title: Rapid onset of ICAM-1 expression is a marker of effective macrophages activation during infection of Francisella tularensis LVS in vitro.
abstract: Francisella tularensis is capable to modulate immunobiological activities of the host cells. We focused on the expression of ICAM-1 (CD54) on J774.2 mouse macrophage cell line infected by F. tularensis live vaccine strain (LVS) in vitro as a putative marker of subsequent elimination of infection. J774.2 cell line cells were infected by F. tularensis LVS strain (multiplicity of infection, 1:100). Cell cultures were stimulated either 3 h before infection or 3 h after infection by either lipopolysaccharide (LPS) or interferon γ (IFN-γ). The expression of ICAM-1 was determined by flow cytometry 6 h after infection. The intensity of ICAM-1 expression after 6 h of J774.2 macrophage cells infection by F. tularensis is very sensitive indicator of the effective macrophages stimulation resulting in the elimination of F. tularensis infection. The mean fluorescence intensity MFI = 49.8 is set-up by our experiments as a reliable threshold of the effective elimination of F. tularensis experimental infection with 83.3% sensitivity and 96.7% specificity, respectively. Simultaneous stimulation of J774.2 macrophage cells by LPS and IFN-γ was essential to elicit the elimination of F. tularensis infection. The ICAM-1 expression determined by flow cytometry can be considered to be highly sensitive and specific approach to predict elimination of F. tularensis infection by J774.2 macrophages.
authors.affiliation: Department of Clinical Immunology, Faculty of Medicine and University Hospital in Hradec Kralove, Charles University Prague, Sokolska 581, 500 05, Hradec Kralove, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Novosad
authors.forename: M
authors.initials: M
authors.lastname: Holicka
authors.forename: M
authors.initials: M
authors.lastname: Novosadova
authors.forename: J
authors.initials: J
authors.lastname: Krejsek
authors.forename: I
authors.initials: I
authors.lastname: Krcmova
mesh_terms: D000818:Animals; D002460:Cell Line; D005434:Flow Cytometry; D005604:Francisella tularensis / Q000276:immunology*; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis*; D007371:Interferon-gamma / Q000276:immunology; D008070:Lipopolysaccharides / Q000276:immunology; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology* / Q000382:microbiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D014406:Tularemia / Q000276:immunology
chemical_list: D008070:Lipopolysaccharides; D018799:Intercellular Adhesion Molecule-1; D007371:Interferon-gamma