title: A CRISPR-Cas system enhances envelope integrity mediating antibiotic resistance and inflammasome evasion.
abstract: Clustered, regularly interspaced, short palindromic repeats-CRISPR associated (CRISPR-Cas) systems defend bacteria against foreign nucleic acids, such as during bacteriophage infection and transformation, processes which cause envelope stress. It is unclear if these machineries enhance membrane integrity to combat this stress. Here, we show that the Cas9-dependent CRISPR-Cas system of the intracellular bacterial pathogen Francisella novicida is involved in enhancing envelope integrity through the regulation of a bacterial lipoprotein. This action ultimately provides increased resistance to numerous membrane stressors, including antibiotics. We further find that this previously unappreciated function of Cas9 is critical during infection, as it promotes evasion of the host innate immune absent in melanoma 2/apoptosis associated speck-like protein containing a CARD (AIM2/ASC) inflammasome. Interestingly, the attenuation of the cas9 mutant is complemented only in mice lacking both the AIM2/ASC inflammasome and the bacterial lipoprotein sensor Toll-like receptor 2, but not in single knockout mice, demonstrating that Cas9 is essential for evasion of both pathways. These data represent a paradigm shift in our understanding of the function of CRISPR-Cas systems as regulators of bacterial physiology and provide a framework with which to investigate the roles of these systems in myriad bacteria, including pathogens and commensals.
authors.affiliation: Department of Microbiology and Immunology, Microbiology and Molecular Genetics Program,Emory Vaccine Center, andYerkes National Primate Research Center, Emory University, Atlanta, GA 30329;
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Sampson
authors.affiliation: Department of Microbiology and Immunology, Microbiology and Molecular Genetics Program,Emory Vaccine Center, andYerkes National Primate Research Center, Emory University, Atlanta, GA 30329;
authors.forename: Brooke A
authors.initials: BA
authors.lastname: Napier
authors.affiliation: Department of Microbiology and Immunology, Microbiology and Molecular Genetics Program.
authors.forename: Max R
authors.initials: MR
authors.lastname: Schroeder
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center, University Medical Centre Rotterdam, Rotterdam, The Netherlands;
authors.forename: Rogier
authors.initials: R
authors.lastname: Louwen
authors.affiliation: Department of Biochemistry, Duke University Medical Center, Durham, NC 27710;
authors.forename: Jinshi
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Emory Vaccine Center, andYerkes National Primate Research Center, Emory University, Atlanta, GA 30329;
authors.forename: Chui-Yoke
authors.initials: CY
authors.lastname: Chin
authors.affiliation: Department of Microbiology and Immunology, Microbiology and Molecular Genetics Program,Emory Vaccine Center, andYerkes National Primate Research Center, Emory University, Atlanta, GA 30329;
authors.forename: Hannah K
authors.initials: HK
authors.lastname: Ratner
authors.affiliation: Department of Microbiology and Immunology, Microbiology and Molecular Genetics Program,Emory Vaccine Center, andYerkes National Primate Research Center, Emory University, Atlanta, GA 30329;
authors.forename: Anna C
authors.initials: AC
authors.lastname: Llewellyn
authors.affiliation: Department of Microbiology and Immunology, Microbiology and Molecular Genetics Program,Emory Vaccine Center, andYerkes National Primate Research Center, Emory University, Atlanta, GA 30329;
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Jones
authors.affiliation: Department of Biology, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30302; and.
authors.forename: Hamed
authors.initials: H
authors.lastname: Laroui
authors.affiliation: Department of Biology, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA 30302; and.
authors.forename: Didier
authors.initials: D
authors.lastname: Merlin
authors.affiliation: Department of Biochemistry, Duke University Medical Center, Durham, NC 27710;
authors.forename: Pei
authors.initials: P
authors.lastname: Zhou
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center, University Medical Centre Rotterdam, Rotterdam, The Netherlands;
authors.forename: Hubert P
authors.initials: HP
authors.lastname: Endtz
authors.affiliation: Emory Vaccine Center, andYerkes National Primate Research Center, Emory University, Atlanta, GA 30329;Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322 david.weiss@emory.edu.
authors.forename: David S
authors.initials: DS
authors.lastname: Weiss
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000276:immunology*; D002462:Cell Membrane / Q000235:genetics / Q000276:immunology; D024881:Drug Resistance, Bacterial / Q000235:genetics / Q000276:immunology*; D005603:Francisella / Q000235:genetics / Q000276:immunology*; D016905:Gram-Negative Bacterial Infections / Q000235:genetics / Q000276:immunology*; D057131:Immune Evasion / Q000235:genetics / Q000276:immunology*; D058847:Inflammasomes / Q000235:genetics / Q000276:immunology*; D055029:Inverted Repeat Sequences / Q000276:immunology; D008074:Lipoproteins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D018345:Mice, Knockout
chemical_list: D001426:Bacterial Proteins; D058847:Inflammasomes; D008074:Lipoproteins
keywords: gene regulation; innate immune evasion