title: Higher frequency of regulatory T cells in granulocyte colony-stimulating factor (G-CSF)-primed bone marrow grafts compared with G-CSF-primed peripheral blood grafts.
abstract: BACKGROUND
  Regulatory T cells (Treg) in allografts are important for the prevention of graft-versus-host disease (GVHD) post-transplantation. The aim of this study was to compare the contents of Tregs and effector T cells in granulocyte colony-stimulating factor (G-CSF)-primed bone marrow grafts (G-BM) and peripheral blood grafts (G-PB).
  
  
  METHODS
  G-BM and G-PB were obtained from 20 allogeneic donors. T-cell subgroups, including conventional T cells and different types of Treg cells, as well as the percentage of Ki67 expression on CD4(+)CD25(high)Foxp3(+) Treg cells, were analyzed using flow cytometry. The levels of interferon-γ (IFN-γ) and interleukin-17 (IL-17) secreted by T cells stimulated with PMA and ionomycin were also determined by flow cytometry.
  
  
  RESULTS
  The percentage of CD4(+)CD25(high)CD127(-/dim)CD62L(+) Treg cells was significantly higher in the G-BM group, with higher proportions of CD45RA(+) naïve Treg cells and higher expression of CD69 on Treg cells in G-BM (P < 0.05). The percentage of Ki67 expression in CD4(+)CD25(high)Foxp3(+) Treg cells in G-BM was significantly higher than that on G-PB. The suppressive functions of Treg cells in inhibiting T-cell activation were comparable between G-BM and G-PB. The proportions of CD4(+)CD25(-)CD69(+) Treg subsets as well as Th1 cells in G-BM were also significantly higher than those in G-PB (P < 0.001). The proportions of conventional T cells and Th17 effector cells were comparable in G-BM compared with those in G-PB. Thus, the ratio of conventional T cells and CD4(+)CD25(high)CD127(-/dim) regulatory T cells were lower in G-BM than that in G-PB (P = 0.014).
  
  
  CONCLUSIONS
  In addition to the much higher T-cell counts in G-PB grafts that may contribute to more severe GVHD, the higher frequency of Treg cells and lower ratio of conventional T cells to Treg cells in G-BM compared with G-PB grafts might reduce GVHD post-transplantation in G-BM compared with G-PB transplantation.
authors.affiliation: Peking University People's Hospital and Peking University Institute of Hematology, Beijing Key Laboratory of Hematopoietic Stem Cell Transplantation, No. 11 Xizhimen South Street, Beijing, 100044, China. zhao_xy@bjmu.edu.cn.
authors.forename: Xiang-Yu
authors.initials: XY
authors.lastname: Zhao
authors.affiliation: Peking University People's Hospital and Peking University Institute of Hematology, Beijing Key Laboratory of Hematopoietic Stem Cell Transplantation, No. 11 Xizhimen South Street, Beijing, 100044, China. wangyutong11@hotmail.com.
authors.forename: Yu-Tong
authors.initials: YT
authors.lastname: Wang
authors.affiliation: Peking University People's Hospital and Peking University Institute of Hematology, Beijing Key Laboratory of Hematopoietic Stem Cell Transplantation, No. 11 Xizhimen South Street, Beijing, 100044, China. rmyymxd@126.com.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Mo
authors.affiliation: Peking University People's Hospital and Peking University Institute of Hematology, Beijing Key Laboratory of Hematopoietic Stem Cell Transplantation, No. 11 Xizhimen South Street, Beijing, 100044, China. zhao.xiaosu@gmail.com.
authors.forename: Xiao-Su
authors.initials: XS
authors.lastname: Zhao
authors.affiliation: Peking University People's Hospital and Peking University Institute of Hematology, Beijing Key Laboratory of Hematopoietic Stem Cell Transplantation, No. 11 Xizhimen South Street, Beijing, 100044, China. ya_zhe2003@126.com.
authors.forename: Ya-Zhe
authors.initials: YZ
authors.lastname: Wang
authors.affiliation: Peking University People's Hospital and Peking University Institute of Hematology, Beijing Key Laboratory of Hematopoietic Stem Cell Transplantation, No. 11 Xizhimen South Street, Beijing, 100044, China. pk200608@126.com.
authors.forename: Ying-Jun
authors.initials: YJ
authors.lastname: Chang
authors.affiliation: Peking University People's Hospital and Peking University Institute of Hematology, Beijing Key Laboratory of Hematopoietic Stem Cell Transplantation, No. 11 Xizhimen South Street, Beijing, 100044, China. huangxiaojun@bjmu.edu.cn.|Peking-Tsinghua Center for Life Sciences, Beijing, 100871, China. huangxiaojun@bjmu.edu.cn.
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Huang
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D001854:Bone Marrow Cells / Q000166:cytology*; D016026:Bone Marrow Transplantation; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology; D005260:Female; D005434:Flow Cytometry; D006086:Graft vs Host Disease / Q000517:prevention & control; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D006801:Humans; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000378:metabolism; D020381:Interleukin-17 / Q000378:metabolism; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D053699:Interleukin-7 Receptor alpha Subunit / Q000378:metabolism; D015759:Ionomycin / Q000737:chemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D037181:Lectins, C-Type / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D036102:Peripheral Blood Stem Cell Transplantation; D050378:T-Lymphocytes, Regulatory / Q000166:cytology*; D013755:Tetradecanoylphorbol Acetate; D014184:Transplantation, Homologous; D055815:Young Adult; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D016179:Granulocyte Colony-Stimulating Factor; D007371:Interferon-gamma; D020381:Interleukin-17; D053645:Interleukin-2 Receptor alpha Subunit; D053699:Interleukin-7 Receptor alpha Subunit; D015759:Ionomycin; D019394:Ki-67 Antigen; D037181:Lectins, C-Type; D013755:Tetradecanoylphorbol Acetate; D000099192:CD69 Antigens; C573415:IFNG protein, human; C508717:IL17A protein, human; C508017:IL2RA protein, human