title: CBA/J mice infected with Trypanosoma cruzi: an experimental model for inflammatory myopathies.
abstract: Idiopathic inflammatory myopathies are inflammatory disorders of unknown origin, characterized by muscle weakness. The aim of our study was to establish and characterize an animal model for chronic inflammatory myopathy which would permit investigations of the role of T-cells in chronic myositis as well as of the mechanisms for muscle weakness in chronic inflammatory muscle disorders. CBA/J mice were infected with the protozoan parasite Trypanosoma cruzi. Immunohistochemistry was used to characterize the distribution and composition of inflammatory infiltrates, and demonstrated a chronic focal inflammation comprised mainly of T-cells and macrophages in infected mice. The inflammatory infiltrates were predominantly found in the endomysium and, to a lesser extent, in perivascular areas. CD8(+) T-cells were found to have invaded nonnecrotic muscle fibers. Degenerating muscle fibers were also found, as well as an increased number of central muscle nuclei. The murine model described in this article may be useful in studying certain aspects of idiopathic inflammatory myopathies such as the role of T-cells in chronic muscle inflammation and chronic myocytotoxicity.
authors.affiliation: Microbiology and Tumorbiology Center, Karolinska Institutet, Stockholm, Sweden.
authors.forename: John
authors.initials: J
authors.lastname: Andersson
authors.forename: Pernilla
authors.initials: P
authors.lastname: Englund
authors.forename: Dan
authors.initials: D
authors.lastname: Sunnemark
authors.forename: Anders
authors.initials: A
authors.lastname: Dahlstedt
authors.forename: Håkan
authors.initials: H
authors.lastname: Westerblad
authors.forename: Inger
authors.initials: I
authors.lastname: Nennesmo
authors.forename: Anders
authors.initials: A
authors.lastname: Orn
authors.forename: Ingrid E
authors.initials: IE
authors.lastname: Lundberg
mesh_terms: D000818:Animals; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism / Q000473:pathology; D014355:Chagas Disease / Q000473:pathology* / Q000503:physiopathology; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008264:Macrophages / Q000166:cytology; D051379:Mice; D008808:Mice, Inbred CBA; D018485:Muscle Fibers, Skeletal / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D018482:Muscle, Skeletal / Q000469:parasitology* / Q000473:pathology* / Q000503:physiopathology; D009187:Myelitis / Q000469:parasitology* / Q000473:pathology* / Q000503:physiopathology; D014349:Trypanosoma cruzi / Q000472:pathogenicity