title: Delayed presence of alternatively activated macrophages during a Francisella tularensis infection.
abstract: Francisella tularensis is an intracellular bacterium that has the ability to multiply within the macrophage. The phenotype of a macrophage can determine whether the infection is cleared or the host succumbs to disease. Previously published data has suggested that F. tularensis LVS actively induces the alternative phenotype as a survival mechanism. In these studies we demonstrate that this is not the case for the more virulent strain of F. tularensis SCHU-S4. During an intranasal mouse model of infection, immuno-histochemistry identified that iNOS positive ("classical") macrophages are present at 72 h post-infection and remain high (supported by CCL-5 release) in numbers. In contrast, arginase/FIZZ-1 positive ("alternative") cells appear later and in low numbers during the development of the disease tularemia.
authors.affiliation: Biomedical Sciences, Dstl Porton Down, Salisbury SP4 0JQ, UK. Electronic address: rvdelia@dstl.gov.uk.
authors.forename: Riccardo V
authors.initials: RV
authors.lastname: D'Elia
authors.affiliation: Biomedical Sciences, Dstl Porton Down, Salisbury SP4 0JQ, UK.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Laws
authors.affiliation: Pathology Department, Animal Health and Veterinary Laboratories Agency - Weybridge, Woodham Lane, New Haw, Addlestone KT15 3NB, UK.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Núñez
authors.affiliation: Biomedical Sciences, Dstl Porton Down, Salisbury SP4 0JQ, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Taylor
authors.affiliation: Biomedical Sciences, Dstl Porton Down, Salisbury SP4 0JQ, UK.
authors.forename: Graeme C
authors.initials: GC
authors.lastname: Clark
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005604:Francisella tularensis / Q000276:immunology* / Q000502:physiology; D006801:Humans; D008264:Macrophages / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000276:immunology; D014406:Tularemia / Q000201:enzymology / Q000235:genetics / Q000276:immunology* / Q000382:microbiology
chemical_list: D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse
keywords: Activation; Alternative; Classical; Francisella; Immunohistochemistry; Macrophages; Tularensis