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Nikolopoulos N, Matos RC, Courtin P, Ayala I, Akherraz H, Simorre JP, Chapot-Chartier MP, Leulier F, Ravaud S, Grangeasse C. DltC acts as an interaction hub for AcpS, DltA and DltB in the teichoic acid D-alanylation pathway of Lactiplantibacillus plantarum. Sci Rep 2022; 12:13133. [PMID: 35907949 PMCID: PMC9338922 DOI: 10.1038/s41598-022-17434-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 07/25/2022] [Indexed: 02/04/2023] Open
Abstract
Teichoic acids (TA) are crucial for the homeostasis of the bacterial cell wall as well as their developmental behavior and interplay with the environment. TA can be decorated by different modifications, modulating thus their biochemical properties. One major modification consists in the esterification of TA by d-alanine, a process known as d-alanylation. TA d-alanylation is performed by the Dlt pathway, which starts in the cytoplasm and continues extracellularly after d-Ala transportation through the membrane. In this study, we combined structural biology and in vivo approaches to dissect the cytoplasmic steps of this pathway in Lactiplantibacillus plantarum, a bacterial species conferring health benefits to its animal host. After establishing that AcpS, DltB, DltC1 and DltA are required for the promotion of Drosophila juvenile growth under chronic undernutrition, we solved their crystal structure and/or used NMR and molecular modeling to study their interactions. Our work demonstrates that the suite of interactions between these proteins is ordered with a conserved surface of DltC1 docking sequentially AcpS, DltA and eventually DltB. Altogether, we conclude that DltC1 acts as an interaction hub for all the successive cytoplasmic steps of the TA d-alanylation pathway.
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Affiliation(s)
- Nikos Nikolopoulos
- Molecular Microbiology and Structural Biochemistry, CNRS UMR 5086, Université Claude Bernard Lyon 1, Lyon, France
| | - Renata C Matos
- Institut de Génomique Fonctionnelle de Lyon, École Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, Lyon, France
| | - Pascal Courtin
- INRAE, AgroParisTech, Micalis Institute, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Isabel Ayala
- Institut de Biologie Structurale, CEA, CNRS UMR 5075, Université Grenoble Alpes, 3800, Grenoble, France
| | - Houssam Akherraz
- Institut de Génomique Fonctionnelle de Lyon, École Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, Lyon, France
| | - Jean-Pierre Simorre
- Institut de Biologie Structurale, CEA, CNRS UMR 5075, Université Grenoble Alpes, 3800, Grenoble, France
| | | | - François Leulier
- Institut de Génomique Fonctionnelle de Lyon, École Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, Lyon, France
| | - Stéphanie Ravaud
- Molecular Microbiology and Structural Biochemistry, CNRS UMR 5086, Université Claude Bernard Lyon 1, Lyon, France.
| | - Christophe Grangeasse
- Molecular Microbiology and Structural Biochemistry, CNRS UMR 5086, Université Claude Bernard Lyon 1, Lyon, France.
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2
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Haubrich BA, Nayyab S, Gallati M, Hernandez J, Williams C, Whitman A, Zimmerman T, Li Q, Chen Y, Zhou CZ, Basu A, Reid CW. Inhibition of Streptococcus pneumoniae growth by masarimycin. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35467499 DOI: 10.1099/mic.0.001182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Despite renewed interest, development of chemical biology methods to study peptidoglycan metabolism has lagged in comparison to the glycobiology field in general. To address this, a panel of diamides were screened against the Gram-positive bacterium Streptococcus pneumoniae to identify inhibitors of bacterial growth. The screen identified the diamide masarimycin as a bacteriostatic inhibitor of S. pneumoniae growth with an MIC of 8 µM. The diamide inhibited detergent-induced autolysis in a concentration-dependent manner, indicating perturbation of peptidoglycan degradation as the mode-of-action. Cell based screening of masarimycin against a panel of autolysin mutants, identified a higher MIC against a ΔlytB strain lacking an endo-N-acetylglucosaminidase involved in cell division. Subsequent biochemical and phenotypic analyses suggested that the higher MIC was due to an indirect interaction with LytB. Further analysis of changes to the cell surface in masarimycin treated cells identified the overexpression of several moonlighting proteins, including elongation factor Tu which is implicated in regulating cell shape. Checkerboard assays using masarimycin in concert with additional antibiotics identified an antagonistic relationship with the cell wall targeting antibiotic fosfomycin, which further supports a cell wall mode-of-action.
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Affiliation(s)
- Brad A Haubrich
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA.,Department of Basic Sciences, Touro University Nevada, College of Osteopathic Medicine, Henderson, NV 89014, USA
| | - Saman Nayyab
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA.,Amherst Department of Molecular and Cellular Biology, University of Massachusetts, 230 Stockbridge Rd Amherst, MA, USA
| | - Mika Gallati
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
| | - Jazmeen Hernandez
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
| | - Caroline Williams
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
| | - Andrew Whitman
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
| | - Tahl Zimmerman
- Department of Family and Consumer Sciences, North Carolina A&T State University, Greensboro, NC, USA
| | - Qiong Li
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, PR China
| | - Yuxing Chen
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, PR China
| | - Cong-Zhao Zhou
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, PR China
| | - Amit Basu
- Department of Chemistry, Brown University, Providence, RI, USA
| | - Christopher W Reid
- Center for Health and Behavioral Sciences, Department of Science and Technology, Bryant University, 1150 Douglas Pike, Smithfield, RI 02917, USA
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3
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Structural, molecular docking computational studies and in-vitro evidence for antibacterial activity of mixed ligand complexes. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.130481] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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4
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Assoni L, Milani B, Carvalho MR, Nepomuceno LN, Waz NT, Guerra MES, Converso TR, Darrieux M. Resistance Mechanisms to Antimicrobial Peptides in Gram-Positive Bacteria. Front Microbiol 2020; 11:593215. [PMID: 33193264 PMCID: PMC7609970 DOI: 10.3389/fmicb.2020.593215] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 09/03/2020] [Indexed: 02/06/2023] Open
Abstract
With the alarming increase of infections caused by pathogenic multidrug-resistant bacteria over the last decades, antimicrobial peptides (AMPs) have been investigated as a potential treatment for those infections, directly through their lytic effect or indirectly, due to their ability to modulate the immune system. There are still concerns regarding the use of such molecules in the treatment of infections, such as cell toxicity and host factors that lead to peptide inhibition. To overcome these limitations, different approaches like peptide modification to reduce toxicity and peptide combinations to improve therapeutic efficacy are being tested. Human defense peptides consist of an important part of the innate immune system, against a myriad of potential aggressors, which have in turn developed different ways to overcome the AMPs microbicidal activities. Since the antimicrobial activity of AMPs vary between Gram-positive and Gram-negative species, so do the bacterial resistance arsenal. This review discusses the mechanisms exploited by Gram-positive bacteria to circumvent killing by antimicrobial peptides. Specifically, the most clinically relevant genera, Streptococcus spp., Staphylococcus spp., Enterococcus spp. and Gram-positive bacilli, have been explored.
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Affiliation(s)
- Lucas Assoni
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Barbara Milani
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Marianna Ribeiro Carvalho
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Lucas Natanael Nepomuceno
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Natalha Tedeschi Waz
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Maria Eduarda Souza Guerra
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Thiago Rojas Converso
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Michelle Darrieux
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
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5
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Amin BH, Abou‐Dobara MI, Diab MA, Gomaa EA, El‐Mogazy MA, El‐Sonbati AZ, EL‐Ghareib MS, Hussien MA, Salama HM. Synthesis, characterization, and biological investigation of new mixed‐ligand complexes. Appl Organomet Chem 2020. [DOI: 10.1002/aoc.5689] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Basma H. Amin
- The Regional Center for Mycology and Biotechnology (RCMB) Al‐Azhar University Cairo Egypt
| | - Mohamed I. Abou‐Dobara
- Botany and Microbiology Department, Faculty of Science Damietta University Damietta Egypt
| | - Mostafa A. Diab
- Chemistry Department, Faculty of Science Damietta University Damietta Egypt
| | - Essam A. Gomaa
- Chemistry Department, Faculty of Science Mansoura University Mansoura 35516 Egypt
| | | | - Adel Z. El‐Sonbati
- Chemistry Department, Faculty of Science Damietta University Damietta Egypt
| | | | - Mostafa A. Hussien
- Department of Chemistry, Faculty of Science King Abdul‐Aziz University PO Box 80203 Jeddah 21589 Saudi Arabia
| | - Hanaa M. Salama
- Chemistry Department, Faculty of Science Port Said University Port Said Egypt
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6
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Mizuno H, Arce L, Tomotsune K, Albarracin L, Funabashi R, Vera D, Islam MA, Vizoso-Pinto MG, Takahashi H, Sasaki Y, Kitazawa H, Villena J. Lipoteichoic Acid Is Involved in the Ability of the Immunobiotic Strain Lactobacillus plantarum CRL1506 to Modulate the Intestinal Antiviral Innate Immunity Triggered by TLR3 Activation. Front Immunol 2020; 11:571. [PMID: 32328062 PMCID: PMC7161159 DOI: 10.3389/fimmu.2020.00571] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 03/12/2020] [Indexed: 12/14/2022] Open
Abstract
Studies have demonstrated that lipoteichoic acid (LTA) is involved in the immunomodulatory properties of some immunobiotic lactobacilli. The aim of this work was to evaluate whether LTA contributes to the capacity of Lactobacillus plantarum CRL1506 in modulating the intestinal innate antiviral immune response. A D-alanyl-lipoteichoic acid biosynthesis protein (dltD) knockout CRL1506 strain (L. plantarumΔdltD) was obtained, and its ability to modulate Toll-like receptor (TLR)-3-mediated immune response was evaluated in vitro in porcine intestinal epithelial (PIE) cells and in vivo in Balb/c mice. Wild-type (WT) CRL1506 (L. plantarum WT) was used as positive control. The challenge of PIE cells with the TLR3 agonist poly(I:C) significantly increased interferon (IFN)-β, interleukin (IL)-6, and monocyte chemoattractant protein (MCP)-1 expressions. PIE cells pretreated with L. plantarumΔdltD or L. plantarum WT showed higher levels of IFN-β while only L. plantarum WT significantly reduced the expression of IL-6 and MCP-1 when compared with poly(I:C)-treated control cells. The oral administration of L. plantarum WT to mice prior the intraperitoneal injection of poly(I:C) significantly increased IFN-β and IL-10 and reduced intraepithelial lymphocytes (CD3+NK1.1+CD8αα+) and pro-inflammatory mediators (TNF-α, IL-6, and IL-15) in the intestinal mucosa. Similar to the WT strain, L. plantarumΔdltD-treated mice showed enhanced levels of IFN-β after poly(I:C) challenge. However, treatment of mice with L. plantarumΔdltD was not able to increase IL-10 or reduce CD3+NK1.1+CD8αα+ cells, TNF-α, IL-6, or IL-15 in the intestine. These results indicate that LTA would be a key molecule in the anti-inflammatory effect induced by the CRL1506 strain in the context of TLR3-mediated inflammation.
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Affiliation(s)
- Hiroya Mizuno
- Food and Feed Immunology Group, Laboratory of Animal Products Chemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Lorena Arce
- Infection Biology Laboratory, Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, Tucumán, Argentina
| | - Kae Tomotsune
- Food and Feed Immunology Group, Laboratory of Animal Products Chemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.,Livestock Immunology Unit, International Education and Research Center for Food Agricultural Immunology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Leonardo Albarracin
- Food and Feed Immunology Group, Laboratory of Animal Products Chemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.,Laboratory of Immunobiotechnology, Reference Centre for Lactobacilli (CERELA-CONICET), Tucuman, Argentina
| | - Ryutaro Funabashi
- Food and Feed Immunology Group, Laboratory of Animal Products Chemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.,Livestock Immunology Unit, International Education and Research Center for Food Agricultural Immunology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Daniela Vera
- Infection Biology Laboratory, Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, Tucumán, Argentina.,Laboratorio de Ciencias Básicas Or. Genética, Facultad de Medicina de la Universidad Nacional de Tucuman, Tucumán, Argentina
| | - Md Aminul Islam
- Food and Feed Immunology Group, Laboratory of Animal Products Chemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.,Department of Medicine, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Maria Guadalupe Vizoso-Pinto
- Infection Biology Laboratory, Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, Tucumán, Argentina.,Laboratorio de Ciencias Básicas Or. Genética, Facultad de Medicina de la Universidad Nacional de Tucuman, Tucumán, Argentina
| | - Hideki Takahashi
- Plant Immunology Unit, International Education and Research Center for Food Agricultural Immunology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Yasuko Sasaki
- Graduate School of Agriculture, Meiji University, Kawasaki, Japan
| | - Haruki Kitazawa
- Food and Feed Immunology Group, Laboratory of Animal Products Chemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.,Livestock Immunology Unit, International Education and Research Center for Food Agricultural Immunology, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Julio Villena
- Food and Feed Immunology Group, Laboratory of Animal Products Chemistry, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan.,Laboratory of Immunobiotechnology, Reference Centre for Lactobacilli (CERELA-CONICET), Tucuman, Argentina
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7
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Scornec H, Palud A, Pédron T, Wheeler R, Petitgonnet C, Boneca IG, Cavin JF, Sansonetti PJ, Licandro H. Study of the cwaRS-ldcA Operon Coding a Two-Component System and a Putative L,D-Carboxypeptidase in Lactobacillus paracasei. Front Microbiol 2020; 11:156. [PMID: 32194510 PMCID: PMC7062640 DOI: 10.3389/fmicb.2020.00156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 01/22/2020] [Indexed: 11/22/2022] Open
Abstract
The cell surface is the primary recognition site between the bacterium and the host. An operon of three genes, LSEI_0219 (cwaR), LSEI_0220 (cwaS), and LSEI_0221 (ldcA), has been previously identified as required for the establishment of Lactobacillus paracasei in the gut. The genes cwaR and cwaS encode a predicted two-component system (TCS) and ldcA a predicted D-alanyl-D-alanine carboxypeptidase which is a peptidoglycan (PG) biosynthesis enzyme. We explored the functionality and the physiological role of these three genes, particularly their impact on the bacterial cell wall architecture and on the bacterial adaptation to environmental perturbations in the gut. The functionality of CwaS/R proteins as a TCS has been demonstrated by biochemical analysis. It is involved in the transcriptional regulation of several genes of the PG biosynthesis. Analysis of the muropeptides of PG in mutants allowed us to re-annotate LSEI_0221 as a putative L,D-carboxypeptidase (LdcA). The absence of this protein coincided with a decrease of two surface antigens: LSEI_0020, corresponding to p40 or msp2 whose implication in the host epithelial homeostasis has been recently studied, and LSEI_2029 which has never been functionally characterized. The inactivation of each of these three genes induces susceptibility to antimicrobial peptides (hBD1, hBD2, and CCL20), which could be the main cause of the gut establishment deficiency. Thus, this operon is necessary for the presence of two surface antigens and for a suitable cell wall architecture.
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Affiliation(s)
- Hélène Scornec
- PAM UMR, AgroSup Dijon, Université de Bourgogne Franche-Comté, Dijon, France
| | - Aurore Palud
- PAM UMR, AgroSup Dijon, Université de Bourgogne Franche-Comté, Dijon, France
| | - Thierry Pédron
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France
- Unité INSERM, Institut Pasteur, Paris, France
| | - Richard Wheeler
- Unité de Biologie et Génétique de la Paroi Bactérienne, Institut Pasteur, Paris, France
- Avenir Group, INSERM, Paris, France
| | - Clément Petitgonnet
- PAM UMR, AgroSup Dijon, Université de Bourgogne Franche-Comté, Dijon, France
| | - Ivo Gomperts Boneca
- Unité de Biologie et Génétique de la Paroi Bactérienne, Institut Pasteur, Paris, France
- Avenir Group, INSERM, Paris, France
| | - Jean-François Cavin
- PAM UMR, AgroSup Dijon, Université de Bourgogne Franche-Comté, Dijon, France
| | - Philippe J. Sansonetti
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France
- Unité INSERM, Institut Pasteur, Paris, France
- Chaire de Microbiologie et Maladies Infectieuses, Collège de France, Paris, France
| | - Hélène Licandro
- PAM UMR, AgroSup Dijon, Université de Bourgogne Franche-Comté, Dijon, France
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8
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Duchêne MC, Rolain T, Knoops A, Courtin P, Chapot-Chartier MP, Dufrêne YF, Hallet BF, Hols P. Distinct and Specific Role of NlpC/P60 Endopeptidases LytA and LytB in Cell Elongation and Division of Lactobacillus plantarum. Front Microbiol 2019; 10:713. [PMID: 31031721 PMCID: PMC6473061 DOI: 10.3389/fmicb.2019.00713] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 03/21/2019] [Indexed: 11/22/2022] Open
Abstract
Peptidoglycan (PG) is an essential lattice of the bacterial cell wall that needs to be continuously remodeled to allow growth. This task is ensured by the concerted action of PG synthases that insert new material in the pre-existing structure and PG hydrolases (PGHs) that cleave the PG meshwork at critical sites for its processing. Contrasting with Bacillus subtilis that contains more than 35 PGHs, Lactobacillus plantarum is a non-sporulating rod-shaped bacterium that is predicted to possess a minimal set of 12 PGHs. Their role in morphogenesis and cell cycle remains mostly unexplored, except for the involvement of the glucosaminidase Acm2 in cell separation and the NlpC/P60 D, L-endopeptidase LytA in cell shape maintenance. Besides LytA, L. plantarum encodes three additional NlpC/P60 endopeptidases (i.e., LytB, LytC and LytD). The in silico analysis of these four endopeptidases suggests that they could have redundant functions based on their modular organization, forming two pairs of paralogous enzymes. In this work, we investigate the role of each Lyt endopeptidase in cell morphogenesis in order to evaluate their distinct or redundant functions, and eventually their synthetic lethality. We show that the paralogous LytC and LytD enzymes are not required for cell shape maintenance, which may indicate an accessory role such as in PG recycling. In contrast, LytA and LytB appear to be key players of the cell cycle. We show here that LytA is required for cell elongation while LytB is involved in the spatio-temporal regulation of cell division. In addition, both PGHs are involved in the proper positioning of the division site. The absence of LytA activity is responsible for the asymmetrical positioning of septa in round cells while the lack of LytB results in a lateral misplacement of division planes in rod-shaped cells. Finally, we show that the co-inactivation of LytA and LytB is synthetically affecting cell growth, which confirms the key roles played by both enzymes in PG remodeling during the cell cycle of L. plantarum. Based on the large distribution of NlpC/P60 endopeptidases in low-GC Gram-positive bacteria, these enzymes are attractive targets for the discovery of novel antimicrobial compounds.
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Affiliation(s)
- Marie-Clémence Duchêne
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Thomas Rolain
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Adrien Knoops
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Pascal Courtin
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | | | - Yves F Dufrêne
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Bernard F Hallet
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Pascal Hols
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-La-Neuve, Belgium
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9
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Abstract
L. plantarum is an important bacterium for applications in food and health. Deep insights into the biology and physiology of this species are therefore necessary for further strain optimization and exploitation; however, the functions of essential genes in the bacterium are mainly unknown due to the lack of accessible genetic tools. The CRISPRi system developed here is ideal to quickly screen for phenotypes of both essential and nonessential genes. Our initial insights into the function of some key cell cycle genes represent the first step toward understanding the cell cycle in this bacterium. Studies of essential genes in bacteria are often hampered by the lack of accessible genetic tools. This is also the case for Lactobacillus plantarum, a key species in food and health applications. Here, we develop a clustered regularly interspaced short palindromic repeat interference (CRISPRi) system for knockdown of gene expression in L. plantarum. The two-plasmid CRISPRi system, in which a nuclease-inactivated Cas9 (dCas9) and a gene-specific single guide RNA (sgRNA) are expressed on separate plasmids, allows efficient knockdown of expression of any gene of interest. We utilized the CRISPRi system to gain initial insights into the functions of key cell cycle genes in L. plantarum. As a proof of concept, we investigated the phenotypes resulting from knockdowns of the cell wall hydrolase-encoding acm2 gene and of the DNA replication initiator gene dnaA and of ezrA, which encodes an early cell division protein. Furthermore, we studied the phenotypes of three cell division genes which have recently been functionally characterized in ovococcal bacteria but whose functions have not yet been investigated in rod-shaped bacteria. We show that the transmembrane CozE proteins do not seem to play any major role in cell division in L. plantarum. On the other hand, RNA-binding proteins KhpA and EloR are critical for proper cell elongation in this bacterium. IMPORTANCEL. plantarum is an important bacterium for applications in food and health. Deep insights into the biology and physiology of this species are therefore necessary for further strain optimization and exploitation; however, the functions of essential genes in the bacterium are mainly unknown due to the lack of accessible genetic tools. The CRISPRi system developed here is ideal to quickly screen for phenotypes of both essential and nonessential genes. Our initial insights into the function of some key cell cycle genes represent the first step toward understanding the cell cycle in this bacterium.
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10
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Abou-Dobara MI, Omar NF, Diab MA, El-Sonbati AZ, Morgan SM, El-Mogazy MA. Allyl rhodanine azo dye derivatives: Potential antimicrobials target d-alanyl carrier protein ligase and nucleoside diphosphate kinase. J Cell Biochem 2019; 120:1667-1678. [PMID: 30187946 DOI: 10.1002/jcb.27473] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 07/18/2018] [Indexed: 01/24/2023]
Abstract
3-Allyl-5-(4-arylazo)-2-thioxothiazolidine-4-one (HLn ) ligands (where n = 1 to 3) were hypothesized to have antimicrobial activities mediated through inhibition of new antimicrobial targets. The ligands (HLn ) were synthesized and characterized by infrared (IR) and 1 H nuclear magnetic resonance (1 H NMR) spectra. The ligands (HLn ) were in silico screened to their potential inhibition to models of d-alanyl carrier protein ligase (DltA) (from Bacillus cereus, PDB code 3FCE) and nucleoside diphosphate kinase (NDK) (from Staphylococcus aureus; PDB code 3Q8U). HL3 ligand has the best energy and mode of binding to both NDK and DltA, even though its binding to DltA was stronger than that to NDK. In antimicrobial activity of HL3 ligand, morphological and cytological changes in HL3 -treated bacteria agreed with the in silico results. The HL3 ligand showed significant antimicrobial activity against B. cereus, S. aureus, and Fusarium oxysporium. The HL3 -treated bacterial cells appeared malformed and incompletely separated. Its cell walls appeared electron-lucent and ruptured. They contained more mesosomes than normal cells. It was found that the HL3 ligand represented as a bactericide against B. cereus and S. aureusby blocking target DltA, and may target NDK.
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Affiliation(s)
- Mohamed I Abou-Dobara
- Botany and Microbiology Department, Faculty of Science, Damietta University, Damietta, Egypt
| | - Noha F Omar
- Botany and Microbiology Department, Faculty of Science, Damietta University, Damietta, Egypt
| | - Mostafa A Diab
- Chemistry Department, Faculty of Science, Damietta University, Damietta, Egypt
| | - Adel Z El-Sonbati
- Chemistry Department, Faculty of Science, Damietta University, Damietta, Egypt
| | - Shaimaa M Morgan
- Environmental Monitoring Laboratory, Ministry of Health, Port Said, Egypt
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11
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Mendonça AA, da Silva PKN, Calazans TLS, de Souza RB, de Barros Pita W, Elsztein C, de Morais Junior MA. Lactobacillus vini: mechanistic response to stress by medium acidification. Microbiology (Reading) 2019; 165:26-36. [DOI: 10.1099/mic.0.000738] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
| | | | | | | | - Will de Barros Pita
- 3Department of Antibiotics, Federal University of Pernambuco, Recife, Brazil
| | - Carolina Elsztein
- 1Department of Genetics, Federal University of Pernambuco, Recife, Brazil
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12
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Carvalho F, Sousa S, Cabanes D. l-Rhamnosylation of wall teichoic acids promotes efficient surface association of Listeria monocytogenes virulence factors InlB and Ami through interaction with GW domains. Environ Microbiol 2018; 20:3941-3951. [PMID: 29984543 DOI: 10.1111/1462-2920.14351] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 06/18/2018] [Accepted: 07/02/2018] [Indexed: 11/29/2022]
Abstract
Wall teichoic acids (WTAs) are important surface glycopolymers involved in various physiological processes occurring in the Gram-positive cell envelope. We previously showed that the decoration of Listeria monocytogenes (Lm) WTAs with l-rhamnose conferred resistance against antimicrobial peptides. Here, we show that WTA l-rhamnosylation also contributes to physiological levels of autolysis in Lm through a mechanism that requires efficient association of Ami, a virulence-promoting autolysin belonging to the GW protein family, to the bacterial cell surface. Importantly, WTA l-rhamnosylation also controls the surface association of another GW protein, the invasin internalin B (InlB), that promotes Lm invasion of host cells. Whereas WTA N-acetylglucosaminylation is not a prerequisite for GW protein surface association, lipoteichoic acids appear to also play a role in the surface anchoring of InlB. Strikingly, while the GW domains of Ami, InlB and Auto (another autolysin contributing to cell invasion and virulence) are sufficient to mediate surface association, this is not the case for the GW domains of the remaining six uncharacterized Lm GW proteins. Overall, we reveal WTA l-rhamnosylation as a bacterial surface modification mechanism that contributes to Lm physiology and pathogenesis by controlling the surface association of GW proteins involved in autolysis and infection.
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Affiliation(s)
- Filipe Carvalho
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Group of Molecular Microbiology, IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Sandra Sousa
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Group of Molecular Microbiology, IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Didier Cabanes
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Group of Molecular Microbiology, IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
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13
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Matos RC, Schwarzer M, Gervais H, Courtin P, Joncour P, Gillet B, Ma D, Bulteau AL, Martino ME, Hughes S, Chapot-Chartier MP, Leulier F. D-Alanylation of teichoic acids contributes to Lactobacillus plantarum-mediated Drosophila growth during chronic undernutrition. Nat Microbiol 2017; 2:1635-1647. [PMID: 28993620 PMCID: PMC5706638 DOI: 10.1038/s41564-017-0038-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 09/06/2017] [Indexed: 02/07/2023]
Abstract
The microbial environment influences animal physiology. However, the underlying molecular mechanisms of such functional interactions are largely undefined. Previously, we showed that during chronic undernutrition, strains of Lactobacillus plantarum, a major commensal partner of Drosophila, promote host juvenile growth and maturation partly through enhanced expression of intestinal peptidases. By screening a transposon insertion library of Lactobacillus plantarum in gnotobiotic Drosophila larvae, we identify a bacterial cell-wall-modifying machinery encoded by the pbpX2-dlt operon that is critical to enhance host digestive capabilities and promote animal growth and maturation. Deletion of this operon leads to bacterial cell wall alteration with a complete loss of D-alanylation of teichoic acids. We show that L. plantarum cell walls bearing D-alanylated teichoic acids are directly sensed by Drosophila enterocytes to ensure optimal intestinal peptidase expression and activity, juvenile growth and maturation during chronic undernutrition. We thus conclude that besides peptidoglycan, teichoic acid modifications participate in the host-commensal bacteria molecular dialogue occurring in the intestine.
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Affiliation(s)
- Renata C Matos
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Martin Schwarzer
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Hugo Gervais
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Pascal Courtin
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Pauline Joncour
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Benjamin Gillet
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Dali Ma
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Anne-Laure Bulteau
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Maria Elena Martino
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | - Sandrine Hughes
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France
| | | | - François Leulier
- Institut de Génomique Fonctionnelle de Lyon (IGFL), Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, 69364, Lyon Cedex 07, France.
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14
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Kamar R, Réjasse A, Jéhanno I, Attieh Z, Courtin P, Chapot-Chartier MP, Nielsen-Leroux C, Lereclus D, El Chamy L, Kallassy M, Sanchis-Borja V. DltX of Bacillus thuringiensis Is Essential for D-Alanylation of Teichoic Acids and Resistance to Antimicrobial Response in Insects. Front Microbiol 2017; 8:1437. [PMID: 28824570 PMCID: PMC5541007 DOI: 10.3389/fmicb.2017.01437] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 07/14/2017] [Indexed: 11/13/2022] Open
Abstract
The dlt operon of Gram-positive bacteria is required for the incorporation of D-alanine esters into cell wall-associated teichoic acids (TAs). Addition of D-alanine to TAs reduces the negative charge of the cell envelope thereby preventing cationic antimicrobial peptides (CAMPs) from reaching their target of action on the bacterial surface. In most gram-positive bacteria, this operon consists of five genes dltXABCD but the involvement of the first ORF (dltX) encoding a small protein of unknown function, has never been investigated. The aim of this study was to establish whether this protein is involved in the D-alanylation process in Bacillus thuringiensis. We, therefore constructed an in frame deletion mutant of dltX, without affecting the expression of the other genes of the operon. The growth characteristics of the dltX mutant and those of the wild type strain were similar under standard in vitro conditions. However, disruption of dltX drastically impaired the resistance of B. thuringiensis to CAMPs and significantly attenuated its virulence in two insect species. Moreover, high-performance liquid chromatography studies showed that the dltX mutant was devoid of D-alanine, and electrophoretic mobility measurements indicated that the cells carried a higher negative surface charge. Scanning electron microscopy experiments showed morphological alterations of these mutant bacteria, suggesting that depletion of D-alanine from TAs affects cell wall structure. Our findings suggest that DltX is essential for the incorporation of D-alanyl esters into TAs. Therefore, DltX plays a direct role in the resistance to CAMPs, thus contributing to the survival of B. thuringiensis in insects. To our knowledge, this work is the first report examining the involvement of dltX in the D-alanylation of TAs.
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Affiliation(s)
- Rita Kamar
- INRA, UMR1319 MicalisJouy-en-Josas, France.,AgroParisTech, UMR MicalisJouy-en-Josas, France.,Laboratoire de Génétique de la Drosophile et Virulence Microbienne, Université Saint-JosephBeirut, Lebanon
| | - Agnès Réjasse
- INRA, UMR1319 MicalisJouy-en-Josas, France.,AgroParisTech, UMR MicalisJouy-en-Josas, France
| | - Isabelle Jéhanno
- INRA, UMR1319 MicalisJouy-en-Josas, France.,AgroParisTech, UMR MicalisJouy-en-Josas, France
| | - Zaynoun Attieh
- Laboratoire de Génétique de la Drosophile et Virulence Microbienne, Université Saint-JosephBeirut, Lebanon
| | - Pascal Courtin
- INRA, UMR1319 MicalisJouy-en-Josas, France.,AgroParisTech, UMR MicalisJouy-en-Josas, France
| | | | | | - Didier Lereclus
- INRA, UMR1319 MicalisJouy-en-Josas, France.,AgroParisTech, UMR MicalisJouy-en-Josas, France
| | - Laure El Chamy
- Laboratoire de Génétique de la Drosophile et Virulence Microbienne, Université Saint-JosephBeirut, Lebanon
| | - Mireille Kallassy
- Laboratoire de Génétique de la Drosophile et Virulence Microbienne, Université Saint-JosephBeirut, Lebanon
| | - Vincent Sanchis-Borja
- INRA, UMR1319 MicalisJouy-en-Josas, France.,AgroParisTech, UMR MicalisJouy-en-Josas, France
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15
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Lee B, Tachon S, Eigenheer RA, Phinney BS, Marco ML. Lactobacillus casei Low-Temperature, Dairy-Associated Proteome Promotes Persistence in the Mammalian Digestive Tract. J Proteome Res 2015; 14:3136-47. [DOI: 10.1021/acs.jproteome.5b00387] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bokyung Lee
- Department of Food Science & Technology, University of California, One Shields Avenue, Davis, California 95616, United States
| | - Sybille Tachon
- Department of Food Science & Technology, University of California, One Shields Avenue, Davis, California 95616, United States
| | - Richard A. Eigenheer
- Proteomics
Core Facility, Genome Center, University of California, 451 East
Health Sciences Drive, Davis, California 95616, United States
| | - Brett S. Phinney
- Proteomics
Core Facility, Genome Center, University of California, 451 East
Health Sciences Drive, Davis, California 95616, United States
| | - Maria L. Marco
- Department of Food Science & Technology, University of California, One Shields Avenue, Davis, California 95616, United States
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16
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Attenuation of Colitis by Lactobacillus casei BL23 Is Dependent on the Dairy Delivery Matrix. Appl Environ Microbiol 2015; 81:6425-35. [PMID: 26162873 DOI: 10.1128/aem.01360-15] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 07/02/2015] [Indexed: 02/07/2023] Open
Abstract
The role of the food delivery matrix in probiotic performance in the intestine is not well understood. Because probiotics are often provided to consumers in dairy products, we investigated the contributions of milk to the health-benefiting performance of Lactobacillus casei BL23 in a dextran sulfate sodium (DSS)-induced murine model of ulcerative colitis. L. casei BL23 protected against the development of colitis when ingested in milk but not in a nutrient-free buffer simulating consumption as a nutritional supplement. Consumption of (acidified) milk alone also provided some protection against weight loss and intestinal inflammation but was not as effective as L. casei and milk in combination. In contrast, L. casei mutants deficient in DltD (lipoteichoic acid d-alanine transfer protein) or RecA (recombinase A) were unable to protect against DSS-induced colitis, even when consumed in the presence of milk. Mice fed either L. casei or milk contained reduced quantities of colonic proinflammatory cytokines, indicating that the L. casei DltD(-) and RecA(-) mutants as well as L. casei BL23 in nutrient-free buffer were effective at modulating immune responses. However, there was not a direct correlation between colitis and quantities of these cytokines at the time of sacrifice. Identification of the cecal microbiota by 16S rRNA gene sequencing showed that L. casei in milk enriched for Comamonadaceae and Bifidobacteriaceae; however, the consumption of neither L. casei nor milk resulted in the restoration of the microbiota to resemble that of healthy animals. These findings strongly indicate that probiotic strain efficacy can be influenced by the food/supplement delivery matrix.
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17
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Xu Y, Wang T, Kong J, Wang HL. Identification and functional characterization of AclB, a novel cell-separating enzyme from Lactobacillus casei. Int J Food Microbiol 2015; 203:93-100. [DOI: 10.1016/j.ijfoodmicro.2015.03.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 03/01/2015] [Accepted: 03/08/2015] [Indexed: 01/23/2023]
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18
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Abstract
The cell wall of Gram-positive bacteria is a complex assemblage of glycopolymers and proteins. It consists of a thick peptidoglycan sacculus that surrounds the cytoplasmic membrane and that is decorated with teichoic acids, polysaccharides, and proteins. It plays a major role in bacterial physiology since it maintains cell shape and integrity during growth and division; in addition, it acts as the interface between the bacterium and its environment. Lactic acid bacteria (LAB) are traditionally and widely used to ferment food, and they are also the subject of more and more research because of their potential health-related benefits. It is now recognized that understanding the composition, structure, and properties of LAB cell walls is a crucial part of developing technological and health applications using these bacteria. In this review, we examine the different components of the Gram-positive cell wall: peptidoglycan, teichoic acids, polysaccharides, and proteins. We present recent findings regarding the structure and function of these complex compounds, results that have emerged thanks to the tandem development of structural analysis and whole genome sequencing. Although general structures and biosynthesis pathways are conserved among Gram-positive bacteria, studies have revealed that LAB cell walls demonstrate unique properties; these studies have yielded some notable, fundamental, and novel findings. Given the potential of this research to contribute to future applied strategies, in our discussion of the role played by cell wall components in LAB physiology, we pay special attention to the mechanisms controlling bacterial autolysis, bacterial sensitivity to bacteriophages and the mechanisms underlying interactions between probiotic bacteria and their hosts.
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19
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GtfA and GtfB are both required for protein O-glycosylation in Lactobacillus plantarum. J Bacteriol 2014; 196:1671-82. [PMID: 24532775 DOI: 10.1128/jb.01401-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Acm2, the major autolysin of Lactobacillus plantarum WCFS1, was recently found to be O-glycosylated with N-acetylhexosamine, likely N-acetylglucosamine (GlcNAc). In this study, we set out to identify the glycosylation machinery by employing a comparative genomics approach to identify Gtf1 homologues, which are involved in fimbria-associated protein 1 (Fap1) glycosylation in Streptococcus parasanguinis. This in silico approach resulted in the identification of 6 candidate L. plantarum WCFS1 genes with significant homology to Gtf1, namely, tagE1 to tagE6. These candidate genes were targeted by systematic gene deletion, followed by assessment of the consequences on glycosylation of Acm2. We observed a changed mobility of Acm2 on SDS-PAGE in the tagE5E6 deletion strain, while deletion of other tagE genes resulted in Acm2 mobility comparable to that of the wild type. Subsequent mass spectrometry analysis of excised and in-gel-digested Acm2 confirmed the loss of glycosylation on Acm2 in the tagE5E6 deletion mutant, whereas a lectin blot using GlcNAc-specific succinylated wheat germ agglutinin (sWGA) revealed that besides Acm2, tagE5E6 deletion also abolished all but one other sWGA-reactive, protease-sensitive signal. Only complementation of both tagE5 and tagE6 restored those sWGA lectin signals, establishing that TagE5 and TagE6 are both required for the glycosylation of Acm2 as well as the vast majority of other sWGA-reactive proteins. Finally, sWGA lectin blotting experiments using a panel of 8 other L. plantarum strains revealed that protein glycosylation is a common feature in L. plantarum strains. With the establishment of these enzymes as protein glycosyltransferases, we propose to rename TagE5 and TagE6 as GtfA and GtfB, respectively.
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20
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Palomino MM, Allievi MC, Gründling A, Sanchez-Rivas C, Ruzal SM. Osmotic stress adaptation in Lactobacillus casei BL23 leads to structural changes in the cell wall polymer lipoteichoic acid. Microbiology (Reading) 2013; 159:2416-2426. [DOI: 10.1099/mic.0.070607-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- Maria Mercedes Palomino
- Section of Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, South Kensington Campus, London, UK
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Ciudad Universitaria, C1428EGA Buenos Aires, Argentina
| | - Mariana C. Allievi
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Ciudad Universitaria, C1428EGA Buenos Aires, Argentina
| | - Angelika Gründling
- Section of Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College London, South Kensington Campus, London, UK
| | - Carmen Sanchez-Rivas
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Ciudad Universitaria, C1428EGA Buenos Aires, Argentina
| | - Sandra M. Ruzal
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Ciudad Universitaria, C1428EGA Buenos Aires, Argentina
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21
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Krawczyk-Balska A, Lipiak M. Critical role of a ferritin-like protein in the control of Listeria monocytogenes cell envelope structure and stability under β-lactam pressure. PLoS One 2013; 8:e77808. [PMID: 24204978 PMCID: PMC3812014 DOI: 10.1371/journal.pone.0077808] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 09/05/2013] [Indexed: 02/08/2023] Open
Abstract
The human pathogen Listeria monocytogenes is susceptible to the β-lactam antibiotics penicillin G and ampicillin, and these are the drugs of choice for the treatment of listerial infections. However, these antibiotics exert only a bacteriostatic effect on this bacterium and consequently, L. monocytogenes is regarded as β-lactam tolerant. It is widely accepted that the phenomenon of bacterial tolerance to β-lactams is due to the lack of adequate autolysin activity, but the mechanisms of L. monocytogenes tolerance to this class of antibiotics are poorly characterized. A ferritin-like protein (Fri) was recently identified as a mediator of β-lactam tolerance in L. monocytogenes, but its function in this process remains unknown. The present study was undertaken to improve our understanding of L. monocytogenes tolerance to β-lactams and to characterize the role of Fri in this phenomenon. A comparative physiological analysis of wild-type L. monocytogenes and a fri deletion mutant provided evidence of a multilevel mechanism controlling autolysin activity in cells grown under β-lactam pressure, which leads to a reduction in the level and/or activity of cell wall-associated autolysins. This is accompanied by increases in the amount of teichoic acids, cell wall thickness and cell envelope integrity of L. monocytogenes grown in the presence of penicillin G, and provides the basis for the innate β-lactam tolerance of this bacterium. Furthermore, this study revealed the inability of the L. monocytogenes Δ fri mutant to deplete autolysins from the cell wall, to adjust the content of teichoic acids and to maintain their D-alanylation at the correct level when treated with penicillin G, thus providing further evidence that Fri is involved in the control of L. monocytogenes cell envelope structure and stability under β-lactam pressure.
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Affiliation(s)
- Agata Krawczyk-Balska
- Department of Applied Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland
| | - Magdalena Lipiak
- Department of Applied Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland
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22
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D-alanine modification of a protease-susceptible outer membrane component by the Bordetella pertussis dra locus promotes resistance to antimicrobial peptides and polymorphonuclear leukocyte-mediated killing. J Bacteriol 2013; 195:5102-11. [PMID: 24013634 DOI: 10.1128/jb.00510-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bordetella pertussis is the causative agent of pertussis, a highly contagious disease of the human respiratory tract. Despite very high vaccine coverage, pertussis has reemerged as a serious threat in the United States and many developing countries. Thus, it is important to pursue research to discover unknown pathogenic mechanisms of B. pertussis. We have investigated a previously uncharacterized locus in B. pertussis, the dra locus, which is homologous to the dlt operons of Gram-positive bacteria. The absence of the dra locus resulted in increased sensitivity to the killing action of antimicrobial peptides (AMPs) and human phagocytes. Compared to the wild-type cells, the mutant cells bound higher levels of cationic proteins and peptides, suggesting that dra contributes to AMP resistance by decreasing the electronegativity of the cell surface. The presence of dra led to the incorporation of d-alanine into an outer membrane component that is susceptible to proteinase K cleavage. We conclude that dra encodes a virulence-associated determinant and contributes to the immune resistance of B. pertussis. With these findings, we have identified a new mechanism of surface modification in B. pertussis which may also be relevant in other Gram-negative pathogens.
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23
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Beaussart A, Rolain T, Duchêne MC, El-Kirat-Chatel S, Andre G, Hols P, Dufrêne Y. Binding mechanism of the peptidoglycan hydrolase Acm2: low affinity, broad specificity. Biophys J 2013; 105:620-9. [PMID: 23931310 PMCID: PMC3736658 DOI: 10.1016/j.bpj.2013.06.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 06/21/2013] [Accepted: 06/25/2013] [Indexed: 01/28/2023] Open
Abstract
Peptidoglycan hydrolases are bacterial secreted enzymes that cleave covalent bonds in the cell-wall peptidoglycan, thereby fulfilling major physiological functions during cell growth and division. Although the molecular structure and functional roles of these enzymes have been widely studied, the molecular details underlying their interaction with peptidoglycans remain largely unknown, mainly owing to the paucity of appropriate probing techniques. Here, we use atomic force microscopy to explore the binding mechanism of the major autolysin Acm2 from the probiotic bacterium Lactobacillus plantarum. Atomic force microscopy imaging shows that incubation of bacterial cells with Acm2 leads to major alterations of the cell-surface nanostructure, leading eventually to cell lysis. Single-molecule force spectroscopy demonstrates that the enzyme binds with low affinity to structurally different peptidoglycans and to chitin, and that glucosamine in the glycan chains is the minimal binding motif. We also find that Acm2 recognizes mucin, the main extracellular component of the intestinal mucosal layer, thereby suggesting that this enzyme may also function as a cell adhesion molecule. The binding mechanism (low affinity and broad specificity) of Acm2 may represent a generic mechanism among cell-wall hydrolases for guiding cell division and cell adhesion.
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Affiliation(s)
| | | | | | | | | | - Pascal Hols
- Université catholique de Louvain, Institute of Life Sciences, Croix du Sud, Louvain-la-Neuve, Belgium
| | - Yves F. Dufrêne
- Université catholique de Louvain, Institute of Life Sciences, Croix du Sud, Louvain-la-Neuve, Belgium
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24
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Bron PA, Tomita S, Mercenier A, Kleerebezem M. Cell surface-associated compounds of probiotic lactobacilli sustain the strain-specificity dogma. Curr Opin Microbiol 2013; 16:262-9. [PMID: 23810459 DOI: 10.1016/j.mib.2013.06.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 06/07/2013] [Accepted: 06/10/2013] [Indexed: 12/31/2022]
Abstract
Probiotic lactobacilli can positively impact on the health status of targeted (diseased) populations but efficacy depends strongly on the strain employed and the molecular basis for this phenomenon is poorly understood. This review discusses the current state-of-the-art in the field of molecular probiotic-host interactions, focusing on subtle strain-specific differences in the biochemical characteristics of cell surface-associated probiotic ligands and the consequences thereof for the immune responses elicited. This research is bound to enhance our understanding of strain-specificity in relation to probiotic functionality and will allow molecular science-based design of screening and characterization assays targeted to improved selection of probiotic candidate strains. Moreover, identified bioactive effector molecules could be isolated or produced for administration in a more pharmacological regime.
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Affiliation(s)
- Peter A Bron
- TI Food and Nutrition, Nieuwe Kanaal 9A, 6709PA Wageningen, The Netherlands
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25
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Rolain T, Bernard E, Beaussart A, Degand H, Courtin P, Egge-Jacobsen W, Bron PA, Morsomme P, Kleerebezem M, Chapot-Chartier MP, Dufrêne YF, Hols P. O-glycosylation as a novel control mechanism of peptidoglycan hydrolase activity. J Biol Chem 2013; 288:22233-47. [PMID: 23760506 DOI: 10.1074/jbc.m113.470716] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Acm2, the major autolysin of Lactobacillus plantarum, is a tripartite protein. Its catalytic domain is surrounded by an O-glycosylated N-terminal region rich in Ala, Ser, and Thr (AST domain), which is of low complexity and unknown function, and a C-terminal region composed of five SH3b peptidoglycan (PG) binding domains. Here, we investigate the contribution of these two accessory domains and of O-glycosylation to Acm2 functionality. We demonstrate that Acm2 is an N-acetylglucosaminidase and identify the pattern of O-glycosylation (21 mono-N-acetylglucosamines) of its AST domain. The O-glycosylation process is species-specific as Acm2 purified from Lactococcus lactis is not glycosylated. We therefore explored the functional role of O-glycosylation by purifying different truncated versions of Acm2 that were either glycosylated or non-glycosylated. We show that SH3b domains are able to bind PG and are responsible for Acm2 targeting to the septum of dividing cells, whereas the AST domain and its O-glycosylation are not involved in this process. Notably, our data reveal that the lack of O-glycosylation of the AST domain significantly increases Acm2 enzymatic activity, whereas removal of SH3b PG binding domains dramatically reduces this activity. Based on this antagonistic role, we propose a model in which access of the Acm2 catalytic domain to its substrate may be hindered by the AST domain where O-glycosylation changes its conformation and/or mediates interdomain interactions. To the best of our knowledge, this is the first time that O-glycosylation is shown to control the activity of a bacterial enzyme.
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Affiliation(s)
- Thomas Rolain
- Institut des Sciences de la Vie, Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
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The impact of Lactobacillus plantarum WCFS1 teichoic acid D-alanylation on the generation of effector and regulatory T-cells in healthy mice. PLoS One 2013; 8:e63099. [PMID: 23646181 PMCID: PMC3639951 DOI: 10.1371/journal.pone.0063099] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 03/28/2013] [Indexed: 12/24/2022] Open
Abstract
To date it remains unclear how probiotics affect the immune system. Bacterial envelope components may play an essential role, as these are the first to establish bacterial-host cell interactions. Teichoic acids (TAs), and especially lipoteichoic acids, are the most pro-inflammatory components of the gram-positive bacterial envelope. This effect is dependent on D-alanyl substitution of the TA backbone and interactions with TLR2 on host cells. Although the pro-inflammatory properties of TAs have been established in vitro, it remains unclear how TAs affect immunomodulation in vivo. In this study, we investigated the role of TA D-alanylation on L. plantarum–induced intestinal and systemic immunomodulation in vivo. For this, we compared the effect of L. plantarum WCFS1 and its TA D-Alanylation negative derivative (dltX-D) on the distribution of dendritic cell and T cell populations and responses in healthy mice. We demonstrated that the majority of the L. plantarum-induced in vivo immunomodulatory effects were dependent on D-alanylation (D-Ala), as some L. plantarum WCFS1-induced immune changes were not observed in the dltX-D-treated group and some were only observed after treatment with dltX-D. Strikingly, not only pro-inflammatory immune responses were abolished in the absence of D-Ala substitution, but also anti-inflammatory responses, such as the L. plantarum-induced generation of regulatory T cells in the spleen. With this study we provide insight in host-microbe interactions, by demonstrating the involvement of D-alanylation of TAs on the bacterial membrane in intestinal and systemic immunomodulation in healthy mice.
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The quest for probiotic effector molecules—Unraveling strain specificity at the molecular level. Pharmacol Res 2013; 69:61-74. [DOI: 10.1016/j.phrs.2012.09.010] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 09/26/2012] [Accepted: 09/27/2012] [Indexed: 12/25/2022]
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Rolain T, Bernard E, Courtin P, Bron PA, Kleerebezem M, Chapot-Chartier MP, Hols P. Identification of key peptidoglycan hydrolases for morphogenesis, autolysis, and peptidoglycan composition of Lactobacillus plantarum WCFS1. Microb Cell Fact 2012; 11:137. [PMID: 23066986 PMCID: PMC3533731 DOI: 10.1186/1475-2859-11-137] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 10/03/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Lactobacillus plantarum is commonly used in industrial fermentation processes. Selected strains are also marketed as probiotics for their health beneficial effects. Although the functional role of peptidoglycan-degrading enzymes is increasingly documented to be important for a range of bacterial processes and host-microbe interactions, little is known about their functional roles in lactobacilli. This knowledge holds important potential for developing more robust strains resistant to autolysis under stress conditions as well as peptidoglycan engineering for a better understanding of the contribution of released muramyl-peptides as probiotic immunomodulators. RESULTS Here, we explored the functional role of the predicted peptidoglycan hydrolase (PGH) complement encoded in the genome of L. plantarum by systematic gene deletion. From twelve predicted PGH-encoding genes, nine could be individually inactivated and their corresponding mutant strains were characterized regarding their cell morphology, growth, and autolysis under various conditions. From this analysis, we identified two PGHs, the predicted N-acetylglucosaminidase Acm2 and NplC/P60 D,L-endopeptidase LytA, as key determinants in the morphology of L. plantarum. Acm2 was demonstrated to be required for the ultimate step of cell separation of daughter cells, whereas LytA appeared to be required for cell shape maintenance and cell-wall integrity. We also showed by autolysis experiments that both PGHs are involved in the global autolytic process with a dominant role for Acm2 in all tested conditions, identifying Acm2 as the major autolysin of L. plantarum WCFS1. In addition, Acm2 and the putative N-acetylmuramidase Lys2 were shown to play redundant roles in both cell separation and autolysis under stress conditions. Finally, the analysis of the peptidoglycan composition of Acm2- and LytA-deficient derivatives revealed their potential hydrolytic activities by the disappearance of specific cleavage products. CONCLUSION In this study, we showed that two PGHs of L. plantarum have a predominant physiological role in a range of growth conditions. We demonstrate that the N-acetylglucosaminidase Acm2 is the major autolysin whereas the D,L-endopeptidase LytA is a key morphogenic determinant. In addition, both PGHs have a direct impact on PG structure by generating a higher diversity of cleavage products that could be of importance for interaction with the innate immune system.
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Affiliation(s)
- Thomas Rolain
- Biochimie et Génétique Moléculaire Bactérienne, Institut des Sciences de la Vie, Université catholique de Louvain, Place Croix du Sud 5/L7,07,06, Louvain-la-Neuve, B-1348, Belgium
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Bron PA, Tomita S, van Swam II, Remus DM, Meijerink M, Wels M, Okada S, Wells JM, Kleerebezem M. Lactobacillus plantarum possesses the capability for wall teichoic acid backbone alditol switching. Microb Cell Fact 2012; 11:123. [PMID: 22967304 PMCID: PMC3511166 DOI: 10.1186/1475-2859-11-123] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 07/28/2012] [Indexed: 02/06/2023] Open
Abstract
Background Specific strains of Lactobacillus plantarum are marketed as health-promoting probiotics. The role and interplay of cell-wall compounds like wall- and lipo-teichoic acids (WTA and LTA) in bacterial physiology and probiotic-host interactions remain obscure. L. plantarum WCFS1 harbors the genetic potential to switch WTA backbone alditol, providing an opportunity to study the impact of WTA backbone modifications in an isogenic background. Results Through genome mining and mutagenesis we constructed derivatives that synthesize alternative WTA variants. The mutants were shown to completely lack WTA, or produce WTA and LTA that lack D-Ala substitution, or ribitol-backbone WTA instead of the wild-type glycerol-containing backbone. DNA micro-array experiments established that the tarIJKL gene cluster is required for the biosynthesis of this alternative WTA backbone, and suggest ribose and arabinose are precursors thereof. Increased tarIJKL expression was not observed in any of our previously performed DNA microarray experiments, nor in qRT-PCR analyses of L. plantarum grown on various carbon sources, leaving the natural conditions leading to WTA backbone alditol switching, if any, to be identified. Human embryonic kidney NF-κB reporter cells expressing Toll like receptor (TLR)-2/6 were exposed to purified WTAs and/or the TA mutants, indicating that WTA is not directly involved in TLR-2/6 signaling, but attenuates this signaling in a backbone independent manner, likely by affecting the release and exposure of immunomodulatory compounds such as LTA. Moreover, human dendritic cells did not secrete any cytokines when purified WTAs were applied, whereas they secreted drastically decreased levels of the pro-inflammatory cytokines IL-12p70 and TNF-α after stimulation with the WTA mutants as compared to the wild-type. Conclusions The study presented here correlates structural differences in WTA to their functional characteristics, thereby providing important information aiding to improve our understanding of molecular host-microbe interactions and probiotic functionality.
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Affiliation(s)
- Peter A Bron
- TI Food & Nutrition, Nieuwe Kanaal 9A, 6709 PA, Wageningen, The Netherlands
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The major autolysin Acm2 from Lactobacillus plantarum undergoes cytoplasmic O-glycosylation. J Bacteriol 2011; 194:325-33. [PMID: 22081384 DOI: 10.1128/jb.06314-11] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The major autolysin Acm2 from the probiotic strain Lactobacillus plantarum WCFS1 contains high proportions of alanine, serine, and threonine in its N-terminal so-called AST domain. It has been suggested that this extracellular protein might be glycosylated, but this has not been experimentally verified. We used high-resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS) to study the possible occurrence of glycans on peptides generated from lactobacillary surface proteins by protease treatment. This approach yielded five glycopeptides in various glycoforms, all derived from the AST domain of Acm2. All five glycopeptides contained the hydroxy-amino acids serine and threonine, suggesting that Acm2 is O-glycosylated. By using lectin blotting with succinylated wheat germ agglutinin, and by comparing the wild-type strain with an Acm2-negative derivative (NZ3557), we found that the attached N-acetylhexosamines are most likely N-acetylglucosamines (GlcNAc). NZ3557 was further used as a genetic background to express an Acm2 variant lacking its secretion signal, resulting in intracellular expression of Acm2. We show that this intracellular version of Acm2 is also glycosylated, indicating that the GlcNAc modification is an intracellular process.
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Lebeer S, Claes IJJ, Vanderleyden J. Anti-inflammatory potential of probiotics: lipoteichoic acid makes a difference. Trends Microbiol 2011; 20:5-10. [PMID: 22030243 DOI: 10.1016/j.tim.2011.09.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Revised: 09/19/2011] [Accepted: 09/27/2011] [Indexed: 12/26/2022]
Abstract
Lipoteichoic acid (LTA) mutants of lactobacilli suppress inflammation in animal models of experimental colitis. The fact that a single mutation of an administered Lactobacillus strain can result in enhanced probiotic efficacy is surprising given the genetic diversity and complexity of the intestinal niche, but at the same time exciting from a microbiological, immunological and gastroenterological point of view. In this Opinion article, we discuss the possible impacts of LTA modification in probiotic bacteria in the context of the current knowledge regarding the proinflammatory capacity of LTA, structure-activity relationships of LTA, intestinal LTA recognition in healthy and colitis conditions and anti-inflammatory molecules of lactobacilli.
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Affiliation(s)
- Sarah Lebeer
- Centre of Microbial and Plant Genetics, K.U. Leuven, Kasteelpark Arenberg 20, Box 2460, B-3001 Leuven, Belgium.
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Andre G, Deghorain M, Bron PA, van Swam II, Kleerebezem M, Hols P, Dufrêne YF. Fluorescence and atomic force microscopy imaging of wall teichoic acids in Lactobacillus plantarum. ACS Chem Biol 2011; 6:366-76. [PMID: 21218855 DOI: 10.1021/cb1003509] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although teichoic acids are major constituents of bacterial cell walls, little is known about the relationships between their spatial localization and their functional roles. Here, we used single-molecule atomic force microscopy (AFM) combined with fluorescence microscopy to image the distribution of wall teichoic acids (WTAs) in Lactobacillus plantarum, in relation with their physiological roles. Phenotype analysis of the wild-type strain and of mutant strains deficient for the synthesis of WTAs (ΔtagO) or cell wall polysaccharides (Δcps1-4) revealed that WTAs are required for proper cell elongation and cell division. Nanoscale imaging by AFM showed that strains expressing WTAs have a highly polarized surface morphology, the poles being much smoother than the side walls. AFM and fluorescence imaging with specific lectin probes demonstrated that the polarized surface structure correlates with a heterogeneous distribution of WTAs, the latter being absent from the surface of the poles. These observations indicate that the polarized distribution of WTAs in L. plantarum plays a key role in controlling cell morphogenesis (surface roughness, cell shape, elongation, and division).
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Affiliation(s)
- Guillaume Andre
- Institute of Condensed Matter and Nanosciences − Bio & Soft Matter, Université catholique de Louvain, Croix du Sud 2/18, B-1348 Louvain-la-Neuve, Belgium
| | - Marie Deghorain
- Institute of Life Sciences − Biochemistry and Molecular Genetics of Bacteria, Université catholique de Louvain, Croix du Sud 5/6, B-1348 Louvain-la-Neuve, Belgium
| | - Peter A. Bron
- Top Institute Food and Nutrition, PO Box 557, 6700 AN Wageningen, The Netherlands
- NIZO food research BV, P.O. Box 20, 6710 BA Ede, The Netherlands
- Kluyver Centre for Genomics of Industrial Fermentation, Julianalaan 67, 2628 BC Delft, The Netherlands
| | - Iris I. van Swam
- Top Institute Food and Nutrition, PO Box 557, 6700 AN Wageningen, The Netherlands
- NIZO food research BV, P.O. Box 20, 6710 BA Ede, The Netherlands
| | - Michiel Kleerebezem
- Top Institute Food and Nutrition, PO Box 557, 6700 AN Wageningen, The Netherlands
- NIZO food research BV, P.O. Box 20, 6710 BA Ede, The Netherlands
- Laboratory of Microbiology, Agrotechnology and Food Sciences, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands
| | - Pascal Hols
- Institute of Life Sciences − Biochemistry and Molecular Genetics of Bacteria, Université catholique de Louvain, Croix du Sud 5/6, B-1348 Louvain-la-Neuve, Belgium
| | - Yves F. Dufrêne
- Institute of Condensed Matter and Nanosciences − Bio & Soft Matter, Université catholique de Louvain, Croix du Sud 2/18, B-1348 Louvain-la-Neuve, Belgium
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McBride SM, Sonenshein AL. The dlt operon confers resistance to cationic antimicrobial peptides in Clostridium difficile. MICROBIOLOGY-SGM 2011; 157:1457-1465. [PMID: 21330441 DOI: 10.1099/mic.0.045997-0] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The dlt operon in Gram-positive bacteria encodes proteins that are necessary for the addition of d-alanine to teichoic acids of the cell wall. The addition of d-alanine to the cell wall results in a net positive charge on the bacterial cell surface and, as a consequence, can decrease the effectiveness of antimicrobials, such as cationic antimicrobial peptides (CAMPs). Although the roles of the dlt genes have been studied for some Gram-positive organisms, the arrangement of these genes in Clostridium difficile and the life cycle of the bacterium in the host are markedly different from those of other pathogens. In the current work, we determined the contribution of the putative C. difficile dlt operon to CAMP resistance. Our data indicate that the dlt operon is necessary for full resistance of C. difficile to nisin, gallidermin, polymyxin B and vancomycin. We propose that the d-alanylation of teichoic acids provides protection against antimicrobial peptides that may be essential for growth of C. difficile in the host.
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Affiliation(s)
- Shonna M McBride
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Abraham L Sonenshein
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA
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Regulation of induced colonic inflammation by Lactobacillus acidophilus deficient in lipoteichoic acid. Proc Natl Acad Sci U S A 2011; 108 Suppl 1:4623-30. [PMID: 21282652 DOI: 10.1073/pnas.1005066107] [Citation(s) in RCA: 204] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Imbalance in the regulatory immune mechanisms that control intestinal cellular and bacterial homeostasis may lead to induction of the detrimental inflammatory signals characterized in humans as inflammatory bowel disease. Induction of proinflammatory cytokines (i.e., IL-12) induced by dendritic cells (DCs) expressing pattern recognition receptors may skew naive T cells to T helper 1 polarization, which is strongly implicated in mucosal autoimmunity. Recent studies show the ability of probiotic microbes to treat and prevent numerous intestinal disorders, including Clostridium difficile-induced colitis. To study the molecular mechanisms involved in the induction and repression of intestinal inflammation, the phosphoglycerol transferase gene that plays a key role in lipoteichoic acid (LTA) biosynthesis in Lactobacillus acidophilus NCFM (NCK56) was deleted. The data show that the L. acidophilus LTA-negative in LTA (NCK2025) not only down-regulated IL-12 and TNFα but also significantly enhanced IL-10 in DCs and controlled the regulation of costimulatory DC functions, resulting in their inability to induce CD4(+) T-cell activation. Moreover, treatment of mice with NCK2025 compared with NCK56 significantly mitigated dextran sulfate sodium and CD4(+)CD45RB(high)T cell-induced colitis and effectively ameliorated dextran sulfate sodium-established colitis through a mechanism that involves IL-10 and CD4(+)FoxP3(+) T regulatory cells to dampen exaggerated mucosal inflammation. Directed alteration of cell surface components of L. acidophilus NCFM establishes a potential strategy for the treatment of inflammatory intestinal disorders.
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Reimundo P, Menéndez A, Méndez J, Pérez-Pascual D, Navais R, Gómez E, Braña A, Guijarro J. dltA gene mutation in the teichoic acids alanylation system of Lactococcus garvieae results in diminished proliferation in its natural host. Vet Microbiol 2010; 143:434-9. [DOI: 10.1016/j.vetmic.2009.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 11/27/2009] [Accepted: 12/02/2009] [Indexed: 10/20/2022]
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Hirose Y, Murosaki S, Fujiki T, Yamamoto Y, Yoshikai Y, Yamashita M. Lipoteichoic acids on Lactobacillus plantarum cell surfaces correlate with induction of interleukin-12p40 production. Microbiol Immunol 2010; 54:143-51. [PMID: 20236424 DOI: 10.1111/j.1348-0421.2009.00189.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heat-killed cells of Lactobacillus plantarum L-137 are potent inducers of IL-12 in vitro as well as in vivo and have been shown to have antiallergic, antitumor, and antiviral effects through this induction, which leads to a Th1 type immune response. To determine why L-137 cells induce much greater IL-12 production than the type strain Lactobacillus plantarum JCM1149, we examined the differences in their CW components. The L-137 CW was found to have a higher alanine content and IL-12p40 induction was significantly greater in comparison with JCM1149 CW, whereas peptidoglycans isolated from both strains did not cause IL-12p40 induction. Because in purified CW preparations from gram-positive bacteria, the presence of LTA, the major proinflammatory structure on these bacteria, has been known to have high alanine content, we investigated the responsiveness of both strains to anti-LTA antibody by flow cytometry. L-137 cells reacted more with anti-LTA antibody than did JCM1149 cells. Furthermore, derivative strains of L-137, cured of a specific plasmid pLTK11 of the 15 endogenous plasmids in wild-type L-137, had poor responsiveness to anti-LTA antibody and showed lower IL-12p40 inducing activity than the wild-type L-137 with pLTK11. Our results suggest that LTA expression on the cell surface causes IL-12p40 induction, and that the above internal plasmid of L-137 influences LTA synthesis and expression on the cell surface.
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Affiliation(s)
- Yoshitaka Hirose
- Food Science Research Center, House Wellness Foods Corporation, 3-20 Imoji, Itami 664-0011, Japan.
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Kleerebezem M, Hols P, Bernard E, Rolain T, Zhou M, Siezen RJ, Bron PA. The extracellular biology of the lactobacilli. FEMS Microbiol Rev 2010. [PMID: 20088967 DOI: 10.1111/j.1574-6976.2009.00208.x] [Citation(s) in RCA: 230] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Lactobacilli belong to the lactic acid bacteria, which play a key role in industrial and artisan food raw-material fermentation, including a large variety of fermented dairy products. Next to their role in fermentation processes, specific strains of Lactobacillus are currently marketed as health-promoting cultures or probiotics. The last decade has witnessed the completion of a large number of Lactobacillus genome sequences, including the genome sequences of some of the probiotic species and strains. This development opens avenues to unravel the Lactobacillus-associated health-promoting activity at the molecular level. It is generally considered likely that an important part of the Lactobacillus effector molecules that participate in the proposed health-promoting interactions with the host (intestinal) system resides in the bacterial cell envelope. For this reason, it is important to accurately predict the Lactobacillus exoproteomes. Extensive annotation of these exoproteomes, combined with comparative analysis of species- or strain-specific exoproteomes, may identify candidate effector molecules, which may support specific effects on host physiology associated with particular Lactobacillus strains. Candidate health-promoting effector molecules of lactobacilli can then be validated via mutant approaches, which will allow for improved strain selection procedures, improved product quality control criteria and molecular science-based health claims.
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Kleerebezem M, Vaughan EE. Probiotic and gut lactobacilli and bifidobacteria: molecular approaches to study diversity and activity. Annu Rev Microbiol 2009; 63:269-90. [PMID: 19575569 DOI: 10.1146/annurev.micro.091208.073341] [Citation(s) in RCA: 234] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Lactobacilli and bifidobacteria have traditionally been recognized as potential health-promoting microbes in the human gastrointestinal tract, which is clearly reflected by the pre- and probiotic supplements on the market. Bacterial genomics of lactobacilli and bifidobacteria is initiating the identification and validation of specific effector molecules that mediate host health effects. Combined with advanced postgenomic mammalian host response analyses, elucidations of the molecular interactions and mechanisms that underlie the host-health effects observed are beginning to be gathered. These developments should be seen in the complexity of the microbiota-host relationships in the intestine, which through the new metagenomic era has regained momentum and will undoubtedly progress to functional microbiomics and host response analyses within the next decade. Taken together, these developments are anticipated to dramatically alter the scope and impact of the probiotic field, offering tremendous new opportunities with accompanying challenges for research and industrial application.
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The dlt operon of Bacillus cereus is required for resistance to cationic antimicrobial peptides and for virulence in insects. J Bacteriol 2009; 191:7063-73. [PMID: 19767427 DOI: 10.1128/jb.00892-09] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The dlt operon encodes proteins that alanylate teichoic acids, the major components of cell walls of gram-positive bacteria. This generates a net positive charge on bacterial cell walls, repulsing positively charged molecules and conferring resistance to animal and human cationic antimicrobial peptides (AMPs) in gram-positive pathogenic bacteria. AMPs damage the bacterial membrane and are the most effective components of the humoral immune response against bacteria. We investigated the role of the dlt operon in insect virulence by inactivating this operon in Bacillus cereus, which is both an opportunistic human pathogen and an insect pathogen. The Delta dlt(Bc) mutant displayed several morphological alterations but grew at a rate similar to that for the wild-type strain. This mutant was less resistant to protamine and several bacterial cationic AMPs, such as nisin, polymyxin B, and colistin, in vitro. It was also less resistant to molecules from the insect humoral immune system, lysozyme, and cationic AMP cecropin B from Spodoptera frugiperda. Delta dlt(Bc) was as pathogenic as the wild-type strain in oral infections of Galleria mellonella but much less virulent when injected into the hemocoels of G. mellonella and Spodoptera littoralis. We detected the dlt operon in three gram-negative genera: Erwinia (Erwinia carotovora), Bordetella (Bordetella pertussis, Bordetella parapertussis, and Bordetella bronchiseptica), and Photorhabdus (the entomopathogenic bacterium Photorhabdus luminescens TT01, the dlt operon of which did not restore cationic AMP resistance in Delta dlt(Bc)). We suggest that the dlt operon protects B. cereus against insect humoral immune mediators, including hemolymph cationic AMPs, and may be critical for the establishment of lethal septicemia in insects and in nosocomial infections in humans.
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Inactivation of DltA modulates virulence factor expression in Streptococcus pyogenes. PLoS One 2009; 4:e5366. [PMID: 19401780 PMCID: PMC2671602 DOI: 10.1371/journal.pone.0005366] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2009] [Accepted: 04/02/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND D-alanylated lipoteichoic acid is a virtually ubiquitous component of gram-positive cell walls. Mutations in the dltABCD operon of numerous species exhibit pleiotropic effects, including reduced virulence, which has been attributed to increased binding of cationic antimicrobial peptides to the more negatively charged cell surface. In this study, we have further investigated the effects that mutating dltA has on virulence factor expression in Streptococcus pyogenes. METHODOLOGY/PRINCIPAL FINDINGS Isogenic Delta dltA mutants had previously been created in two distinct M1T1 isolates of S. pyogenes. Immunoblots, flow cytometry, and immunofluorescence were used to quantitate M protein levels in these strains, as well as to assess their ability to bind complement. Bacteria were tested for their ability to interact with human PMN and to grow in whole human blood. Message levels for emm, sic, and various regulatory elements were assessed by quantitative RT-PCR. Cell walls of Delta dltA mutants contained much less M protein than cell walls of parent strains and this correlated with reduced levels of emm transcripts, increased deposition of complement, increased association of bacteria with polymorphonuclear leukocytes, and reduced bacterial growth in whole human blood. Transcription of at least one other gene of the mga regulon, sic, which encodes a protein that inactivates antimicrobial peptides, was also dramatically reduced in Delta dltA mutants. Concomitantly, ccpA and rofA were unaffected, while rgg and arcA were up-regulated. CONCLUSIONS/SIGNIFICANCE This study has identified a novel mechanism for the reduced virulence of dltA mutants of Streptococcus pyogenes in which gene regulatory networks somehow sense and respond to the loss of DltA and lack of D-alanine esterification of lipoteichoic acid. The mechanism remains to be determined, but the data indicate that the status of D-alanine-lipoteichoic acid can significantly influence the expression of at least some streptococcal virulence factors and provide further impetus to targeting the dlt operon of gram-positive pathogens in the search for novel antimicrobial compounds.
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Rigaux P, Daniel C, Hisbergues M, Muraille E, Hols P, Pot B, Pestel J, Jacquet A. Immunomodulatory properties of Lactobacillus plantarum and its use as a recombinant vaccine against mite allergy. Allergy 2009; 64:406-14. [PMID: 19120072 DOI: 10.1111/j.1398-9995.2008.01825.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Selected lactic acid bacteria were reported to prevent atopic dermatitis and experimental asthma but the mechanisms of their immunomodulatory effects are not fully elucidated. In this study, the signaling pathways triggered by Lactobacillus plantarum NCIMB8826 were investigated and the potential use of this strain producing a variant of the mite allergen Der p 1 as live vaccine vehicle was evaluated. METHODS Mouse bone marrow-derived dendritic cells were stimulated with wild-type or a L. plantarum teichoic acid mutant to evaluate the secretion of cytokines. A recombinant L. plantarum expressing Der p 1 was engineered, its in vitro immunomodulatory properties were characterized and its prophylactic potential was evaluated in a Der p 1-sensitization murine model. RESULTS Mouse dendritic cells stimulated by L. plantarum triggered the release of interleukin-10 (IL-10), IL-12 p40, IL-12 p70 and tumor necrosis factor-alpha (TNF-alpha). IL-12 p40 secretion was dependent on nuclear factor-kappaB (NF-kappaB), mitogen-activated protein (MAP) kinases, Toll-like receptor 2 (TLR2), TLR9 and on the bacterial teichoic acid composition. Recombinant L. plantarum producing Der p 1 exhibited similar immunostimulatory properties as wild-type. Prophylactic intranasal pretreatment of mice with this recombinant strain prevented the development of the typical Th2-biased allergic response by a drastic reduction of specific IgE and the induction of protective allergen-specific IgG2a antibodies. Moreover, both wild-type or recombinant L. plantarum reduced airway eosinophilia following aerosolized allergen exposure and IL-5 secretion upon allergen restimulation. CONCLUSION By combining both Th1-type immunostimulatory properties and an efficient allergen delivery capacity, recombinant L. plantarum producing Der p 1 represents a promising vaccine against house dust mite allergy.
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Affiliation(s)
- P Rigaux
- Laboratoire d'Allergologie Expérimentale, Université Libre de Bruxelles, Charleroi, Belgium
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42
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Genes and molecules of lactobacilli supporting probiotic action. Microbiol Mol Biol Rev 2009; 72:728-64, Table of Contents. [PMID: 19052326 DOI: 10.1128/mmbr.00017-08] [Citation(s) in RCA: 613] [Impact Index Per Article: 40.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Lactobacilli have been crucial for the production of fermented products for centuries. They are also members of the mutualistic microbiota present in the human gastrointestinal and urogenital tract. Recently, increasing attention has been given to their probiotic, health-promoting capacities. Many human intervention studies demonstrating health effects have been published. However, as not all studies resulted in positive outcomes, scientific interest arose regarding the precise mechanisms of action of probiotics. Many reported mechanistic studies have addressed mainly the host responses, with less attention being focused on the specificities of the bacterial partners, notwithstanding the completion of Lactobacillus genome sequencing projects, and increasing possibilities of genomics-based and dedicated mutant analyses. In this emerging and highly interdisciplinary field, microbiologists are facing the challenge of molecular characterization of probiotic traits. This review addresses the advances in the understanding of the probiotic-host interaction with a focus on the molecular microbiology of lactobacilli. Insight into the molecules and genes involved should contribute to a more judicious application of probiotic lactobacilli and to improved screening of novel potential probiotics.
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43
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Hüfner E, Britton RA, Roos S, Jonsson H, Hertel C. Global transcriptional response of Lactobacillus reuteri to the sourdough environment. Syst Appl Microbiol 2008; 31:323-38. [DOI: 10.1016/j.syapm.2008.06.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Revised: 06/25/2008] [Accepted: 06/26/2008] [Indexed: 10/21/2022]
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Kramer NE, Hasper HE, van den Bogaard PTC, Morath S, de Kruijff B, Hartung T, Smid EJ, Breukink E, Kok J, Kuipers OP. Increased D-alanylation of lipoteichoic acid and a thickened septum are main determinants in the nisin resistance mechanism of Lactococcus lactis. MICROBIOLOGY-SGM 2008; 154:1755-1762. [PMID: 18524930 DOI: 10.1099/mic.0.2007/015412-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Nisin is a post-translationally modified antimicrobial peptide produced by Lactococcus lactis which binds to lipid II in the membrane to form pores and inhibit cell-wall synthesis. A nisin-resistant (Nis(R)) strain of L. lactis, which is able to grow at a 75-fold higher nisin concentration than its parent strain, was investigated with respect to changes in the cell wall. Direct binding studies demonstrated that less nisin was able to bind to lipid II in the membranes of L. lactis Nis(R) than in the parent strain. In contrast to vancomycin binding, which showed ring-like binding, nisin was observed to bind in patches close to cell-division sites in both the wild-type and the Nis(R) strains. Comparison of modifications in lipoteichoic acid of the L. lactis strains revealed an increase in d-alanyl esters and galactose as substituents in L. lactis Nis(R), resulting in a less negatively charged cell wall. Moreover, the cell wall displays significantly increased thickness at the septum. These results indicate that shielding the membrane and thus the lipid II molecule, thereby decreasing abduction of lipid II and subsequent pore-formation, is a major defence mechanism of L. lactis against nisin.
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Affiliation(s)
- Naomi E Kramer
- Department of Biochemistry of Membranes, Center for Biomembranes and Lipid Enzymology, Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.,Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands
| | - Hester E Hasper
- Department of Biochemistry of Membranes, Center for Biomembranes and Lipid Enzymology, Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Patrick T C van den Bogaard
- Eukaryotic Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands
| | - Siegfried Morath
- European Commission, Joint Research Centre, IHCP, European Centre for the Validation of Alternative Methods, 21020 Ispra, Italy
| | - Ben de Kruijff
- Department of Biochemistry of Membranes, Center for Biomembranes and Lipid Enzymology, Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Thomas Hartung
- European Commission, Joint Research Centre, IHCP, European Centre for the Validation of Alternative Methods, 21020 Ispra, Italy
| | - Eddy J Smid
- NIZO Food Research, Flavour and Natural Ingredients Section, PO Box 20, 6710 BA Ede, The Netherlands
| | - Eefjan Breukink
- Department of Biochemistry of Membranes, Center for Biomembranes and Lipid Enzymology, Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Jan Kok
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands
| | - Oscar P Kuipers
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands
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45
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Variations in the degree of D-Alanylation of teichoic acids in Lactococcus lactis alter resistance to cationic antimicrobials but have no effect on bacterial surface hydrophobicity and charge. Appl Environ Microbiol 2008; 74:4764-7. [PMID: 18539809 DOI: 10.1128/aem.00078-08] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An increase of the degree of d-alanylation of teichoic acids in Lactococcus lactis resulted in a significant increase of bacterial resistance toward the cationic antimicrobials nisin and lysozyme, whereas the absence of D-alanylation led to a decreased resistance toward the same compounds. In contrast, the same variations of the D-alanylation degree did not modify bacterial cell surface charge and hydrophobicity. Bacterial adhesion to polystyrene and glass surfaces was not modified either.
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46
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Walter J, Loach DM, Alqumber M, Rockel C, Hermann C, Pfitzenmaier M, Tannock GW. D-alanyl ester depletion of teichoic acids in Lactobacillus reuteri 100-23 results in impaired colonization of the mouse gastrointestinal tract. Environ Microbiol 2008; 9:1750-60. [PMID: 17564608 DOI: 10.1111/j.1462-2920.2007.01292.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The dlt operon of Gram-positive bacteria encodes proteins required for the incorporation of D-alanine esters into cell wall-associated teichoic acids (TA). D-alanylation of TA has been shown to be important for acid tolerance, resistance to antimicrobial peptides, adhesion, biofilm formation, and virulence of a variety of pathogenic organisms. The aim of this study was to determine the importance of D-alanylation for colonization of the gastrointestinal tract by Lactobacillus reuteri 100-23. Insertional inactivation of the dltA gene resulted in complete depletion of D-alanine substitution of lipoteichoic acids. The dlt mutant had similar growth characteristics as the wild type under standard in vitro conditions, but formed lower population sizes in the gastrointestinal tract of ex-Lactobacillus-free mice, and was almost eliminated from the habitat in competition experiments with the parental strain. In contrast to the wild type, the dlt mutant was unable to form a biofilm on the forestomach epithelium during gut colonization. Transmission electron microscope observations showed evidence of cell wall damage of mutant bacteria present in the forestomach. The dlt mutant had impaired growth under acidic culture conditions and increased susceptibility to the cationic peptide nisin relative to the wild type. Ex vivo adherence of the dlt mutant to the forestomach epithelium was not impaired. This study showed that D-alanylation is an important cell function of L. reuteri that seems to protect this commensal organism against the hostile conditions prevailing in the murine forestomach.
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Affiliation(s)
- Jens Walter
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin, New Zealand.
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47
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Rice KC, Bayles KW. Molecular control of bacterial death and lysis. Microbiol Mol Biol Rev 2008; 72:85-109, table of contents. [PMID: 18322035 PMCID: PMC2268280 DOI: 10.1128/mmbr.00030-07] [Citation(s) in RCA: 258] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Although the phenomenon of bacterial cell death and lysis has been studied for over 100 years, the contribution of these important processes to bacterial physiology and development has only recently been recognized. Contemporary study of cell death and lysis in a number of different bacteria has revealed that these processes, once thought of as being passive and unregulated, are actually governed by highly complex regulatory systems. An emerging paradigm in this field suggests that, analogous to programmed cell death in eukaryotes, regulated cell death and lysis in bacteria play an important role in both developmental processes, such as competence and biofilm development, and the elimination of damaged cells, such as those irreversibly injured by environmental or antibiotic stress. Further study in this exciting field of bacterial research may provide new insight into the potential evolutionary link between control of cell death in bacteria and programmed cell death (apoptosis) in eukaryotes.
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Affiliation(s)
- Kelly C Rice
- Department of Microbiology and Pathology, University of Nebraska Medical Center, 668 S. 41st St., PYH4014, Omaha, NE 68198-6245, USA
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48
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Draing C, Sigel S, Deininger S, Traub S, Munke R, Mayer C, Hareng L, Hartung T, von Aulock S, Hermann C. Cytokine induction by Gram-positive bacteria. Immunobiology 2008; 213:285-96. [PMID: 18406374 DOI: 10.1016/j.imbio.2007.12.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Revised: 11/30/2007] [Accepted: 12/10/2007] [Indexed: 01/13/2023]
Abstract
Despite similar clinical relevance of Gram-positive and Gram-negative infections, immune activation by Gram-positive bacteria is by far less well understood than immune activation by Gram-negative bacteria. Our group has made available highly purified lipoteichoic acids (LTA) as a key Gram-positive immunostimulatory component. We have characterized the reasons for lower potency of LTA compared to Gram-negative lipopolysaccharide (LPS), identifying lack of IL-12/IFNgamma induction as a general characteristic of TLR2 agonists, and need for presentation of LTA on surfaces for enhanced immunostimulatory potency, as major aspects. Aspects of chemokine induction, where LTA is more potent than LPS, have been addressed. Furthermore, novel complement and plant defence activation, as well as CD36 as a new LTA receptor, were identified. The bacterial costimuli and modulators of LTA inducible responses are being investigated: LTA isolated from so far 16 bacterial species, although different in structure, behave remarkably similar while whole live and killed bacteria differ with regard to the pattern of induced responses. The purification and characterization of the respective components of the bacterial cell wall has begun.
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Affiliation(s)
- Christian Draing
- Biochemical Pharmacology, University of Konstanz, 78457 Konstanz, Germany
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49
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Meyrand M, Boughammoura A, Courtin P, Mézange C, Guillot A, Chapot-Chartier MP. Peptidoglycan N-acetylglucosamine deacetylation decreases autolysis in Lactococcus lactis. Microbiology (Reading) 2007; 153:3275-3285. [PMID: 17906127 DOI: 10.1099/mic.0.2007/005835-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The gene xynD (renamed pgdA) of Lactococcus lactis IL1403 was shown to encode a peptidoglycan N-acetylglucosamine deacetylase. Inactivation of pgdA in L. lactis led to fully acetylated peptidoglycan, whereas cloning of pgdA on a multicopy plasmid vector resulted in an increased degree of peptidoglycan deacetylation, as shown by analysis of peptidoglycan constituent muropeptides. An increased amount of N-unsubstituted glucosamine residues in peptidoglycan resulted in a reduction of the rate of autolysis of L. lactis cells. The activity of the L. lactis major autolysin AcmA was tested on L. lactis cells or peptidoglycan with different degrees of de-N-acetylation. Deacetylated peptidoglycan exhibited decreased susceptibility to AcmA hydrolysis. This reduced susceptibility to AcmA did not result from reduced AcmA binding to peptidoglycan with an increasing degree of de-N-acetylation. In conclusion, enzymic N-acetylglucosamine deacetylation protects peptidoglycan from hydrolysis by the major autolysin AcmA in L. lactis cells, and this leads to decreased cellular autolysis.
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Affiliation(s)
- Mickael Meyrand
- INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France
| | - Aïda Boughammoura
- INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France
| | - Pascal Courtin
- INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France
| | - Christine Mézange
- INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France
| | - Alain Guillot
- INRA, Unité de Biochimie Bactérienne, UR477, 78350 Jouy-en-Josas, France
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Ahmed ABF, Noguchi K, Asami Y, Nomura K, Fujii H, Sakata M, Tokita A, Noda K, Kuroda A. Evaluation of cell wall binding domain of Staphylococcus aureus autolysin as affinity reagent for bacteria and its application to bacterial detection. J Biosci Bioeng 2007; 104:55-61. [PMID: 17697984 DOI: 10.1263/jbb.104.55] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Accepted: 04/21/2007] [Indexed: 11/17/2022]
Abstract
We evaluated the cell wall binding (CWB) domain of Staphylococcus aureus autolysin as an affinity reagent for bacteria. A fusion of CWB domain and green fluorescent protein (CWB-GFP) bound to S. aureus with a dissociation constant of 15 nM. CWB-GFP bound to a wide range of gram-positive bacteria, but not to most gram-negative bacteria. We suspected that the outer membrane of gram-negative bacteria inhibits the access of CWB-GFP to peptidoglycan layer. Indeed, CWB-GFP bound to gram-negative bacteria when they were treated with benzalkonium chloride. Because CWB-GFP bound to the bacterial peptidoglycan layer, it appeared to be an effective affinity reagent for bacteria and CWB fusion with reporter proteins could be applied to detect bacteria. We also constructed a fusion of CWB and luciferase, which can be used for the rapid detection of bacteria.
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Affiliation(s)
- Abo Bakr F Ahmed
- Department of Molecular Biotechnology, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima, Hiroshima, Japan
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