizes bacterial lipoproteins of both Gram-positive and Gram-negative origin. Present on a variety of immune cells, TLR2 is critical for host protection against several bacterial infections, including those caused by Staphylococcus aureus. This major human pathogen causes increasing health care problems due to its increased resistance to antibiotics. S. aureus secretes a wide variety of proteins that inhibit innate immune responses. Recently, several staphylococcal superantigen-like proteins (SSLs) have been described to mediate immune evasive properties. Here, we describe that SSL3 specifically binds and inhibits TLR2 activation on human and murine neutrophils and monocytes. Through binding of the extracellular TLR2 domain, SSL3 inhibits IL-8 production by HEK cells expressing TLR1/2 and TLR2/6 dimers, stimulated with their specific ligands. The SSL3-TLR2 interaction is partially glycan dependent as binding of SSL3 to TLR2 is affected upon removal of sialic acid residues. Moreover, the SSL3(R308A) mutant lacking glycan-binding properties shows lower TLR2 inhibition. An SSL3 mutant, lacking the N-terminal 126 amino acids, still retains full TLR2 inhibiting activity. Of other SSLs tested, only SSL4, which shares the highest homology with SSL3, blocks TLR2 activation. SSL3 is the first-described bacterial protein that blocks TLR2 activation through direct extracellular interaction with the receptor. This unique function of SSL3 adds to the arsenal of immune evasive molecules that S. aureus can employ to subvert both innate and adaptive immunity.
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Affiliation(s)
- B W Bardoel
- Medical Microbiology, University Medical Center, Utrecht, The Netherlands
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35
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Is there a future for a Staphylococcus aureus vaccine? Vaccine 2011; 30:2921-7. [PMID: 22115633 DOI: 10.1016/j.vaccine.2011.11.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 10/21/2011] [Accepted: 11/01/2011] [Indexed: 12/21/2022]
Abstract
Multiple attempts to develop a vaccine to prevent Staphylococcus aureus infections have failed. To date, all have been based upon the development of opsonic antibodies. New information suggests that cell mediated immunity may be critical for protection against S. aureus infections. The arm of the immune system that provides the protection contains the Th17/IL-17 axis. Th17 cells release IL-17, which are important for mobilization and activation of neutrophils. Naturally, antibodies aid the neutrophils in the uptake and killing of staphylococci, but immune globulin does not seem to be sufficient to afford protection. New approaches that focus on Th17/IL-17 may allow for the development of a successful S. aureus vaccine.
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The Sbi protein is a multifunctional immune evasion factor of Staphylococcus aureus. Infect Immun 2011; 79:3801-9. [PMID: 21708997 DOI: 10.1128/iai.05075-11] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The second immunoglobulin-binding protein (Sbi) of Staphylococcus aureus has two N-terminal domains that bind the Fc region of IgG in a fashion similar to that of protein A and two domains that can bind to the complement protein C3 and promote its futile consumption in the fluid phase. It has been proposed that Sbi helps bacteria to avoid innate immune defenses. By comparing a mutant defective in Sbi with mutants defective in protein A, clumping factor A, iron-regulated surface determinant H, and capsular polysaccharide, it was shown that Sbi is indeed an immune evasion factor that promotes bacterial survival in whole human blood and the avoidance of neutrophil-mediated opsonophagocytosis. Sbi is present in the culture supernatant and is also associated with the cell envelope. S. aureus strains that expressed truncates of Sbi lacking N-terminal domains D1 and D2 (D1D2) or D3 and D4 (D3D4) or a C-terminal truncate that was no longer retained in the cell envelope were analyzed. Both the secreted and envelope-associated forms of Sbi contributed to immune evasion. The IgG-binding domains contributed only when Sbi was attached to the cell, while only the secreted C3-binding domains were biologically active.
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Kretschmer D, Gleske AK, Rautenberg M, Wang R, Köberle M, Bohn E, Schöneberg T, Rabiet MJ, Boulay F, Klebanoff SJ, van Kessel KA, van Strijp JA, Otto M, Peschel A. Human formyl peptide receptor 2 senses highly pathogenic Staphylococcus aureus. Cell Host Microbe 2010; 7:463-73. [PMID: 20542250 PMCID: PMC3417054 DOI: 10.1016/j.chom.2010.05.012] [Citation(s) in RCA: 213] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 04/09/2010] [Accepted: 05/10/2010] [Indexed: 11/17/2022]
Abstract
Virulence of emerging community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and other highly pathogenic S. aureus strains depends on their production of phenol-soluble modulin (PSM) peptide toxins, which combine the capacities to attract and lyse neutrophils. The molecular basis of PSM-stimulated neutrophil recruitment has remained unclear. Here, we demonstrate that the human formyl peptide receptor 2 (FPR2/ALX), which has previously been implicated in control of endogenous inflammatory processes, senses PSMs at nanomolar concentrations and initiates proinflammatory neutrophil responses to CA-MRSA. Specific blocking of FPR2/ALX or deletion of PSM genes in CA-MRSA severely diminished neutrophil detection of CA-MRSA. Furthermore, a specific inhibitor of FPR2/ALX and of its functional mouse counterpart blocked PSM-mediated leukocyte infiltration in vivo in a mouse model. Thus, the innate immune system uses a distinct FPR2/ALX-dependent mechanism to specifically sense bacterial peptide toxins and detect highly virulent bacterial pathogens. FPR2/ALX represents an attractive target for new anti-infective or anti-inflammatory strategies.
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Affiliation(s)
- Dorothee Kretschmer
- Cellular and Molecular Microbiology Division, Medical Microbiology and Hygiene Institute, University of Tübingen, Elfriede-Aulhorn-Straβe 6, 72076 Tübingen, Germany
| | - Anne-Kathrin Gleske
- Cellular and Molecular Microbiology Division, Medical Microbiology and Hygiene Institute, University of Tübingen, Elfriede-Aulhorn-Straβe 6, 72076 Tübingen, Germany
| | - Maren Rautenberg
- Cellular and Molecular Microbiology Division, Medical Microbiology and Hygiene Institute, University of Tübingen, Elfriede-Aulhorn-Straβe 6, 72076 Tübingen, Germany
| | - Rong Wang
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bldg 33, 1W10, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Martin Köberle
- Cellular and Molecular Microbiology Division, Medical Microbiology and Hygiene Institute, University of Tübingen, Elfriede-Aulhorn-Straβe 6, 72076 Tübingen, Germany
- University of Tübingen, Dermatology, Liebermeister-Straβe 25, 72076 Tübingen, Germany
| | - Erwin Bohn
- Cellular and Molecular Microbiology Division, Medical Microbiology and Hygiene Institute, University of Tübingen, Elfriede-Aulhorn-Straβe 6, 72076 Tübingen, Germany
| | - Torsten Schöneberg
- Institute of Biochemistry, Medical Faculty, University of Leipzig, Johannisallee 30 04103 Leipzig, Germany
| | - Marie-Joséphe Rabiet
- CEA, DSV, iRTSV, Laboratoire Biochimie et Biophysique des Systèmes Intégrés, 17 rue des Martyrs, Grenoble, F-38054, France
- CNRS, UMR 5092, Grenoble F-38054, France
- Université Joseph Fourier, Grenoble, F-38000, France
| | - Francois Boulay
- CEA, DSV, iRTSV, Laboratoire Biochimie et Biophysique des Systèmes Intégrés, 17 rue des Martyrs, Grenoble, F-38054, France
- CNRS, UMR 5092, Grenoble F-38054, France
- Université Joseph Fourier, Grenoble, F-38000, France
| | - Seymour J. Klebanoff
- Department of Medicine, University of Washington School of Medicine, Box 357185, Seattle WA 98195-7185, USA
| | - Kok A. van Kessel
- Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, Netherlands
| | - Jos A. van Strijp
- Medical Microbiology, University Medical Center Utrecht, 3584 CX Utrecht, Netherlands
| | - Michael Otto
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bldg 33, 1W10, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Andreas Peschel
- Cellular and Molecular Microbiology Division, Medical Microbiology and Hygiene Institute, University of Tübingen, Elfriede-Aulhorn-Straβe 6, 72076 Tübingen, Germany
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Laarman A, Milder F, van Strijp J, Rooijakkers S. Complement inhibition by gram-positive pathogens: molecular mechanisms and therapeutic implications. J Mol Med (Berl) 2010; 88:115-20. [PMID: 20062962 PMCID: PMC2832872 DOI: 10.1007/s00109-009-0572-y] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Revised: 11/25/2009] [Accepted: 11/27/2009] [Indexed: 12/15/2022]
Abstract
The plasma proteins of the complement system are essential in the innate immune response against bacteria. Complement labels bacteria with opsonins to support phagocytosis and generates chemoattractants to attract phagocytes to the site of infection. In turn, bacterial human pathogens have evolved different strategies to specifically impair the complement response. Here, we review the large arsenal of complement inhibitors produced by the gram-positive pathogens Staphylococcus aureus and Group A Streptococcus. We discuss how these bacterial molecules provide us with new tools to treat both infectious and inflammatory disease conditions in humans.
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Affiliation(s)
- Alexander Laarman
- Medical Microbiology, University Medical Center Utrecht, PO G04.614, Heidelberglaan 100, 3584 CX Utrecht, the Netherlands
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Foster TJ. Colonization and infection of the human host by staphylococci: adhesion, survival and immune evasion. Vet Dermatol 2010; 20:456-70. [PMID: 20178484 DOI: 10.1111/j.1365-3164.2009.00825.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The natural habitat of Staphylococcus aureus in humans is the moist squamous epithelium of the anterior nares. Several bacterial surface proteins are implicated in promoting adhesion to desquamated epithelial cells. Clumping factor B (ClfB) and iron-regulated surface determinant A both promote nasal colonization in rodent models, and in the case of ClfB, humans. One of the ligands involved in adhesion is cytokeratin 10. Reduction in nasal colonization can be achieved by active and passive immunization. S. aureus is well endowed with secreted and surface components that compromise innate immune responses, particularly the function of neutrophils. S. aureus secretes proteins that reduce migration of neutrophils from the bloodstream to the site of infection by impeding diapedesis and receptors for chemotactic molecules. Several secreted proteins interfere with complement C3 and C5 convertases, thus reducing the level of C3b opsonin and the chemotactic peptide C5a. Host proteases are recruited to the cell surface to enhance destruction of opsonic C3b and IgG. Surface components ClfA, protein A and polysaccharide capsule compromise the recognition of opsonins on the bacterial cell surface. If engulfed by neutrophils the intracellular bacterium can resist reactive oxygen intermediates, nitric oxide radicals, defensin peptides and bactericidal proteins. A prior infection by S. aureus does not induce complete protective immunity. This could be due to immunosuppression caused by expression of superantigen proteins that disrupt normal activation of T cells and B cells during antigen presentation. By studying the molecular pathogenesis of S. aureus infections markers might be found for investigating S. pseudintermedius infections of dogs.
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Affiliation(s)
- Timothy J Foster
- Microbiology Department, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland.
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Are formyl peptide receptors novel targets for therapeutic intervention in ischaemia-reperfusion injury? Trends Pharmacol Sci 2010; 31:266-76. [PMID: 20483490 PMCID: PMC7112865 DOI: 10.1016/j.tips.2010.04.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Revised: 04/06/2010] [Accepted: 04/06/2010] [Indexed: 01/13/2023]
Abstract
Ischaemia–reperfusion (I/R) injury is a common feature of several diseases associated with high morbidity and mortality, such as stroke and myocardial infarction. The damaged tissue displays cardinal signs of inflammation and microvascular injury that, unless resolved, lead to long-term tissue damage with associated dysfunction. Current therapies are limited and are often associated with many side effects. Increasing evidence suggests that members of the formyl peptide receptor (FPR) family, in particular human FPR2/ALX, might have an important role in the pathophysiology of I/R injury. It was recently demonstrated that several peptides and non-peptidyl small-molecule compounds have anti-inflammatory and pro-resolving properties via their action on members of the FPR family. Here I review this evidence and suggest that FPR ligands, particularly in the brain, could be novel and exciting anti-inflammatory therapeutics for the treatment of a variety of clinical conditions, including stroke.
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Bestebroer J, de Haas CJ, van Strijp JA. How microorganisms avoid phagocyte attraction. FEMS Microbiol Rev 2010; 34:395-414. [DOI: 10.1111/j.1574-6976.2009.00202.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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Gustafsson E, Rosén A, Barchan K, van Kessel KPM, Haraldsson K, Lindman S, Forsberg C, Ljung L, Bryder K, Walse B, Haas PJ, van Strijp JAG, Furebring C. Directed evolution of chemotaxis inhibitory protein of Staphylococcus aureus generates biologically functional variants with reduced interaction with human antibodies. Protein Eng Des Sel 2009; 23:91-101. [PMID: 19959567 DOI: 10.1093/protein/gzp062] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS) is a protein that binds and blocks the C5a receptor (C5aR) and formylated peptide receptor, thereby inhibiting the immune cell recruitment associated with inflammation. If CHIPS was less reactive with existing human antibodies, it would be a promising anti-inflammatory drug candidate. Therefore, we applied directed evolution and computational/rational design to the CHIPS gene in order to generate new CHIPS variants displaying lower interaction with human IgG, yet retaining biological function. The optimization was performed in four rounds: one round of random mutagenesis to add diversity into the CHIPS gene and three rounds of DNA recombination by Fragment INduced Diversity (FIND). Every round was screened by phage selection and/or ELISA for decreased interaction with human IgG and retained C5aR binding. The mean binding of human anti-CHIPS IgG decreased with every round of evolution. For further optimization, new amino acid substitutions were introduced by rational design, based on the mutations identified during directed evolution. Finally, seven CHIPS variants with low interaction with human IgG and retained C5aR blocking capacity could be identified.
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Prat C, Haas PJ, Bestebroer J, de Haas CJC, van Strijp JAG, van Kessel KPM. A homolog of formyl peptide receptor-like 1 (FPRL1) inhibitor from Staphylococcus aureus (FPRL1 inhibitory protein) that inhibits FPRL1 and FPR. THE JOURNAL OF IMMUNOLOGY 2009; 183:6569-78. [PMID: 19846866 DOI: 10.4049/jimmunol.0801523] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The members of the formyl peptide receptor (FPR) family are involved in the sensing of chemoattractant substances, including bacteria-derived N-formylated peptides and host-derived peptides and proteins. We have recently described two chemoattractant receptor inhibitors from Staphylococcus aureus. Chemotaxis inhibitory protein of S. aureus (CHIPS) blocks the formyl peptide receptor (FPR) and the receptor for complement C5a (C5aR), while FPR-like 1 (FPRL1) inhibitory protein (FLIPr) blocks the FPRL1. Here, we describe another staphylococcal chemoattractant-inhibiting protein with 73% overall homology to FLIPr and identical first 25 aa, which we termed FLIPr-like. This protein inhibits neutrophil calcium mobilization and chemotaxis induced by the FPRL1-ligand MMK-1 and FPR-ligand fMLP. While its FPRL1-inhibitory activity lies in the comparable nanomolar range of FLIPr, its antagonism of the FPR is approximately 100-fold more potent than that of FLIPr and comparable to that of CHIPS. The second N-terminal phenylalanine was required for its inhibition of the FPR, but it was dispensable for the FPRL1. Furthermore, the deletion of the first seven amino acids reduced its antagonism of the FPRL1, and the exchange of the first six amino acids with that of CHIPS-conferred receptor specificity. Finally, studies with cells transfected with several chemoattractant receptors confirmed that FLIPr-like specifically binds to the FPR and FPRL1. In conclusion, the newly described excreted protein from S. aureus, FLIPr-like, is a potent inhibitor of the FPR- and FPRL1-mediated neutrophil responses and may be used to selectively modulate these chemoattractant receptors.
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Affiliation(s)
- Cristina Prat
- Medical Microbiology, University Medical Center Utrecht, Utrecht, the Netherlands
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Structural models for the complex of chemotaxis inhibitory protein of Staphylococcus aureus with the C5a receptor. Biochem Biophys Res Commun 2009; 390:481-4. [PMID: 19799858 DOI: 10.1016/j.bbrc.2009.09.113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 09/24/2009] [Indexed: 01/03/2023]
Abstract
The study presents structural models for the complex of the chemotaxis inhibitory protein of Staphylococcus aureus, CHIPS, and receptor for anaphylotoxin C5a, C5aR. The models are based on the recently found NMR structure of the complex between CHIPS fragment 31-121 and C5aR fragment 7-28, as well as on previous results of molecular modeling of C5aR. Simple and straightforward modeling procedure selected low-energy conformations of the C5aR fragment 8-41 that simultaneously fit the NMR structure of the C5aR 10-18 fragment and properly orient the NMR structure of CHIPS(31-121) relative to C5aR. Extensive repacking of the side chains of CHIPS(31-121) and C5aR(8-41) predicted specific residue-residue interactions on the interface between CHIPS and C5aR. Many of these interactions were rationalized with experimental data obtained by site-directed mutagenesis of CHIPS and C5aR. The models correctly showed that CHIPS binds only to the first binding site of C5a to C5aR not competing with C5a fragment 59-74, which binds the second binding site of C5aR. The models also predict that two elements of CHIPS, fragments 48-58 and 97-111, may be used as structural templates for potential inhibitors of C5a.
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Ye RD, Boulay F, Wang JM, Dahlgren C, Gerard C, Parmentier M, Serhan CN, Murphy PM. International Union of Basic and Clinical Pharmacology. LXXIII. Nomenclature for the formyl peptide receptor (FPR) family. Pharmacol Rev 2009; 61:119-61. [PMID: 19498085 DOI: 10.1124/pr.109.001578] [Citation(s) in RCA: 600] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Formyl peptide receptors (FPRs) are a small group of seven-transmembrane domain, G protein-coupled receptors that are expressed mainly by mammalian phagocytic leukocytes and are known to be important in host defense and inflammation. The three human FPRs (FPR1, FPR2/ALX, and FPR3) share significant sequence homology and are encoded by clustered genes. Collectively, these receptors bind an extraordinarily numerous and structurally diverse group of agonistic ligands, including N-formyl and nonformyl peptides of different composition, that chemoattract and activate phagocytes. N-formyl peptides, which are encoded in nature only by bacterial and mitochondrial genes and result from obligatory initiation of bacterial and mitochondrial protein synthesis with N-formylmethionine, is the only ligand class common to all three human receptors. Surprisingly, the endogenous anti-inflammatory peptide annexin 1 and its N-terminal fragments also bind human FPR1 and FPR2/ALX, and the anti-inflammatory eicosanoid lipoxin A4 is an agonist at FPR2/ALX. In comparison, fewer agonists have been identified for FPR3, the third member in this receptor family. Structural and functional studies of the FPRs have produced important information for understanding the general pharmacological principles governing all leukocyte chemoattractant receptors. This article aims to provide an overview of the discovery and pharmacological characterization of FPRs, to introduce an International Union of Basic and Clinical Pharmacology (IUPHAR)-recommended nomenclature, and to discuss unmet challenges, including the mechanisms used by these receptors to bind diverse ligands and mediate different biological functions.
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Affiliation(s)
- Richard D Ye
- Department of Pharmacology, University of Illinois College of Medicine, 835 South Wolcott Avenue, M/C 868, Chicago, Illinois 60612, USA.
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Staphylococcal superantigen-like 10 inhibits CXCL12-induced human tumor cell migration. Neoplasia 2009; 11:333-44. [PMID: 19308288 DOI: 10.1593/neo.81508] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Revised: 02/10/2009] [Accepted: 02/12/2009] [Indexed: 02/07/2023] Open
Abstract
PURPOSE Tumor cell migration and metastasis share many similarities with leukocyte trafficking, which is critically regulated by chemokines and their receptors. CXCR4 is the most widely expressed chemokine receptor in many different types of cancer and has been linked to tumor dissemination and poor prognosis. Several CXCR4 antagonists have been synthesized. A totally novel approach to discover chemokine receptor antagonists is the use of bacteria. Bacteria produce chemokine receptor inhibitors to prevent neutrophil extravasation and migration toward the infection site to escape clearance by innate immune cells. The aim of the current study was to find and identify the mechanism of a bacterial protein that specifically targets CXCR4, a chemokine receptor shared by neutrophils and cancer cells. EXPERIMENTAL DESIGN Several staphylococcal proteins were screened for their capacity to prevent binding of a function-blocking antibody against CXCR4. RESULTS Staphylococcal superantigen-like 10 was found to bind CXCR4 expressed on human T acute lymphoblastic leukemia, lymphoma, and cervical carcinoma cell lines. It potently inhibited CXCL12-induced calcium mobilization and cell migration. CONCLUSIONS Staphylococcal superantigen-like 10 is a potential lead in the development of new anticancer compounds preventing metastasis by targeting CXCR4.
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Gustafsson E, Haas PJ, Walse B, Hijnen M, Furebring C, Ohlin M, van Strijp JAG, van Kessel KPM. Identification of conformational epitopes for human IgG on Chemotaxis inhibitory protein of Staphylococcus aureus. BMC Immunol 2009; 10:13. [PMID: 19284584 PMCID: PMC2662796 DOI: 10.1186/1471-2172-10-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Accepted: 03/11/2009] [Indexed: 11/17/2022] Open
Abstract
Background The Chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS) blocks the Complement fragment C5a receptor (C5aR) and formylated peptide receptor (FPR) and is thereby a potent inhibitor of neutrophil chemotaxis and activation of inflammatory responses. The majority of the healthy human population has antibodies against CHIPS that have been shown to interfere with its function in vitro. The aim of this study was to define potential epitopes for human antibodies on the CHIPS surface. We also initiate the process to identify a mutated CHIPS molecule that is not efficiently recognized by preformed anti-CHIPS antibodies and retains anti-inflammatory activity. Results In this paper, we panned peptide displaying phage libraries against a pool of CHIPS specific affinity-purified polyclonal human IgG. The selected peptides could be divided into two groups of sequences. The first group was the most dominant with 36 of the 48 sequenced clones represented. Binding to human affinity-purified IgG was verified by ELISA for a selection of peptide sequences in phage format. For further analysis, one peptide was chemically synthesized and antibodies affinity-purified on this peptide were found to bind the CHIPS molecule as studied by ELISA and Surface Plasmon Resonance. Furthermore, seven potential conformational epitopes responsible for antibody recognition were identified by mapping phage selected peptide sequences on the CHIPS surface as defined in the NMR structure of the recombinant CHIPS31–121 protein. Mapped epitopes were verified by in vitro mutational analysis of the CHIPS molecule. Single mutations introduced in the proposed antibody epitopes were shown to decrease antibody binding to CHIPS. The biological function in terms of C5aR signaling was studied by flow cytometry. A few mutations were shown to affect this biological function as well as the antibody binding. Conclusion Conformational epitopes recognized by human antibodies have been mapped on the CHIPS surface and amino acid residues involved in both antibody and C5aR interaction could be defined. This information has implications for the development of an effective anti-inflammatory agent based on a functional CHIPS molecule with low interaction with human IgG.
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Veldkamp KE, Strijp JAG. Innate Immune Evasion by Staphylococci. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 666:19-31. [DOI: 10.1007/978-1-4419-1601-3_2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Abstract
Staphylococcus aureus secretes several virulence factors modulating immune responses. Staphylococcal superantigen-like (SSL) proteins are a family of 14 exotoxins with homology to superantigens, but with generally unknown function. Recently, we showed that SSL5 binds to P-selectin glycoprotein ligand 1 dependently of sialyl Lewis X and inhibits P-selectin-dependent neutrophil rolling. Here, we show that SSL5 potently and specifically inhibits leukocyte activation by anaphylatoxins and all classes of chemokines. SSL5 inhibited calcium mobilization, actin polymerization, and chemotaxis induced by chemokines and anaphylatoxins but not by other chemoattractants. Antibody competition experiments showed that SSL5 targets several chemokine and anaphylatoxin receptors. In addition, transfection studies showed that SSL5 binds glycosylated N-termini of all G protein-coupled receptors (GPCRs) but only inhibits stimuli of protein nature that require the receptor N-terminus for activation. Furthermore, SSL5 increased binding of chemokines to cells independent of chemokine receptors through their common glycosaminoglycan-binding site. Importance of glycans was shown for both GPCR and chemokine binding. Thus, SSL5 is an important immunomodulatory protein of S aureus that targets several crucial, initial stages of leukocyte extravasation. It is therefore a potential new antiinflammatory compound for diseases associated with chemoattractants and their receptors and disorders characterized by excessive recruitment of leukocytes.
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Gustafsson E, Forsberg C, Haraldsson K, Lindman S, Ljung L, Furebring C. Purification of truncated and mutated Chemotaxis Inhibitory Protein of Staphylococcus aureus--an anti-inflammatory protein. Protein Expr Purif 2008; 63:95-101. [PMID: 18950716 DOI: 10.1016/j.pep.2008.09.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 09/24/2008] [Accepted: 09/29/2008] [Indexed: 01/19/2023]
Abstract
The Chemotaxis Inhibitory Protein of Staphylococcus aureus (CHIPS) binds and blocks the C5a receptor (C5aR) and formyl-peptide receptor (FPR). This way, CHIPS is a potent inhibitor of the immune cell recruitment associated with inflammation. Truncation of the protein and the introduction of mutations, shifts the expression towards the insoluble fraction of Escherichia coli, whereas the wild-type protein can be solubly expressed. A protocol for expression and tag independent purification of biologically active CHIPS variants has been established to enable further characterization of an improved CHIPS variant, called ADC-1004. The CHIPS variants were purified by washing of E. coli inclusion bodies followed by refolding and gel filtration. New techniques were utilized to optimize the purification process. Expression in inclusion bodies was increased by the use of Ultra Yield flasks and optimal refolding conditions were determined by the use of the iFOLD Refolding System 2. The folding and biological activity of the purified proteins were analyzed by circular dichroism (CD) spectroscopy and flow cytometry, respectively, and compared to solubly produced CHIPS(31-113) and wild-type CHIPS(1-121). We show that the CHIPS variants produced in inclusion bodies can be refolded and purified to achieve equal biological activity as solubly produced CHIPS(31-113) and wild-type CHIPS(1-121). The truncation causes minor structural changes while purification from inclusion bodies or the soluble fraction does not further affect the structure.
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Affiliation(s)
- Erika Gustafsson
- Alligator Bioscience AB, Scheelevägen 19A. S-223 70 Lund, Sweden.
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