title: [Apoptosis and its mechanisms of spleen CD4⁺ CD25⁺ regulatory T cells in severe aplastic anemia mouse model].
abstract: OBJECTIVE
  To explore the apoptosis and its mechanisms of spleen CD4⁺ CD25⁺ regulatory T (Treg) cells in severe aplastic anemia (SAA) mouse model induced by interferon (IFN-γ) in combination with busulphan (BU).
  
  
  METHODS
  The BALB/c female mice SAA model was induced by intraperitoneal injection with IFN-γ and intragastric administration with BU (combined group, n=16), with BU group (n=16), IFN-γ group (n=16) and normal group (n=16) as controls. Spleen Treg cells were purified by using of immunomagnetic beads. Apoptosis was detected by flow cytometry. AKt and TGF-β expression was measured by Western blot.
  
  
  RESULTS
  Apoptosis of spleen Treg cells in combined group [(33.21±0.65)%] was significantly higher than that in BU group [(21.58±0.64)%], IFN-γ group [(17.62±1.05)%], and control[(27.38±1.89)%] (P<0.05). A significantly lower expression of AKt and TGF-β protein was also seen in combined group (0.30±0.05 and 0.17±0.05), as compared to the other three groups (P<0.05).
  
  
  CONCLUSIONS
  Excessive apoptosis of Treg cells was found in SAA mouse model, which may be a cause of Treg cells decrease in patients with AA. The down-regulated expression of AKt and TGF-β could play a role in increased apoptosis of Treg cells. Our data may provide a new treatment strategy in AA.
authors.affiliation: Departmentof Hematology, Affiliated Hospital of Nantong University, Nantong 226001, China.
authors.forename: Wen-ping
authors.initials: WP
authors.lastname: Lu
authors.forename: Zeng-hua
authors.initials: ZH
authors.lastname: Lin
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
authors.forename: Hai-yan
authors.initials: HY
authors.lastname: Liu
authors.forename: Xu-li
authors.initials: XL
authors.lastname: Wang
mesh_terms: D000741:Anemia, Aplastic / Q000517:prevention & control*; D000818:Animals; D017209:Apoptosis; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000166:cytology; D050378:T-Lymphocytes, Regulatory / Q000166:cytology*