title: Low frequency of circulating CD8+ T stem cell memory cells in chronic chagasic patients with severe forms of the disease.
abstract: BACKGROUND
  CD8+ T cells have been shown to play a crucial role in Trypanosoma cruzi infection. Memory CD8+ T cells can be categorised based on their distinct differentiation stages and functional activities as follows: stem cell memory (TSCM), central memory (TCM), transitional memory (TTM), effector memory (TEM) and terminal effector (TTE) cells. Currently, the immune mechanisms that control T. cruzi in the chronic phase of the infection are unknown.
  
  
  RESULTS
  To characterise the CD8+ T cell subsets that could be participating in the control of T. cruzi infection, in this study, we compared total and T. cruzi-specific circulating CD8+ T cells with distinctive phenotypic and functional features in chronic chagasic patients (CCPs) with different degrees of cardiac dysfunction. We observed a decreased frequency of total TSCM along with an increased frequency of TTE in CCPs with severe disease. Antigen-specific TSCM cells were not detectable in CCPs with severe forms of the disease. A functional profile of CD8+ T cell subsets among CCPs revealed a high frequency of monofunctional CD8+ T cells in the most severe patients with IFN-γ+- or TNF-α+-producing cells.
  
  
  CONCLUSIONS
  These findings suggest that CD8+ TSCM cells may be associated with the immune response to T. cruzi and outcome of Chagas disease, given that these cells may be involved in repopulating the T cell pool that controls infection.
authors.affiliation: Grupo Inmunobiología y Biología Celular, Pontificia Universidad Javeriana, Bogotá, Colombia; Laboratorio de Parasitología Molecular, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia.
authors.forename: Jose
authors.initials: J
authors.lastname: Mateus
authors.affiliation: Grupo Inmunobiología y Biología Celular, Pontificia Universidad Javeriana, Bogotá, Colombia; Laboratorio de Parasitología Molecular, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia.
authors.forename: Paola
authors.initials: P
authors.lastname: Lasso
authors.affiliation: Laboratorio de Parasitología Molecular, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia.
authors.forename: Paula
authors.initials: P
authors.lastname: Pavia
authors.affiliation: Fundación Clínica Abood Shaio, Bogotá, Colombia.
authors.forename: Fernando
authors.initials: F
authors.lastname: Rosas
authors.affiliation: Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia.
authors.forename: Nubia
authors.initials: N
authors.lastname: Roa
authors.affiliation: Laboratorio de Parasitología, Instituto Nacional de Salud, Bogotá, Colombia.
authors.forename: Carlos Andrés
authors.initials: CA
authors.lastname: Valencia-Hernández
authors.affiliation: Grupo de Ciencias Básicas Médicas, Facultad de Medicina, Universidad de los Andes, Bogotá, Colombia.
authors.forename: John Mario
authors.initials: JM
authors.lastname: González
authors.affiliation: Laboratorio de Parasitología Molecular, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia.
authors.forename: Concepción J
authors.initials: CJ
authors.lastname: Puerta
authors.affiliation: Grupo Inmunobiología y Biología Celular, Pontificia Universidad Javeriana, Bogotá, Colombia.
authors.forename: Adriana
authors.initials: A
authors.lastname: Cuéllar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000913:Antibodies, Protozoan; D018414:CD8-Positive T-Lymphocytes / Q000502:physiology*; D002598:Chagas Cardiomyopathy / Q000097:blood / Q000276:immunology*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016176:T-Lymphocyte Subsets / Q000502:physiology*
chemical_list: D000913:Antibodies, Protozoan