title: Decay-accelerating factor 1 deficiency exacerbates Trypanosoma cruzi-induced murine chronic myositis.
abstract: BACKGROUND
  Murine infection with Trypanosoma cruzi (Tc) has been used to study the role of T-cells in the pathogenesis of human inflammatory idiopathic myositis. Absence of decay-accelerating factor 1 (Daf1) has been shown to enhance murine T-cell responses and autoimmunity.
  
  
  METHODS
  To determine whether Daf1 deficiency can exacerbate Tc-induced myositis, C57BL/6 DAF(+/+) and DAF(-/-) mice were inoculated with 5 × 10(4) trypomastigotes, and their morbidity, parasitemia, parasite burden, histopathology, and T-cell expansion were studied in the acute and chronic stages.
  
  
  RESULTS
  DAF(-/-) mice had lower parasitemia and parasite burden but higher morbidity, muscle histopathology, and increased number of CD44(+) (activated/memory phenotype) splenic CD4(+) and CD8(+) T-cells.
  
  
  CONCLUSIONS
  An enhanced CD8(+) T-cell immune-specific response may explain the lower parasitemia and parasite burden levels and the increase in histopathological lesions. We propose that Tc-inoculated DAF(-/-) mice are a useful model to study T-cell mediated immunity in skeletal muscle tissues.
authors.affiliation: Microbiology, Parasitology, and Immunology Department, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina.
authors.forename: María E
authors.initials: ME
authors.lastname: Solana
authors.forename: María F
authors.initials: MF
authors.lastname: Ferrer
authors.forename: María Mercedes
authors.initials: MM
authors.lastname: Novoa
authors.forename: Wen-Chao
authors.initials: WC
authors.lastname: Song
authors.forename: Ricardo M
authors.initials: RM
authors.lastname: Gómez
mesh_terms: D000818:Animals; D018958:CD55 Antigens / Q000235:genetics* / Q000378:metabolism; D014355:Chagas Disease / Q000235:genetics / Q000276:immunology* / Q000469:parasitology; D002908:Chronic Disease; D004195:Disease Models, Animal; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009220:Myositis / Q000235:genetics / Q000276:immunology* / Q000469:parasitology*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D014349:Trypanosoma cruzi / Q000254:growth & development / Q000276:immunology*
chemical_list: D018958:CD55 Antigens; C521184:decay-accelerating factor 1, mouse