title: Functional CD5+ B cells develop predominantly in the spleen of NOD/SCID/gammac(null) (NOG) mice transplanted either with human umbilical cord blood, bone marrow, or mobilized peripheral blood CD34+ cells.
abstract: OBJECTIVE
  Human CD5+ B cells are the major B cell subset in fetal spleen and umbilical cord blood (CB), and their number gradually diminishes in both spleen and peripheral blood from infancy through childhood while conventional B cells increase. In this study, we investigated whether CD5+ cells differentiate from adult hematopoietic stem cells (HSCs) as well as fetal ones in immunodeficient mice.
  
  
  METHODS
  In our system, NOD/SCID/gammac(null) (NOG) mice were transplanted with CD34+ cells from CB (hCB model), adult bone marrow (hBM model), and mobilized peripheral blood (hMPB model).
  
  
  RESULTS
  In these model mice, a high proportion of CD19+IgM+CD5+ mature B cells appeared in the spleen, regardless of the CD34+ cell origin, 4 to 8 weeks after transplantation, while the majority were CD19+IgM-CD5- immature B cells in BM. The CD19+CD5- BM cells showed to express CD5 after the coculture with NOG spleen cells. In the sera of immunized hCB model mice with DNP-KLH, antigen-specific IgM but not IgG was enhanced.
  
  
  CONCLUSIONS
  Our results show that adult CD34+ cells develop into functional CD5+ B cells in NOG spleen as much as fetal CD34+ cells do.
authors.affiliation: Third Department of Internal Medicine, National Defense Medical College, Saitama, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Matsumura
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Kametani
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ando
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Hirano
authors.forename: Ikumi
authors.initials: I
authors.lastname: Katano
authors.forename: Ryoji
authors.initials: R
authors.lastname: Ito
authors.forename: Masashi
authors.initials: M
authors.lastname: Shiina
authors.forename: Hideo
authors.initials: H
authors.lastname: Tsukamoto
authors.forename: Yuki
authors.initials: Y
authors.lastname: Saito
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tokuda
authors.forename: Shunichi
authors.initials: S
authors.lastname: Kato
authors.forename: Mamoru
authors.initials: M
authors.lastname: Ito
authors.forename: Kazuo
authors.initials: K
authors.lastname: Motoyoshi
authors.forename: Sonoko
authors.initials: S
authors.lastname: Habu
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000276:immunology; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D001854:Bone Marrow Cells / Q000166:cytology / Q000276:immunology; D018956:CD5 Antigens / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology*; D019070:Cell Lineage / Q000276:immunology; D005312:Fetal Blood / Q000166:cytology / Q000276:immunology; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D013154:Spleen / Q000166:cytology / Q000276:immunology*; D033581:Stem Cell Transplantation; D014183:Transplantation, Heterologous
chemical_list: D018952:Antigens, CD34; D018956:CD5 Antigens