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Mattos-Graner RO, Klein MI, Alves LA. The complement system as a key modulator of the oral microbiome in health and disease. Crit Rev Microbiol 2024; 50:138-167. [PMID: 36622855 DOI: 10.1080/1040841x.2022.2163614] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/22/2022] [Accepted: 12/23/2022] [Indexed: 01/10/2023]
Abstract
In this review, we address the interplay between the complement system and host microbiomes in health and disease, focussing on oral bacteria known to contribute to homeostasis or to promote dysbiosis associated with dental caries and periodontal diseases. Host proteins modulating complement activities in the oral environment and expression profiles of complement proteins in oral tissues were described. In addition, we highlight a sub-set of bacterial proteins involved in complement evasion and/or dysregulation previously characterized in pathogenic species (or strains), but further conserved among prototypical commensal species of the oral microbiome. Potential roles of these proteins in host-microbiome homeostasis and in the emergence of commensal strain lineages with increased virulence were also addressed. Finally, we provide examples of how commensal bacteria might exploit the complement system in competitive or cooperative interactions within the complex microbial communities of oral biofilms. These issues highlight the need for studies investigating the effects of the complement system on bacterial behaviour and competitiveness during their complex interactions within oral and extra-oral host sites.
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Affiliation(s)
- Renata O Mattos-Graner
- Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Marlise I Klein
- Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas (UNICAMP), Sao Paulo, Brazil
| | - Lívia Araújo Alves
- Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas (UNICAMP), Sao Paulo, Brazil
- School of Dentistry, Cruzeiro do Sul University (UNICSUL), Sao Paulo, Brazil
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Huang Y, Wang T, Chen Y, Lin H, Chen D. Amyloid hexapeptide prevent dental caries by antibiofilm formation. J Dent 2023; 135:104596. [PMID: 37353107 DOI: 10.1016/j.jdent.2023.104596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/11/2023] [Accepted: 06/19/2023] [Indexed: 06/25/2023] Open
Abstract
OBJECTIVES Biofilm formed by cariogenic microbes is the direct cause of dental caries, therefore, prevention of dental caries should be anti-biofilm-based. Previously, we found the amyloid hexapeptides efficiently inhibited biofilm formation by aggregating into amyloid fibrils agglutinating microbes. This study aimed to select the most stable amyloid hexapeptide GIDLKI (GI6) and study its anti-caries effect. METHODS Biofilms of multi-species bacteria, derived from mixed saliva, were cultured to evaluate the anti-biofilm formation effect of GI6. And then, the primary cariogenic bacterium Streptococcus mutans (S.mutans) was cultured in BHI with various pH, gradient concentrations of sucrose, glucose, and calcium ions to evaluate the anti-biofilm formation effects of GI6. Then models of human enamel block caries and twenty male SPF-SD rat caries induced by S. mutans biofilm were constructed, and confocal laser scanning microscopy, scanning electron microscopy, and micro-computed tomography were applied to investigate the anti-biofilm formation, anti-caries effects and use safety of GI6. RESULTS GI6 could inhibit the multi-species bacteria biofilm formation and remained effective in anti-biofilm activity against S. mutans in environments closely related to caries. GI6 suppressed S. mutans biofilm formation and thus prevented or alleviated the development of caries in human tooth blocks and rat teeth. GI6 did not affect the intestinal flora, serum biochemical parameters, and the pathological changes of various organs. CONCLUSIONS Amyloid hexapeptides, including but not limited to GI6, are novel effective anti-caries agents that can be used to prevent dental caries safely. CLINICAL SIGNIFICANCE This study explored the anti-biofilm formation and anti-caries effect of GI6 in vitro, highlighting the anti-biofilm formation therapy for dental caries and setting a foundation for the practical application of GI6 for the treatment of dental caries.
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Affiliation(s)
- Yiyi Huang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University. Guangdong Provincial Key Laboratory of Stomatology. Guangzhou, Guangdong, 510000, China
| | - Tingyu Wang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University. Guangdong Provincial Key Laboratory of Stomatology. Guangzhou, Guangdong, 510000, China
| | - Yucong Chen
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University. Guangdong Provincial Key Laboratory of Stomatology. Guangzhou, Guangdong, 510000, China
| | - Huancai Lin
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University. Guangdong Provincial Key Laboratory of Stomatology. Guangzhou, Guangdong, 510000, China.
| | - Dongru Chen
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University. Guangdong Provincial Key Laboratory of Stomatology. Guangzhou, Guangdong, 510000, China.
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Pandey SD, Perpich JD, Stocke KS, Mansfield JM, Kikuchi Y, Yakoumatos L, Muszyński A, Azadi P, Tettelin H, Whiteley M, Uriarte SM, Bagaitkar J, Vickerman M, Lamont RJ. Impact of Polymicrobial Infection on Fitness of Streptococcus gordonii In Vivo. mBio 2023; 14:e0065823. [PMID: 37042761 PMCID: PMC10294625 DOI: 10.1128/mbio.00658-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 03/21/2023] [Indexed: 04/13/2023] Open
Abstract
Pathogenic microbial ecosystems are often polymicrobial, and interbacterial interactions drive emergent properties of these communities. In the oral cavity, Streptococcus gordonii is a foundational species in the development of plaque biofilms, which can contribute to periodontal disease and, after gaining access to the bloodstream, target remote sites such as heart valves. Here, we used a transposon sequencing (Tn-Seq) library of S. gordonii to identify genes that influence fitness in a murine abscess model, both as a monoinfection and as a coinfection with an oral partner species, Porphyromonas gingivalis. In the context of a monoinfection, conditionally essential genes were widely distributed among functional pathways. Coinfection with P. gingivalis almost completely changed the nature of in vivo gene essentiality. Community-dependent essential (CoDE) genes under the coinfection condition were primarily related to DNA replication, transcription, and translation, indicating that robust growth and replication are required to survive with P. gingivalis in vivo. Interestingly, a group of genes in an operon encoding streptococcal receptor polysaccharide (RPS) were associated with decreased fitness of S. gordonii in a coinfection with P. gingivalis. Individual deletion of two of these genes (SGO_2020 and SGO_2024) resulted in the loss of RPS production by S. gordonii and increased susceptibility to killing by neutrophils. P. gingivalis protected the RPS mutants by inhibiting neutrophil recruitment, degranulation, and neutrophil extracellular trap (NET) formation. These results provide insight into genes and functions that are important for S. gordonii survival in vivo and the nature of polymicrobial synergy with P. gingivalis. Furthermore, we show that RPS-mediated immune protection in S. gordonii is dispensable and detrimental in the presence of a synergistic partner species that can interfere with neutrophil killing mechanisms. IMPORTANCE Bacteria responsible for diseases originating at oral mucosal membranes assemble into polymicrobial communities. However, we know little regarding the fitness determinants of the organisms that initiate community formation. Here, we show that the extracellular polysaccharide of Streptococcus gordonii, while important for streptococcal survival as a monoinfection, is detrimental to survival in the context of a coinfection with Porphyromonas gingivalis. We found that the presence of P. gingivalis compensates for immune protective functions of extracellular polysaccharide, rendering production unnecessary. The results show that fitness determinants of bacteria in communities differ substantially from those of individual species in isolation. Furthermore, constituents of communities can undertake activities that relieve the burden of energetically costly biosynthetic reactions on partner species.
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Affiliation(s)
- Satya D. Pandey
- Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, Kentucky, USA
| | - John D. Perpich
- Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, Kentucky, USA
- Department of Pharmaceutical Science, Sullivan University, Louisville, Kentucky, USA
| | - Kendall S. Stocke
- Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, Kentucky, USA
| | - Jillian M. Mansfield
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, Buffalo, New York, USA
| | - Yuichiro Kikuchi
- Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, Kentucky, USA
| | - Lan Yakoumatos
- Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, Kentucky, USA
| | - Artur Muszyński
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Parastoo Azadi
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Hervé Tettelin
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Marvin Whiteley
- School of Biological Sciences, Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Silvia M. Uriarte
- Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, Kentucky, USA
| | - Juhi Bagaitkar
- Center for Microbial Pathogenesis, Nationwide Children's Hospital, Columbus, Ohio, USA
- Department of Pediatrics, The Ohio State College of Medicine, Columbus, Ohio, USA
| | - Margaret Vickerman
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, Buffalo, New York, USA
| | - Richard J. Lamont
- Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, Kentucky, USA
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Guo H, Tang Y, Li Y, Tian H, Zhang T, Li Y, Liu L, He B, Hu L, Jiang G. Endocytosis-Mediated Transport of Pb in Rat Blood Cells. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:8514-8523. [PMID: 37252706 DOI: 10.1021/acs.est.3c02182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Blood is an important reservoir for Pb storage in living organisms, and the storage of Pb in blood cells inhibits its discharge from blood. However, the mechanism and molecular targets of Pb entry and exit from blood cells have not been elucidated, which is the major barrier to reducing blood Pb levels in normal human beings. In this study, we explored the effect of Pb-binding proteins on blood Pb levels in rats at environmentally relevant concentrations (0.32 μg/g) by identifying the functions of Pb-binding proteins and validating them with inhibitors. The results showed that Pb-binding proteins in blood cells were mainly related to phagocytosis, while in plasma, they were mainly involved in the regulation of endopeptidase activity. Meanwhile, at the normal population Pb levels, endocytosis inhibitors, endopeptidase activity inhibitors, and coadministration of both can reduce the level of Pb in MEL (mouse erythroleukemia cells) cells by up to 50, 40, and 50%, respectively, while in rat blood, the reduction can reach up to 26, 13, and 32%, respectively. Collectively, these findings reveal that endocytosis increases blood Pb levels and provides a possible molecular target for Pb excretion at ambient concentrations.
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Affiliation(s)
- Hua Guo
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yinyin Tang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yu Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Haozhong Tian
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Tingting Zhang
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yingying Li
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
| | - Lihong Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Bin He
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Ligang Hu
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- School of Environment and Health, Jianghan University, Wuhan 430056, China
| | - Guibin Jiang
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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Burcham LR, Bath JR, Werlang CA, Lyon LM, Liu N, Evans C, Ribbeck K, Doran KS. Role of MUC5B during Group B Streptococcal Vaginal Colonization. mBio 2022; 13:e0003922. [PMID: 35323039 PMCID: PMC9040740 DOI: 10.1128/mbio.00039-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 03/07/2022] [Indexed: 12/27/2022] Open
Abstract
The female reproductive tract (FRT) is a complex environment, rich in mucin glycoproteins that form a dense network on the surface of the underlying epithelia. Group B Streptococcus (GBS) asymptomatically colonizes 25-30% of healthy women, but during pregnancy can cause ascending infection in utero or be transmitted to the newborn during birth to cause invasive disease. Though the cervicovaginal mucosa is a natural site for GBS colonization, the specific interactions between GBS and mucins remain unknown. Here we demonstrate for the first time that MUC5B interacts directly with GBS and promotes barrier function by inhibiting both bacterial attachment to human epithelial cells and ascension from the vagina to the uterus in a murine model of GBS colonization. RNA sequencing analysis of GBS exposed to MUC5B identified 128 differentially expressed GBS genes, including upregulation of the pilus island-2b (PI-2b) locus. We subsequently show that PI-2b is important for GBS attachment to reproductive cells, binding to immobilized mucins, and vaginal colonization in vivo. Our results suggest that while MUC5B plays an important role in host defense, GBS upregulates pili in response to mucins to help promote persistence within the vaginal tract, illustrating the dynamic interplay between pathogen and host. IMPORTANCE Mucin glycoproteins are a major component that contributes to the complexity of the female reproductive tract (FRT). Group B Streptococcus (GBS) is present in the FRT of 25-30% of healthy women, but during pregnancy can ascend to the uterus to cause preterm birth and fetal infection in utero. Here we show that a prominent mucin found in the FRT, MUC5B, promotes host defense by inhibiting GBS interaction with epithelial cells found in the FRT and ascension from the vagina to the uterus in vivo. In response to MUC5B, GBS induces the expression of surface expressed pili, which in turn contributes to GBS persistence within the vaginal lumen. These observations highlight the importance and complexity of GBS-mucin interactions that warrant further investigation.
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Affiliation(s)
- Lindsey R. Burcham
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Jade R. Bath
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Caroline A. Werlang
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Laurie M. Lyon
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Naoko Liu
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Christopher Evans
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Katharina Ribbeck
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Kelly S. Doran
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
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Lee GKC, Kang H, Beeler-Marfisi J, Sears W, Lillie BN, Bienzle D. Effects of equine SALSA on neutrophil phagocytosis and macrophage cytokine production. PLoS One 2022; 17:e0264911. [PMID: 35286327 PMCID: PMC8920288 DOI: 10.1371/journal.pone.0264911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 02/21/2022] [Indexed: 11/19/2022] Open
Abstract
Salivary scavenger and agglutinin (SALSA) is a secreted protein with various immunomodulatory roles. In humans, the protein agglutinates and inactivates microorganisms, and inhibits the release of pro-inflammatory cytokines. Saliva, which is rich in SALSA, accelerates bacterial phagocytosis, but SALSA’s contribution is unclear. In horses, the functions of SALSA in inflammation remain undetermined, so they were investigated through phagocytosis and cytokine assays. Equine SALSA was purified from duodenal tissue, which contains abundant SALSA. To assess phagocytosis, fluorescently-labelled bacteria were incubated with 20, 10, 5, or 2.5 μg/mL of SALSA or phosphate buffered saline (PBS), and then incubated at 37°C or on ice with whole blood from seven healthy horses. Fluorescence was measured by gating on neutrophils using a flow cytometer, and compared between groups. To assess effects on cytokine production, alveolar macrophages were isolated from bronchoalveolar lavage fluid of five healthy horses and cultured in serum-free media for 24 hours with different concentrations of SALSA plus 1 μg/mL lipopolysaccharide (LPS), only LPS, or only media. Cytokines were measured in supernatant using an equine-specific multiplex bead immunoassay. There was significantly greater phagocytosis in samples incubated at 37°C compared to incubation on ice. Samples incubated with 20 μg/mL of SALSA at 37°C had less phagocytosis compared to samples with 10 or 2.5 μg/mL SALSA, or PBS. Alveolar macrophages incubated with SALSA plus LPS released significantly less CXC motif chemokine ligand 1, interleukin-8, interleukin-10, and tumor necrosis factor α, and more granulocyte colony stimulating factor (G-CSF), compared to macrophages incubated with LPS alone. These findings indicate anti-inflammatory effects, which may be due to interference with toll-like receptor 4 recognition of LPS or downstream signaling. Increase in G-CSF following incubation with SALSA suggests a novel mechanism for immunoregulation of alveolar macrophages by SALSA, addressing a knowledge gap regarding its functions in horses.
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Affiliation(s)
- Gary Kwok Cheong Lee
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
- * E-mail:
| | - Heng Kang
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
| | | | - William Sears
- Department of Population Medicine, University of Guelph, Guelph, Ontario, Canada
| | - Brandon N. Lillie
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
| | - Dorothee Bienzle
- Department of Pathobiology, University of Guelph, Guelph, Ontario, Canada
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Cai YM. Non-surface Attached Bacterial Aggregates: A Ubiquitous Third Lifestyle. Front Microbiol 2020; 11:557035. [PMID: 33343514 PMCID: PMC7746683 DOI: 10.3389/fmicb.2020.557035] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 11/13/2020] [Indexed: 01/03/2023] Open
Abstract
Bacteria are now generally believed to adopt two main lifestyles: planktonic individuals, or surface-attached biofilms. However, in recent years medical microbiologists started to stress that suspended bacterial aggregates are a major form of bacterial communities in chronic infection sites. Despite sharing many similarities with surface-attached biofilms and are thus generally defined as biofilm-like aggregates, these non-attached clumps of cells in vivo show much smaller sizes and different formation mechanisms. Furthermore, ex vivo clinical isolates were frequently reported to be less attached to abiotic surfaces when compared to standard type strains. While this third lifestyle is starting to draw heavy attention in clinical studies, it has a long history in natural and environmental sciences. For example, marine gel particles formed by bacteria attachment to phytoplankton exopolymers have been well documented in oceans; large river and lake snows loaded with bacterial aggregates are frequently found in freshwater systems; multispecies bacterial "flocs" have long been used in wastewater treatment. This review focuses on non-attached aggregates found in a variety of natural and clinical settings, as well as some recent technical developments facilitating aggregate research. The aim is to summarise the characteristics of different types of bacterial aggregates, bridging the knowledge gap, provoking new perspectives for researchers from different fields, and highlighting the importance of more research input in this third lifestyle of bacteria closely relevant to our daily life.
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Affiliation(s)
- Yu-Ming Cai
- National Biofilms Innovation Centre, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
- Biological Sciences, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
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Maes M, Dyson ZA, Smith SE, Goulding DA, Ludden C, Baker S, Kellam P, Reece ST, Dougan G, Bartholdson Scott J. A novel therapeutic antibody screening method using bacterial high-content imaging reveals functional antibody binding phenotypes of Escherichia coli ST131. Sci Rep 2020; 10:12414. [PMID: 32709982 PMCID: PMC7382476 DOI: 10.1038/s41598-020-69300-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 06/26/2020] [Indexed: 01/28/2023] Open
Abstract
The increase of antimicrobial resistance (AMR), and lack of new classes of licensed antimicrobials, have made alternative treatment options for AMR pathogens increasingly attractive. Recent studies have demonstrated anti-bacterial efficacy of a humanised monoclonal antibody (mAb) targeting the O25b O-antigen of Escherichia coli ST131. To evaluate the phenotypic effects of antibody binding to diverse clinical E. coli ST131 O25b bacterial isolates in high-throughput, we designed a novel mAb screening method using high-content imaging (HCI) and image-based morphological profiling to screen a mAb targeting the O25b O-antigen. Screening the antibody against a panel of 86 clinical E. coli ST131 O25:H4 isolates revealed 4 binding phenotypes: no binding (18.60%), weak binding (4.65%), strong binding (69.77%) and strong agglutinating binding (6.98%). Impaired antibody binding could be explained by the presence of insertion sequences or mutations in O-antigen or lipopolysaccharide core biosynthesis genes, affecting the amount, structure or chain length of the O-antigen. The agglutinating binding phenotype was linked with lower O-antigen density, enhanced antibody-mediated phagocytosis and increased serum susceptibly. This study highlights the need to screen candidate mAbs against large panels of clinically relevant isolates, and that HCI can be used to evaluate mAb binding affinity and potential functional efficacy against AMR bacteria.
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Affiliation(s)
- Mailis Maes
- Department of Medicine, Cambridge Institute for Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, UK
| | - Zoe A Dyson
- Department of Medicine, Cambridge Institute for Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, UK
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, VIC, 3004, Australia
- London School of Hygiene and Tropical Medicine, London, UK
| | | | | | | | - Stephen Baker
- Department of Medicine, Cambridge Institute for Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, UK
| | - Paul Kellam
- Kymab Ltd, Babraham Research Campus, Cambridge, UK
- Department of Infectious Disease, Imperial College London, London, UK
| | | | - Gordon Dougan
- Department of Medicine, Cambridge Institute for Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, UK
| | - Josefin Bartholdson Scott
- Department of Medicine, Cambridge Institute for Therapeutic Immunology & Infectious Disease, University of Cambridge, Cambridge, UK.
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Cross BW, Ruhl S. Glycan recognition at the saliva - oral microbiome interface. Cell Immunol 2018; 333:19-33. [PMID: 30274839 DOI: 10.1016/j.cellimm.2018.08.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 08/16/2018] [Accepted: 08/17/2018] [Indexed: 01/25/2023]
Abstract
The mouth is a first critical interface where most potentially harmful substances or pathogens contact the host environment. Adaptive and innate immune defense mechanisms are established there to inactivate or eliminate pathogenic microbes that traverse the oral environment on the way to their target organs and tissues. Protein and glycoprotein components of saliva play a particularly important role in modulating the oral microbiota and helping with the clearance of pathogens. It has long been acknowledged that glycobiological and glycoimmunological aspects play a pivotal role in oral host-microbe, microbe-host, and microbe-microbe interactions in the mouth. In this review, we aim to delineate how glycan-mediated host defense mechanisms in the oral cavity support human health. We will describe the role of glycans attached to large molecular size salivary glycoproteins which act as a first line of primordial host defense in the human mouth. We will further discuss how glycan recognition contributes to both colonization and clearance of oral microbes.
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Affiliation(s)
- Benjamin W Cross
- Department of Oral Biology, University at Buffalo, Buffalo, NY, United States
| | - Stefan Ruhl
- Department of Oral Biology, University at Buffalo, Buffalo, NY, United States.
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