title: Prevention of spontaneous arthritis by inhibiting homeostatic expansion of autoreactive CD4+ T cells in the K/BxN mouse model.
abstract: OBJECTIVE
  K/BxN-transgenic mice are a model of autoimmune arthritis, similar to rheumatoid arthritis. This study was undertaken to determine whether inhibition of lymphopenia-provoked homeostatic expansion can prevent spontaneous development of disease in the K/BxN model.
  
  
  METHODS
  To inhibit homeostatic expansion of autoreactive T cells, K/BxN mice with disease in the preclinical stage were adoptively transferred with CD4+ T cells purified from nontransgenic BxN or Thy1.1+ BxN mice. To observe the profile of proliferation of CD4+ T cells derived from the hosts, carboxyfluorescein diacetate succinimidyl ester-labeled autologous CD4+ T cells were cotransferred to K/BxN mice together with BxN CD4+ T cells. Disease onset and progression were scored, and the dynamics and phenotypes of recipient CD4+ T cells were determined by flow cytometry, before and after cell infusion.
  
  
  RESULTS
  During the preclinical phase of disease, K/BxN mice exhibited CD4+ T lymphopenia, which was followed by a compensatory expansion of these cells during the early clinical phase. The majority of CD4+ T cells acquired a memory phenotype (CD44(high),CD62L(low),CD25-), which is a hallmark of homeostatically expanding cells. Importantly, K/BxN mice subjected to syngeneic T cell transfer did not develop symptoms of arthritis and also possessed fewer transgenic T cell receptor-encoded Vbeta6+,CD4+ T cells. This effect was associated with decreased proliferation of recipient-derived CD4+ T cells but not with the function of CD25+ T regulatory cells present in donor cells.
  
  
  CONCLUSIONS
  These results provide the first evidence that lymphopenia-associated homeostatic proliferation of autoreactive CD4+ T cells potentiates autoimmune arthritis, and that inhibition of this process protects mice from the development of this pathologic condition.
authors.affiliation: Hanyang University, Seoul, Korea.
authors.forename: Eunkyeong
authors.initials: E
authors.lastname: Jang
authors.forename: Hong Ro
authors.initials: HR
authors.lastname: Kim
authors.forename: Sin Hye
authors.initials: SH
authors.lastname: Cho
authors.forename: Doo-Jin
authors.initials: DJ
authors.lastname: Paik
authors.forename: Jung Mogg
authors.initials: JM
authors.lastname: Kim
authors.forename: Sang-Koo
authors.initials: SK
authors.lastname: Lee
authors.forename: Jeehee
authors.initials: J
authors.lastname: Youn
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D001169:Arthritis, Experimental / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D001172:Arthritis, Rheumatoid / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000473:pathology / Q000637:transplantation; D049109:Cell Proliferation; D017690:Cell Transplantation; D005434:Flow Cytometry; D006706:Homeostasis / Q000276:immunology; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D008822:Mice, Transgenic; D013154:Spleen / Q000166:cytology / Q000276:immunology; D018344:T-Lymphocytopenia, Idiopathic CD4-Positive / Q000276:immunology* / Q000473:pathology; D014185:Transplantation, Isogeneic