Presence of B cell progenitors in the thymus

J Immunol. 1997 May 1;158(9):4193-9.

Abstract

We characterize B cell progenitors in the thymus. Although mature thymic B cells are surface Ig+, B220(high), but CD43-, B cell progenitors in the thymus were found to be slg-, B220(med), and CD43+. Most progenitors showed rearranged Ig D-J and V-D-J patterns when DNA from sorted B cell progenitors was amplified by PCR, blotted, and probed. When B cell progenitors were purified from the thymus and injected intrathymically into Ig heavy chain (Igh) allotype-disparate recipients, B cells bearing donor-type Igh6 were detected in the thymus but not in the periphery. Thymic B cells generated from these progenitors were CD5+ cells, although there was a broad range of expression of CD5 molecules. Furthermore, B cells purified from thymus that had been inoculated with B cell progenitors were able to differentiate into Ab-forming cells under the influence of CD40 ligand plus IL-10, and secreted IgM with donor Igh6 allotype. We thus clarified the existence of B cell progenitors in the thymus and also characterized the surface markers and their developmental functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, CD*
  • Antigens, Differentiation, B-Lymphocyte / analysis
  • CD40 Ligand
  • Cell Differentiation
  • Female
  • Flow Cytometry
  • Gene Rearrangement, B-Lymphocyte, Heavy Chain
  • Genes, Immunoglobulin
  • Leukocyte Common Antigens / analysis*
  • Leukosialin
  • Membrane Glycoproteins / pharmacology
  • Mice
  • Mice, Inbred C3H
  • Receptors, Antigen, B-Cell / analysis*
  • Sialoglycoproteins / analysis*
  • Thymus Gland / cytology*

Substances

  • Antigens, CD
  • Antigens, Differentiation, B-Lymphocyte
  • Leukosialin
  • Membrane Glycoproteins
  • Receptors, Antigen, B-Cell
  • Sialoglycoproteins
  • Spn protein, mouse
  • CD40 Ligand
  • Leukocyte Common Antigens