Ontogeny of thymic B cells in normal mice

Cell Immunol. 1991 Mar;133(1):109-15. doi: 10.1016/0008-8749(91)90183-c.


Ontogeny of thymic B cells and their surface characteristics were analyzed using monoclonal antibodies (mAbs) against B220 molecules (CD45, CD45R). A small number of B cells were detected in fetal thymus on Gestation Day 14 (approximately 3.5% of the low-density fraction). Similarly, the percentage of B cells in the low-density fraction was 3.2% on Gestation Day 18, and 3.5% on Day 1 after birth. These were the same level as that of adult mice. CD5+ B cells, which form the major population of thymic B cells, were also found in the fetal life (0.5% on Day 14 and 2.2% on Day 16 in the low-density cells). The percentage of CD5+ B cells in B cell-enriched fraction was about 65% on Day 1 after birth, which is the same level as that in adult mice. These results indicate that a small number of B cells or cells in the B-cell lineage are present in the fetal thymus and also suggest the importance of these thymic B cells in the negative selection of T cells during early developmental stages.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Newborn / immunology
  • Antibodies, Monoclonal
  • Antigens, Differentiation / analysis
  • Antigens, Differentiation, B-Lymphocyte / analysis
  • B-Lymphocyte Subsets / cytology
  • B-Lymphocytes / cytology*
  • CD5 Antigens
  • Cell Differentiation
  • Flow Cytometry
  • Histocompatibility Antigens / analysis
  • Immunoglobulin M / analysis
  • Leukocyte Common Antigens
  • Mice
  • Mice, Inbred BALB C
  • Receptors, Antigen, B-Cell / analysis
  • Thymus Gland / cytology*
  • Thymus Gland / embryology


  • Antibodies, Monoclonal
  • Antigens, Differentiation
  • Antigens, Differentiation, B-Lymphocyte
  • CD5 Antigens
  • Histocompatibility Antigens
  • Immunoglobulin M
  • Receptors, Antigen, B-Cell
  • Leukocyte Common Antigens