title: Contribution of CD4+CD25+ T cells to the regression phase of experimental autoimmune uveoretinitis.
abstract: OBJECTIVE
  To investigate the role of CD4(+)CD25(+) Treg cells in the development of experimental autoimmune uveoretinitis (EAU).
  
  
  METHODS
  EAU was induced in B10RIII mice by immunization with IRBP(161-180) in complete Freund's adjuvant and evaluated clinically and pathologically on days 0, 7, 14, 21, and 28. Lymphocytes from draining lymph nodes (LNs) were subjected to flow cytometry to analyze the frequency of CD4(+)CD25(+) Treg cells. CD4(+)CD25(+) Treg cells and CD4(+)CD25(-) T cells were separated by means of magnetic-assisted cell sorting and cocultured or crossover cultured for 3 days. Proliferation of CD4(+)CD25(-) T cells was measured using a modified MTT assay. The levels of IFN-gamma and IL-17 in the supernatants were determined by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Clinical and histopathologic results showed a severe intraocular inflammation in the immunized mice. The frequency of CD4(+)Foxp3(+) T cells and CD4(+)CD25(+)Foxp3(+) T cells in the draining LN lymphocytes was increased on day 7, reached its peak on day 14, and maintained a high level up to day 42. CD4(+)CD25(+) Treg cells obtained from mice on days 14 and 28 after immunization showed a stronger inhibitory effect on the proliferation of CD4(+)CD25(-) T cells and the production of IFN-gamma by CD4(+)CD25(-) T cells compared with those obtained from control mice. CD4(+)CD25(+) Treg cells did not affect IL-17 production. Transfer of CD4(+)CD25(+) Treg cells obtained from EAU mice was able to suppress EAU induction by IRBP(161-180) that was not observed after transfer of cells from mice that had received CFA alone, suggesting antigen specificity of the Treg response.
  
  
  CONCLUSIONS
  A significantly increased frequency and immunoregulatory action of CD4(+)CD25(+) Treg cells is associated with the development and regression of EAU, suggesting that CD4(+)CD25(+) Treg cells are induced during EAU and may be involved in its regression.
authors.affiliation: The First Affiliated Hospital, Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, Chongqing Eye Institute, Chongqing, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Sun
authors.forename: Peizeng
authors.initials: P
authors.lastname: Yang
authors.forename: Liping
authors.initials: L
authors.lastname: Du
authors.forename: Hongyan
authors.initials: H
authors.lastname: Zhou
authors.forename: Xiangrong
authors.initials: X
authors.lastname: Ren
authors.forename: Aize
authors.initials: A
authors.lastname: Kijlstra
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D001327:Autoimmune Diseases / Q000139:chemically induced / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control; D015704:CD4 Antigens / Q000378:metabolism*; D002469:Cell Separation; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000378:metabolism; D007371:Interferon-gamma; D020381:Interleukin-17; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism*; D008198:Lymph Nodes / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D010446:Peptide Fragments / Q000633:toxicity; D012173:Retinitis / Q000139:chemically induced / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control; D012177:Retinol-Binding Proteins / Q000633:toxicity; D050378:T-Lymphocytes, Regulatory / Q000502:physiology*; D014605:Uveitis / Q000139:chemically induced / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control
chemical_list: D015704:CD4 Antigens; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D020381:Interleukin-17; D053645:Interleukin-2 Receptor alpha Subunit; D010446:Peptide Fragments; D012177:Retinol-Binding Proteins; D007371:Interferon-gamma