title: Natural killer cells limit cardiac inflammation and fibrosis by halting eosinophil infiltration.
abstract: Myocarditis is a leading cause of sudden cardiac failure in young adults. Natural killer (NK) cells, a subset of the innate lymphoid cell compartment, are protective in viral myocarditis. Herein, we demonstrated that these protective qualities extend to suppressing autoimmune inflammation. Experimental autoimmune myocarditis (EAM) was initiated in BALB/c mice by immunization with myocarditogenic peptide. During EAM, activated cardiac NK cells secreted interferon γ, perforin, and granzyme B, and expressed CD69, tumor necrosis factor-related apoptosis-inducing ligand treatment, and CD27 on their cell surfaces. The depletion of NK cells during EAM with anti-asialo GM1 antibody significantly increased myocarditis severity, and was accompanied by elevated fibrosis and a 10-fold increase in the percentage of cardiac-infiltrating eosinophils. The resultant influx of eosinophils to the heart was directly responsible for the increased disease severity in the absence of NK cells, because treatment with polyclonal antibody asialogangloside GM-1 did not augment myocarditis severity in eosinophil-deficient ΔdoubleGATA1 mice. We demonstrate that NK cells limit eosinophilic infiltration both indirectly, through altering eosinophil-related chemokine production by cardiac fibroblasts, and directly, by inducing eosinophil apoptosis in vitro. Altogether, we define a new pathway of eosinophilic regulation through interactions with NK cells.
authors.affiliation: The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: SuFey
authors.initials: S
authors.lastname: Ong
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Davinna L
authors.initials: DL
authors.lastname: Ligons
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Jobert G
authors.initials: JG
authors.lastname: Barin
authors.affiliation: The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Lei
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Monica V
authors.initials: MV
authors.lastname: Talor
authors.affiliation: The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Nicola
authors.initials: N
authors.lastname: Diny
authors.affiliation: The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Jillian A
authors.initials: JA
authors.lastname: Fontes
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Gebremariam
authors.affiliation: Department of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: David A
authors.initials: DA
authors.lastname: Kass
authors.affiliation: The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland; Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Noel R
authors.initials: NR
authors.lastname: Rose
authors.affiliation: The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland; Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland. Electronic address: dcihako1@jhmi.edu.
authors.forename: Daniela
authors.initials: D
authors.lastname: Čiháková
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000276:immunology; D004804:Eosinophils / Q000276:immunology* / Q000473:pathology; D005355:Fibrosis / Q000276:immunology / Q000473:pathology; D007249:Inflammation / Q000473:pathology; D007694:Killer Cells, Natural / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009205:Myocarditis / Q000276:immunology* / Q000473:pathology; D009206:Myocardium / Q000276:immunology* / Q000473:pathology