title: Regulatory T cell induction during Plasmodium chabaudi infection modifies the clinical course of experimental autoimmune encephalomyelitis.
abstract: BACKGROUND
  Experimental autoimmune encephalomyelitis (EAE) is used as an animal model for human multiple sclerosis (MS), which is an inflammatory demyelinating autoimmune disease of the central nervous system characterized by activation of Th1 and/or Th17 cells. Human autoimmune diseases can be either exacerbated or suppressed by infectious agents. Recent studies have shown that regulatory T cells play a crucial role in the escape mechanism of Plasmodium spp. both in humans and in experimental models. These cells suppress the Th1 response against the parasite and prevent its elimination. Regulatory T cells have been largely associated with protection or amelioration in several autoimmune diseases, mainly by their capacity to suppress proinflammatory response.
  
  
  RESULTS
  In this study, we verified that CD4(+)CD25(+) regulatory T cells (T regs) generated during malaria infection (6 days after EAE induction) interfere with the evolution of EAE. We observed a positive correlation between the reduction of EAE clinical symptoms and an increase of parasitemia levels. Suppression of the disease was also accompanied by a decrease in the expression of IL-17 and IFN-γ and increases in the expression of IL-10 and TGF-β1 relative to EAE control mice. The adoptive transfer of CD4(+)CD25(+) cells from P. chabaudi-infected mice reduced the clinical evolution of EAE, confirming the role of these T regs.
  
  
  CONCLUSIONS
  These data corroborate previous findings showing that infections interfere with the prevalence and evolution of autoimmune diseases by inducing regulatory T cells, which regulate EAE in an apparently non-specific manner.
authors.affiliation: Departmento de Genética, Evolução e Bioagentes, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil. asfarias@unicamp.br
authors.forename: Alessandro S
authors.initials: AS
authors.lastname: Farias
authors.forename: Rafael L
authors.initials: RL
authors.lastname: Talaisys
authors.forename: Yara C
authors.initials: YC
authors.lastname: Blanco
authors.forename: Stefanie C P
authors.initials: SC
authors.lastname: Lopes
authors.forename: Ana Leda F
authors.initials: AL
authors.lastname: Longhini
authors.forename: Fernando
authors.initials: F
authors.lastname: Pradella
authors.forename: Leonilda M B
authors.initials: LM
authors.lastname: Santos
authors.forename: Fabio T M
authors.initials: FT
authors.lastname: Costa
mesh_terms: D000818:Animals; D015551:Autoimmunity / Q000276:immunology; D002470:Cell Survival; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D018450:Disease Progression; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000150:complications / Q000235:genetics / Q000276:immunology* / Q000469:parasitology*; D005786:Gene Expression Regulation; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D008288:Malaria / Q000150:complications / Q000235:genetics / Q000276:immunology* / Q000469:parasitology*; D051379:Mice; D008810:Mice, Inbred C57BL; D016788:Plasmodium chabaudi / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D016207:Cytokines; D053645:Interleukin-2 Receptor alpha Subunit