Ligation of CD45 on B cells can facilitate production of secondary Ig isotypes

J Immunol. 1994 Feb 1;152(3):1014-21.


The possibility that isotype switching in B cells may be affected by engagement of the CD45 molecule on B cells has been investigated in microcultures containing limiting numbers of B cells and nonlimiting numbers of both alloreactive Th cells and purified dendritic cells (DC). Addition of Abs to the B cell-specific isoform, B220, to the microcultures leads to an increase in the proportion of B cell clones that secrete secondary Ig isotypes. In the presence of anti-CD45 Ab, microculture wells show a 39% frequency of secondary isotypes (560/1440) compared with a 11% frequency in control microcultures (89/780). Cross-linking appears to enhance this effect. Even in cultures of B cells and DC without T cells, addition of anti-B220 induces isotype switching in a significant number of microwells. Cross-linking and capping B220 molecules results in co-capping of surface Ig and MHC class II molecules. The results suggest that signal transduction through the CD45 molecule may affect pathways involved in isotype switching.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • B-Lymphocyte Subsets / immunology*
  • Dendritic Cells / immunology
  • Immunoglobulin D / metabolism
  • Immunoglobulin Isotypes / biosynthesis*
  • Immunologic Capping
  • Leukocyte Common Antigens / physiology*
  • Lymphocyte Cooperation
  • Mice
  • Mice, Inbred C3H
  • Mice, Inbred C57BL
  • Receptor Aggregation
  • Receptors, Antigen, B-Cell / metabolism
  • Signal Transduction
  • T-Lymphocytes / immunology


  • Immunoglobulin D
  • Immunoglobulin Isotypes
  • Receptors, Antigen, B-Cell
  • Leukocyte Common Antigens