title: A Nuclease fromStreptococcus mutansFacilitates Biofilm Dispersal and Escape from Killing by Neutrophil Extracellular Traps.
abstract: Streptococcus mutansis the primary etiologic agent of dental caries and occasionally infective endocarditis, with the ability to form biofilms and disperse cells into distal sites to exacerbate and spread infection. In this study, we identified a nuclease (DeoC) as aS. mutansbiofilm dispersal modulating factor through microarray analysis.In vitroassays revealed a dispersal defect of adeoCdeletion mutant, and functional studies with purified protein were indicative of the biofilm dispersal activity of DeoC. Neutrophils are a key host response factor restraining bacterial spreading through the formation of neutrophil extracellular traps (NETs), which consist of a nuclear DNA backbone associated with antimicrobial peptides. Therefore, we hypothesized that the dispersedS. mutansmight utilize DeoC to degrade NETs and escape killing by the immune system. It was found thatS. mutansinduced NET formation upon contact with neutrophils, while the presence of NETs in turn enhanced thedeoCexpression ofS. mutans. Fluorescence microscopy inspection showed thatdeoCdeletion resulted in a decreased NET degradation ability ofS. mutansand enhanced susceptibility to neutrophil killing. Data obtained from this study assigned two important roles for DeoC inS. mutans: contributing to the spread of infection through mediating biofilm dispersal, and facilitating the escape ofS. mutansfrom neutrophil killing through NET degradation.
authors.affiliation: Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-Sen University Guangzhou, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.affiliation: Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-Sen University Guangzhou, China.
authors.forename: Luping
authors.initials: L
authors.lastname: Sun
authors.affiliation: Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-Sen University Guangzhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-Sen University Guangzhou, China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Guo
authors.affiliation: Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-Sen University Guangzhou, China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-Sen University Guangzhou, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Wei
authors.affiliation: Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-Sen University Guangzhou, China.
authors.forename: Junqi
authors.initials: J
authors.lastname: Ling
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D003851:Deoxyribonucleases / Q000235:genetics / Q000494:pharmacology*; D065206:Extracellular Traps / Q000187:drug effects* / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D050296:Microbial Viability; D009504:Neutrophils / Q000276:immunology / Q000382:microbiology; D017382:Reactive Oxygen Species / Q000032:analysis; D011994:Recombinant Proteins; D017384:Sequence Deletion; D013295:Streptococcus mutans / Q000201:enzymology* / Q000235:genetics / Q000276:immunology
chemical_list: D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; D003851:Deoxyribonucleases
keywords: Streptococcus mutans; biofilm dispersal; immune defense; neutrophil extracellular traps; nuclease