title: Distribution and functional plasticity of peripheral blood Th(c)17 and Th(c)1 in rheumatoid arthritis.
abstract: With the discovery of Th17 cells, it became unclear whether rheumatoid arthritis (RA) is a Th1-mediated and/or a Th17-mediated disease.
  
  
  OBJECTIVE
  The aim of this study was to identify and characterize the pro-inflammatory function of IL-17-producing T cell subsets (Th(c)17) in RA. Flow cytometry analysis was performed on peripheral blood from RA patients with inactive or low disease activity (LDA, n = 19) and moderate to high disease activity (HDA, n = 13) to analyze the number and functional activity of Th(c)17 and Th(c)1 cell subsets according to the frequency of IL-2-, TNF-α- and IFN-γ-producers cells, as well as, their cytokine amount. Additionally, 13 age-matched healthy volunteers were added to the study. Our data point to a slight increase in Tc17 frequency in RA patients, more evident in HDA, and a higher ability of Th17 to produce IL-17, whereas a lower production of TNF-α was noted either in Th17 or Tc17 cells, particularly from HDA. A similar decrease was observed in Th(c)1 for almost all studied pro-inflammatory cytokines, with the exception of IL-2, which was increased in Tc1 from LDA patients. Analysing the proportion of pro-inflammatory cytokines-producing cells, a polarization to a Tc1 phenotype seemed to occur in CD8 T cells, while CD4 T cells appear to be decreased in their frequency of IFN-γ-producing cells. Taken together, the functional plasticity features of Th17 and Tc17 cells suggest a particular contribution to the local cytokine production, pointing an underestimated role, namely of Tc1 and Tc17 cells, in the RA pathophysiology.
authors: Centro do Sangue e da Transplantação de Coimbra, Instituto Português do Sangue e da Transplantação, Edifício São Jerónimo, 4º Piso Praceta Mota Pinto, 3001-301 Coimbra, Portugal.
authors: Ana
authors: A
authors: Henriques
authors: Vera
authors: V
authors: Gomes
authors: Cátia
authors: C
authors: Duarte
authors: Susana
authors: S
authors: Pedreiro
authors: Tiago
authors: T
authors: Carvalheiro
authors: Marlene
authors: M
authors: Areias
authors: Armando
authors: A
authors: Caseiro
authors: António José
authors: AJ
authors: Gabriel
authors: Paula
authors: P
authors: Laranjeira
authors: Maria Luísa
authors: ML
authors: Pais
authors: José António Pereira
authors: JA
authors: da Silva
authors: Artur
authors: A
authors: Paiva
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000473:pathology; D002452:Cell Count; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D016176:T-Lymphocyte Subsets / Q000473:pathology*; D018417:Th1 Cells / Q000473:pathology*; D058504:Th17 Cells / Q000473:pathology*