title: Activation of Natural Killer Cells in Patients with Chronic Bone and Joint Infection due to Staphylococci Expressing or Not the Small Colony Variant Phenotype.
abstract: Chronic bone and joint infections (BJI) are devastating diseases. Relapses are frequently observed, as some pathogens, especially staphylococci, can persist intracellularly by expressing a particular phenotype called small colony variant (SCV). As natural killer (NK) cells are lymphocytes specialized in the killing of host cells infected by intracellular pathogens, we studied NK cells of patients with chronic BJI due to staphylococci expressing or not SCVs (10 patients in both groups). Controls were patients infected with other bacteria without detectable expression of SCVs, and healthy volunteers. NK cell phenotype was evaluated from PBMCs by flow cytometry. Degranulation capacity was evaluated after stimulation with K562 cells in vitro. We found that NK cells were activated in terms of CD69 expression, loss of CD16 and perforin, in all infected patients in comparison with healthy volunteers, independently of the SCV phenotype. Peripheral NK cells in patients with chronic BJI display signs of recent activation and degranulation in vivo in response to CD16-mediated signals, regardless of the type of bacteria involved. This could involve a universal capacity of isolates responsible for chronic BJI to produce undetectable SCVs in vivo, which might be a target of future intervention.
authors.affiliation: Laboratoire d'Immunologie, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, 69310 Pierre-Bénite, France ; Université Claude Bernard Lyon 1, 69100 Villeurbanne, France ; Centre International de Recherche en Infectiologie, CIRI, Inserm U1111, CNRS UMR5308, ENS de Lyon, UCBL1, 69007 Lyon, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Viel
authors.affiliation: Laboratoire d'Immunologie, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, 69310 Pierre-Bénite, France ; Université Claude Bernard Lyon 1, 69100 Villeurbanne, France ; Centre International de Recherche en Infectiologie, CIRI, Inserm U1111, CNRS UMR5308, ENS de Lyon, UCBL1, 69007 Lyon, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Rouzaire
authors.affiliation: Université Claude Bernard Lyon 1, 69100 Villeurbanne, France ; Centre International de Recherche en Infectiologie, CIRI, Inserm U1111, CNRS UMR5308, ENS de Lyon, UCBL1, 69007 Lyon, France ; Laboratoire de Bactériologie, Hôpital de la Croix-Rousse, Hospices Civils de Lyon, 69004 Lyon, France ; Centre National de Référence des Staphylocoques, 69008 Lyon, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Laurent
authors.affiliation: Université Claude Bernard Lyon 1, 69100 Villeurbanne, France ; Centre International de Recherche en Infectiologie, CIRI, Inserm U1111, CNRS UMR5308, ENS de Lyon, UCBL1, 69007 Lyon, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Walzer
authors.affiliation: Laboratoire d'Immunologie, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, 69310 Pierre-Bénite, France ; Université Claude Bernard Lyon 1, 69100 Villeurbanne, France ; Centre International de Recherche en Infectiologie, CIRI, Inserm U1111, CNRS UMR5308, ENS de Lyon, UCBL1, 69007 Lyon, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Bienvenu
authors.affiliation: Université Claude Bernard Lyon 1, 69100 Villeurbanne, France ; Centre International de Recherche en Infectiologie, CIRI, Inserm U1111, CNRS UMR5308, ENS de Lyon, UCBL1, 69007 Lyon, France ; Centre National de Référence des Staphylocoques, 69008 Lyon, France ; Service de Maladies Infectieuses et Tropicales, Hôpital de la Croix-Rousse, Hospices Civils de Lyon, 93 Grande rue de la Croix-Rousse, 69004 Lyon, France ; Centre Interrégional Rhône-Alpes Auvergne de Référence des IOA Complexes, 69004 Lyon, France.
authors.forename: Florent
authors.initials: F
authors.lastname: Valour
authors.affiliation: Université Claude Bernard Lyon 1, 69100 Villeurbanne, France ; Centre International de Recherche en Infectiologie, CIRI, Inserm U1111, CNRS UMR5308, ENS de Lyon, UCBL1, 69007 Lyon, France ; Service de Maladies Infectieuses et Tropicales, Hôpital de la Croix-Rousse, Hospices Civils de Lyon, 93 Grande rue de la Croix-Rousse, 69004 Lyon, France ; Centre Interrégional Rhône-Alpes Auvergne de Référence des IOA Complexes, 69004 Lyon, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Chidiac
authors.affiliation: Université Claude Bernard Lyon 1, 69100 Villeurbanne, France ; Centre International de Recherche en Infectiologie, CIRI, Inserm U1111, CNRS UMR5308, ENS de Lyon, UCBL1, 69007 Lyon, France ; Centre National de Référence des Staphylocoques, 69008 Lyon, France ; Service de Maladies Infectieuses et Tropicales, Hôpital de la Croix-Rousse, Hospices Civils de Lyon, 93 Grande rue de la Croix-Rousse, 69004 Lyon, France ; Centre Interrégional Rhône-Alpes Auvergne de Référence des IOA Complexes, 69004 Lyon, France.
authors.forename: Tristan
authors.initials: T
authors.lastname: Ferry
authors.affiliation: Université Claude Bernard Lyon 1, 69100 Villeurbanne, France.
authors.forename: The Lyon Bji Study
authors.initials: TL
authors.lastname: Group