title: Quorum Sensing Controls Adaptive Immunity through the Regulation of Multiple CRISPR-Cas Systems.
abstract: Bacteria commonly exist in high cell density populations, making them prone to viral predation and horizontal gene transfer (HGT) through transformation and conjugation. To combat these invaders, bacteria possess an arsenal of defenses, such as CRISPR-Cas adaptive immunity. Many bacterial populations coordinate their behavior as cell density increases, using quorum sensing (QS) signaling. In this study, we demonstrate that QS regulation results in increased expression of the type I-E, I-F, and III-A CRISPR-Cas systems in Serratia cells in high-density populations. Strains unable to communicate via QS were less effective at defending against invaders targeted by any of the three CRISPR-Cas systems. Additionally, the acquisition of immunity by the type I-E and I-F systems was impaired in the absence of QS signaling. We propose that bacteria can use chemical communication to modulate the balance between community-level defense requirements in high cell density populations and host fitness costs of basal CRISPR-Cas activity.
authors.affiliation: Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
authors.forename: Adrian G
authors.initials: AG
authors.lastname: Patterson
authors.affiliation: Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
authors.forename: Simon A
authors.initials: SA
authors.lastname: Jackson
authors.affiliation: Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
authors.forename: Corinda
authors.initials: C
authors.lastname: Taylor
authors.affiliation: Ferrier Research Institute, Victoria University of Wellington, 69 Gracefield Road, Lower Hutt 5010, New Zealand.
authors.forename: Gary B
authors.initials: GB
authors.lastname: Evans
authors.affiliation: Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK.
authors.forename: George P C
authors.initials: GPC
authors.lastname: Salmond
authors.affiliation: Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
authors.forename: Rita
authors.initials: R
authors.lastname: Przybilski
authors.affiliation: Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
authors.forename: Raymond H J
authors.initials: RHJ
authors.lastname: Staals
authors.affiliation: Department of Microbiology and Immunology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand. Electronic address: peter.fineran@otago.ac.nz.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Fineran
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology; D064130:CRISPR-Associated Proteins / Q000235:genetics / Q000276:immunology; D064113:CRISPR-Cas Systems / Q000276:immunology*; D064112:Clustered Regularly Interspaced Short Palindromic Repeats; D004706:Endodeoxyribonucleases / Q000235:genetics* / Q000276:immunology; D015964:Gene Expression Regulation, Bacterial / Q000276:immunology*; D053038:Quorum Sensing / Q000187:drug effects / Q000235:genetics* / Q000276:immunology; D012097:Repressor Proteins / Q000235:genetics / Q000276:immunology; D012705:Serratia / Q000187:drug effects / Q000235:genetics* / Q000276:immunology
chemical_list: D001426:Bacterial Proteins; D064130:CRISPR-Associated Proteins; C092312:N-butyrylhomoserine lactone; D012097:Repressor Proteins; D004706:Endodeoxyribonucleases; D015107:4-Butyrolactone
keywords: CRISPR-Cas; bacterial communication; horizontal gene transfer; phage resistance; quorum sensing; regulation