1
|
Xu S, Tan S, Romanos P, Reedy JL, Zhang Y, Mansour MK, Vyas JM, Mecsas J, Mou H, Leong JM. Blocking HXA 3-mediated neutrophil elastase release during S. pneumoniae lung infection limits pulmonary epithelial barrier disruption and bacteremia. mBio 2024; 15:e0185624. [PMID: 39120139 PMCID: PMC11389395 DOI: 10.1128/mbio.01856-24] [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: 06/20/2024] [Accepted: 07/08/2024] [Indexed: 08/10/2024] Open
Abstract
Streptococcus pneumoniae (Sp), a leading cause of community-acquired pneumonia, can spread from the lung into the bloodstream to cause septicemia and meningitis, with a concomitant threefold increase in mortality. Limitations in vaccine efficacy and a rise in antimicrobial resistance have spurred searches for host-directed therapies that target pathogenic immune processes. Polymorphonuclear leukocytes (PMNs) are essential for infection control but can also promote tissue damage and pathogen spread. The major Sp virulence factor, pneumolysin, triggers acute inflammation by stimulating the 12-lipoxygenase (12-LOX) eicosanoid synthesis pathway in epithelial cells. This pathway is required for systemic spread in a mouse pneumonia model and produces a number of bioactive lipids, including hepoxilin A3 (HXA3), a hydroxy epoxide PMN chemoattractant that has been hypothesized to facilitate breach of mucosal barriers. To understand how 12-LOX-dependent inflammation promotes dissemination during Sp lung infection and dissemination, we utilized bronchial stem cell-derived air-liquid interface cultures that lack this enzyme to show that HXA3 methyl ester (HXA3-ME) is sufficient to promote basolateral-to-apical PMN transmigration, monolayer disruption, and concomitant Sp barrier breach. In contrast, PMN transmigration in response to the non-eicosanoid chemoattractant N-formyl-L-methionyl-L-leucyl-phenylalanine (fMLP) did not lead to epithelial disruption or bacterial translocation. Correspondingly, HXA3-ME but not fMLP increased the release of neutrophil elastase (NE) from Sp-infected PMNs. Pharmacologic blockade of NE secretion or activity diminished epithelial barrier disruption and bacteremia after pulmonary challenge of mice. Thus, HXA3 promotes barrier-disrupting PMN transmigration and NE release, pathological events that can be targeted to curtail systemic disease following pneumococcal pneumonia.IMPORTANCEStreptococcus pneumoniae (Sp), a leading cause of pneumonia, can spread from the lung into the bloodstream to cause systemic disease. Limitations in vaccine efficacy and a rise in antimicrobial resistance have spurred searches for host-directed therapies that limit pathologic host immune responses to Sp. Excessive polymorphonuclear leukocyte (PMN) infiltration into Sp-infected airways promotes systemic disease. Using stem cell-derived respiratory cultures that reflect bona fide lung epithelium, we identified eicosanoid hepoxilin A3 as a critical pulmonary PMN chemoattractant that is sufficient to drive PMN-mediated epithelial damage by inducing the release of neutrophil elastase. Inhibition of the release or activity of this protease in mice limited epithelial barrier disruption and bacterial dissemination, suggesting a new host-directed treatment for Sp lung infection.
Collapse
Affiliation(s)
- Shuying Xu
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Graduate Program in Immunology, Tufts Graduate School of Biomedical Sciences, Boston, Massachusetts, USA
| | - Shumin Tan
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Patricia Romanos
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Program in Biotechnology, Francisco de Vitoria University, Madrid, Spain
| | - Jennifer L Reedy
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Yihan Zhang
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Michael K Mansour
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Jatin M Vyas
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Joan Mecsas
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Hongmei Mou
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - John M Leong
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Stuart B Levy Center for the Integrated Management of Antimicrobial Resistance, Tufts University, Boston, Massachusetts, USA
| |
Collapse
|
2
|
Xu S, Tan S, Romanos P, Reedy JL, Zhang Y, Mansour MK, Vyas JM, Mecsas J, Mou H, Leong JM. Blocking HXA 3-mediated neutrophil elastase release during S. pneumoniae lung infection limits pulmonary epithelial barrier disruption and bacteremia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.25.600637. [PMID: 38979170 PMCID: PMC11230237 DOI: 10.1101/2024.06.25.600637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Streptococcus pneumoniae (Sp), a leading cause of community-acquired pneumonia, can spread from the lung into the bloodstream to cause septicemia and meningitis, with a concomitant three-fold increase in mortality. Limitations in vaccine efficacy and a rise in antimicrobial resistance have spurred searches for host-directed therapies that target pathogenic immune processes. Polymorphonuclear leukocytes (PMNs) are essential for infection control but can also promote tissue damage and pathogen spread. The major Sp virulence factor, pneumolysin (PLY), triggers acute inflammation by stimulating the 12-lipoxygenase (12-LOX) eicosanoid synthesis pathway in epithelial cells. This pathway is required for systemic spread in a mouse pneumonia model and produces a number of bioactive lipids, including hepoxilin A3 (HXA3), a hydroxy epoxide PMN chemoattractant that has been hypothesized to facilitate breach of mucosal barriers. To understand how 12-LOX-dependent inflammation promotes dissemination during Sp lung infection and dissemination, we utilized bronchial stem cell-derived air-liquid interface (ALI) cultures that lack this enzyme to show that HXA3 methyl ester (HXA3-ME) is sufficient to promote basolateral-to-apical PMN transmigration, monolayer disruption, and concomitant Sp barrier breach. In contrast, PMN transmigration in response to the non-eicosanoid chemoattractant fMLP did not lead to epithelial disruption or bacterial translocation. Correspondingly, HXA3-ME but not fMLP increased release of neutrophil elastase (NE) from Sp-infected PMNs. Pharmacologic blockade of NE secretion or activity diminished epithelial barrier disruption and bacteremia after pulmonary challenge of mice. Thus, HXA3 promotes barrier disrupting PMN transmigration and NE release, pathological events that can be targeted to curtail systemic disease following pneumococcal pneumonia.
Collapse
Affiliation(s)
- Shuying Xu
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA
- Graduate Program in Immunology, Tufts Graduate School of Biomedical Sciences, Boston, MA
| | - Shumin Tan
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA
| | - Patricia Romanos
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA
- Francisco de Vitoria University, Madrid, Spain
| | - Jennifer L. Reedy
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA
| | - Yihan Zhang
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA
| | - Michael K. Mansour
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA
| | - Jatin M. Vyas
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA
| | - Joan Mecsas
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA
| | - Hongmei Mou
- Mucosal Immunology and Biology Research Center, Massachusetts General Hospital, Boston, MA
| | - John M. Leong
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA
- Stuart B Levy Center for the Integrated Management of Antimicrobial Resistance, Tufts University, Boston, MA
| |
Collapse
|
3
|
Roodsant TJ, van der Putten B, Brizuela J, Coolen JPM, Baltussen TJH, Schipper K, Pannekoek Y, van der Ark KCH, Schultsz C. The streptococcal phase-variable type I restriction modification system SsuCC20p dictates the methylome of Streptococcus suis impacting the transcriptome and virulence in a zebrafish larvae infection model. mBio 2024; 15:e0225923. [PMID: 38063379 PMCID: PMC10790761 DOI: 10.1128/mbio.02259-23] [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: 10/03/2023] [Accepted: 10/05/2023] [Indexed: 01/17/2024] Open
Abstract
IMPORTANCE Phase variation allows a single strain to produce phenotypic diverse subpopulations. Phase-variable restriction modification (RM) systems are systems that allow for such phase variation via epigenetic regulation of gene expression levels. The phase-variable RM system SsuCC20p was found in multiple streptococcal species and was acquired by an emerging zoonotic lineage of Streptococcus suis. We show that the phase variability of SsuCC20p is dependent on a recombinase encoded within the SsuCC20p locus. We characterized the genome methylation profiles of the different phases of SsuCC20p and demonstrated the consequential impact on the transcriptome and virulence in a zebrafish infection model. Acquiring mobile genetic elements containing epigenetic regulatory systems, like phase-variable RM systems, enables bacterial pathogens to produce diverse phenotypic subpopulations that are better adapted to specific (host) environments encountered during infection.
Collapse
Affiliation(s)
- Thomas J. Roodsant
- Department of Global Health, Amsterdam Institute for Global Health and Development, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
- Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Boas van der Putten
- Department of Global Health, Amsterdam Institute for Global Health and Development, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
- Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Jaime Brizuela
- Department of Global Health, Amsterdam Institute for Global Health and Development, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
- Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Jordy P. M. Coolen
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Tim J. H. Baltussen
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, the Netherlands
| | - Kim Schipper
- Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Yvonne Pannekoek
- Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Kees C. H. van der Ark
- Department of Global Health, Amsterdam Institute for Global Health and Development, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
- Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Constance Schultsz
- Department of Global Health, Amsterdam Institute for Global Health and Development, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
- Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| |
Collapse
|
4
|
Bazant J, Ott B, Hudel M, Hain T, Lucas R, Mraheil MA. Impact of Endogenous Pneumococcal Hydrogen Peroxide on the Activity and Release of Pneumolysin. Toxins (Basel) 2023; 15:593. [PMID: 37888624 PMCID: PMC10611280 DOI: 10.3390/toxins15100593] [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: 08/10/2023] [Revised: 09/21/2023] [Accepted: 09/26/2023] [Indexed: 10/28/2023] Open
Abstract
Streptococcus pneumoniae is the leading cause of community-acquired pneumonia. The pore-forming cholesterol-dependent cytolysin (CDC) pneumolysin (PLY) and the physiological metabolite hydrogen peroxide (H2O2) can greatly increase the virulence of pneumococci. Although most studies have focused on the contribution of both virulence factors to the course of pneumococcal infection, it is unknown whether or how H2O2 can affect PLY activity. Of note, S. pneumoniae exploits endogenous H2O2 as an intracellular signalling molecule to modulate the activity of several proteins. Here, we demonstrate that H2O2 negatively affects the haemolytic activity of PLY in a concentration-dependent manner. Prevention of cysteine-dependent sulfenylation upon substitution of the unique and highly conserved cysteine residue to serine in PLY significantly reduces the toxin's susceptibility to H2O2 treatment and completely abolishes the ability of DTT to activate PLY. We also detect a clear gradual correlation between endogenous H2O2 generation and PLY release, with decreased H2O2 production causing a decline in the release of PLY. Comparative transcriptome sequencing analysis of the wild-type S. pneumoniae strain and three mutants impaired in H2O2 production indicates enhanced expression of several genes involved in peptidoglycan (PG) synthesis and in the production of choline-binding proteins (CPBs). One explanation for the impact of H2O2 on PLY release is the observed upregulation of the PG bridge formation alanyltransferases MurM and MurN, which evidentially negatively affect the PLY release. Our findings shed light on the significance of endogenous pneumococcal H2O2 in controlling PLY activity and release.
Collapse
Affiliation(s)
- Jasmin Bazant
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| | - Benjamin Ott
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| | - Martina Hudel
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| | - Torsten Hain
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| | - Rudolf Lucas
- Vascular Biology Center, Department of Pharmacology and Toxicology and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Mobarak Abu Mraheil
- Institute of Medical Microbiology, German Center for Infection Research, Partner Site Giessen-Marburg-Langen, Justus-Liebig University Giessen, Schubertstrasse 81, 35392 Giessen, Germany; (J.B.); (B.O.); (M.H.); (T.H.)
| |
Collapse
|
5
|
Domon H, Hirayama S, Isono T, Sasagawa K, Takizawa F, Maekawa T, Yanagihara K, Terao Y. Macrolides Decrease the Proinflammatory Activity of Macrolide-Resistant Streptococcus pneumoniae. Microbiol Spectr 2023; 11:e0014823. [PMID: 37191519 PMCID: PMC10269745 DOI: 10.1128/spectrum.00148-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/25/2023] [Indexed: 05/17/2023] Open
Abstract
Over the past 2 decades, the prevalence of macrolide-resistant Streptococcus pneumoniae (MRSP) has increased considerably, due to widespread macrolide use. Although macrolide usage has been proposed to be associated with treatment failure in patients with pneumococcal diseases, macrolides may be clinically effective for treating these diseases, regardless of the susceptibility of the causative pneumococci to macrolides. As we previously demonstrated that macrolides downregulate the transcription of various genes in MRSP, including the gene encoding the pore-forming toxin pneumolysin, we hypothesized that macrolides affect the proinflammatory activity of MRSP. Using HEK-Blue cell lines, we found that the supernatants from macrolide-treated MRSP cultures induced decreased NF-κB activation in cells expressing Toll-like receptor 2 and nucleotide-binding oligomerization domain 2 compared to the supernatants from untreated MRSP cells, suggesting that macrolides inhibit the release of these ligands from MRSP. Real-time PCR analysis revealed that macrolides significantly downregulated the transcription of various genes encoding peptidoglycan synthesis-, lipoteichoic acid synthesis-, and lipoprotein synthesis-related molecules in MRSP cells. The silkworm larva plasma assay demonstrated that the peptidoglycan concentrations in the supernatants from macrolide-treated MRSP cultures were significantly lower than those from untreated MRSP cultures. Triton X-114 phase separation revealed that lipoprotein expression decreased in macrolide-treated MRSP cells compared to the lipoprotein expression in untreated MRSP cells. Consequently, macrolides may decrease the expression of bacterial ligands of innate immune receptors, resulting in the decreased proinflammatory activity of MRSP. IMPORTANCE To date, the clinical efficacy of macrolides in pneumococcal disease is assumed to be linked to their ability to inhibit the release of pneumolysin. However, our previous study demonstrated that oral administration of macrolides to mice intratracheally infected with macrolide-resistant Streptococcus pneumoniae resulted in decreased levels of pneumolysin and proinflammatory cytokines in bronchoalveolar lavage fluid samples compared to the levels in samples from untreated infected control mice, without affecting the bacterial load in the fluid. This finding suggests that additional mechanisms by which macrolides negatively regulate proinflammatory cytokine production may be involved in their efficacy in vivo. Furthermore, in this study, we demonstrated that macrolides downregulated the transcription of various proinflammatory-component-related genes in S. pneumoniae, which provides an additional explanation for the clinical benefits of macrolides.
Collapse
Affiliation(s)
- Hisanori Domon
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Satoru Hirayama
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Toshihito Isono
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Karin Sasagawa
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Fumio Takizawa
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tomoki Maekawa
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Katsunori Yanagihara
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Yutaka Terao
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
- Center for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| |
Collapse
|
6
|
Cima Cabal MD, Molina F, López-Sánchez JI, Pérez-Santín E, Del Mar García-Suárez M. Pneumolysin as a target for new therapies against pneumococcal infections: A systematic review. PLoS One 2023; 18:e0282970. [PMID: 36947540 PMCID: PMC10032530 DOI: 10.1371/journal.pone.0282970] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 02/28/2023] [Indexed: 03/23/2023] Open
Abstract
BACKGROUND This systematic review evaluates pneumolysin (PLY) as a target for new treatments against pneumococcal infections. Pneumolysin is one of the main virulence factors produced by all types of pneumococci. This toxin (53 kDa) is a highly conserved protein that binds to cholesterol in eukaryotic cells, forming pores that lead to cell destruction. METHODS The databases consulted were MEDLINE, Web of Science, and Scopus. Articles were independently screened by title, abstract, and full text by two researchers, and using consensus to resolve any disagreements that occurred. Articles in other languages different from English, patents, cases report, notes, chapter books and reviews were excluded. Searches were restricted to the years 2000 to 2021. Methodological quality was evaluated using OHAT framework. RESULTS Forty-one articles describing the effects of different molecules that inhibit PLY were reviewed. Briefly, the inhibitory molecules found were classified into three main groups: those exerting a direct effect by binding and/or blocking PLY, those acting indirectly by preventing its effects on host cells, and those whose mechanisms are unknown. Although many molecules are proposed as toxin blockers, only some of them, such as antibiotics, peptides, sterols, and statins, have the probability of being implemented as clinical treatment. In contrast, for other molecules, there are limited studies that demonstrate efficacy in animal models with sufficient reliability. DISCUSSION Most of the studies reviewed has a good level of confidence. However, one of the limitations of this systematic review is the lack of homogeneity of the studies, what prevented to carry out a statistical comparison of the results or meta-analysis. CONCLUSION A panel of molecules blocking PLY activity are associated with the improvement of the inflammatory process triggered by the pneumococcal infection. Some molecules have already been used in humans for other purposes, so they could be safe for use in patients with pneumococcal infections. These patients might benefit from a second line treatment during the initial stages of the infection preventing acute respiratory distress syndrome and invasive pneumococcal diseases. Additional research using the presented set of compounds might further improve the clinical management of these patients.
Collapse
Affiliation(s)
- María Dolores Cima Cabal
- Escuela Superior de Ingeniería y Tecnología (ESIT), Universidad Internacional de La Rioja, UNIR, Logroño, La Rioja, Spain
| | - Felipe Molina
- Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain
| | - José Ignacio López-Sánchez
- Escuela Superior de Ingeniería y Tecnología (ESIT), Universidad Internacional de La Rioja, UNIR, Logroño, La Rioja, Spain
| | - Efrén Pérez-Santín
- Escuela Superior de Ingeniería y Tecnología (ESIT), Universidad Internacional de La Rioja, UNIR, Logroño, La Rioja, Spain
| | - María Del Mar García-Suárez
- Escuela Superior de Ingeniería y Tecnología (ESIT), Universidad Internacional de La Rioja, UNIR, Logroño, La Rioja, Spain
| |
Collapse
|
7
|
Mitochondrial ROS production by neutrophils is required for host antimicrobial function against Streptococcus pneumoniae and is controlled by A2B adenosine receptor signaling. PLoS Pathog 2022; 18:e1010700. [DOI: 10.1371/journal.ppat.1010700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 11/28/2022] [Accepted: 11/07/2022] [Indexed: 11/15/2022] Open
Abstract
Polymorphonuclear cells (PMNs) control Streptococcus pneumoniae (pneumococcus) infection through various antimicrobial activities. We previously found that reactive oxygen species (ROS) were required for optimal antibacterial function, however, the NADPH oxidase is known to be dispensable for the ability of PMNs to kill pneumococci. In this study, we explored the role of ROS produced by the mitochondria in PMN antimicrobial defense against pneumococci. We found that the mitochondria are an important source of overall intracellular ROS produced by murine PMNs in response to infection. We investigated the host and bacterial factors involved and found that mitochondrial ROS (MitROS) are produced independent of bacterial capsule or pneumolysin but presence of live bacteria that are in direct contact with PMNs enhanced the response. We further found that MyD88-/- PMNs produced less MitROS in response to pneumococcal infection suggesting that released bacterial products acting as TLR ligands are sufficient for inducing MitROS production in PMNs. To test the role of MitROS in PMN function, we used an opsonophagocytic killing assay and found that MitROS were required for the ability of PMNs to kill pneumococci. We then investigated the role of MitROS in host resistance and found that MitROS are produced by PMNs in response to pneumococcal infection. Importantly, treatment of mice with a MitROS scavenger prior to systemic challenge resulted in reduced survival of infected hosts. In exploring host pathways that control MitROS, we focused on extracellular adenosine, which is known to control PMN anti-pneumococcal activity, and found that signaling through the A2B adenosine receptor inhibits MitROS production by PMNs. A2BR-/- mice produced more MitROS and were significantly more resistant to infection. Finally, we verified the clinical relevance of our findings using human PMNs. In summary, we identified a novel pathway that controls MitROS production by PMNs, shaping host resistance against S. pneumoniae.
Collapse
|
8
|
Batori RK, Chen F, Bordan Z, Haigh S, Su Y, Verin AD, Barman SA, Stepp DW, Chakraborty T, Lucas R, Fulton DJR. Protective role of Cav-1 in pneumolysin-induced endothelial barrier dysfunction. Front Immunol 2022; 13:945656. [PMID: 35967431 PMCID: PMC9363592 DOI: 10.3389/fimmu.2022.945656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 07/04/2022] [Indexed: 01/16/2023] Open
Abstract
Pneumolysin (PLY) is a bacterial pore forming toxin and primary virulence factor of Streptococcus pneumonia, a major cause of pneumonia. PLY binds cholesterol-rich domains of the endothelial cell (EC) plasma membrane resulting in pore assembly and increased intracellular (IC) Ca2+ levels that compromise endothelial barrier integrity. Caveolae are specialized plasmalemma microdomains of ECs enriched in cholesterol. We hypothesized that the abundance of cholesterol-rich domains in EC plasma membranes confers cellular susceptibility to PLY. Contrary to this hypothesis, we found increased PLY-induced IC Ca2+ following membrane cholesterol depletion. Caveolin-1 (Cav-1) is an essential structural protein of caveolae and its regulation by cholesterol levels suggested a possible role in EC barrier function. Indeed, Cav-1 and its scaffolding domain peptide protected the endothelial barrier from PLY-induced disruption. In loss of function experiments, Cav-1 was knocked-out using CRISPR-Cas9 or silenced in human lung microvascular ECs. Loss of Cav-1 significantly enhanced the ability of PLY to disrupt endothelial barrier integrity. Rescue experiments with re-expression of Cav-1 or its scaffolding domain peptide protected the EC barrier against PLY-induced barrier disruption. Dynamin-2 (DNM2) is known to regulate caveolar membrane endocytosis. Inhibition of endocytosis, with dynamin inhibitors or siDNM2 amplified PLY induced EC barrier dysfunction. These results suggest that Cav-1 protects the endothelial barrier against PLY by promoting endocytosis of damaged membrane, thus reducing calcium entry and PLY-dependent signaling.
Collapse
Affiliation(s)
- Robert K. Batori
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Feng Chen
- Department of Forensic Medicine, Nanjing Medical University, Nanjing, China
| | - Zsuzsanna Bordan
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Stephen Haigh
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Yunchao Su
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Alexander D. Verin
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
- Division of Critical Care and Pulmonary Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Scott A. Barman
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - David W. Stepp
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
- Department of Phyiology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Trinad Chakraborty
- Institute of Human Microbiology, Justus-Liebig University, Giessen, Germany
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
- Division of Critical Care and Pulmonary Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - David J. R. Fulton
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, United States
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| |
Collapse
|
9
|
Huang LD, Yang MJ, Huang YY, Jiang KY, Yan J, Sun AH. Molecular Characterization of Predominant Serotypes, Drug Resistance, and Virulence Genes of Streptococcus pneumoniae Isolates From East China. Front Microbiol 2022; 13:892364. [PMID: 35722327 PMCID: PMC9198556 DOI: 10.3389/fmicb.2022.892364] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
Streptococcus pneumoniae is a common diplococcus pathogen found worldwide. The characterization of predominant serotypes, drug resistance, and virulence genes of S. pneumoniae isolates prevailing in different areas and countries is clinically important for choice of antibiotics and improvement of vaccines. In this study, pneumonia (78.7%) and meningitis (37.0%) were the predominant diseases observed in the 282 (children) and 27 (adults) S. pneumoniae-infected patients (p < 0.05) from seven hospitals in different areas of East China. Of the 309 pneumococcal isolates, 90.3% were classified by PCR into 15 serotypes, with serotypes 19F (27.2%) and the 6A/B (19.1%) being most predominant (p < 0.05). Importantly, serotypes 15A and 15B/C combined for a total of 10.4% of the isolates, but these serotypes are not included in the 13-valent pneumococcal capsule conjugate vaccine used in China. Antimicrobial susceptibility analysis by the E-test showed that >95% of the 309 pneumococcal isolates were susceptible to moxifloxacin and levofloxacin, as well as 18.4, 85.8, and 81.6% of the isolates displayed susceptibility to penicillin, cefotaxime, and imipenem, respectively. A significant correlation between the prevalence of predominant serotypes and their penicillin resistance was observed (p < 0.05). In particular, >95% of all the pneumococcal isolates showed resistance to erythromycin and azithromycin. Of the nine detected virulence genes, the lytA, ply, hysA, and nanA were the most common with 95–100% positive rates in the 309 pneumococcal isolates, while the pavA and psaA genes displayed a significant correlation with pneumococcal bacteremia and meningitis (p < 0.05). Overall, our data suggested that the predominant serotypes, drug resistance, and virulence genes of the S. pneumoniae isolates prevailing in East China are distinct from those observed in other areas of China and adjacent countries.
Collapse
Affiliation(s)
- Li-Dan Huang
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, China
| | - Mei-Juan Yang
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, China
| | - Yan-Ying Huang
- Hangzhou Chest Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Ke-Yi Jiang
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, China
| | - Jie Yan
- Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, China
| | - Ai-Hua Sun
- School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, China
| |
Collapse
|
10
|
Pereira JM, Xu S, Leong JM, Sousa S. The Yin and Yang of Pneumolysin During Pneumococcal Infection. Front Immunol 2022; 13:878244. [PMID: 35529870 PMCID: PMC9074694 DOI: 10.3389/fimmu.2022.878244] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/23/2022] [Indexed: 12/15/2022] Open
Abstract
Pneumolysin (PLY) is a pore-forming toxin produced by the human pathobiont Streptococcus pneumoniae, the major cause of pneumonia worldwide. PLY, a key pneumococcal virulence factor, can form transmembrane pores in host cells, disrupting plasma membrane integrity and deregulating cellular homeostasis. At lytic concentrations, PLY causes cell death. At sub-lytic concentrations, PLY triggers host cell survival pathways that cooperate to reseal the damaged plasma membrane and restore cell homeostasis. While PLY is generally considered a pivotal factor promoting S. pneumoniae colonization and survival, it is also a powerful trigger of the innate and adaptive host immune response against bacterial infection. The dichotomy of PLY as both a key bacterial virulence factor and a trigger for host immune modulation allows the toxin to display both "Yin" and "Yang" properties during infection, promoting disease by membrane perforation and activating inflammatory pathways, while also mitigating damage by triggering host cell repair and initiating anti-inflammatory responses. Due to its cytolytic activity and diverse immunomodulatory properties, PLY is integral to every stage of S. pneumoniae pathogenesis and may tip the balance towards either the pathogen or the host depending on the context of infection.
Collapse
Affiliation(s)
- Joana M. Pereira
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Molecular and Cellular (MC) Biology PhD Program, ICBAS - Instituto de Ciência Biomédicas Abel Salazar, University of Porto, Porto, Portugal
| | - Shuying Xu
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, United States
- Graduate Program in Immunology, Tufts Graduate School of Biomedical Sciences, Boston, MA, United States
| | - John M. Leong
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, United States
| | - Sandra Sousa
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| |
Collapse
|
11
|
Stevens EJ, Morse DJ, Bonini D, Duggan S, Brignoli T, Recker M, Lees JA, Croucher NJ, Bentley S, Wilson DJ, Earle SG, Dixon R, Nobbs A, Jenkinson H, van Opijnen T, Thibault D, Wilkinson OJ, Dillingham MS, Carlile S, McLoughlin RM, Massey RC. Targeted control of pneumolysin production by a mobile genetic element in Streptococcus pneumoniae. Microb Genom 2022; 8:000784. [PMID: 35416147 PMCID: PMC9453066 DOI: 10.1099/mgen.0.000784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Streptococcus pneumoniae is a major human pathogen that can cause severe invasive diseases such as pneumonia, septicaemia and meningitis. Young children are at a particularly high risk, with an estimated 3-4 million cases of severe disease and between 300 000 and 500 000 deaths attributable to pneumococcal disease each year. The haemolytic toxin pneumolysin (Ply) is a primary virulence factor for this bacterium, yet despite its key role in pathogenesis, immune evasion and transmission, the regulation of Ply production is not well defined. Using a genome-wide association approach, we identified a large number of potential affectors of Ply activity, including a gene acquired horizontally on the antibiotic resistance-conferring Integrative and Conjugative Element (ICE) ICESp23FST81. This gene encodes a novel modular protein, ZomB, which has an N-terminal UvrD-like helicase domain followed by two Cas4-like domains with potent ATP-dependent nuclease activity. We found the regulatory effect of ZomB to be specific for the ply operon, potentially mediated by its high affinity for the BOX repeats encoded therein. Using a murine model of pneumococcal colonization, we further demonstrate that a ZomB mutant strain colonizes both the upper respiratory tract and lungs at higher levels when compared to the wild-type strain. While the antibiotic resistance-conferring aspects of ICESp23FST81 are often credited with contributing to the success of the S. pneumoniae lineages that acquire it, its ability to control the expression of a major virulence factor implicated in bacterial transmission is also likely to have played an important role.
Collapse
Affiliation(s)
- Emily J Stevens
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, BS8 1TD, UK
| | - Daniel J Morse
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, BS8 1TD, UK
| | - Dora Bonini
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, BS8 1TD, UK
| | - Seána Duggan
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, BS8 1TD, UK
| | - Tarcisio Brignoli
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, BS8 1TD, UK
| | - Mario Recker
- Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Exeter, TR10 9FE, UK.,Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - John A Lees
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, St. Mary's Campus, Imperial College London, London, W2 1PG, UK
| | - Nicholas J Croucher
- MRC Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, St. Mary's Campus, Imperial College London, London, W2 1PG, UK
| | - Stephen Bentley
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK
| | - Daniel J Wilson
- Big Data Institute, Nuffield Department of Population Health, University of Oxford, Oxford, OX3 7LF, UK
| | - Sarah G Earle
- Big Data Institute, Nuffield Department of Population Health, University of Oxford, Oxford, OX3 7LF, UK
| | - Robert Dixon
- Big Data Institute, Nuffield Department of Population Health, University of Oxford, Oxford, OX3 7LF, UK
| | - Angela Nobbs
- Bristol Dental School, University of Bristol, Bristol, BS1 2LY, UK
| | - Howard Jenkinson
- Bristol Dental School, University of Bristol, Bristol, BS1 2LY, UK
| | | | - Derek Thibault
- Biology Department, Boston College, Chestnut Hill, MA, USA
| | - Oliver J Wilkinson
- DNA-Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK
| | - Mark S Dillingham
- DNA-Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol, BS8 1TD, UK
| | - Simon Carlile
- Host Pathogen Interactions Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Rachel M McLoughlin
- Host Pathogen Interactions Group, School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland
| | - Ruth C Massey
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, BS8 1TD, UK.,Schools of Microbiology and Medicine and APC Microbiome Ireland, University College Cork, Cork, Ireland
| |
Collapse
|
12
|
Simmons SR, Tchalla EYI, Bhalla M, Bou Ghanem EN. The Age-Driven Decline in Neutrophil Function Contributes to the Reduced Efficacy of the Pneumococcal Conjugate Vaccine in Old Hosts. Front Cell Infect Microbiol 2022; 12:849224. [PMID: 35402289 PMCID: PMC8984502 DOI: 10.3389/fcimb.2022.849224] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 02/28/2022] [Indexed: 01/04/2023] Open
Abstract
Despite the availability of vaccines, Streptococcus pneumoniae (pneumococcus) remains a serious cause of infections in the elderly. The efficacy of anti-pneumococcal vaccines declines with age. While age-driven changes in antibody responses are well defined, less is known about the role of innate immune cells such as polymorphonuclear leukocytes (PMNs) in the reduced vaccine protection seen in aging. Here we explored the role of PMNs in protection against S. pneumoniae in vaccinated hosts. We found that depletion of PMNs in pneumococcal conjugate vaccine (PCV) treated young mice prior to pulmonary challenge with S. pneumoniae resulted in dramatic loss of host protection against infection. Immunization boosted the ability of PMNs to kill S. pneumoniae and this was dependent on bacterial opsonization by antibodies. Bacterial opsonization with immune sera increased several PMN anti-microbial activities including bacterial uptake, degranulation and ROS production. As expected, PCV failed to protect old mice against S. pneumoniae. In probing the role of PMNs in this impaired protection, we found that aging was accompanied by an intrinsic decline in PMN function. PMNs from old mice failed to effectively kill S. pneumoniae even when the bacteria were opsonized with immune sera from young controls. In exploring mechanisms, we found that PMNs from old mice produced less of the antimicrobial peptide CRAMP and failed to efficiently kill engulfed pneumococci. Importantly, adoptive transfer of PMNs from young mice reversed the susceptibility of vaccinated old mice to pneumococcal infection. Overall, this study demonstrates that the age-driven decline in PMN function impairs vaccine-mediated protection against Streptococcus pneumoniae.
Collapse
|
13
|
Bhalla M, Heinzinger LR, Morenikeji OB, Marzullo B, Thomas BN, Bou Ghanem EN. Transcriptome Profiling Reveals CD73 and Age-Driven Changes in Neutrophil Responses against Streptococcus pneumoniae. Infect Immun 2021; 89:e0025821. [PMID: 34310891 PMCID: PMC8519284 DOI: 10.1128/iai.00258-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/15/2021] [Indexed: 11/20/2022] Open
Abstract
Neutrophils are required for host resistance against Streptococcus pneumoniae, but their function declines with age. We previously found that CD73, an enzyme required for antimicrobial activity, is downregulated in neutrophils (also known as polymorphonuclear leukocytes [PMNs]) from aged mice. This study explored transcriptional changes in neutrophils induced by S. pneumoniae to identify pathways controlled by CD73 and dysregulated with age. Pure bone marrow-derived neutrophils isolated from wild-type (WT) young and old and CD73 knockout (CD73KO) young mice were mock challenged or infected with S. pneumoniae ex vivo. RNA sequencing (RNA-Seq) was performed to identify differentially expressed genes (DEGs). We found that infection triggered distinct global transcriptional changes across hosts that were strongest in CD73KO neutrophils. Surprisingly, there were more downregulated than upregulated genes in all groups upon infection. Downregulated DEGs indicated a dampening of immune responses in old and CD73KO hosts. Further analysis revealed that CD73KO neutrophils expressed higher numbers of long noncoding RNAs (lncRNAs) than those in WT controls. Predicted network analysis indicated that CD73KO-specific lncRNAs control several signaling pathways. We found that genes in the c-Jun N-terminal kinase (JNK)-mitogen-activated protein kinase (MAPK) pathway were upregulated upon infection in CD73KO mice and in WT old mice, but not in WT young mice. This corresponded to functional differences, as phosphorylation of the downstream AP-1 transcription factor component c-Jun was significantly higher in neutrophils from infected CD73KO mice and old mice. Importantly, inhibition of JNK/AP-1 rescued the ability of these neutrophils to kill S. pneumoniae. Together, our findings revealed that the ability of neutrophils to modify their gene expression to better adapt to bacterial infection is in part regulated by CD73 and declines with age.
Collapse
Affiliation(s)
- Manmeet Bhalla
- Department of Microbiology and Immunology, State University of New York at Buffalo School of Medicine, Buffalo, New York, USA
| | - Lauren R. Heinzinger
- Department of Microbiology and Immunology, State University of New York at Buffalo School of Medicine, Buffalo, New York, USA
| | - Olanrewaju B. Morenikeji
- Department of Biomedical Sciences, College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, New York, USA
- Division of Biological and Health Sciences, University of Pittsburgh–Bradford, Bradford, Pennsylvania, USA
| | - Brandon Marzullo
- Department of Biochemistry and Center of Excellence in Bioinformatics and Life Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Bolaji N. Thomas
- Department of Biomedical Sciences, College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, New York, USA
| | - Elsa N. Bou Ghanem
- Department of Microbiology and Immunology, State University of New York at Buffalo School of Medicine, Buffalo, New York, USA
| |
Collapse
|
14
|
Kelliher JL, Grunenwald CM, Abrahams RR, Daanen ME, Lew CI, Rose WE, Sauer JD. PASTA kinase-dependent control of peptidoglycan synthesis via ReoM is required for cell wall stress responses, cytosolic survival, and virulence in Listeria monocytogenes. PLoS Pathog 2021; 17:e1009881. [PMID: 34624065 PMCID: PMC8528326 DOI: 10.1371/journal.ppat.1009881] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 10/20/2021] [Accepted: 09/27/2021] [Indexed: 02/01/2023] Open
Abstract
Pathogenic bacteria rely on protein phosphorylation to adapt quickly to stress, including that imposed by the host during infection. Penicillin-binding protein and serine/threonine-associated (PASTA) kinases are signal transduction systems that sense cell wall integrity and modulate multiple facets of bacterial physiology in response to cell envelope stress. The PASTA kinase in the cytosolic pathogen Listeria monocytogenes, PrkA, is required for cell wall stress responses, cytosolic survival, and virulence, yet its substrates and downstream signaling pathways remain incompletely defined. We combined orthogonal phosphoproteomic and genetic analyses in the presence of a β-lactam antibiotic to define PrkA phosphotargets and pathways modulated by PrkA. These analyses synergistically highlighted ReoM, which was recently identified as a PrkA target that influences peptidoglycan (PG) synthesis, as an important phosphosubstrate during cell wall stress. We find that deletion of reoM restores cell wall stress sensitivities and cytosolic survival defects of a ΔprkA mutant to nearly wild-type levels. While a ΔprkA mutant is defective for PG synthesis during cell wall stress, a double ΔreoM ΔprkA mutant synthesizes PG at rates similar to wild type. In a mouse model of systemic listeriosis, deletion of reoM in a ΔprkA background almost fully restored virulence to wild-type levels. However, loss of reoM alone also resulted in attenuated virulence, suggesting ReoM is critical at some points during pathogenesis. Finally, we demonstrate that the PASTA kinase/ReoM cell wall stress response pathway is conserved in a related pathogen, methicillin-resistant Staphylococcus aureus. Taken together, our phosphoproteomic analysis provides a comprehensive overview of the PASTA kinase targets of an important model pathogen and suggests that a critical role of PrkA in vivo is modulating PG synthesis through regulation of ReoM to facilitate cytosolic survival and virulence. Many antibiotics target bacterial cell wall biosynthesis, justifying continued study of this process and the ways bacteria respond to cell wall insults during infection. Penicillin-binding protein and serine/threonine-associated (PASTA) kinases are master regulators of cell wall stress responses in bacteria and are conserved in several major pathogens, including Listeria monocytogenes, Staphylococcus aureus, and Mycobacterium tuberculosis. We previously showed that the PASTA kinase in L. monocytogenes, PrkA, is essential for the response to cell wall stress and for virulence. In this work, we combined proteomic and genetic approaches to identify PrkA substrates in L. monocytogenes. We show that regulation of one candidate from both screens, ReoM, increases synthesis of the cell wall component peptidoglycan and that this regulation is required for pathogenesis. We also demonstrate that the PASTA kinase-ReoM pathway regulates cell wall stress responses in another significant pathogen, methicillin-resistant S. aureus. Additionally, we uncover a PrkA-independent role for ReoM in vivo in L. monocytogenes, suggesting a need for nuanced modulation of peptidoglycan synthesis during infection. Cumulatively, this study provides new insight into how bacterial pathogens control cell wall synthesis during infection.
Collapse
Affiliation(s)
- Jessica L. Kelliher
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Caroline M. Grunenwald
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Rhiannon R. Abrahams
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - McKenzie E. Daanen
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Cassandra I. Lew
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Warren E. Rose
- School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - John-Demian Sauer
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
| |
Collapse
|
15
|
Nishimoto AT, Rosch JW, Tuomanen EI. Pneumolysin: Pathogenesis and Therapeutic Target. Front Microbiol 2020; 11:1543. [PMID: 32714314 PMCID: PMC7343714 DOI: 10.3389/fmicb.2020.01543] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 06/15/2020] [Indexed: 01/08/2023] Open
Abstract
Streptococcus pneumoniae is an opportunistic pathogen responsible for widespread illness and is a major global health issue for children, the elderly, and the immunocompromised population. Pneumolysin (PLY) is a cholesterol-dependent cytolysin (CDC) and key pneumococcal virulence factor involved in all phases of pneumococcal disease, including transmission, colonization, and infection. In this review we cover the biology and cytolytic function of PLY, its contribution to S. pneumoniae pathogenesis, and its known interactions and effects on the host with regard to tissue damage and immune response. Additionally, we review statins as a therapeutic option for CDC toxicity and PLY toxoid as a vaccine candidate in protein-based vaccines.
Collapse
Affiliation(s)
- Andrew T Nishimoto
- Department of Infectious Disease, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Jason W Rosch
- Department of Infectious Disease, St. Jude Children's Research Hospital, Memphis, TN, United States
| | - Elaine I Tuomanen
- Department of Infectious Disease, St. Jude Children's Research Hospital, Memphis, TN, United States
| |
Collapse
|
16
|
Banerji R, Kanojiya P, Saroj SD. Role of interspecies bacterial communication in the virulence of pathogenic bacteria. Crit Rev Microbiol 2020; 46:136-146. [DOI: 10.1080/1040841x.2020.1735991] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Rajashri Banerji
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, India
| | - Poonam Kanojiya
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, India
| | - Sunil D. Saroj
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Pune, India
| |
Collapse
|
17
|
Siwapornchai N, Lee JN, Tchalla EYI, Bhalla M, Yeoh JH, Roggensack SE, Leong JM, Bou Ghanem EN. Extracellular adenosine enhances the ability of PMNs to kill Streptococcus pneumoniae by inhibiting IL-10 production. J Leukoc Biol 2020; 108:867-882. [PMID: 32017200 DOI: 10.1002/jlb.4ma0120-115rr] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 01/14/2020] [Accepted: 01/17/2020] [Indexed: 12/18/2022] Open
Abstract
Polymorphonuclear leukocytes (PMNs) are crucial for initial control of Streptococcus pneumoniae (pneumococcus) lung infection; however, as the infection progresses their persistence in the lungs becomes detrimental. Here we explored why the antimicrobial efficacy of PMNs declines over the course of infection. We found that the progressive inability of PMNs to control infection correlated with phenotypic differences characterized by a decrease in CD73 expression, an enzyme required for production of extracellular adenosine (EAD). EAD production by CD73 was crucial for the ability of both murine and human PMNs to kill S. pneumoniae. In exploring the mechanisms by which CD73 controlled PMN function, we found that CD73 mediated its antimicrobial activity by inhibiting IL-10 production. PMNs from wild-type mice did not increase IL-10 production in response to S. pneumoniae; however, CD73-/- PMNs up-regulated IL-10 production upon pneumococcal infection in vitro and during lung challenge. IL-10 inhibited the ability of WT PMNs to kill pneumococci. Conversely, blocking IL-10 boosted the bactericidal activity of CD73-/- PMNs as well as host resistance of CD73-/- mice to pneumococcal pneumonia. CD73/IL-10 did not affect apoptosis, bacterial uptake, and intracellular killing or production of antimicrobial neutrophil elastase and myeloperoxidase. Rather, inhibition of IL-10 production by CD73 was important for optimal reactive oxygen species (ROS) production by PMNs. ROS contributed to PMN antimicrobial function as their removal or detoxification impaired the ability of PMNs to efficiently kill S. pneumoniae. This study demonstrates that CD73 controls PMN antimicrobial phenotype during S. pneumoniae infection.
Collapse
Affiliation(s)
- Nalat Siwapornchai
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - James N Lee
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Essi Y I Tchalla
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, USA
| | - Manmeet Bhalla
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, USA
| | - Jun Hui Yeoh
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, USA
| | - Sara E Roggensack
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - John M Leong
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Elsa N Bou Ghanem
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, USA
| |
Collapse
|
18
|
Hobbs JK, Pluvinage B, Robb M, Smith SP, Boraston AB. Two complementary α-fucosidases from Streptococcus pneumoniae promote complete degradation of host-derived carbohydrate antigens. J Biol Chem 2019; 294:12670-12682. [PMID: 31266803 DOI: 10.1074/jbc.ra119.009368] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/24/2019] [Indexed: 12/13/2022] Open
Abstract
An important aspect of the interaction between the opportunistic bacterial pathogen Streptococcus pneumoniae and its human host is its ability to harvest host glycans. The pneumococcus can degrade a variety of complex glycans, including N- and O-linked glycans, glycosaminoglycans, and carbohydrate antigens, an ability that is tightly linked to the virulence of S. pneumoniae Although S. pneumoniae is known to use a sophisticated enzyme machinery to attack the human glycome, how it copes with fucosylated glycans, which are primarily histo-blood group antigens, is largely unknown. Here, we identified two pneumococcal enzymes, SpGH29C and SpGH95C, that target α-(1→3/4) and α-(1→2) fucosidic linkages, respectively. X-ray crystallography studies combined with functional assays revealed that SpGH29C is specific for the LewisA and LewisX antigen motifs and that SpGH95C is specific for the H(O)-antigen motif. Together, these enzymes could defucosylate LewisY and LewisB antigens in a complementary fashion. In vitro reconstruction of glycan degradation cascades disclosed that the individual or combined activities of these enzymes expose the underlying glycan structure, promoting the complete deconstruction of a glycan that would otherwise be resistant to pneumococcal enzymes. These experiments expand our understanding of the extensive capacity of S. pneumoniae to process host glycans and the likely roles of α-fucosidases in this. Overall, given the importance of enzymes that initiate glycan breakdown in pneumococcal virulence, such as the neuraminidase NanA and the mannosidase SpGH92, we anticipate that the α-fucosidases identified here will be important factors in developing more refined models of the S. pneumoniae-host interaction.
Collapse
Affiliation(s)
- Joanne K Hobbs
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Benjamin Pluvinage
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Melissa Robb
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Steven P Smith
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Alisdair B Boraston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| |
Collapse
|
19
|
Miyachiro MM, Granato D, Trindade DM, Ebel C, Paes Leme AF, Dessen A. Complex Formation between Mur Enzymes from Streptococcus pneumoniae. Biochemistry 2019; 58:3314-3324. [DOI: 10.1021/acs.biochem.9b00277] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Mayara M. Miyachiro
- Brazilian Biosciences National Laboratory (LNBio), CNPEM, Campinas 13084-971, São Paulo, Brazil
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), F-38000 Grenoble, France
| | - Daniela Granato
- Brazilian Biosciences National Laboratory (LNBio), CNPEM, Campinas 13084-971, São Paulo, Brazil
| | - Daniel Maragno Trindade
- Brazilian Biosciences National Laboratory (LNBio), CNPEM, Campinas 13084-971, São Paulo, Brazil
| | - Christine Ebel
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), F-38000 Grenoble, France
| | | | - Andréa Dessen
- Brazilian Biosciences National Laboratory (LNBio), CNPEM, Campinas 13084-971, São Paulo, Brazil
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), F-38000 Grenoble, France
| |
Collapse
|
20
|
Porfírio S, Carlson RW, Azadi P. Elucidating Peptidoglycan Structure: An Analytical Toolset. Trends Microbiol 2019; 27:607-622. [DOI: 10.1016/j.tim.2019.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 01/16/2019] [Accepted: 01/29/2019] [Indexed: 01/04/2023]
|
21
|
A Quorum Sensing-Regulated Protein Binds Cell Wall Components and Enhances Lysozyme Resistance in Streptococcus pyogenes. J Bacteriol 2018; 200:JB.00701-17. [PMID: 29555699 DOI: 10.1128/jb.00701-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 03/10/2018] [Indexed: 12/28/2022] Open
Abstract
The Rgg2/3 quorum sensing (QS) system is conserved among all sequenced isolates of group A Streptococcus (GAS; Streptococcus pyogenes). The molecular architecture of the system consists of a transcriptional activator (Rgg2) and a transcriptional repressor (Rgg3) under the control of autoinducing peptide pheromones (SHP2 and SHP3). Activation of the Rgg2/3 pathway leads to increases in biofilm formation and resistance to the bactericidal effects of the host factor lysozyme. In this work, we show that deletion of a small gene, spy49_0414c, abolished both phenotypes in response to pheromone signaling. The gene encodes a small, positively charged, secreted protein, referred to as StcA. Analysis of recombinant StcA showed that it can directly interact with GAS cell wall preparations containing phosphodiester-linked carbohydrate polymers but not with preparations devoid of them. Immunofluorescence microscopy detected antibody against StcA bound to the surface of paraformaldehyde-fixed wild-type cells. Expression of StcA in bacterial culture induced a shift in the electrostatic potential of the bacterial cell surface, which became more positively charged. These results suggest that StcA promotes phenotypes by way of ionic interactions with the GAS cell wall, most likely with negatively charged cell wall-associated polysaccharides.IMPORTANCE This study focuses on a small protein, StcA, that is expressed and secreted under induction of Rgg2/3 QS, ionically associating with negatively charged domains on the cell surface. These data present a novel mechanism of resistance to the host factor lysozyme by GAS and have implications in the relevance of this circuit in the interaction between the bacterium and the human host that is mediated by the bacterial cell surface.
Collapse
|
22
|
Insight into the novel inhibition mechanism of apigenin to Pneumolysin by molecular modeling. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
23
|
Bandara M, Skehel JM, Kadioglu A, Collinson I, Nobbs AH, Blocker AJ, Jenkinson HF. The accessory Sec system (SecY2A2) in Streptococcus pneumoniae is involved in export of pneumolysin toxin, adhesion and biofilm formation. Microbes Infect 2017; 19:402-412. [PMID: 28456649 PMCID: PMC5526788 DOI: 10.1016/j.micinf.2017.04.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 03/27/2017] [Accepted: 04/17/2017] [Indexed: 01/04/2023]
Abstract
In Streptococcus pneumoniae TIGR4, genes encoding a SecY2A2 accessory Sec system are present within a locus encoding a serine-rich repeat surface protein PsrP. Mutant strains deleted in secA2 or psrP were deficient in biofilm formation, while the ΔsecA2 mutant was reduced in binding to airway epithelial cells. Cell wall protein (CWP) fractions from the ΔsecA2 mutant, but not from the ΔpsrP mutant, were reduced in haemolytic (pneumolysin) activity. Contact-dependent pneumolysin (Ply) activity of wild type TIGR4 cells was ten-fold greater than that of ΔsecA2 mutant cells suggesting that Ply was not active at the ΔsecA2 cell surface. Ply protein was found to be present in the CWP fraction from the ΔsecA2 mutant, but showed aberrant electrophoretic migration indicative of protein modification. Proteomic analyses led to the discovery that the ΔsecA2 mutant CWP fraction was deficient in two glycosidases as well as other enzymes involved in carbohydrate metabolism. Taken collectively the results suggest that positioning of Ply into the cell wall compartment in active form, together with glycosyl hydrolases and adhesins, requires a functional accessory Sec system.
Collapse
Affiliation(s)
- Mikaila Bandara
- School of Oral and Dental Sciences, University of Bristol, Lower Maudlin Street, Bristol, BS1 2LY, UK; School of Cellular & Molecular Medicine, University of Bristol, University Walk, Bristol, BS8 1TD, UK; School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - J Mark Skehel
- Biological Mass Spectrometry and Proteomics, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Aras Kadioglu
- Department of Clinical Infection, Microbiology & Immunology, Institute of Infection and Global Health, University of Liverpool, 8 West Derby Street, Liverpool L69 7BE, UK
| | - Ian Collinson
- School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD, UK
| | - Angela H Nobbs
- School of Oral and Dental Sciences, University of Bristol, Lower Maudlin Street, Bristol, BS1 2LY, UK
| | - Ariel J Blocker
- School of Cellular & Molecular Medicine, University of Bristol, University Walk, Bristol, BS8 1TD, UK; School of Biochemistry, University of Bristol, University Walk, Bristol, BS8 1TD, UK.
| | - Howard F Jenkinson
- School of Oral and Dental Sciences, University of Bristol, Lower Maudlin Street, Bristol, BS1 2LY, UK.
| |
Collapse
|
24
|
Robb M, Hobbs JK, Woodiga SA, Shapiro-Ward S, Suits MDL, McGregor N, Brumer H, Yesilkaya H, King SJ, Boraston AB. Molecular Characterization of N-glycan Degradation and Transport in Streptococcus pneumoniae and Its Contribution to Virulence. PLoS Pathog 2017; 13:e1006090. [PMID: 28056108 PMCID: PMC5215778 DOI: 10.1371/journal.ppat.1006090] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 11/27/2016] [Indexed: 11/19/2022] Open
Abstract
The carbohydrate-rich coating of human tissues and cells provide a first point of contact for colonizing and invading bacteria. Commensurate with N-glycosylation being an abundant form of protein glycosylation that has critical functional roles in the host, some host-adapted bacteria possess the machinery to process N-linked glycans. The human pathogen Streptococcus pneumoniae depolymerizes complex N-glycans with enzymes that sequentially trim a complex N-glycan down to the Man3GlcNAc2 core prior to the release of the glycan from the protein by endo-β-N-acetylglucosaminidase (EndoD), which cleaves between the two GlcNAc residues. Here we examine the capacity of S. pneumoniae to process high-mannose N-glycans and transport the products. Through biochemical and structural analyses we demonstrate that S. pneumoniae also possesses an α-(1,2)-mannosidase (SpGH92). This enzyme has the ability to trim the terminal α-(1,2)-linked mannose residues of high-mannose N-glycans to generate Man5GlcNAc2. Through this activity SpGH92 is able to produce a substrate for EndoD, which is not active on high-mannose glycans with α-(1,2)-linked mannose residues. Binding studies and X-ray crystallography show that NgtS, the solute binding protein of an ABC transporter (ABCNG), is able to bind Man5GlcNAc, a product of EndoD activity, with high affinity. Finally, we evaluated the contribution of EndoD and ABCNG to growth of S. pneumoniae on a model N-glycosylated glycoprotein, and the contribution of these enzymes and SpGH92 to virulence in a mouse model. We found that both EndoD and ABCNG contribute to growth of S. pneumoniae, but that only SpGH92 and EndoD contribute to virulence. Therefore, N-glycan processing, but not transport of the released glycan, is required for full virulence in S. pneumoniae. To conclude, we synthesize our findings into a model of N-glycan processing by S. pneumoniae in which both complex and high-mannose N-glycans are targeted, and in which the two arms of this degradation pathway converge at ABCNG. Streptococcus pneumoniae (pneumococcus) is a bacterium that causes extensive morbidity and mortality in humans. Vaccines and antibiotics are effective forms of prevention and treatment, respectively, but present challenges as it is a constant race to vaccinate against the enormous and ever evolving pool of different serotypes of the bacterium while resistance to antibiotics continues to trend upwards. It is thus necessary to better understand the molecular aspects of the host-pneumococcus interaction in order to inform the potential generation of alternative treatment strategies. S. pneumoniae relies on its ability to process the carbohydrates presented on the surface of host cells for full-virulence. In this study, we examine the capability of the bacterium to process high-mannose N-linked sugars, a heretofore unknown ability for S. pneumoniae. The results show that the pneumococcal genome encodes enzymes capable of processing these sugars and that, remarkably, the initiating reaction performed by an enzyme that removes terminal α-(1,2)-linked mannose residues is critical to virulence in a mouse model. This study illuminates an extensive pathway in S. pneumoniae that targets N-linked sugars and is key to the host-pathogen interaction, therefore revealing a potential target for therapeutic intervention.
Collapse
Affiliation(s)
- Melissa Robb
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Joanne K. Hobbs
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Shireen A. Woodiga
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
| | - Sarah Shapiro-Ward
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Michael D. L. Suits
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Nicholas McGregor
- Michael Smith Laboratories and Department of Chemistry, University of British Columbia, 2185 East Mall, Vancouver, British Columbia, Canada
| | - Harry Brumer
- Michael Smith Laboratories and Department of Chemistry, University of British Columbia, 2185 East Mall, Vancouver, British Columbia, Canada
| | - Hasan Yesilkaya
- Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, United Kingdom
| | - Samantha J. King
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children’s Hospital, Columbus, Ohio, United States of America
| | - Alisdair B. Boraston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
- * E-mail:
| |
Collapse
|
25
|
Bryant JC, Dabbs RC, Oswalt KL, Brown LR, Rosch JW, Seo KS, Donaldson JR, McDaniel LS, Thornton JA. Pyruvate oxidase of Streptococcus pneumoniae contributes to pneumolysin release. BMC Microbiol 2016; 16:271. [PMID: 27829373 PMCID: PMC5103497 DOI: 10.1186/s12866-016-0881-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 10/28/2016] [Indexed: 11/21/2022] Open
Abstract
Background Streptococcus pneumoniae is one of the leading causes of community acquired pneumonia and acute otitis media. Certain aspects of S. pneumoniae’s virulence are dependent upon expression and release of the protein toxin pneumolysin (PLY) and upon the activity of the peroxide-producing enzyme, pyruvate oxidase (SpxB). We investigated the possible synergy of these two proteins and identified that release of PLY is enhanced by expression of SpxB prior to stationary phase growth. Results Mutants lacking the spxB gene were defective in PLY release and complementation of spxB restored PLY release. This was demonstrated by cytotoxic effects of sterile filtered supernatants upon epithelial cells and red blood cells. Additionally, peroxide production appeared to contribute to the mechanism of PLY release since a significant correlation was found between peroxide production and PLY release among a panel of clinical isolates. Exogenous addition of H2O2 failed to induce PLY release and catalase supplementation prevented PLY release in some strains, indicating peroxide may exert its effect intracellularly or in a strain-dependent manner. SpxB expression did not trigger bacterial cell death or LytA-dependent autolysis, but did predispose cells to deoxycholate lysis. Conclusions Here we demonstrate a novel link between spxB expression and PLY release. These findings link liberation of PLY toxin to oxygen availability and pneumococcal metabolism. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0881-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Joseph C Bryant
- Department of Biological Sciences, Mississippi State University, 295 E Lee Blvd., Harned Hall, Rm 219, Mississippi State, MS, 39762, USA
| | - Ridge C Dabbs
- Department of Biological Sciences, Mississippi State University, 295 E Lee Blvd., Harned Hall, Rm 219, Mississippi State, MS, 39762, USA
| | - Katie L Oswalt
- Department of Biological Sciences, Mississippi State University, 295 E Lee Blvd., Harned Hall, Rm 219, Mississippi State, MS, 39762, USA
| | - Lindsey R Brown
- Department of Biological Sciences, Mississippi State University, 295 E Lee Blvd., Harned Hall, Rm 219, Mississippi State, MS, 39762, USA
| | - Jason W Rosch
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Keun S Seo
- Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Janet R Donaldson
- Department of Biological Sciences, University of Southern Mississippi, Hattiesburg, MS, USA
| | - Larry S McDaniel
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS, USA
| | - Justin A Thornton
- Department of Biological Sciences, Mississippi State University, 295 E Lee Blvd., Harned Hall, Rm 219, Mississippi State, MS, 39762, USA.
| |
Collapse
|
26
|
Kohler S, Voß F, Gómez Mejia A, Brown JS, Hammerschmidt S. Pneumococcal lipoproteins involved in bacterial fitness, virulence, and immune evasion. FEBS Lett 2016; 590:3820-3839. [DOI: 10.1002/1873-3468.12352] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 08/01/2016] [Accepted: 08/05/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Sylvia Kohler
- Department Genetics of Microorganisms; Interfaculty Institute for Genetics and Functional Genomics; University of Greifswald; Germany
| | - Franziska Voß
- Department Genetics of Microorganisms; Interfaculty Institute for Genetics and Functional Genomics; University of Greifswald; Germany
| | - Alejandro Gómez Mejia
- Department Genetics of Microorganisms; Interfaculty Institute for Genetics and Functional Genomics; University of Greifswald; Germany
| | - Jeremy S. Brown
- Department of Medicine; Centre for Inflammation and Tissue Repair; University College Medical School; London UK
| | - Sven Hammerschmidt
- Department Genetics of Microorganisms; Interfaculty Institute for Genetics and Functional Genomics; University of Greifswald; Germany
| |
Collapse
|
27
|
Fisher JF, Mobashery S. β-Lactam Resistance Mechanisms: Gram-Positive Bacteria and Mycobacterium tuberculosis. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a025221. [PMID: 27091943 DOI: 10.1101/cshperspect.a025221] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The value of the β-lactam antibiotics for the control of bacterial infection has eroded with time. Three Gram-positive human pathogens that were once routinely susceptible to β-lactam chemotherapy-Streptococcus pneumoniae, Enterococcus faecium, and Staphylococcus aureus-now are not. Although a fourth bacterium, the acid-fast (but not Gram-positive-staining) Mycobacterium tuberculosis, has intrinsic resistance to earlier β-lactams, the emergence of strains of this bacterium resistant to virtually all other antibiotics has compelled the evaluation of newer β-lactam combinations as possible contributors to the multidrug chemotherapy required to control tubercular infection. The emerging molecular-level understanding of these resistance mechanisms used by these four bacteria provides the conceptual framework for bringing forward new β-lactams, and new β-lactam strategies, for the future control of their infections.
Collapse
Affiliation(s)
- Jed F Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670
| |
Collapse
|
28
|
Staying in Shape: the Impact of Cell Shape on Bacterial Survival in Diverse Environments. Microbiol Mol Biol Rev 2016; 80:187-203. [PMID: 26864431 DOI: 10.1128/mmbr.00031-15] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bacteria display an abundance of cellular forms and can change shape during their life cycle. Many plausible models regarding the functional significance of cell morphology have emerged. A greater understanding of the genetic programs underpinning morphological variation in diverse bacterial groups, combined with assays of bacteria under conditions that mimic their varied natural environments, from flowing freshwater streams to diverse human body sites, provides new opportunities to probe the functional significance of cell shape. Here we explore shape diversity among bacteria, at the levels of cell geometry, size, and surface appendages (both placement and number), as it relates to survival in diverse environments. Cell shape in most bacteria is determined by the cell wall. A major challenge in this field has been deconvoluting the effects of differences in the chemical properties of the cell wall and the resulting cell shape perturbations on observed fitness changes. Still, such studies have begun to reveal the selective pressures that drive the diverse forms (or cell wall compositions) observed in mammalian pathogens and bacteria more generally, including efficient adherence to biotic and abiotic surfaces, survival under low-nutrient or stressful conditions, evasion of mammalian complement deposition, efficient dispersal through mucous barriers and tissues, and efficient nutrient acquisition.
Collapse
|
29
|
Barnett TC, Cole JN, Rivera-Hernandez T, Henningham A, Paton JC, Nizet V, Walker MJ. Streptococcal toxins: role in pathogenesis and disease. Cell Microbiol 2015; 17:1721-41. [PMID: 26433203 DOI: 10.1111/cmi.12531] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 08/13/2015] [Accepted: 09/02/2015] [Indexed: 12/15/2022]
Abstract
Group A Streptococcus (Streptococcus pyogenes), group B Streptococcus (Streptococcus agalactiae) and Streptococcus pneumoniae (pneumococcus) are host-adapted bacterial pathogens among the leading infectious causes of human morbidity and mortality. These microbes and related members of the genus Streptococcus produce an array of toxins that act against human cells or tissues, resulting in impaired immune responses and subversion of host physiological processes to benefit the invading microorganism. This toxin repertoire includes haemolysins, proteases, superantigens and other agents that ultimately enhance colonization and survival within the host and promote dissemination of the pathogen.
Collapse
Affiliation(s)
- Timothy C Barnett
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Jason N Cole
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia.,Department of Pediatrics and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, USA
| | - Tania Rivera-Hernandez
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Anna Henningham
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia.,Department of Pediatrics and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, USA
| | - James C Paton
- Research Centre for Infectious Diseases, Department of Molecular and Cellular Biology, School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Victor Nizet
- Department of Pediatrics and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, USA
| | - Mark J Walker
- Australian Infectious Diseases Research Centre and School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Queensland, Australia
| |
Collapse
|
30
|
Substrate recognition and catalysis by LytB, a pneumococcal peptidoglycan hydrolase involved in virulence. Sci Rep 2015; 5:16198. [PMID: 26537571 PMCID: PMC4633669 DOI: 10.1038/srep16198] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 10/12/2015] [Indexed: 12/21/2022] Open
Abstract
Streptococcus pneumoniae is a major cause of life-threatening diseases worldwide. Here we provide an in-depth functional characterization of LytB, the peptidoglycan hydrolase responsible for physical separation of daughter cells. Identified herein as an N-acetylglucosaminidase, LytB is involved also in colonization and invasion of the nasopharynx, biofilm formation and evasion of host immunity as previously demonstrated. We have shown that LytB cleaves the GlcNAc-β-(1,4)-MurNAc glycosidic bond of peptidoglycan building units. The hydrolysis occurs at sites with fully acetylated GlcNAc moieties, with preference for uncross-linked muropeptides. The necessity of GlcN acetylation and the presence of a single acidic moiety (Glu585) essential for catalysis strongly suggest a substrate-assisted mechanism with anchimeric assistance of the acetamido group of GlcNAc moieties. Additionally, modelling of the catalytic region bound to a hexasaccharide tripentapeptide provided insights into substrate-binding subsites and peptidoglycan recognition. Besides, cell-wall digestion products and solubilisation rates might indicate a tight control of LytB activity to prevent unrestrained breakdown of the cell wall. Choline-independent localization at the poles of the cell, mediated by the choline-binding domain, peptidoglycan modification, and choline-mediated (lipo)teichoic-acid attachment contribute to the high selectivity of LytB. Moreover, so far unknown chitin hydrolase and glycosyltransferase activities were detected using GlcNAc oligomers as substrate.
Collapse
|
31
|
Disentangling competence for genetic transformation and virulence in Streptococcus pneumoniae. Curr Genet 2015; 62:97-103. [PMID: 26403231 DOI: 10.1007/s00294-015-0520-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 10/23/2022]
Abstract
Horizontal gene transfer mediated by the competence regulon is a major driver of genome plasticity in Streptococcus pneumoniae. When pneumococcal cells enter the competent state, about 6% of the genes in the genome are up-regulated. Among these, some genes are essential for genetic transformation while others are dispensable for the process. Exhaustive deletion analyses show that some up-regulated genes dispensable for genetic transformation contribute to pneumococcal-mediated pneumonia and bacteremia infections. Interestingly, virulence functions of such genes are either dependent or independent of the competent state. Among the competent-state-dependent genes are those mediating allolysis, a process where small fraction of non-competent cells within the pneumococcal population are lysed by their competent counterparts, releasing DNA presumably for transformation. Inadvertently, the pore-forming toxin pneumolysin is also released during allolysis, contributing to virulence. In this review, we discuss recent advances in our understanding of pneumococcal virulence processes mediated by the competence regulon. We proposed that coupling of competence induction and bacterial fitness drives the natural selection to favor an intact competence regulon, which in turn, provides the long-term benefits of genetic plasticity.
Collapse
|
32
|
Minimal Peptidoglycan (PG) Turnover in Wild-Type and PG Hydrolase and Cell Division Mutants of Streptococcus pneumoniae D39 Growing Planktonically and in Host-Relevant Biofilms. J Bacteriol 2015; 197:3472-85. [PMID: 26303829 DOI: 10.1128/jb.00541-15] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 08/15/2015] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED We determined whether there is turnover of the peptidoglycan (PG) cell wall of the ovococcus bacterial pathogen Streptococcus pneumoniae (pneumococcus). Pulse-chase experiments on serotype 2 strain D39 radiolabeled with N-acetylglucosamine revealed little turnover and release of PG breakdown products during growth compared to published reports of PG turnover in Bacillus subtilis. PG dynamics were visualized directly by long-pulse-chase-new-labeling experiments using two colors of fluorescent d-amino acid (FDAA) probes to microscopically detect regions of new PG synthesis. Consistent with minimal PG turnover, hemispherical regions of stable "old" PG persisted in D39 and TIGR4 (serotype 4) cells grown in rich brain heart infusion broth, in D39 cells grown in chemically defined medium containing glucose or galactose as the carbon source, and in D39 cells grown as biofilms on a layer of fixed human epithelial cells. In contrast, B. subtilis exhibited rapid sidewall PG turnover in similar FDAA-labeling experiments. High-performance liquid chromatography (HPLC) analysis of biochemically released peptides from S. pneumoniae PG validated that FDAAs incorporated at low levels into pentamer PG peptides and did not change the overall composition of PG peptides. PG dynamics were also visualized in mutants lacking PG hydrolases that mediate PG remodeling, cell separation, or autolysis and in cells lacking the MapZ and DivIVA division regulators. In all cases, hemispheres of stable old PG were maintained. In PG hydrolase mutants exhibiting aberrant division plane placement, FDAA labeling revealed patches of inert PG at turns and bulge points. We conclude that growing S. pneumoniae cells exhibit minimal PG turnover compared to the PG turnover in rod-shaped cells. IMPORTANCE PG cell walls are unique to eubacteria, and many bacterial species turn over and recycle their PG during growth, stress, colonization, and virulence. Consequently, PG breakdown products serve as signals for bacteria to induce antibiotic resistance and as activators of innate immune responses. S. pneumoniae is a commensal bacterium that colonizes the human nasopharynx and opportunistically causes serious respiratory and invasive diseases. The results presented here demonstrate a distinct demarcation between regions of old PG and regions of new PG synthesis and minimal turnover of PG in S. pneumoniae cells growing in culture or in host-relevant biofilms. These findings suggest that S. pneumoniae minimizes the release of PG breakdown products by turnover, which may contribute to evasion of the innate immune system.
Collapse
|