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Bonnecaze L, Jumel K, Vial A, Khemtemourian L, Feuillie C, Molinari M, Lecomte S, Mathelié-Guinlet M. N-Formylation modifies membrane damage associated with PSMα3 interfacial fibrillation. NANOSCALE HORIZONS 2024; 9:1175-1189. [PMID: 38689531 DOI: 10.1039/d4nh00088a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
The virulence of Staphylococcus aureus, a multi-drug resistant pathogen, notably depends on the expression of the phenol soluble modulins α3 (PSMα3) peptides, able to self-assemble into amyloid-like cross-α fibrils. Despite remarkable advances evidencing the crucial, yet insufficient, role of fibrils in PSMα3 cytotoxic activities towards host cells, the relationship between its molecular structures, assembly propensities, and modes of action remains an open intriguing problem. In this study, combining atomic force microscopy (AFM) imaging and infrared spectroscopy, we first demonstrated in vitro that the charge provided by the N-terminal capping of PSMα3 alters its interactions with model membranes of controlled lipid composition without compromising its fibrillation kinetics or morphology. N-formylation eventually dictates PSMα3-membrane binding via electrostatic interactions with the lipid head groups. Furthermore, PSMα3 insertion within the lipid bilayer is favoured by hydrophobic interactions with the lipid acyl chains only in the fluid phase of membranes and not in the gel-like ordered domains. Strikingly, our real-time AFM imaging emphasizes how intermediate protofibrillar entities, formed along PSMα3 self-assembly and promoted at the membrane interface, likely disrupt membrane integrity via peptide accumulation and subsequent membrane thinning in a peptide concentration and lipid-dependent manner. Overall, our multiscale and multimodal approach sheds new light on the key roles of N-formylation and intermediate self-assembling entities, rather than mature fibrils, in dictating deleterious interactions of PSMα3 with membrane lipids, likely underscoring its ultimate cellular toxicity in vivo, and in turn S. aureus pathogenesis.
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Affiliation(s)
- Laura Bonnecaze
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France.
| | - Katlyn Jumel
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France.
| | - Anthony Vial
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France.
| | | | - Cécile Feuillie
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France.
| | - Michael Molinari
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France.
| | - Sophie Lecomte
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, F-33600 Pessac, France.
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2
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Aboelnaga N, Elsayed SW, Abdelsalam NA, Salem S, Saif NA, Elsayed M, Ayman S, Nasr M, Elhadidy M. Deciphering the dynamics of methicillin-resistant Staphylococcus aureus biofilm formation: from molecular signaling to nanotherapeutic advances. Cell Commun Signal 2024; 22:188. [PMID: 38519959 PMCID: PMC10958940 DOI: 10.1186/s12964-024-01511-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 02/01/2024] [Indexed: 03/25/2024] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) represents a global threat, necessitating the development of effective solutions to combat this emerging superbug. In response to selective pressures within healthcare, community, and livestock settings, MRSA has evolved increased biofilm formation as a multifaceted virulence and defensive mechanism, enabling the bacterium to thrive in harsh conditions. This review discusses the molecular mechanisms contributing to biofilm formation across its developmental stages, hence representing a step forward in developing promising strategies for impeding or eradicating biofilms. During staphylococcal biofilm development, cell wall-anchored proteins attach bacterial cells to biotic or abiotic surfaces; extracellular polymeric substances build scaffolds for biofilm formation; the cidABC operon controls cell lysis within the biofilm, and proteases facilitate dispersal. Beside the three main sequential stages of biofilm formation (attachment, maturation, and dispersal), this review unveils two unique developmental stages in the biofilm formation process for MRSA; multiplication and exodus. We also highlighted the quorum sensing as a cell-to-cell communication process, allowing distant bacterial cells to adapt to the conditions surrounding the bacterial biofilm. In S. aureus, the quorum sensing process is mediated by autoinducing peptides (AIPs) as signaling molecules, with the accessory gene regulator system playing a pivotal role in orchestrating the production of AIPs and various virulence factors. Several quorum inhibitors showed promising anti-virulence and antibiofilm effects that vary in type and function according to the targeted molecule. Disrupting the biofilm architecture and eradicating sessile bacterial cells are crucial steps to prevent colonization on other surfaces or organs. In this context, nanoparticles emerge as efficient carriers for delivering antimicrobial and antibiofilm agents throughout the biofilm architecture. Although metal-based nanoparticles have been previously used in combatting biofilms, its non-degradability and toxicity within the human body presents a real challenge. Therefore, organic nanoparticles in conjunction with quorum inhibitors have been proposed as a promising strategy against biofilms. As nanotherapeutics continue to gain recognition as an antibiofilm strategy, the development of more antibiofilm nanotherapeutics could offer a promising solution to combat biofilm-mediated resistance.
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Affiliation(s)
- Nirmeen Aboelnaga
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
| | - Salma W Elsayed
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
- Department of Microbiology & Immunology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Nehal Adel Abdelsalam
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Salma Salem
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
| | - Nehal A Saif
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
| | - Manar Elsayed
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
| | - Shehab Ayman
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
| | - Maha Nasr
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Mohamed Elhadidy
- Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt.
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt.
- Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
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3
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Yamazaki Y, Ito T, Tamai M, Nakagawa S, Nakamura Y. The role of Staphylococcus aureus quorum sensing in cutaneous and systemic infections. Inflamm Regen 2024; 44:9. [PMID: 38429810 PMCID: PMC10905890 DOI: 10.1186/s41232-024-00323-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/15/2024] [Indexed: 03/03/2024] Open
Abstract
BACKGROUND Staphylococcus aureus is a leading cause of human bacterial infections worldwide. It is the most common causative agent of skin and soft tissue infections, and can also cause various other infections, including pneumonia, osteomyelitis, as well as life-threatening infections, such as sepsis and infective endocarditis. The pathogen can also asymptomatically colonize human skin, nasal cavity, and the intestine. S. aureus colonizes approximately 20-30% of human nostrils, being an opportunistic pathogen for subsequent infection. Its strong ability to silently spread via human contact makes it difficult to eradicate S. aureus. A major concern with S. aureus is its capacity to develop antibiotic resistance and adapt to diverse environmental conditions. The variability in the accessory gene regulator (Agr) region of the genome contributes to a spectrum of phenotypes within the bacterial population, enhancing the likelihood of survival in different environments. Agr functions as a central quorum sensing (QS) system in S. aureus, allowing bacteria to adjust gene expression in response to population density. Depending on Agr expression, S. aureus secretes various toxins, contributing to virulence in infectious diseases. Paradoxically, expressing Agr may be disadvantageous in certain situations, such as in hospitals, causing S. aureus to generate Agr mutants responsible for infections in healthcare settings. MAIN BODY This review aims to demonstrate the molecular mechanisms governing the diverse phenotypes of S. aureus, ranging from a harmless colonizer to an organism capable of infecting various human organs. Emphasis will be placed on QS and its role in orchestrating S. aureus behavior across different contexts. SHORT CONCLUSION The pathophysiology of S. aureus infection is substantially influenced by phenotypic changes resulting from factors beyond Agr. Future studies are expected to give the comprehensive understanding of S. aureus overall profile in various settings.
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Affiliation(s)
- Yuriko Yamazaki
- Cutaneous Allergy and Host Defense, Immunology Frontier Research Center, Osaka, University, Osaka, 565-0871, Japan
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Tomoka Ito
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Masakazu Tamai
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Seitaro Nakagawa
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Yuumi Nakamura
- Cutaneous Allergy and Host Defense, Immunology Frontier Research Center, Osaka, University, Osaka, 565-0871, Japan.
- Department of Dermatology, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan.
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4
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Zhu Z, Hu Z, Li S, Fang R, Ono HK, Hu DL. Molecular Characteristics and Pathogenicity of Staphylococcus aureus Exotoxins. Int J Mol Sci 2023; 25:395. [PMID: 38203566 PMCID: PMC10778951 DOI: 10.3390/ijms25010395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 12/24/2023] [Accepted: 12/26/2023] [Indexed: 01/12/2024] Open
Abstract
Staphylococcus aureus stands as one of the most pervasive pathogens given its morbidity and mortality worldwide due to its roles as an infectious agent that causes a wide variety of diseases ranging from moderately severe skin infections to fatal pneumonia and sepsis. S. aureus produces a variety of exotoxins that serve as important virulence factors in S. aureus-related infectious diseases and food poisoning in both humans and animals. For example, staphylococcal enterotoxins (SEs) produced by S. aureus induce staphylococcal foodborne poisoning; toxic shock syndrome toxin-1 (TSST-1), as a typical superantigen, induces toxic shock syndrome; hemolysins induce cell damage in erythrocytes and leukocytes; and exfoliative toxin induces staphylococcal skin scalded syndrome. Recently, Panton-Valentine leucocidin, a cytotoxin produced by community-associated methicillin-resistant S. aureus (CA-MRSA), has been reported, and new types of SEs and staphylococcal enterotoxin-like toxins (SEls) were discovered and reported successively. This review addresses the progress of and novel insights into the molecular structure, biological activities, and pathogenicity of both the classic and the newly identified exotoxins produced by S. aureus.
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Affiliation(s)
- Zhihao Zhu
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada 034-8628, Japan; (Z.Z.); (Z.H.); (H.K.O.)
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China;
| | - Zuo Hu
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada 034-8628, Japan; (Z.Z.); (Z.H.); (H.K.O.)
| | - Shaowen Li
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China;
| | - Rendong Fang
- Joint International Research Laboratory of Animal Health and Animal Food Safety, College of Veterinary Medicine, Southwest University, Chongqing 400715, China;
| | - Hisaya K. Ono
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada 034-8628, Japan; (Z.Z.); (Z.H.); (H.K.O.)
| | - Dong-Liang Hu
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada 034-8628, Japan; (Z.Z.); (Z.H.); (H.K.O.)
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5
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Kristoffersen K, Hansen KH, Andreasen M. Differential Effects of Lipid Bilayers on αPSM Peptide Functional Amyloid Formation. Int J Mol Sci 2023; 25:102. [PMID: 38203273 PMCID: PMC10779341 DOI: 10.3390/ijms25010102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/16/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
Phenol-soluble modulins (PSMs) are key virulence factors of S. aureus, and they comprise the structural scaffold of biofilm as they self-assemble into functional amyloids. They have been shown to interact with cell membranes as they display toxicity towards human cells through cell lysis, with αPSM3 being the most cytotoxic. In addition to causing cell lysis in mammalian cells, PSMs have also been shown to interact with bacterial cell membranes through antimicrobial effects. Here, we present a study on the effects of lipid bilayers on the aggregation mechanism of αPSM using chemical kinetics to study the effects of lipid vesicles on the aggregation kinetics and using circular dichroism (CD) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM) to investigate the corresponding secondary structure of the aggregates. We found that the effects of lipid bilayers on αPSM aggregation were not homogeneous between lipid type and αPSM peptides, although none of the lipids caused changes in the dominating aggregation mechanism. In the case of αPSM3, all types of lipids slowed down aggregation to a varying degree, with 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) having the most pronounced effect. For αPSM1, lipids had opposite effects, where DOPC decelerated aggregation and lipopolysaccharide (LPS) accelerated the aggregation, while 1,2-dioleoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DOPG) had no effect. For αPSM4, both DOPG and LPS accelerated the aggregation, but only at high concentration, while DOPC showed no effect. None of the lipids was capable of inducing aggregation of αPSM2. Our data reveal a complex interaction pattern between PSMs peptides and lipid bilayers that causes changes in the aggregation kinetics by affecting different kinetic parameters along with only subtle changes in morphology.
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Affiliation(s)
| | | | - Maria Andreasen
- Department of Biomedicine, Aarhus University, Willhelm Meyer’s Allé 3, 8000 Aarhus, Denmark
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6
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Campbell AE, McCready-Vangi AR, Uberoi A, Murga-Garrido SM, Lovins VM, White EK, Pan JTC, Knight SAB, Morgenstern AR, Bianco C, Planet PJ, Gardner SE, Grice EA. Variable staphyloxanthin production by Staphylococcus aureus drives strain-dependent effects on diabetic wound-healing outcomes. Cell Rep 2023; 42:113281. [PMID: 37858460 PMCID: PMC10680119 DOI: 10.1016/j.celrep.2023.113281] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 08/24/2023] [Accepted: 09/28/2023] [Indexed: 10/21/2023] Open
Abstract
Strain-level variation in Staphylococcus aureus is a factor that contributes to disease burden and clinical outcomes in skin disorders and chronic wounds. However, the microbial mechanisms that drive these variable host responses are poorly understood. To identify mechanisms underlying strain-specific outcomes, we perform high-throughput phenotyping screens on S. aureus isolates cultured from diabetic foot ulcers. Isolates from non-healing wounds produce more staphyloxanthin, a cell membrane pigment. In murine diabetic wounds, staphyloxanthin-producing isolates delay wound closure significantly compared with staphyloxanthin-deficient isolates. Staphyloxanthin promotes resistance to oxidative stress and enhances bacterial survival in neutrophils. Comparative genomic and transcriptomic analysis of genetically similar clinical isolates with disparate staphyloxanthin phenotypes reveals a mutation in the sigma B operon, resulting in marked differences in stress response gene expression. Our work illustrates a framework to identify traits that underlie strain-level variation in disease burden and suggests more precise targets for therapeutic intervention in S. aureus-positive wounds.
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Affiliation(s)
- Amy E Campbell
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Amelia R McCready-Vangi
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Aayushi Uberoi
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sofía M Murga-Garrido
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Victoria M Lovins
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ellen K White
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jamie Ting-Chun Pan
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Simon A B Knight
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alexis R Morgenstern
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Colleen Bianco
- Division of Infectious Disease, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Paul J Planet
- Division of Infectious Disease, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Departments of Pediatrics and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sue E Gardner
- College of Nursing, University of Iowa, Iowa City, IA 52242, USA
| | - Elizabeth A Grice
- Departments of Dermatology and Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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7
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Jiang T, Tang XY, Mao Y, Zhou YQ, Wang JJ, Li RM, Xie XR, Zhang HM, Fang B, Ouyang NJ, Tang GH. Matrix mechanics regulate the polarization state of bone marrow-derived neutrophils through the JAK1/STAT3 signaling pathway. Acta Biomater 2023; 168:159-173. [PMID: 37467837 DOI: 10.1016/j.actbio.2023.07.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 07/11/2023] [Accepted: 07/11/2023] [Indexed: 07/21/2023]
Abstract
Matrix mechanics regulate essential cell behaviors through mechanotransduction, and as one of its most important elements, substrate stiffness was reported to regulate cell functions such as viability, communication, migration, and differentiation. Neutrophils (Neus) predominate the early inflammatory response and initiate regeneration. The activation of Neus can be regulated by physical cues; however, the functional alterations of Neus by substrate stiffness remain unknown, which is critical in determining the outcomes of engineered tissue mimics. Herein, a three-dimensional (3D) culture system made of hydrogels was developed to explore the effects of varying stiffnesses (1.5, 2.6, and 5.7 kPa) on the states of Neus. Neus showed better cell integrity and viability in the 3D system. Moreover, it was shown that the stiffer matrix tended to induce Neus toward an anti-inflammatory phenotype (N2) with less adhesion molecule expression, less reactive oxygen species (ROS) production, and more anti-inflammatory cytokine secretion. Additionally, the aortic ring assay indicated that Neus cultured in a stiffer matrix significantly increased vascular sprouting. RNA sequencing showed that a stiffer matrix could significantly activate JAK1/STAT3 signaling in Neus and the inhibition of JAK1 ablated the stiffness-dependent increase in the expression of CD182 (an N2 marker). Taken together, these results demonstrate that a stiffer matrix promotes Neus to shift to the N2 phenotype, which was regulated by JAK1/STAT3 pathway. This study lays the groundwork for further research on fabricating engineered tissue mimics, which may provide more treatment options for ischemic diseases and bone defects. STATEMENT OF SIGNIFICANCE.
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Affiliation(s)
- Ting Jiang
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Key Laboratory of Stomatology, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, Shanghai 200011, PR China; Oral Bioengineering Lab, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, PR China
| | - Xin-Yue Tang
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Key Laboratory of Stomatology, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, Shanghai 200011, PR China; Oral Bioengineering Lab, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, PR China
| | - Yi Mao
- Department of Oral Surgery, Shanghai Ninth People's Hospital, Shanghai Key Laboratory of Stomatology, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, Shanghai 200011, PR China; Oral Bioengineering Lab, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, PR China
| | - Yu-Qi Zhou
- Oral Bioengineering Lab, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, PR China
| | - Jia-Jia Wang
- Department of Oral Surgery, Shanghai Ninth People's Hospital, Shanghai Key Laboratory of Stomatology, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, Shanghai 200011, PR China; Oral Bioengineering Lab, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, PR China
| | - Ruo-Mei Li
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Key Laboratory of Stomatology, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, Shanghai 200011, PR China; Oral Bioengineering Lab, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, PR China
| | - Xin-Ru Xie
- Department of Oral Surgery, Shanghai Ninth People's Hospital, Shanghai Key Laboratory of Stomatology, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, Shanghai 200011, PR China; Oral Bioengineering Lab, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, PR China
| | - Hong-Ming Zhang
- Oral Bioengineering Lab, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, PR China
| | - Bing Fang
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Key Laboratory of Stomatology, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, Shanghai 200011, PR China; Oral Bioengineering Lab, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, PR China.
| | - Ning-Juan Ouyang
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Key Laboratory of Stomatology, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, Shanghai 200011, PR China.
| | - Guo-Hua Tang
- Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Key Laboratory of Stomatology, Shanghai Jiao Tong University School of Medicine; College of Stomatology, Shanghai Jiao Tong University; National Center for Stomatology; National Clinical Research Center for Oral Diseases; Shanghai Key Laboratory of Stomatology; Shanghai Research Institute of Stomatology, Shanghai 200011, PR China; Oral Bioengineering Lab, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai 200011, PR China.
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8
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Tao Z, Wang H, Ke K, Shi D, Zhu L. Flavone inhibits Staphylococcus aureus virulence via inhibiting the sae two component system. Microb Pathog 2023; 180:106128. [PMID: 37148922 DOI: 10.1016/j.micpath.2023.106128] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/08/2023] [Accepted: 04/26/2023] [Indexed: 05/08/2023]
Abstract
The rising prevalence of antibiotic resistance in Staphylococcus aureus calls for the development of innovative antimicrobial agents targeting novel pathways. S. aureus generates various virulence factors that compromise host defense mechanisms. Flavone, a core structure of flavonoids, has been shown to diminish the production of staphyloxanthin and alpha-hemolysin. Nonetheless, the influence of flavone on the majority of other virulence factors in S. aureus and its underlying molecular mechanism remain elusive. In this study, we examined the impact of flavone on the transcriptional profile of S. aureus using transcriptome sequencing. Our findings revealed that flavone substantially downregulated the expression of over 30 virulence factors implicated in immune evasion by the pathogen. Gene set enrichment analysis of the fold change-ranked gene list in relation to the Sae regulon indicated a robust association between flavone-induced downregulation and membership in the Sae regulon. Through the analysis of Sae target promoter-gfp fusion expression patterns, we observed a dose-dependent inhibition of Sae target promoter activity by flavone. Moreover, we discovered that flavone protected human neutrophils from S. aureus-mediated killing. Flavone also decreased the expression of alpha-hemolysin and other hemolytic toxins, resulting in a reduction in S. aureus' hemolytic capacity. Additionally, our data suggested that the inhibitory effect of flavone on the Sae system operates independently of its capacity to lower staphyloxanthin levels. In conclusion, our study proposes that flavone exhibits a broad inhibitory action on multiple virulence factors of S. aureus by targeting the Sae system, consequently diminishing the bacterium's pathogenicity.
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Affiliation(s)
- Zhanhua Tao
- Institute of Eco-Environmental Research, Guangxi Academy of Sciences, Nanning, 530003, Guangxi, China; Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Nanning, 530003, Guangxi, China.
| | - Haoren Wang
- The First Affiliated Hospital of Jiamusi University, Jiamusi, 154002, Heilongjiang, China.
| | - Ke Ke
- Guangxi Academy of Sciences, Nanning, 530003, Guangxi, China.
| | - Deqiang Shi
- Guangxi Academy of Sciences, Nanning, 530003, Guangxi, China.
| | - Libo Zhu
- Guangxi Academy of Sciences, Nanning, 530003, Guangxi, China.
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9
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Abstract
Neutrophils or polymorphonuclear neutrophils (PMNs) are an important component of innate host defense. These phagocytic leukocytes are recruited to infected tissues and kill invading microbes. There are several general characteristics of neutrophils that make them highly effective as antimicrobial cells. First, there is tremendous daily production and turnover of granulocytes in healthy adults-typically 1011 per day. The vast majority (~95%) of these cells are neutrophils. In addition, neutrophils are mobilized rapidly in response to chemotactic factors and are among the first leukocytes recruited to infected tissues. Most notably, neutrophils contain and/or produce an abundance of antimicrobial molecules. Many of these antimicrobial molecules are toxic to host cells and can destroy host tissues. Thus, neutrophil activation and turnover are highly regulated processes. To that end, aged neutrophils undergo apoptosis constitutively, a process that contains antimicrobial function and proinflammatory capacity. Importantly, apoptosis facilitates nonphlogistic turnover of neutrophils and removal by macrophages. This homeostatic process is altered by interaction with microbes and their products, as well as host proinflammatory molecules. Microbial pathogens can delay neutrophil apoptosis, accelerate apoptosis following phagocytosis, or cause neutrophil cytolysis. Here, we review these processes and provide perspective on recent studies that have potential to impact this paradigm.
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Affiliation(s)
- Scott D Kobayashi
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Frank R DeLeo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Mark T Quinn
- Department of Microbiology & Cell Biology, Montana State University, Bozeman, Montana, USA
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10
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Otto M. Critical Assessment of the Prospects of Quorum-Quenching Therapy for Staphylococcus aureus Infection. Int J Mol Sci 2023; 24:ijms24044025. [PMID: 36835436 PMCID: PMC9958572 DOI: 10.3390/ijms24044025] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/04/2023] [Accepted: 02/08/2023] [Indexed: 02/19/2023] Open
Abstract
Staphylococcus aureus is an important pathogen that causes a high number of infections and is one of the leading causes of death in hospitalized patients. Widespread antibiotic resistance such as in methicillin-resistant S. aureus (MRSA) has prompted research into potential anti-virulence-targeted approaches. Targeting the S. aureus accessory gene regulator (Agr) quorum-sensing system, a master regulator of virulence, is the most frequently proposed anti-virulence strategy for S. aureus. While much effort has been put into the discovery and screening for Agr inhibitory compounds, in vivo analysis of their efficacy in animal infection models is still rare and reveals various shortcomings and problems. These include (i) an almost exclusive focus on topical skin infection models, (ii) technical problems that leave doubt as to whether observed in vivo effects are due to quorum-quenching, and (iii) the discovery of counterproductive biofilm-increasing effects. Furthermore, potentially because of the latter, invasive S. aureus infection is associated with Agr dysfunctionality. Altogether, the potential of Agr inhibitory drugs is nowadays seen with low enthusiasm given the failure to provide sufficient in vivo evidence for their potential after more than two decades since the initiation of such efforts. However, current Agr inhibition-based probiotic approaches may lead to a new application of Agr inhibition strategies in preventing S. aureus infections by targeting colonization or for otherwise difficult-to-treat skin infections such as atopic dermatitis.
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Affiliation(s)
- Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20814, USA
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11
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Wang GZ, Warren EA, Haas AL, Peña AS, Kiedrowski MR, Lomenick B, Chou TF, Bomberger JM, Tirrell DA, Limoli DH. Staphylococcal secreted cytotoxins are competition sensing signals for Pseudomonas aeruginosa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.29.526047. [PMID: 36747623 PMCID: PMC9900984 DOI: 10.1101/2023.01.29.526047] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Coinfection with two notorious opportunistic pathogens, the Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus , dominates chronic pulmonary infections. While coinfection is associated with poor patient outcomes, the interspecies interactions responsible for such decline remain unknown. Here, we dissected molecular mechanisms of interspecies sensing between P. aeruginosa and S. aureus . We discovered that P. aeruginosa senses S. aureus secreted peptides and, counterintuitively, moves towards these toxins. P. aeruginosa tolerates such a strategy through "competition sensing", whereby it preempts imminent danger/competition by arming cells with type six secretion (T6S) and iron acquisition systems. Intriguingly, while T6S is predominantly described as weaponry targeting Gram-negative and eukaryotic cells, we find that T6S is essential for full P. aeruginosa competition with S. aureus , a previously undescribed role for T6S. Importantly, competition sensing was activated during coinfection of bronchial epithelia, including T6S islands targeting human cells. This study reveals critical insight into both interspecies competition and how antagonism may cause collateral damage to the host environment.
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12
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Cao J, Zhang H, He Z, Piao Z, Zong X, Sun B. Genotypic and Phenotypic Characterization of Some psms Hypervirulent Clinical Isolates of Staphylococcus aureus in a Tertiary Hospital in Hefei, Anhui. Infect Drug Resist 2023; 16:1471-1484. [PMID: 36949844 PMCID: PMC10025015 DOI: 10.2147/idr.s399688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 02/17/2023] [Indexed: 03/15/2023] Open
Abstract
Background Staphylococcus aureus is a highly successful pathogen that can cause various infectious diseases, from relatively mild skin infections to life-threatening severe systemic diseases. The widespread pathogenicity of S. aureus is mainly due to its ability to produce many virulence factors that help destroy various host cells, causing disease. Our primary goal in this study was to explore the genes of highly virulent strains, to identify genes closely associated with high virulence, and to provide ideas for the treatment of infection by highly virulent clinical strains. Results This study collected 221 clinical strains from The First Affiliated Hospital Of The University of Science and Technology of China (USTC); their hemolytic abilities were tested. Eight isolates were selected based on their highly hemolytic ability and tested their hemolytic activity again; their phenotypes and gene sequences were also explored. Whole-genome sequencing (WGS) showed six plasmids (pN315, pNE131, pSJH901, pSJH101, SAP106B, and MSSA476), eight antibiotic resistance genes [blaR1, blaI, blaZ, mecA, erm(C), erm(T), tet(38), and fosB-Saur] and seventy-two virulence related genes. Three highly virulent strains, namely X21111206, 21092239, and 21112607, were found according the Galleria mellonella infection model. Therefore, we selected 10 representative virulence genes for qRT-PCR: psmα, psmβ, hlgA, hlgB, hlgC, hla, clfA, clfB, spa, and sak. Among them, the expression levels of psmα and psmβ, the three isolates, were significantly higher than the positive control NCTC8325. Conclusion Significant differences appear in the expression of virulence genes in the highly virulent strains, particularly the psmα and psmβ, It may be that the high expression of psm gene is the cause of the high virulence of Staphylococcus aureus. We can reduce the pathogenicity of Staphylococcus aureus by inhibiting the expression of psm gene, which may provide a strong basis for psm as a new target for clinical treatment of S. aureus infection.
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Affiliation(s)
- Jiaxin Cao
- College of Life Science and Technology, Mudanjiang Normal University, Mudanjiang, People’s Republic of China
- School of Life Science and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Huimin Zhang
- College of Life Science and Technology, Mudanjiang Normal University, Mudanjiang, People’s Republic of China
- School of Life Science and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Zhien He
- School of Life Science and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
| | - Zhongwan Piao
- College of Life Science and Technology, Mudanjiang Normal University, Mudanjiang, People’s Republic of China
- Correspondence: Baolin Sun; Zhongwan Piao, Email ;
| | - Xianchun Zong
- College of Life Science and Technology, Mudanjiang Normal University, Mudanjiang, People’s Republic of China
| | - Baolin Sun
- College of Life Science and Technology, Mudanjiang Normal University, Mudanjiang, People’s Republic of China
- School of Life Science and Medicine, University of Science and Technology of China, Hefei, People’s Republic of China
- Correspondence: Baolin Sun; Zhongwan Piao, Email ;
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13
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Intracellular Habitation of Staphylococcus aureus: Molecular Mechanisms and Prospects for Antimicrobial Therapy. Biomedicines 2022; 10:biomedicines10081804. [PMID: 36009351 PMCID: PMC9405036 DOI: 10.3390/biomedicines10081804] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 12/23/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections pose a global health threat, especially with the continuous development of antibiotic resistance. As an opportunistic pathogen, MRSA infections have a high mortality rate worldwide. Although classically described as an extracellular pathogen, many studies have shown over the past decades that MRSA also has an intracellular aspect to its infectious cycle, which has been observed in vitro in both non-professional as well as professional phagocytes. In vivo, MRSA has been shown to establish an intracellular niche in liver Kupffer cells upon bloodstream infection. The staphylococci have evolved various evasion strategies to survive the antimicrobial environment of phagolysosomes and use these compartments to hide from immune cells and antibiotics. Ultimately, the host cells get overwhelmed by replicating bacteria, leading to cell lysis and bacterial dissemination. In this review, we describe the different intracellular aspects of MRSA infection and briefly mention S. aureus evasion strategies. We discuss how this intracellular niche of bacteria may assist in antibiotic tolerance development, and lastly, we describe various new antibacterial strategies that target the intracellular bacterial niche.
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14
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McKellar SW, Ivanova I, Arede P, Zapf RL, Mercier N, Chu LC, Mediati DG, Pickering AC, Briaud P, Foster RG, Kudla G, Fitzgerald JR, Caldelari I, Carroll RK, Tree JJ, Granneman S. RNase III CLASH in MRSA uncovers sRNA regulatory networks coupling metabolism to toxin expression. Nat Commun 2022; 13:3560. [PMID: 35732654 PMCID: PMC9217828 DOI: 10.1038/s41467-022-31173-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 06/03/2022] [Indexed: 01/13/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterial pathogen responsible for significant human morbidity and mortality. Post-transcriptional regulation by small RNAs (sRNAs) has emerged as an important mechanism for controlling virulence. However, the functionality of the majority of sRNAs during infection is unknown. To address this, we performed UV cross-linking, ligation, and sequencing of hybrids (CLASH) in MRSA to identify sRNA-RNA interactions under conditions that mimic the host environment. Using a double-stranded endoribonuclease III as bait, we uncovered hundreds of novel sRNA-RNA pairs. Strikingly, our results suggest that the production of small membrane-permeabilizing toxins is under extensive sRNA-mediated regulation and that their expression is intimately connected to metabolism. Additionally, we also uncover an sRNA sponging interaction between RsaE and RsaI. Taken together, we present a comprehensive analysis of sRNA-target interactions in MRSA and provide details on how these contribute to the control of virulence in response to changes in metabolism.
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Affiliation(s)
- Stuart W McKellar
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Ivayla Ivanova
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Pedro Arede
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Rachel L Zapf
- Department of Biological Sciences, Ohio University, Athens, OH, 45701, USA
| | - Noémie Mercier
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, F-67000, Strasbourg, France
| | - Liang-Cui Chu
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Daniel G Mediati
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, 2052, NSW, Australia
| | - Amy C Pickering
- The Roslin Institute and Edinburgh Infectious Diseases, University of Edinburgh, Easter Bush Campus, Edinburgh, Scotland, UK
| | - Paul Briaud
- Department of Biological Sciences, Ohio University, Athens, OH, 45701, USA
| | - Robert G Foster
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - Grzegorz Kudla
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - J Ross Fitzgerald
- The Roslin Institute and Edinburgh Infectious Diseases, University of Edinburgh, Easter Bush Campus, Edinburgh, Scotland, UK
| | - Isabelle Caldelari
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, F-67000, Strasbourg, France
| | - Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, OH, 45701, USA
- The Infectious and Tropical Disease Institute, Ohio University, Athens, OH, 45701, USA
| | - Jai J Tree
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, 2052, NSW, Australia
| | - Sander Granneman
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK.
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15
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Protein profiling of mechanically processed lipoaspirates: discovering wound healing and anti-fibrotic biomarkers in nanofat. Plast Reconstr Surg 2022; 150:341e-354e. [PMID: 35666150 DOI: 10.1097/prs.0000000000009345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Nanofat is an injectable oily emulsion, rich in adipose derived stem cells (ADSCs) and growth factors. It is prepared from lipoaspirates through mechanical emulsification and filtration. Despite being successfully used in several procedures in regenerative medicine such as scar attenuation, skin rejuvenation and treatment of chronic wounds, little is known about exactly how nanofat induces regeneration in treated skin at the molecular level. METHODS Microfat and nanofat samples were isolated from 18 healthy patients. Proteomic profiling was performed through untargeted mass spectrometry proteomics and multiplex antibody arrays. Pathway enrichment analysis of differentially expressed proteins between microfat and nanofat was performed using Gene Ontology, Reactome and KEGG as reference databases. RESULTS Untargeted proteomics showed that upregulated genes in nanofat are involved in innate immunity responses, coagulation and wound healing, while downregulated genes were linked to cellular migration and extracellular matrix (ECM) production. Secretome array screening of microfat and nanofat samples showed no significantly different expression, which strongly suggests that the mechanical emulsification step does not affect the concentration of tissue regeneration biomarkers. The identified proteins are involved in wound healing, cellular migration, extracellular matrix remodelling, angiogenesis, stress response and immune response. CONCLUSIONS Mechanical processing of lipoaspirates into nanofat significantly influences the proteome profile by enhancing inflammation, antimicrobial and wound healing pathways. Nanofat is extremely rich in tissue repair and tissue remodelling factors. CLINICAL RELEVANCE STATEMENT This study shows that the effects of Micro- and Nanofat treatment are based on upregulated inflammation, antimicrobial and wound healing pathways. Mechanical emulsification does not alter the concentration of tissue regeneration biomarkers.
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16
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Jiang JM, Chen G, Chen YY, Wan SJ, Chen SM, Ren HG, Lin ZX, Feng H, Zhang H, Xu HX. The anti-infective activity of Salvia miltiorrhiza against Staphylococcus aureus by attenuating accessory gene regulator system-mediated virulence. Food Funct 2022; 13:5050-5060. [PMID: 35403637 DOI: 10.1039/d1fo01888d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Due to the rapid evolution of antibiotic resistance in Staphylococcus aureus, antivirulence therapy may be a promising alternative for the effective control of the spread of resistant pathogens. The Chinese Materia Medica has been widely used for the treatment of diseases and production of health foods, and it remains a valuable resource for the discovery of compounds possessing antivirulence activity. Through a Caenorhabditis elegans infection model, an EtOAc-soluble fraction of 80% EtOH extract of Salvia miltiorrhiza Bunge (SMEA) was found to possess potential anti-infective activity against S. aureus. Then, several in vitro assays indicated that SMEA had robust antivirulence activity at the dose of 400 μg mL-1, reducing hemolytic activity and α-hemolysin expression in S. aureus. Furthermore, at 100 mg kg-1, SMEA reduced abscess formation in the main organs of mice challenged with S. aureus. In order to identify the bioactive components of SMEA and investigate the mechanisms underlying the antivirulence activity, SMEA was separated using bioassay-guided fractionation. As a result, eight compounds were identified in SMEA. Among them, tanshinone IIB (TNB) showed strong antivirulence activity both in vitro and in vivo. Furthermore, at 24 μg mL-1, TNB significantly reduced the expression of RNAIII and psmα, indicating that the mechanism underlying TNB activity was related to the accessory gene regulator quorum sensing system. In conclusion, TNB's antivirulence properties make it a promising candidate for drug development against S. aureus infections.
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Affiliation(s)
- Jia-Ming Jiang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, P.R. China.
| | - Gan Chen
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, P.R. China.
| | - Yu-Yu Chen
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, P.R. China.
| | - Shi-Jie Wan
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, P.R. China.
| | - Si-Min Chen
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, P.R. China.
| | - Han-Gui Ren
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, P.R. China.
| | - Zhi-Xiu Lin
- School of Chinese Medicine, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, P.R. China
| | - Hui Feng
- Shanghai Guanghua Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, P.R. China
| | - Hong Zhang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, P.R. China.
| | - Hong-Xi Xu
- Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, P.R. China.
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17
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The Influence of Antibiotic Resistance on Innate Immune Responses to Staphylococcus aureus Infection. Antibiotics (Basel) 2022; 11:antibiotics11050542. [PMID: 35625186 PMCID: PMC9138074 DOI: 10.3390/antibiotics11050542] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/13/2022] [Accepted: 04/18/2022] [Indexed: 11/16/2022] Open
Abstract
Staphylococcus aureus (S. aureus) causes a broad range of infections and is associated with significant morbidity and mortality. S. aureus produces a diverse range of cellular and extracellular factors responsible for its invasiveness and ability to resist immune attack. In recent years, increasing resistance to last-line anti-staphylococcal antibiotics daptomycin and vancomycin has been observed. Resistant strains of S. aureus are highly efficient in invading a variety of professional and nonprofessional phagocytes and are able to survive inside host cells. Eliciting immune protection against antibiotic-resistant S. aureus infection is a global challenge, requiring both innate and adaptive immune effector mechanisms. Dendritic cells (DC), which sit at the interface between innate and adaptive immune responses, are central to the induction of immune protection against S. aureus. However, it has been observed that S. aureus has the capacity to develop further antibiotic resistance and acquire increased resistance to immunological recognition by the innate immune system. In this article, we review the strategies utilised by S. aureus to circumvent antibiotic and innate immune responses, especially the interaction between S. aureus and DC, focusing on how this relationship is perturbed with the development of antibiotic resistance.
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18
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Raghuram V, Alexander AM, Loo HQ, Petit RA, Goldberg JB, Read TD. Species-Wide Phylogenomics of the Staphylococcus aureus Agr Operon Revealed Convergent Evolution of Frameshift Mutations. Microbiol Spectr 2022; 10:e0133421. [PMID: 35044202 PMCID: PMC8768832 DOI: 10.1128/spectrum.01334-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 01/03/2022] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus is a prominent nosocomial pathogen that causes several life-threatening diseases, such as pneumonia and bacteremia. S. aureus modulates the expression of its arsenal of virulence factors through sensing and integrating responses to environmental signals. The agr (accessory gene regulator) quorum sensing (QS) system is a major regulator of virulence phenotypes in S. aureus. There are four agr specificity groups each with a different autoinducer peptide sequence encoded by the agrD gene. Although agr is critical for the expression of many toxins, paradoxically, S. aureus strains often have nonfunctional agr activity due to loss-of-function mutations in the four-gene agr operon. To understand patterns in agr variability across S. aureus, we undertook a species-wide genomic investigation. We developed a software tool (AgrVATE; https://github.com/VishnuRaghuram94/AgrVATE) for typing and detecting frameshift mutations in the agr operon. In an analysis of over 40,000 S. aureus genomes, we showed a close association between agr type and S. aureus clonal complex. We also found a strong linkage between agrBDC alleles (encoding the peptidase, autoinducing peptide itself, and peptide sensor, respectively) but not agrA (encoding the response regulator). More than 5% of the genomes were found to have frameshift mutations in the agr operon. While 52% of these frameshifts occurred only once in the entire species, we observed cases where the recurring mutations evolved convergently across different clonal lineages with no evidence of long-term phylogenetic transmission, suggesting that strains with agr frameshifts were evolutionarily short-lived. Overall, genomic analysis of agr operon suggests evolution through multiple processes with functional consequences that are not fully understood. IMPORTANCE Staphylococcus aureus is a globally pervasive pathogen that produces a plethora of toxic molecules that can harm host immune cells. Production of these toxins is mainly controlled by an active agr quorum-sensing system, which senses and responds to bacterial cell density. However, there are many reports of S. aureus strains with genetic changes leading to impaired agr activity that are often found during chronic bloodstream infections and may be associated with increased disease severity. We developed an open-source software called AgrVATE to type agr systems and identify mutations. We used AgrVATE for a species-wide genomic survey of S. aureus, finding that more than 5% of strains in the public database had nonfunctional agr systems. We also provided new insights into the evolution of these genetic mutations in the agr system. Overall, this study contributes to our understanding of a common but relatively understudied means of virulence regulation in S. aureus.
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Affiliation(s)
- Vishnu Raghuram
- Microbiology and Molecular Genetics Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Ashley M. Alexander
- Population Biology, Ecology, and Evolution Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, Georgia, USA
| | - Hui Qi Loo
- Department of Biology, Emory University, Atlanta, Georgia, USA
| | - Robert A. Petit
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, Georgia, USA
| | - Joanna B. Goldberg
- Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis, and Sleep, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Timothy D. Read
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, Georgia, USA
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19
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Kraus RF, Gruber MA. Neutrophils-From Bone Marrow to First-Line Defense of the Innate Immune System. Front Immunol 2022; 12:767175. [PMID: 35003081 PMCID: PMC8732951 DOI: 10.3389/fimmu.2021.767175] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 12/03/2021] [Indexed: 12/16/2022] Open
Abstract
Neutrophils (polymorphonuclear cells; PMNs) form a first line of defense against pathogens and are therefore an important component of the innate immune response. As a result of poorly controlled activation, however, PMNs can also mediate tissue damage in numerous diseases, often by increasing tissue inflammation and injury. According to current knowledge, PMNs are not only part of the pathogenesis of infectious and autoimmune diseases but also of conditions with disturbed tissue homeostasis such as trauma and shock. Scientific advances in the past two decades have changed the role of neutrophils from that of solely immune defense cells to cells that are responsible for the general integrity of the body, even in the absence of pathogens. To better understand PMN function in the human organism, our review outlines the role of PMNs within the innate immune system. This review provides an overview of the migration of PMNs from the vascular compartment to the target tissue as well as their chemotactic processes and illuminates crucial neutrophil immune properties at the site of the lesion. The review is focused on the formation of chemotactic gradients in interaction with the extracellular matrix (ECM) and the influence of the ECM on PMN function. In addition, our review summarizes current knowledge about the phenomenon of bidirectional and reverse PMN migration, neutrophil microtubules, and the microtubule organizing center in PMN migration. As a conclusive feature, we review and discuss new findings about neutrophil behavior in cancer environment and tumor tissue.
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Affiliation(s)
- Richard Felix Kraus
- Department of Anesthesiology, University Medical Center Regensburg, Regensburg, Germany
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20
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Staphylococcus aureus-A Known Opponent against Host Defense Mechanisms and Vaccine Development-Do We Still Have a Chance to Win? Int J Mol Sci 2022; 23:ijms23020948. [PMID: 35055134 PMCID: PMC8781139 DOI: 10.3390/ijms23020948] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/11/2022] [Accepted: 01/13/2022] [Indexed: 02/07/2023] Open
Abstract
The main purpose of this review is to present justification for the urgent need to implement specific prophylaxis of invasive Staphylococcus aureus infections. We emphasize the difficulties in achieving this goal due to numerous S. aureus virulence factors important for the process of infection and the remarkable ability of these bacteria to avoid host defense mechanisms. We precede these considerations with a brief overview of the global necessitiy to intensify the use of vaccines against other pathogens as well, particularly in light of an impasse in antibiotic therapy. Finally, we point out global trends in research into modern technologies used in the field of molecular microbiology to develop new vaccines. We focus on the vaccines designed to fight the infections caused by S. aureus, which are often resistant to the majority of available therapeutic options.
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21
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Nguyen TH, Cheung GYC, Rigby KM, Kamenyeva O, Kabat J, Sturdevant DE, Villaruz AE, Liu R, Piewngam P, Porter AR, Firdous S, Chiou J, Park MD, Hunt RL, Almufarriji FMF, Tan VY, Asiamah TK, McCausland JW, Fisher EL, Yeh AJ, Bae JS, Kobayashi SD, Wang JM, Barber DL, DeLeo FR, Otto M. Rapid pathogen-specific recruitment of immune effector cells in the skin by secreted toxins. Nat Microbiol 2022; 7:62-72. [PMID: 34873293 PMCID: PMC8732318 DOI: 10.1038/s41564-021-01012-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 10/29/2021] [Indexed: 12/31/2022]
Abstract
Swift recruitment of phagocytic leucocytes is critical in preventing infection when bacteria breach through the protective layers of the skin. According to canonical models, this occurs via an indirect process that is initiated by contact of bacteria with resident skin cells and which is independent of the pathogenic potential of the invader. Here we describe a more rapid mechanism of leucocyte recruitment to the site of intrusion of the important skin pathogen Staphylococcus aureus that is based on direct recognition of specific bacterial toxins, the phenol-soluble modulins (PSMs), by circulating leucocytes. We used a combination of intravital imaging, ear infection and skin abscess models, and in vitro gene expression studies to demonstrate that this early recruitment was dependent on the transcription factor EGR1 and contributed to the prevention of infection. Our findings refine the classical notion of the non-specific and resident cell-dependent character of the innate immune response to bacterial infection by demonstrating a pathogen-specific high-alert mechanism involving direct recruitment of immune effector cells by secreted bacterial products.
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Affiliation(s)
- Thuan H Nguyen
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- University of Maryland School of Medicine, Baltimore, MD, USA
| | - Gordon Y C Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kevin M Rigby
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Pathogen-Host Cell Biology Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
- miRagen Therapeutics, Inc., Boulder, CO, USA
| | - Olena Kamenyeva
- Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Juraj Kabat
- Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Daniel E Sturdevant
- Genomics Unit, Research Technology Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Amer E Villaruz
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ryan Liu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Pipat Piewngam
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Adeline R Porter
- Pathogen-Host Cell Biology Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Saba Firdous
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Chlamydia Pathogenesis Section, NIAID, Bethesda, MD, USA
| | - Janice Chiou
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Graduate School in Biomedical Science, Cedars Sinai Medical Center, Los Angeles, CA, USA
| | - Matthew D Park
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Rachelle L Hunt
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Microbial Pathogenesis Department, Yale University, New Haven, CT, USA
| | - Fawaz M F Almufarriji
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- School of Molecular and Cell Biology, University of Leeds, Leeds, UK
| | - Vee Y Tan
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Tuberculosis Research Section, NIAID, Bethesda, MD, USA
| | - Titus K Asiamah
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Joshua W McCausland
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Johns Hopkins University, Baltimore, MD, USA
| | - Emilie L Fisher
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Vanderbilt University, Nashville, TN, USA
| | - Anthony J Yeh
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- William Carey University College of Osteopathic Medicine, Hattiesburg, MS, USA
| | - Justin S Bae
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Harvard University, Cambridge, MA, USA
| | - Scott D Kobayashi
- Pathogen-Host Cell Biology Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Ji Ming Wang
- Laboratory of Cancer and Immunometabolism, Center for Cancer Research, National Cancer Institute at Frederick, Frederick, MD, USA
| | - Daniel L Barber
- T-Lymphocyte Biology Unit, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Frank R DeLeo
- Pathogen-Host Cell Biology Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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22
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Mortaz E, Nomani M, Adcock I, Folkerts G, Garssen J. Galactooligosaccharides (GOS) and 2′-fucosyllactose (2′-FL) can directly suppress growth of specific pathogenic microbes and impact phagocytosis of neutrophils. Nutrition 2022; 96:111601. [DOI: 10.1016/j.nut.2022.111601] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 01/03/2022] [Accepted: 01/09/2022] [Indexed: 11/16/2022]
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23
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Affiliation(s)
- Leslie A Fogel
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
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24
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Zhou X, Zheng Y, Lv Q, Kong D, Ji B, Han X, Zhou D, Sun Z, Zhu L, Liu P, Jiang H, Jiang Y. Staphylococcus aureus N-terminus formylated δ-toxin tends to form amyloid fibrils, while the deformylated δ-toxin tends to form functional oligomer complexes. Virulence 2021; 12:1418-1437. [PMID: 34028320 PMCID: PMC8158037 DOI: 10.1080/21505594.2021.1928395] [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: 12/22/2020] [Revised: 05/04/2021] [Accepted: 05/07/2021] [Indexed: 11/29/2022] Open
Abstract
The community-associated Methicillin-resistant Staphylococcus aureus strain (CA-MRSA) is highly virulent and has become a major focus of public health professionals. Phenol-soluble modulins (PSM) are key factors in its increased virulence. δ-Toxin belongs to PSM family and has copious secretion in many S. aureus strains. In addition, δ-toxin exists in the S. aureus culture supernatant as both N-terminus formylated δ-toxin (fδ-toxin) and deformylated δ-toxin (dfδ-toxin) groups. Although δ-toxin has been studied for more than 70 years, its functions remain unclear. We isolated and purified PSMs from the supernatant of S. aureus MW2, and found fibrils and oligomers aggregates by Size Exclusion Chromatography. After analyzing PSM aggregates and using peptide simulations, we found that the difference in the monomer structure of fδ-toxin and dfδ-toxin might ultimately lead to differences in the aggregation ability: fδ-toxin and dfδ-toxin tend to form fibrils and oligomers respectively. Of note, we found that fδ-toxin fibrils enhanced the stability of biofilms, while dfδ-toxin oligomers promoted their dispersal. Additionally, oligomeric dfδ-toxin combined with PSMα to form a complex with enhanced functionality. Due to the different aggregation capabilities and functions of fδ-toxin and dfδ-toxin, we speculate that they may be involved in the regulation of physiological activities of S. aureus. Moreover, the dfδ-toxin oligomer not only provides a new form of complex in the study of PSMα, but also has significance as a reference in oligomer research pertaining to some human amyloid diseases.
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Affiliation(s)
- Xinyu Zhou
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China
| | - Yuling Zheng
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China
| | - Qingyu Lv
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China
| | - Decong Kong
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China
| | - Bin Ji
- Institute of Nano Biomedicine and Engineering, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Xuelian Han
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China
| | - Dongsheng Zhou
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China
| | - Zeyu Sun
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China
| | - Li Zhu
- Beijing Institute of Biotechnology, Beijing, China
| | - Peng Liu
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China
| | - Hua Jiang
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China
| | - Yongqiang Jiang
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, China
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25
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Damour A, Robin B, Deroche L, Broutin L, Bellin N, Verdon J, Lina G, Leclère FM, Garcia M, Cremniter J, Lévêque N, Bodet C. Phenol-soluble modulins α are major virulence factors of Staphylococcus aureus secretome promoting inflammatory response in human epidermis. Virulence 2021; 12:2474-2492. [PMID: 34516337 PMCID: PMC8451463 DOI: 10.1080/21505594.2021.1975909] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 08/03/2021] [Accepted: 08/25/2021] [Indexed: 11/10/2022] Open
Abstract
Staphylococcus aureus is a skin commensal microorganism commonly colonizing healthy humans. Nevertheless, S. aureus can also be responsible for cutaneous infections and contribute to flare-up of inflammatory skin diseases such as atopic dermatitis (AD), which is characterized by dysbiosis of the skin microbiota with S. aureus as the predominant species. However, the role of major virulence factors of this pathogen such as phenol-soluble modulin (PSM) toxins in epidermal inflammation remains poorly understood. Stimulation of primary human keratinocytes with sublytic concentrations of synthetic and purified PSM α3 resulted in upregulation of a large panel of pro-inflammatory chemokine and cytokine gene expression, including CXCL1, CXCL2, CXCL3, CXCL5, CXCL8, CCL20, IL-1α, IL-1β, IL-6, IL-36γ and TNF-α, while inducing the release of CXCL8, CCL20, TNF-α and IL-6. In addition, using S. aureus culture supernatant from mutants deleted from genes encoding either α-type PSMs or all PSM production, PSMs were shown to be the main factors of S. aureus secretome responsible for pro-inflammatory mediator induction in human keratinocytes. On the other hand, α-type PSM-containing supernatant triggered an intense induction of pro-inflammatory mediator expression and secretion during both topical and basal layer stimulation of an ex vivo model of human skin explants, a physiologically relevant model of pluristratified epidermis. Taken together, the results of this study show that PSMs and more specifically α-type PSMs are major virulence factors of S. aureus inducing a potent inflammatory response during infection of the human epidermis and could thereby contribute to AD flare-up through exacerbation of skin inflammation.
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Affiliation(s)
- Alexia Damour
- Laboratoire Inflammation Tissus Epithéliaux et Cytokines EA 4331, Université De Poitiers, Poitiers, France
| | - Brandon Robin
- Laboratoire Inflammation Tissus Epithéliaux et Cytokines EA 4331, Université De Poitiers, Poitiers, France
| | - Luc Deroche
- Laboratoire Inflammation Tissus Epithéliaux et Cytokines EA 4331, Université De Poitiers, Poitiers, France
| | - Lauranne Broutin
- Laboratoire Inflammation Tissus Epithéliaux et Cytokines EA 4331, Université De Poitiers, Poitiers, France
- Laboratoire De Bactériologie, CHU de Poitiers, Poitiers, France
| | - Nicolas Bellin
- Laboratoire Inflammation Tissus Epithéliaux et Cytokines EA 4331, Université De Poitiers, Poitiers, France
| | - Julien Verdon
- Laboratoire Ecologie et Biologie des Interactions, UMR CNRS 7267, Université De Poitiers, Poitiers, France
| | - Gérard Lina
- CIRI Centre International de Recherche en Infectiologie, Inserm U1111, Université Lyon 1, Ecole Normale Supérieure de Lyon, Lyon, France
- Centre National de Référence des Staphylocoques, Institut des Agent Infectieux, Hôpital de La Croix Rousse, Hospices Civils de Lyon, Lyon, France
| | - Franck Marie Leclère
- Laboratoire Inflammation Tissus Epithéliaux et Cytokines EA 4331, Université De Poitiers, Poitiers, France
- Département de Chirurgie Plastique, Reconstructive et Esthétique, CHU de Poitiers, Poitiers, France
| | - Magali Garcia
- Laboratoire Inflammation Tissus Epithéliaux et Cytokines EA 4331, Université De Poitiers, Poitiers, France
- Laboratoire de Virologie et Mycobactériologie, CHU de Poitiers, Poitiers, France
| | - Julie Cremniter
- Laboratoire Inflammation Tissus Epithéliaux et Cytokines EA 4331, Université De Poitiers, Poitiers, France
- Laboratoire De Bactériologie, CHU de Poitiers, Poitiers, France
| | - Nicolas Lévêque
- Laboratoire Inflammation Tissus Epithéliaux et Cytokines EA 4331, Université De Poitiers, Poitiers, France
- Laboratoire de Virologie et Mycobactériologie, CHU de Poitiers, Poitiers, France
| | - Charles Bodet
- Laboratoire Inflammation Tissus Epithéliaux et Cytokines EA 4331, Université De Poitiers, Poitiers, France
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26
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Further Insight into the Mechanism of Human PMN Lysis following Phagocytosis of Staphylococcus aureus. Microbiol Spectr 2021; 9:e0088821. [PMID: 34704790 PMCID: PMC8549732 DOI: 10.1128/spectrum.00888-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Staphylococcus aureus is an important human pathogen that can cause a variety of diseases ranging from mild superficial skin infections to life-threatening conditions like necrotizing pneumonia, endocarditis, and septicemia. Polymorphonuclear leukocytes (PMNs; neutrophils in particular herein) are essential for host defense against S. aureus infections, and the microbe is phagocytosed readily. Most ingested bacteria are killed, but some S. aureus strains—such as the epidemic USA300 strain—have an enhanced ability to cause PMN lysis after phagocytosis. Although progress has been made, the mechanism for lysis after phagocytosis of S. aureus remains incompletely determined. Here, we tested the hypothesis that disruption of phagosome integrity and escape of S. aureus from the PMN phagosome into the cytoplasm precedes PMN lysis. We used USA300 wild-type and isogenic deletion strains to evaluate and/or verify the role of selected S. aureus molecules in this cytolytic process. Compared to the wild-type USA300 strain, Δagr, Δhla, ΔlukGH, and Δpsm strains each caused significantly less lysis of human PMNs 3 h and/or 6 h after phagocytosis, consistent with previous studies. Most notably, confocal microscopy coupled with selective permeabilization assays demonstrated that phagosome membrane integrity is largely maintained prior to PMN lysis after S. aureus phagocytosis. We conclude that PMN lysis does not require escape of S. aureus from the phagosome to the cytoplasm and that these are independent phenomena. The findings are consistent with the ability of S. aureus (via selected molecules) to trigger lysis of human PMNs by an undetermined signaling mechanism. IMPORTANCES. aureus strain USA300 has the ability to cause rapid lysis of human neutrophils after phagocytosis. Although this phenomenon likely contributes to the success of USA300 as a human pathogen, our knowledge of the mechanism remains incomplete. Here, we used a selective permeabilization assay coupled with confocal microscopy to demonstrate that USA300 is contained within human neutrophil phagosomes until the point of host cell lysis. Thus, consistent with a process in macrophages, S. aureus fails to escape into the neutrophil cytoplasm prior to cytolysis.
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27
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Kretschmer D, Breitmeyer R, Gekeler C, Lebtig M, Schlatterer K, Nega M, Stahl M, Stapels D, Rooijakkers S, Peschel A. Staphylococcus aureus Depends on Eap Proteins for Preventing Degradation of Its Phenol-Soluble Modulin Toxins by Neutrophil Serine Proteases. Front Immunol 2021; 12:701093. [PMID: 34552584 PMCID: PMC8451722 DOI: 10.3389/fimmu.2021.701093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/18/2021] [Indexed: 11/13/2022] Open
Abstract
Neutrophil granulocytes act as a first line of defense against pathogenic staphylococci. However, Staphylococcus aureus has a remarkable capacity to survive neutrophil killing, which distinguishes it from the less-pathogenic Staphylococcus epidermidis. Both species release phenol-soluble modulin (PSM) toxins, which activate the neutrophil formyl-peptide receptor 2 (FPR2) to promote neutrophil influx and phagocytosis, and which disrupt neutrophils or their phagosomal membranes at high concentrations. We show here that the neutrophil serine proteases (NSPs) neutrophil elastase, cathepsin G and proteinase 3, which are released into the extracellular space or the phagosome upon neutrophil FPR2 stimulation, effectively degrade PSMs thereby preventing their capacity to activate and destroy neutrophils. Notably, S. aureus, but not S. epidermidis, secretes potent NSP-inhibitory proteins, Eap, EapH1, EapH2, which prevented the degradation of PSMs by NSPs. Accordingly, a S. aureus mutant lacking all three NSP inhibitory proteins was less effective in activating and destroying neutrophils and it survived less well in the presence of neutrophils than the parental strain. We show that Eap proteins promote pathology via PSM-mediated FPR2 activation since murine intraperitoneal infection with the S. aureus parental but not with the NSP inhibitors mutant strain, led to a significantly higher bacterial load in the peritoneum and kidneys of mFpr2-/- compared to wild-type mice. These data demonstrate that NSPs can very effectively detoxify some of the most potent staphylococcal toxins and that the prominent human pathogen S. aureus has developed efficient inhibitors to preserve PSM functions. Preventing PSM degradation during infection represents an important survival strategy to ensure FPR2 activation.
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Affiliation(s)
- Dorothee Kretschmer
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Ricarda Breitmeyer
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Cordula Gekeler
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Marco Lebtig
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Katja Schlatterer
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
| | - Mulugeta Nega
- Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany.,Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Microbial Genetics, University of Tübingen, Tübingen, Germany
| | - Mark Stahl
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Daphne Stapels
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Suzan Rooijakkers
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | - Andreas Peschel
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), Infection Biology, University of Tübingen, Tübingen, Germany.,German Center for Infection Research, Partner Site Tübingen, Tübingen, Germany.,Cluster of Excellence EXC2124 "Controlling Microbes to Fight Infections", Tübingen, Germany
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28
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Ahmad-Mansour N, Loubet P, Pouget C, Dunyach-Remy C, Sotto A, Lavigne JP, Molle V. Staphylococcus aureus Toxins: An Update on Their Pathogenic Properties and Potential Treatments. Toxins (Basel) 2021; 13:677. [PMID: 34678970 PMCID: PMC8540901 DOI: 10.3390/toxins13100677] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/18/2021] [Accepted: 09/21/2021] [Indexed: 01/12/2023] Open
Abstract
Staphylococcus aureus is a clinically important pathogen that causes a wide range of human infections, from minor skin infections to severe tissue infection and sepsis. S. aureus has a high level of antibiotic resistance and is a common cause of infections in hospitals and the community. The rising prevalence of community-acquired methicillin-resistant S. aureus (CA-MRSA), combined with the important severity of S. aureus infections in general, has resulted in the frequent use of anti-staphylococcal antibiotics, leading to increasing resistance rates. Antibiotic-resistant S. aureus continues to be a major health concern, necessitating the development of novel therapeutic strategies. S. aureus uses a wide range of virulence factors, such as toxins, to develop an infection in the host. Recently, anti-virulence treatments that directly or indirectly neutralize S. aureus toxins have showed promise. In this review, we provide an update on toxin pathogenic characteristics, as well as anti-toxin therapeutical strategies.
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Affiliation(s)
- Nour Ahmad-Mansour
- Laboratory of Pathogen Host Interactions, CNRS UMR5235, Université de Montpellier, 34000 Montpellier, France;
| | - Paul Loubet
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Department of Infectious and Tropical Diseases, Université de Montpellier, 30908 Nîmes, France; (P.L.); (A.S.)
| | - Cassandra Pouget
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Université de Montpellier, 30908 Nîmes, France;
| | - Catherine Dunyach-Remy
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Department of Microbiology and Hospital Hygiene, Université de Montpellier, 30908 Nîmes, France; (C.D.-R.); (J.-P.L.)
| | - Albert Sotto
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Department of Infectious and Tropical Diseases, Université de Montpellier, 30908 Nîmes, France; (P.L.); (A.S.)
| | - Jean-Philippe Lavigne
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Department of Microbiology and Hospital Hygiene, Université de Montpellier, 30908 Nîmes, France; (C.D.-R.); (J.-P.L.)
| | - Virginie Molle
- Laboratory of Pathogen Host Interactions, CNRS UMR5235, Université de Montpellier, 34000 Montpellier, France;
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29
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Intracellular Staphylococcus aureus employs the cysteine protease staphopain A to induce host cell death in epithelial cells. PLoS Pathog 2021; 17:e1009874. [PMID: 34473800 PMCID: PMC8443034 DOI: 10.1371/journal.ppat.1009874] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 09/15/2021] [Accepted: 08/07/2021] [Indexed: 11/19/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen, which can invade and survive in non-professional and professional phagocytes. Uptake by host cells is thought to contribute to pathogenicity and persistence of the bacterium. Upon internalization by epithelial cells, cytotoxic S. aureus strains can escape from the phagosome, replicate in the cytosol and induce host cell death. Here, we identified a staphylococcal cysteine protease to induce cell death after translocation of intracellular S. aureus into the host cell cytoplasm. We demonstrated that loss of staphopain A function leads to delayed onset of host cell death and prolonged intracellular replication of S. aureus in epithelial cells. Overexpression of staphopain A in a non-cytotoxic strain facilitated intracellular killing of the host cell even in the absence of detectable intracellular replication. Moreover, staphopain A contributed to efficient colonization of the lung in a mouse pneumonia model. In phagocytic cells, where intracellular S. aureus is exclusively localized in the phagosome, staphopain A did not contribute to cytotoxicity. Our study suggests that staphopain A is utilized by S. aureus to exit the epithelial host cell and thus contributes to tissue destruction and dissemination of infection. Staphylococcus aureus is an antibiotic-resistant pathogen that emerges in hospital and community settings and can cause a variety of diseases ranging from skin abscesses to lung inflammation and blood poisoning. The bacterium can asymptomatically colonize the upper respiratory tract and skin of humans and take advantage of opportune conditions, like immunodeficiency or breached barriers, to cause infection. Although S. aureus was not regarded as intracellular bacterium, it can be internalized by human cells and subsequently exit the host cells by induction of cell death, which is considered to cause tissue destruction and spread of infection. The bacterial virulence factors and underlying molecular mechanisms involved in the intracellular lifestyle of S. aureus remain largely unknown. We identified a bacterial cysteine protease to contribute to host cell death of epithelial cells mediated by intracellular S. aureus. Staphopain A induced killing of the host cell after translocation of the pathogen into the cell cytosol, while bacterial proliferation was not required. Further, the protease enhanced survival of the pathogen during lung infection. These findings reveal a novel, intracellular role for the bacterial protease staphopain A.
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30
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Nomani M, Varahram M, Tabarsi P, Hashemian SM, Jamaati H, Malekmohammad M, Ghazi M, Adcock IM, Mortaz E. Decreased neutrophil-mediated bacterial killing in COVID-19 patients. Scand J Immunol 2021; 94:e13083. [PMID: 35993347 PMCID: PMC8237074 DOI: 10.1111/sji.13083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 05/17/2021] [Accepted: 05/26/2021] [Indexed: 01/12/2023]
Abstract
The coronavirus disease COVID-19 was first described in December 2019. The peripheral blood of COVID-19 patients have increased numbers of neutrophils which are important in controlling the bacterial infections observed in COVID-19. We sought to evaluate the cytotoxic capacity of neutrophils in COVID-19 patients. 34 confirmed COVID-19 patients (29 severe, five mild disease), and nine healthy controls were recruited from the Masih Daneshvari Hospital (Tehran, Iran) from March to May 2020. Polymorphonuclear (PMN) cells were isolated from whole blood and incubated with green fluorescent protein (GFP)-labelled methicillin-resistant Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA). Bacterial growth was determined by measuring the florescence of co-cultures of bacteria and neutrophils and reported as the lag time before exponential growth. The number of viable bacteria was determined after 70 hours as colony-forming units (CFU). The immunophenotype of tested cells was evaluated by flow cytometry. Isolated neutrophils have higher surface expression of CD16 and CD62L with negative markers for PMN-MDSC. Bacterial growth in the presence of SA (22 ± 0.9 versus 9.2 ± 0.5 h, P < .01) and PA (12.4 ± 0.6 versus 4.5 ± 0.22, P < .01) was significantly reduced in COVID-19 patients. After 70 h incubation of PMN with bacteria (SA and PA), CFUs were significant increased in COVID-19 patients SA (2.6 ± 0.09 × 108 CFU/mL-severe patients and 1.4 ± 0.06 × 108 CFU/mL-mild patients, P < .001) and PA (2.2 ± 0.09 × 109 CFU/mL-severe patients and 1.6 ± 0.03 × 109 CFU/mL-mild patients, P < .001). Gentamycin proliferation assays confirmed the presence of intracellular bacteria. Reduced bacterial killing by neutrophils from COVID-19 patients may be responsible for the high bacterial yield seen in these patients.
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Affiliation(s)
- Masoumeh Nomani
- Clinical Tuberculosis and Epidemiology Research CenterNational Research Institute of Tuberculosis and Lung DiseasesShahid Beheshti University of Medical SciencesTehranIran
| | - Mohammad Varahram
- Mycobacteriology Research CenterNational Research Institute of Tuberculosis and Lung Diseases (NRITLD)Masih Daneshvari HospitalShahid Beheshti University of Medical SciencesTehranIran
| | - Payam Tabarsi
- Clinical Tuberculosis and Epidemiology Research CenterNational Research Institute of Tuberculosis and Lung DiseasesShahid Beheshti University of Medical SciencesTehranIran
| | - Seyed MohammadReza Hashemian
- Chronic Respiratory Diseases Research CenterNational Research Institute of Tuberculosis and Lung Diseases (NRITLD)Shahid Beheshti University of Medical SciencesTehranIran
| | - Hamidreza Jamaati
- Chronic Respiratory Diseases Research CenterNational Research Institute of Tuberculosis and Lung Diseases (NRITLD)Shahid Beheshti University of Medical SciencesTehranIran
| | - Majid Malekmohammad
- Chronic Respiratory Diseases Research CenterNational Research Institute of Tuberculosis and Lung Diseases (NRITLD)Shahid Beheshti University of Medical SciencesTehranIran
| | - Mona Ghazi
- Department of MicrobiologySchool of MedicineShahid Beheshti University of Medical SciencesTehranIran
| | - Ian M. Adcock
- National Heart and Lung InstituteImperial College LondonLondonUK
| | - Esmaeil Mortaz
- Clinical Tuberculosis and Epidemiology Research CenterNational Research Institute of Tuberculosis and Lung DiseasesShahid Beheshti University of Medical SciencesTehranIran
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31
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Najarzadeh Z, Zaman M, Sereikaite V, Strømgaard K, Andreasen M, Otzen DE. Heparin promotes fibrillation of most phenol-soluble modulin virulence peptides from Staphylococcus aureus. J Biol Chem 2021; 297:100953. [PMID: 34270957 PMCID: PMC8363829 DOI: 10.1016/j.jbc.2021.100953] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/29/2021] [Accepted: 07/08/2021] [Indexed: 10/26/2022] Open
Abstract
Phenol-soluble modulins (PSMs), such as α-PSMs, β-PSMs, and δ-toxin, are virulence peptides secreted by different Staphylococcus aureus strains. PSMs are able to form amyloid fibrils, which may strengthen the biofilm matrix that promotes bacterial colonization of and extended growth on surfaces (e.g., cell tissue) and increases antibiotic resistance. Many components contribute to biofilm formation, including the human-produced highly sulfated glycosaminoglycan heparin. Although heparin promotes S. aureus infection, the molecular basis for this is unclear. Given that heparin is known to induce fibrillation of a wide range of proteins, we hypothesized that heparin aids bacterial colonization by promoting PSM fibrillation. Here, we address this hypothesis using a combination of thioflavin T-fluorescence kinetic studies, CD, FTIR, electron microscopy, and peptide microarrays to investigate the mechanism of aggregation, the structure of the fibrils, and identify possible binding regions. We found that heparin accelerates fibrillation of all α-PSMs (except PSMα2) and δ-toxin but inhibits β-PSM fibrillation by blocking nucleation or reducing fibrillation levels. Given that S. aureus secretes higher levels of α-PSM than β-PSM peptides, heparin is therefore likely to promote fibrillation overall. Heparin binding is driven by multiple positively charged lysine residues in α-PSMs and δ-toxins, the removal of which strongly reduced binding affinity. Binding of heparin did not affect the structure of the resulting fibrils, that is, the outcome of the aggregation process. Rather, heparin provided a scaffold to catalyze or inhibit fibrillation. Based on our findings, we speculate that heparin may strengthen the bacterial biofilm and therefore enhance colonization via increased PSM fibrillation.
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Affiliation(s)
- Zahra Najarzadeh
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Aarhus C, Denmark
| | - Masihuz Zaman
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Vita Sereikaite
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen Ø, Denmark
| | - Kristian Strømgaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen Ø, Denmark
| | - Maria Andreasen
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark.
| | - Daniel E Otzen
- Interdisciplinary Nanoscience Centre (iNANO), Aarhus University, Aarhus C, Denmark.
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32
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Five major two components systems of Staphylococcus aureus for adaptation in diverse hostile environment. Microb Pathog 2021; 159:105119. [PMID: 34339796 DOI: 10.1016/j.micpath.2021.105119] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 05/21/2021] [Accepted: 07/28/2021] [Indexed: 11/21/2022]
Abstract
Staphylococcus aureus is an eminent and opportunistic human pathogen that can colonize in the intestines, skin tissue and perineal regions of the host and cause severe infectious diseases. The presence of complex regulatory network and existence of virulent gene expression along with tuning metabolism enables the S. aureus to adopt the diversity of environments. Two component system (TCS) is a widely distributed mechanism in S. aureus that permit it for changing gene expression profile in response of environment stimuli. TCS usually consist of transmembrane histidine kinase (HK) and cytosolic response regulator. S. aureus contains totally 16 conserved pairs of two component systems, involving in different signaling mechanisms. There is a connection among these regulatory circuits and they can easily have effect on each other's expression. This review has discussed five major types of TCS in S. aureus and covers the recent knowledge of their virulence gene expression. We can get more understanding towards staphylococcal pathogenicity by getting insights about gene regulatory pathways via TCS, which can further provide implications in vaccine formation and new ways for drug design to combat serious infections caused by S. aureus in humans.
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33
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Hommes JW, Kratofil RM, Wahlen S, de Haas CJC, Hildebrand RB, Hovingh GK, Otto M, van Eck M, Hoekstra M, Korporaal SJA, Surewaard BGJ. High density lipoproteins mediate in vivo protection against staphylococcal phenol-soluble modulins. Sci Rep 2021; 11:15357. [PMID: 34321507 PMCID: PMC8319287 DOI: 10.1038/s41598-021-94651-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/28/2021] [Indexed: 12/30/2022] Open
Abstract
Staphylococcus aureus virulence has been associated with the production of phenol-soluble modulins (PSMs). These PSMs have distinct virulence functions and are known to activate, attract and lyse neutrophils. These PSM-associated biological functions are inhibited by lipoproteins in vitro. We set out to address whether lipoproteins neutralize staphylococcal PSM-associated virulence in experimental animal models. Serum from both LCAT an ABCA1 knockout mice strains which are characterised by near absence of high-density lipoprotein (HDL) levels, was shown to fail to protect against PSM-induced neutrophil activation and lysis in vitro. Importantly, PSM-induced peritonitis in LCAT-/- mice resulted in increased lysis of resident peritoneal macrophages and enhanced neutrophil recruitment into the peritoneal cavity. Notably, LCAT-/- mice were more likely to succumb to staphylococcal bloodstream infections in a PSM-dependent manner. Plasma from homozygous carriers of ABCA1 variants characterized by very low HDL-cholesterol levels, was found to be less protective against PSM-mediated biological functions compared to healthy humans. Therefore, we conclude that lipoproteins present in blood can protect against staphylococcal PSMs, the key virulence factor of community-associated methicillin resistant S. aureus.
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Affiliation(s)
- Josefien W Hommes
- Department of Microbiology, Immunology, and Infectious Disease. Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Rachel M Kratofil
- Department of Microbiology, Immunology, and Infectious Disease. Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Sigrid Wahlen
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Diagnostic Sciences, Laboratory of Experimental Immunology, Ghent University, Ghent, Belgium
| | - Carla J C de Haas
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Reeni B Hildebrand
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Gorlaeus Laboratories, Leiden, The Netherlands
| | - G Kees Hovingh
- Department of Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Micheal Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Miranda van Eck
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Gorlaeus Laboratories, Leiden, The Netherlands
| | - Menno Hoekstra
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Gorlaeus Laboratories, Leiden, The Netherlands
| | - Suzanne J A Korporaal
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Gorlaeus Laboratories, Leiden, The Netherlands.,Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Bas G J Surewaard
- Department of Microbiology, Immunology, and Infectious Disease. Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada. .,Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
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34
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Raineri EJM, Altulea D, van Dijl JM. Staphylococcal trafficking and infection - from 'nose to gut' and back. FEMS Microbiol Rev 2021; 46:6321165. [PMID: 34259843 PMCID: PMC8767451 DOI: 10.1093/femsre/fuab041] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 07/11/2021] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus is an opportunistic human pathogen, which is a leading cause of infections worldwide. The challenge in treating S. aureus infection is linked to the development of multidrug-resistant strains and the mechanisms employed by this pathogen to evade the human immune defenses. In addition, S. aureus can hide asymptomatically in particular ‘protective’ niches of the human body for prolonged periods of time. In the present review, we highlight recently gained insights in the role of the human gut as an endogenous S. aureus reservoir next to the nasopharynx and oral cavity. In addition, we address the contribution of these ecological niches to staphylococcal transmission, including the roles of particular triggers as modulators of the bacterial dissemination. In this context, we present recent advances concerning the interactions between S. aureus and immune cells to understand their possible roles as vehicles of dissemination from the gut to other body sites. Lastly, we discuss the factors that contribute to the switch from colonization to infection. Altogether, we conclude that an important key to uncovering the pathogenesis of S. aureus infection lies hidden in the endogenous staphylococcal reservoirs, the trafficking of this bacterium through the human body and the subsequent immune responses.
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Affiliation(s)
- Elisa J M Raineri
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Dania Altulea
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Jan Maarten van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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35
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Matsumoto M, Nakagawa S, Zhang L, Nakamura Y, Villaruz AE, Otto M, Wolz C, Inohara N, Núñez G. Interaction between Staphylococcus Agr virulence and neutrophils regulates pathogen expansion in the skin. Cell Host Microbe 2021; 29:930-940.e4. [PMID: 33852876 PMCID: PMC11024063 DOI: 10.1016/j.chom.2021.03.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/01/2021] [Accepted: 03/16/2021] [Indexed: 01/27/2023]
Abstract
Staphylococcus aureus commonly infects the skin, but the host-pathogen interactions controlling bacterial growth remain unclear. S. aureus virulence is regulated by the Agr quorum-sensing system that controls factors including phenol-soluble modulins (PSMs), a group of cytotoxic peptides. We found a differential requirement for Agr and PSMα for pathogen growth in the skin. In neutrophil-deficient mice, S. aureus growth on the epidermis was unaffected, but the pathogen penetrated the dermis through mechanisms that require PSMα. In the dermis, pathogen expansion required Agr in wild-type mice, but not in neutrophil-deficient mice. Agr limited oxidative and non-oxidative killing in neutrophils by inhibiting pathogen late endosome localization and promoting phagosome escape. Unlike Agr, the SaeR/S virulence program was dispensable for growth in the epidermis and promoted dermal pathogen expansion independently of neutrophils. Thus, S. aureus growth and invasion are differentially regulated with Agr limiting intracellular killing within neutrophils to promote pathogen expansion in the dermis and subcutaneous tissue.
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Affiliation(s)
- Masanori Matsumoto
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
| | - Seitaro Nakagawa
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Lingzhi Zhang
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Yuumi Nakamura
- Cutaneous Immunology, Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan
| | - Amer E Villaruz
- Pathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, 72076, Germany
| | - Naohiro Inohara
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Gabriel Núñez
- Department of Pathology and Rogel Cancer Center, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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36
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Abstract
Staphylococcus aureus is both a commensal and a pathogenic bacterium for humans. Its ability to induce severe infections is based on a wide range of virulence factors. S. aureus community-acquired pneumonia (SA-CAP) is rare and severe, and the contribution of certain virulence factors in this disease has been recognized over the past 2 decades. First, the factors involved in metabolism adaptation are crucial for S. aureus survival in the lower respiratory tract, and toxins and enzymes are required for it to cross the pulmonary epithelial barrier. S. aureus subsequently faces host defense mechanisms, including the epithelial barrier, but most importantly the immune system. Here, again, S. aureus uses myriad virulence factors to successfully escape from the host's defenses and takes advantage of them. The impact of S. aureus virulence, combined with the collateral damage caused by an overwhelming immune response, leads to severe tissue damage and adverse clinical outcomes. In this review, we summarize step by step all of the S. aureus factors implicated in CAP and described to date, and we provide an outlook for future research.
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Affiliation(s)
- Mariane Pivard
- CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, Lyon, France
| | - Karen Moreau
- CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, Lyon, France
| | - François Vandenesch
- CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, Lyon, France
- Centre National de Référence des Staphylocoques, Institut des agents infectieux, Hospices Civils de Lyon, Lyon, France
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37
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Pettygrove BA, Kratofil RM, Alhede M, Jensen PØ, Newton M, Qvortrup K, Pallister KB, Bjarnsholt T, Kubes P, Voyich JM, Stewart PS. Delayed neutrophil recruitment allows nascent Staphylococcus aureus biofilm formation and immune evasion. Biomaterials 2021; 275:120775. [PMID: 34243039 DOI: 10.1016/j.biomaterials.2021.120775] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 02/19/2021] [Accepted: 03/20/2021] [Indexed: 02/07/2023]
Abstract
Biofilms that form on implanted medical devices cause recalcitrant infections. The early events enabling contaminating bacteria to evade immune clearance, before a mature biofilm is established, are poorly understood. Live imaging in vitro demonstrated that Staphylococcus aureus sparsely inoculated on an abiotic surface can go undiscovered by human neutrophils, grow, and form aggregates. Small (~50 μm2) aggregates of attached bacteria resisted killing by human neutrophils, resulting in neutrophil lysis and bacterial persistence. In vivo, neutrophil recruitment to a peritoneal implant was spatially heterogenous, with some bacterial aggregates remaining undiscovered by neutrophils after 24 h. Intravital imaging in mouse skin revealed that attached S. aureus aggregates grew and remained undiscovered by neutrophils for up to 3 h. These results suggest a model in which delayed recruitment of neutrophils to an abiotic implant presents a critical window in which bacteria establish a nascent biofilm and acquire tolerance to neutrophil killing.
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Affiliation(s)
- Brian A Pettygrove
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA; Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Rachel M Kratofil
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Maria Alhede
- Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Peter Ø Jensen
- Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark; Institute for Inflammation Research, Center for Rheumatology and Spine Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Microbiology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Michelle Newton
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Klaus Qvortrup
- Department of Biomedical Sciences/CFIM, University of Copenhagen, Copenhagen, Denmark
| | - Kyler B Pallister
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark; Department of Clinical Microbiology, Copenhagen University Hospital, Copenhagen, Denmark
| | - Paul Kubes
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada; Calvin, Phoebe and Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB, Canada
| | - Jovanka M Voyich
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Philip S Stewart
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA; Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT, USA.
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38
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Pérez-Figueroa E, Álvarez-Carrasco P, Ortega E, Maldonado-Bernal C. Neutrophils: Many Ways to Die. Front Immunol 2021; 12:631821. [PMID: 33746968 PMCID: PMC7969520 DOI: 10.3389/fimmu.2021.631821] [Citation(s) in RCA: 80] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 02/08/2021] [Indexed: 12/21/2022] Open
Abstract
Neutrophils or polymorphonuclear leukocytes (PMN) are key participants in the innate immune response for their ability to execute different effector functions. These cells express a vast array of membrane receptors that allow them to recognize and eliminate infectious agents effectively and respond appropriately to microenvironmental stimuli that regulate neutrophil functions, such as activation, migration, generation of reactive oxygen species, formation of neutrophil extracellular traps, and mediator secretion, among others. Currently, it has been realized that activated neutrophils can accomplish their effector functions and simultaneously activate mechanisms of cell death in response to different intracellular or extracellular factors. Although several studies have revealed similarities between the mechanisms of cell death of neutrophils and other cell types, neutrophils have distinctive properties, such as a high production of reactive oxygen species (ROS) and nitrogen species (RNS), that are important for their effector function in infections and pathologies such as cancer, autoimmune diseases, and immunodeficiencies, influencing their cell death mechanisms. The present work offers a synthesis of the conditions and molecules implicated in the regulation and activation of the processes of neutrophil death: apoptosis, autophagy, pyroptosis, necroptosis, NETosis, and necrosis. This information allows to understand the duality encountered by PMNs upon activation. The effector functions are carried out to eliminate invading pathogens, but in several instances, these functions involve activation of signaling cascades that culminate in the death of the neutrophil. This process guarantees the correct elimination of pathogenic agents, damaged or senescent cells, and the timely resolution of the inflammation that is essential for the maintenance of homeostasis in the organism. In addition, they alert the organism when the immunological system is being deregulated, promoting the activation of other cells of the immune system, such as B and T lymphocytes, which produce cytokines that potentiate the microbicide functions.
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Affiliation(s)
- Erandi Pérez-Figueroa
- Unidad de Investigación en Inmunología y Proteómica, Hospital Infantil de México Federico Gómez, Secretaría de Salud, Mexico City, Mexico
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Pablo Álvarez-Carrasco
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Enrique Ortega
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico City, Mexico
| | - Carmen Maldonado-Bernal
- Unidad de Investigación en Inmunología y Proteómica, Hospital Infantil de México Federico Gómez, Secretaría de Salud, Mexico City, Mexico
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39
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Rungelrath V, DeLeo FR. Staphylococcus aureus, Antibiotic Resistance, and the Interaction with Human Neutrophils. Antioxid Redox Signal 2021; 34:452-470. [PMID: 32460514 PMCID: PMC8020508 DOI: 10.1089/ars.2020.8127] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Significance:Staphylococcus aureus is among the leading causes of bacterial infections worldwide. The high burden of S. aureus among human and animal hosts, which includes asymptomatic carriage and infection, is coupled with a notorious ability of the microbe to become resistant to antibiotics. Notably, S. aureus has the ability to produce molecules that promote evasion of host defense, including the ability to avoid killing by neutrophils. Recent Advances: Significant progress has been made to better understand S. aureus-host interactions. These discoveries include elucidation of the role played by numerous S. aureus virulence molecules during infection. Based on putative functions, a number of these virulence molecules, including S. aureus alpha-hemolysin and protein A, have been identified as therapeutic targets. Although it has not been possible to develop a vaccine that can prevent S. aureus infections, monoclonal antibodies specific for S. aureus virulence molecules have the potential to moderate the severity of disease. Critical Issues: Therapeutic options for treatment of methicillin-resistant S. aureus (MRSA) are limited, and the microbe typically develops resistance to new antibiotics. New prophylactics and/or therapeutics are needed. Future Directions: Research that promotes an enhanced understanding of S. aureus-host interaction is an important step toward developing new therapeutic approaches directed to moderate disease severity and facilitate treatment of infection. This research effort includes studies that enhance our view of the interaction of S. aureus with human neutrophils. Antioxid. Redox Signal. 34, 452-470.
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Affiliation(s)
- Viktoria Rungelrath
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Frank R DeLeo
- Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
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Horvatek P, Salzer A, Hanna AMF, Gratani FL, Keinhörster D, Korn N, Borisova M, Mayer C, Rejman D, Mäder U, Wolz C. Inducible expression of (pp)pGpp synthetases in Staphylococcus aureus is associated with activation of stress response genes. PLoS Genet 2020; 16:e1009282. [PMID: 33378356 PMCID: PMC7802963 DOI: 10.1371/journal.pgen.1009282] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 01/12/2021] [Accepted: 11/18/2020] [Indexed: 11/30/2022] Open
Abstract
The stringent response is characterized by the synthesis of the messenger molecules pppGpp, ppGpp or pGpp (here collectively designated (pp)pGpp). The phenotypic consequences resulting from (pp)pGpp accumulation vary among species and can be mediated by different underlying mechanisms. Most genome-wide analyses have been performed under stress conditions, which often mask the immediate effects of (pp)pGpp-mediated regulatory circuits. In Staphylococcus aureus, (pp)pGpp can be synthesized via the RelA-SpoT-homolog, RelSau upon amino acid limitation or via one of the two small (pp)pGpp synthetases RelP or RelQ upon cell wall stress. We used RNA-Seq to compare the global effects in response to induction of the synthetase of rel-Syn (coding for the enzymatic region of RelSau) or relQ without the need to apply additional stress conditions. Induction of rel-Syn resulted in changes in the nucleotide pool similar to induction of the stringent response via the tRNA synthetase inhibitor mupirocin: a reduction in the GTP pool, an increase in the ATP pool and synthesis of pppGpp, ppGpp and pGpp. Induction of all three enzymes resulted in similar changes in the transcriptome. However, RelQ was less active than Rel-Syn and RelP, indicating strong restriction of its (pp)pGpp-synthesis activity in vivo. (pp)pGpp induction resulted in the downregulation of many genes involved in protein and RNA/DNA metabolism. Many of the (pp)pGpp upregulated genes are part of the GTP sensitive CodY regulon and thus likely regulated through lowering of the GTP pool. New CodY independent transcriptional changes were detected including genes involved in the SOS response, iron storage (e.g. ftnA, dps), oxidative stress response (e.g., perR, katA, sodA) and the psmα1–4 and psmß1-2 operons coding for cytotoxic, phenol soluble modulins (PSMs). Analyses of the ftnA, dps and psm genes in different regulatory mutants revealed that their (pp)pGpp-dependent regulation can occur independent of the regulators PerR, Fur, SarA or CodY. Moreover, psm expression is uncoupled from expression of the quorum sensing system Agr, the main known psm activator. The expression of central genes of the oxidative stress response protects the bacteria from anticipated ROS stress derived from PSMs or exogenous sources. Thus, we identified a new link between the stringent response and oxidative stress in S. aureus that is likely crucial for survival upon phagocytosis. Most bacteria make use of the second messenger (pp)pGpp to reprogram bacterial metabolism under nutrient-limiting conditions. In the human pathogen Staphylococcus aureus, (pp)pGpp plays an important role in virulence, phagosomal escape and antibiotic tolerance. Here, we analyzed the immediate consequences of (pp)pGpp synthesis upon transcriptional induction of the (pp)pGpp-producing enzymes Rel, RelP or RelQ. (pp)pGpp synthesis provokes immediate changes in the nucleotide pool and severely impacts the expression of hundreds of genes. A main consequence of (pp)pGpp synthesis in S. aureus is the induction of ROS-inducing toxic phenol soluble modulins (PSMs) and simultaneous expression of the detoxifying system to protect the producer. This mechanism is likely of special advantage for the pathogen after phagocytosis.
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Affiliation(s)
- Petra Horvatek
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, Germany
| | - Andrea Salzer
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, Germany
| | | | - Fabio Lino Gratani
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, Germany
- Quantitative Proteomics & Proteome Center Tuebingen, University of Tuebingen, Germany
| | - Daniela Keinhörster
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, Germany
| | - Natalya Korn
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, Germany
| | - Marina Borisova
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, Germany
| | - Christoph Mayer
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, Germany
| | - Dominik Rejman
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Ulrike Mäder
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, Germany
- * E-mail:
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41
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Wilden JJ, Hrincius ER, Niemann S, Boergeling Y, Löffler B, Ludwig S, Ehrhardt C. Impact of Staphylococcus aureus Small Colony Variants on Human Lung Epithelial Cells with Subsequent Influenza Virus Infection. Microorganisms 2020; 8:E1998. [PMID: 33333815 PMCID: PMC7765246 DOI: 10.3390/microorganisms8121998] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/07/2020] [Accepted: 12/11/2020] [Indexed: 12/29/2022] Open
Abstract
Human beings are exposed to microorganisms every day. Among those, diverse commensals and potential pathogens including Staphylococcus aureus (S. aureus) compose a significant part of the respiratory tract microbiota. Remarkably, bacterial colonization is supposed to affect the outcome of viral respiratory tract infections, including those caused by influenza viruses (IV). Since 30% of the world's population is already colonized with S. aureus that can develop metabolically inactive dormant phenotypes and seasonal IV circulate every year, super-infections are likely to occur. Although IV and S. aureus super-infections are widely described in the literature, the interactions of these pathogens with each other and the host cell are only scarcely understood. Especially, the effect of quasi-dormant bacterial subpopulations on IV infections is barely investigated. In the present study, we aimed to investigate the impact of S. aureus small colony variants on the cell intrinsic immune response during a subsequent IV infection in vitro. In fact, we observed a significant impact on the regulation of pro-inflammatory factors, contributing to a synergistic effect on cell intrinsic innate immune response and induction of harmful cell death. Interestingly, the cytopathic effect, which was observed in presence of both pathogens, was not due to an increased pathogen load.
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Affiliation(s)
- Janine J. Wilden
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, 48149 Muenster, Germany; (J.J.W.); (E.R.H.); (Y.B.); (S.L.)
| | - Eike R. Hrincius
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, 48149 Muenster, Germany; (J.J.W.); (E.R.H.); (Y.B.); (S.L.)
| | - Silke Niemann
- Institute of Medical Microbiology, Westfaelische Wilhelms-University Muenster, 48149 Muenster, Germany;
| | - Yvonne Boergeling
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, 48149 Muenster, Germany; (J.J.W.); (E.R.H.); (Y.B.); (S.L.)
| | - Bettina Löffler
- Institute of Medical Microbiology, Jena University Hospital, 07747 Jena, Germany;
- Cluster of Excellence EXC 2051 “Balance of the Microverse”, FSU Jena, 07743 Jena, Germany
| | - Stephan Ludwig
- Institute of Virology Muenster (IVM), Westfaelische Wilhelms-University Muenster, 48149 Muenster, Germany; (J.J.W.); (E.R.H.); (Y.B.); (S.L.)
- Cluster of Excellence EXC 1003 “Cells in Motion”, WWU Muenster, 48149 Muenster, Germany
| | - Christina Ehrhardt
- Section of Experimental Virology, Institute of Medical Microbiology, Jena University Hospital, 07745 Jena, Germany
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Ha KP, Clarke RS, Kim GL, Brittan JL, Rowley JE, Mavridou DAI, Parker D, Clarke TB, Nobbs AH, Edwards AM. Staphylococcal DNA Repair Is Required for Infection. mBio 2020; 11:e02288-20. [PMID: 33203752 PMCID: PMC7683395 DOI: 10.1128/mbio.02288-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 10/14/2020] [Indexed: 01/07/2023] Open
Abstract
To cause infection, Staphylococcus aureus must withstand damage caused by host immune defenses. However, the mechanisms by which staphylococcal DNA is damaged and repaired during infection are poorly understood. Using a panel of transposon mutants, we identified the rexBA operon as being important for the survival of Staphylococcus aureus in whole human blood. Mutants lacking rexB were also attenuated for virulence in murine models of both systemic and skin infections. We then demonstrated that RexAB is a member of the AddAB family of helicase/nuclease complexes responsible for initiating the repair of DNA double-strand breaks. Using a fluorescent reporter system, we were able to show that neutrophils cause staphylococcal DNA double-strand breaks through reactive oxygen species (ROS) generated by the respiratory burst, which are repaired by RexAB, leading to the induction of the mutagenic SOS response. We found that RexAB homologues in Enterococcus faecalis and Streptococcus gordonii also promoted the survival of these pathogens in human blood, suggesting that DNA double-strand break repair is required for Gram-positive bacteria to survive in host tissues. Together, these data demonstrate that DNA is a target of host immune cells, leading to double-strand breaks, and that the repair of this damage by an AddAB-family enzyme enables the survival of Gram-positive pathogens during infection.IMPORTANCE To cause infection, bacteria must survive attack by the host immune system. For many bacteria, including the major human pathogen Staphylococcus aureus, the greatest threat is posed by neutrophils. These immune cells ingest the invading organisms and try to kill them with a cocktail of chemicals that includes reactive oxygen species (ROS). The ability of S. aureus to survive this attack is crucial for the progression of infection. However, it was not clear how the ROS damaged S. aureus and how the bacterium repaired this damage. In this work, we show that ROS cause breaks in the staphylococcal DNA, which must be repaired by a two-protein complex known as RexAB; otherwise, the bacterium is killed, and it cannot sustain infection. This provides information on the type of damage that neutrophils cause S. aureus and the mechanism by which this damage is repaired, enabling infection.
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Affiliation(s)
- Kam Pou Ha
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Rebecca S Clarke
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Gyu-Lee Kim
- Department of Pathology, Immunology and Laboratory Medicine, Center for Immunity and Inflammation, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Jane L Brittan
- Bristol Dental School, University of Bristol, Bristol, United Kingdom
| | - Jessica E Rowley
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Despoina A I Mavridou
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
| | - Dane Parker
- Department of Pathology, Immunology and Laboratory Medicine, Center for Immunity and Inflammation, Rutgers New Jersey Medical School, Newark, New Jersey, USA
| | - Thomas B Clarke
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Angela H Nobbs
- Bristol Dental School, University of Bristol, Bristol, United Kingdom
| | - Andrew M Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
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Romp E, Arakandy V, Fischer J, Wolz C, Siegmund A, Löffler B, Tuchscherr L, Werz O, Garscha U. Exotoxins from Staphylococcus aureus activate 5-lipoxygenase and induce leukotriene biosynthesis. Cell Mol Life Sci 2020; 77:3841-3858. [PMID: 31807813 PMCID: PMC11105070 DOI: 10.1007/s00018-019-03393-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 11/14/2019] [Accepted: 11/22/2019] [Indexed: 11/29/2022]
Abstract
Massive neutrophil infiltration is an early key event in infectious inflammation, accompanied by chemotactic leukotriene (LT)B4 generation. LTB4 biosynthesis is mediated by 5-lipoxygenase (5-LOX), but which pathogenic factors cause 5-LOX activation during bacterial infections is elusive. Here, we reveal staphylococcal exotoxins as 5-LOX activators. Conditioned medium of wild-type Staphylococcus aureus but not of exotoxin-deficient strains induced 5-LOX activation in transfected HEK293 cells. Two different staphylococcal exotoxins mimicked the effects of S. aureus-conditioned medium: (1) the pore-forming toxin α-hemolysin and (2) amphipathic α-helical phenol-soluble modulin (PSM) peptides. Interestingly, in human neutrophils, 5-LOX activation was exclusively evoked by PSMs, which was prevented by the selective FPR2/ALX receptor antagonist WRW4. 5-LOX activation by PSMs was confirmed in vivo as LT formation in infected paws of mice was impaired in response to PSM-deficient S. aureus. Conclusively, exotoxins from S. aureus are potent pathogenic factors that activate 5-LOX and induce LT formation in neutrophils.
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Affiliation(s)
- Erik Romp
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University Jena, Philosophenweg 14, 07743, Jena, Germany
| | - Vandana Arakandy
- Institute of Medical Microbiology, University Hospital Jena, 07747, Jena, Germany
| | - Jana Fischer
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University Jena, Philosophenweg 14, 07743, Jena, Germany
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, 72076, Tuebingen, Germany
| | - Anke Siegmund
- Institute of Medical Microbiology, University Hospital Jena, 07747, Jena, Germany
| | - Bettina Löffler
- Institute of Medical Microbiology, University Hospital Jena, 07747, Jena, Germany
| | - Lorena Tuchscherr
- Institute of Medical Microbiology, University Hospital Jena, 07747, Jena, Germany
| | - Oliver Werz
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University Jena, Philosophenweg 14, 07743, Jena, Germany
| | - Ulrike Garscha
- Department of Pharmaceutical/Medicinal Chemistry, Institute of Pharmacy, Friedrich-Schiller-University Jena, Philosophenweg 14, 07743, Jena, Germany.
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Weiß E, Schlatterer K, Beck C, Peschel A, Kretschmer D. Formyl-Peptide Receptor Activation Enhances Phagocytosis of Community-Acquired Methicillin-Resistant Staphylococcus aureus. J Infect Dis 2020; 221:668-678. [PMID: 31573600 DOI: 10.1093/infdis/jiz498] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 09/27/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Formyl-peptide receptors (FPRs) are important pattern recognition receptors that sense specific bacterial peptides. Formyl-peptide receptors are highly expressed on neutrophils and monocytes, and their activation promotes the migration of phagocytes to sites of infection. It is currently unknown whether FPRs may also influence subsequent processes such as bacterial phagocytosis and killing. Staphylococcus aureus, especially highly pathogenic community-acquired methicillin-resistant S aureus strains, release high amounts of FPR2 ligands, the phenol-soluble modulins. METHODS We demonstrate that FPR activation leads to upregulation of complement receptors 1 and 3 as well as FCγ receptor I on neutrophils and, consequently, increased opsonic phagocytosis of S aureus and other pathogens. RESULTS Increased phagocytosis promotes killing of S aureus and interleukin-8 release by neutrophils. CONCLUSIONS We show here for the first time that FPRs govern opsonic phagocytosis. Manipulation of FPR2 activation could open new therapeutic opportunities against bacterial pathogens.
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Affiliation(s)
- Elisabeth Weiß
- Infection Biology, Interfaculty Institute for Microbiology and Infection Medicine Tübingen, University of Tübingen, Tübingen, Germany
| | - Katja Schlatterer
- Infection Biology, Interfaculty Institute for Microbiology and Infection Medicine Tübingen, University of Tübingen, Tübingen, Germany
| | - Christian Beck
- Infection Biology, Interfaculty Institute for Microbiology and Infection Medicine Tübingen, University of Tübingen, Tübingen, Germany
| | - Andreas Peschel
- Infection Biology, Interfaculty Institute for Microbiology and Infection Medicine Tübingen, University of Tübingen, Tübingen, Germany
| | - Dorothee Kretschmer
- Infection Biology, Interfaculty Institute for Microbiology and Infection Medicine Tübingen, University of Tübingen, Tübingen, Germany
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45
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Bhattacharya M, Berends ETM, Zheng X, Hill PJ, Chan R, Torres VJ, Wozniak DJ. Leukocidins and the Nuclease Nuc Prevent Neutrophil-Mediated Killing of Staphylococcus aureus Biofilms. Infect Immun 2020; 88:e00372-20. [PMID: 32719153 PMCID: PMC7504955 DOI: 10.1128/iai.00372-20] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 07/17/2020] [Indexed: 02/07/2023] Open
Abstract
Bacterial biofilms are linked with chronic infections and have properties distinct from those of planktonic, single-celled bacteria. The virulence mechanisms associated with Staphylococcus aureus biofilms are becoming better understood. Human neutrophils are critical for the innate immune response to S. aureus infection. Here, we describe two virulence strategies that converge to promote the ability of S. aureus biofilms to evade killing by neutrophils. Specifically, we show that while neutrophils exposed to S. aureus biofilms produce extracellular traps (NETs) and phagocytose bacteria, both mechanisms are inefficient in clearance of the biofilm biomass. This is attributed to the leukocidin LukAB, which promotes S. aureus survival during phagocytosis. We also show that the persistence of biofilm bacteria trapped in NETs is facilitated by S. aureus nuclease (Nuc)-mediated degradation of NET DNA. This study describes key aspects of the interaction between primary human neutrophils and S. aureus biofilms and provides insight into how S. aureus evades the neutrophil response to cause persistent infections.
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Affiliation(s)
| | - Evelien T M Berends
- Department of Microbiology, New York University School of Medicine, New York, New York, USA
| | - Xuhui Zheng
- Department of Microbiology, New York University School of Medicine, New York, New York, USA
| | - Preston J Hill
- Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio, USA
| | - Rita Chan
- Department of Microbiology, New York University School of Medicine, New York, New York, USA
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, New York, USA
| | - Daniel J Wozniak
- Department of Microbiology, Ohio State University, Columbus, Ohio, USA
- Department of Microbial Infection and Immunity, Ohio State University, Columbus, Ohio, USA
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Alhede M, Lorenz M, Fritz BG, Jensen PØ, Ring HC, Bay L, Bjarnsholt T. Bacterial aggregate size determines phagocytosis efficiency of polymorphonuclear leukocytes. Med Microbiol Immunol 2020; 209:669-680. [PMID: 32880037 PMCID: PMC7568703 DOI: 10.1007/s00430-020-00691-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023]
Abstract
The ability of bacteria to aggregate and form biofilms impairs phagocytosis by polymorphonuclear leukocytes (PMNs). The aim of this study was to examine if the size of aggregates is critical for successful phagocytosis and how bacterial biofilms evade phagocytosis. We investigated the live interaction between PMNs and Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Staphylococcus epidermidis using confocal scanning laser microscopy. Aggregate size significantly affected phagocytosis outcome and larger aggregates were less likely to be phagocytized. Aggregates of S. epidermidis were also less likely to be phagocytized than equally-sized aggregates of the other three species. We found that only aggregates of approx. 5 μm diameter or smaller were consistently phagocytosed. We demonstrate that planktonic and aggregated cells of all four species significantly reduced the viability of PMNs after 4 h of incubation. Our results indicate that larger bacterial aggregates are less likely to be phagocytosed by PMNs and we propose that, if the aggregates become too large, circulating PMNs may not be able to phagocytose them quickly enough, which may lead to chronic infection.
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Affiliation(s)
- Maria Alhede
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Melanie Lorenz
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Blaine Gabriel Fritz
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Peter Østrup Jensen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.,Department of Clinical Microbiology, Rigshospitalet, Afsnit 9301, Juliane Maries Vej 22, DK-2100, Copenhagen Ø, Denmark.,Institute for Inflammation Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, 2100, Copenhagen, Denmark
| | - Hans Christian Ring
- Department of Dermatology, Bispebjerg Hospital, Nielsine Nielsens Vej 9, København, NV, Denmark
| | - Lene Bay
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark. .,Department of Clinical Microbiology, Rigshospitalet, Afsnit 9301, Juliane Maries Vej 22, DK-2100, Copenhagen Ø, Denmark.
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47
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Butrico CE, Cassat JE. Quorum Sensing and Toxin Production in Staphylococcus aureus Osteomyelitis: Pathogenesis and Paradox. Toxins (Basel) 2020; 12:toxins12080516. [PMID: 32806558 PMCID: PMC7471978 DOI: 10.3390/toxins12080516] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/04/2020] [Accepted: 08/10/2020] [Indexed: 01/18/2023] Open
Abstract
Staphylococcus aureus is a Gram-positive pathogen capable of infecting nearly every vertebrate organ. Among these tissues, invasive infection of bone (osteomyelitis) is particularly common and induces high morbidity. Treatment of osteomyelitis is notoriously difficult and often requires debridement of diseased bone in conjunction with prolonged antibiotic treatment to resolve infection. During osteomyelitis, S. aureus forms characteristic multicellular microcolonies in distinct niches within bone. Virulence and metabolic responses within these multicellular microcolonies are coordinated, in part, by quorum sensing via the accessory gene regulator (agr) locus, which allows staphylococcal populations to produce toxins and adapt in response to bacterial density. During osteomyelitis, the Agr system significantly contributes to dysregulation of skeletal homeostasis and disease severity but may also paradoxically inhibit persistence in the host. Moreover, the Agr system is subject to complex crosstalk with other S. aureus regulatory systems, including SaeRS and SrrAB, which can significantly impact the progression of osteomyelitis. The objective of this review is to highlight Agr regulation, its implications on toxin production, factors that affect Agr activation, and the potential paradoxical influences of Agr regulation on disease progression during osteomyelitis.
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Affiliation(s)
- Casey E. Butrico
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
| | - James E. Cassat
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation (VI4), Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Correspondence: ; Tel.: +1-615-936-6494
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Abstract
This review of the literature concerning bacteria, antibiotics and tissue repair shows there are extensive data supporting microbial interference with wound healing once bacterial burden exceeds 104 CFU per unit of measure, The mechanism of bacterial interference lies largely in prolonging the inflammatory phase of tissue repair. Reducing the microbial bioburden allows tissue repair to continue. Systemic and topical antimicrobials appear critical to reducing the bioburden and facilitating repair. The current controversy over the use of antimicrobials in patients with chronically infected wounds, in particular, revolves around the definition of infection. The reliance on classic clinical signs of inflammation to support antimicrobial use in these patients is tenuous due to the lack of correlation of these signs with the microbial burden known to impair tissue repair.
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Polyketides from marine-derived Aspergillus welwitschiae inhibit Staphylococcus aureus virulence factors and potentiate vancomycin antibacterial activity in vivo. Microb Pathog 2020; 143:104066. [DOI: 10.1016/j.micpath.2020.104066] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/09/2020] [Accepted: 02/12/2020] [Indexed: 12/11/2022]
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50
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Hua X, Jia Y, Yang Q, Zhang W, Dong Z, Liu S. Transcriptional Analysis of the Effects of Gambogic Acid and Neogambogic Acid on Methicillin-Resistant Staphylococcus aureus. Front Pharmacol 2019; 10:986. [PMID: 31572177 PMCID: PMC6753875 DOI: 10.3389/fphar.2019.00986] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 07/31/2019] [Indexed: 11/13/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infection is a major threat to human health, as this bacterium has developed resistance to a variety of conventional antibiotics. This is especially true of MRSA biofilms, which not only exhibit enhanced pathogenicity but also are resistant to most antibiotics. In this work, we demonstrated that two natural products with antitumor activity, namely, gambogic acid (GA) and neogambogic acid (NGA), have significant inhibitory activity toward MRSA. GA and NGA can not only effectively inhibit planktonic MRSA strains in vivo and in vitro, but also have strong inhibitory effects on MRSA biofilms formation. By transcriptome sequencing, Q-RT-PCR and PRM, we found that GA and NGA could reduce the expression of S. aureus virulence factors by inhibiting the saeRS two-component, thus achieving inhibition of MRSA. We found that GA and NGA had anti-MRSA activity in vivo and in vitro and identified saeRS to be the target, indicating that saeRS inhibitors may be used to treat biofilm-related infections.
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Affiliation(s)
- Xin Hua
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - Yue Jia
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Qin Yang
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Wanjiang Zhang
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhimin Dong
- Innovation Team of Livestock and Poultry Epidemic Disease Prevention and Control, Tianjin Animal Science and Veterinary Research Institute, Tianjin, China
| | - Siguo Liu
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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