title: Expression of regulatory T cells in jejunum, colon, and cervical and mesenteric lymph nodes of dogs naturally infected with Leishmania infantum.
abstract: Using flow cytometry, we evaluated the frequencies of CD4(+) and CD8(+) T cells and Foxp3(+) regulatory T cells (Tregs) in mononuclear cells in the jejunum, colon, and cervical and mesenteric lymph nodes of dogs naturally infected with Leishmania infantum and in uninfected controls. All infected dogs showed chronic lymphadenitis and enteritis. Despite persistent parasite loads, no erosion or ulcers were evident in the epithelial mucosa. The colon harbored more parasites than the jejunum. Frequencies of total CD4(+), total Foxp3, and CD4(+) Foxp3(+) cells were higher in the jejunum than in the colon. Despite negative enzyme-linked immunosorbent assay (ELISA) serum results for cytokines, levels of interleukin-10 (IL-10), gamma interferon (IFN-γ), transforming growth factor beta (TGF-β), and tumor necrosis factor alpha (TNF-α) were higher in the jejunum than in the colon for infected dogs. However, IL-4 levels were higher in the colon than in the jejunum for infected dogs. There was no observed correlation between clinical signs and histopathological changes or immunological and parasitological findings in the gastrointestinal tract (GIT) of canines with visceral leishmaniasis. However, distinct segments of the GIT presented different immunological and parasitological responses. The jejunum showed a lower parasite load, with increased frequencies and expression of CD4, Foxp3, and CD8 receptors and IL-10, TGF-β, IFN-γ, and TNF-α cytokines. The colon showed a higher parasite load, with increasing expression of IL-4. Leishmania infantum infection increased expression of CD4, Foxp3, IL-10, TGF-β, IFN-γ, and TNF-α and reduced CD8 and IL-4 expression in both the jejunum and the colon.
authors.affiliation: Departamento de Patologia Geral, Universidade Federal de Minas Gerais, Minas Gerais, Brasil.
authors.forename: Maria M
authors.initials: MM
authors.lastname: Figueiredo
authors.affiliation: Departamento de Cirurgia, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brasil.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Deoti
authors.affiliation: Departamento de Patologia Geral, Universidade Federal de Minas Gerais, Minas Gerais, Brasil.
authors.forename: Izabela F
authors.initials: IF
authors.lastname: Amorim
authors.affiliation: Departamento de Patologia Geral, Universidade Federal de Minas Gerais, Minas Gerais, Brasil.
authors.forename: Aldair J W
authors.initials: AJ
authors.lastname: Pinto
authors.affiliation: Departamento de Patologia Geral, Universidade Federal de Minas Gerais, Minas Gerais, Brasil.
authors.forename: Andrea
authors.initials: A
authors.lastname: Moraes
authors.affiliation: Departamento de Patologia Geral, Universidade Federal de Minas Gerais, Minas Gerais, Brasil.
authors.forename: Carolina S
authors.initials: CS
authors.lastname: Carvalho
authors.affiliation: Departamento de Patologia Geral, Universidade Federal de Minas Gerais, Minas Gerais, Brasil.
authors.forename: Sydnei Magno
authors.initials: SM
authors.lastname: da Silva
authors.affiliation: Departamento de Patologia Geral, Universidade Federal de Minas Gerais, Minas Gerais, Brasil.
authors.forename: Ana C B
authors.initials: AC
authors.lastname: de Assis
authors.affiliation: Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brasil.
authors.forename: Ana M C
authors.initials: AM
authors.lastname: de Faria
authors.affiliation: Departamento de Patologia Geral, Universidade Federal de Minas Gerais, Minas Gerais, Brasil wagnertafuri@gmail.com.
authors.forename: Wagner L
authors.initials: WL
authors.lastname: Tafuri
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000382:microbiology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000382:microbiology; D002584:Cervix Uteri / Q000276:immunology* / Q000382:microbiology; D003106:Colon / Q000276:immunology* / Q000382:microbiology; D004283:Dog Diseases / Q000276:immunology / Q000382:microbiology; D004285:Dogs; D004751:Enteritis / Q000276:immunology / Q000382:microbiology; D004847:Epithelial Cells / Q000276:immunology / Q000382:microbiology; D005260:Female; D051858:Forkhead Transcription Factors / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D016753:Interleukin-10 / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D007583:Jejunum / Q000276:immunology* / Q000382:microbiology; D018314:Leishmania infantum / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000276:immunology* / Q000382:microbiology; D008198:Lymph Nodes / Q000276:immunology* / Q000382:microbiology; D008199:Lymphadenitis / Q000276:immunology / Q000382:microbiology; D008297:Male; D009092:Mucous Membrane / Q000276:immunology / Q000382:microbiology; D059208:Parasite Load; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D016212:Transforming Growth Factor beta / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D051858:Forkhead Transcription Factors; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma