Characterization of immature B cells by a novel monoclonal antibody, by turnover and by mitogen reactivity

Eur J Immunol. 1998 Nov;28(11):3738-48. doi: 10.1002/(SICI)1521-4141(199811)28:11<3738::AID-IMMU3738>3.0.CO;2-Q.


The transit of immature to mature sIgM+ B cells, the life span, maturation kinetics and response to polyclonal activators have been analyzed with the help of a new mAb (493), that distinguishes immature, 493+ from mature, 493 B cells in a variety of mouse strains tested. Analysis of the turnover of immature 493+ B cells by bromodeoxyuridine (BrdU) labeling kinetics indicate that only 10-20 % of the cells reach the spleen as immature 493+ cells. The life span of 493+ B cells in bone marrow and spleen is around 4 days. BrdU chase experiments show that most of the immature cells in spleen enter the pool of mature, 493+ B cells where they gain a longer life span of 15-20 weeks. Immature and mature B cells respond equally well to LPS stimulation; anti-CD40, however, stimulates mature B cells better than immature B cells. IgM cross-linking of mature B cells results in proliferation, while it induces apoptosis in immature B cells. This apoptosis of immature cells can be inhibited by costimulation with anti-CD40 or by overexpression of bcl-2. We speculate that Ig receptor ligand-mediated apoptosis (negative selection) plays a major role in the transit of immature B cells from bone marrow to spleen, but only a minor role in the transit from immature B cells to mature B cells in the spleen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Anti-Idiotypic / immunology
  • Antibodies, Monoclonal / immunology*
  • B-Lymphocytes / physiology*
  • Bromodeoxyuridine / metabolism
  • CD40 Antigens / physiology
  • Hematopoietic Stem Cells / physiology
  • Lipopolysaccharides / pharmacology
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C3H
  • Mice, Inbred CBA
  • Rats
  • Rats, Inbred Lew


  • Antibodies, Anti-Idiotypic
  • Antibodies, Monoclonal
  • CD40 Antigens
  • Lipopolysaccharides
  • anti-IgM
  • Bromodeoxyuridine