CD40 ligand-independent B cell activation revealed by CD40 ligand-deficient T cell clones: evidence for distinct activation requirements for antibody formation and B cell proliferation

Eur J Immunol. 1995 Jun;25(6):1788-93. doi: 10.1002/eji.1830250646.


We report the capacity of CD40 ligand (CD40L)-negative T cell clones to activate human B cells. CD40L-negative T cells induce a level of B cell proliferation 10-20% of that seen with normal T cells. The signal provided by the negative clones is synergistic with that derived from a CD40L transfectant, and restores B cell proliferation to normal levels, showing that CD40L-negative T cell clones are not inherently inhibitory for B cells. Although their capacity to induce proliferation was much reduced, CD40L-negative T cell clones were still strong inducers of B cell differentiation to plasma cells. This differentiation to plasma cells was inhibited by a CD40L transfectant. The data are discussed with regard to the normal in vivo mechanism for maintaining B cell memory and memory antibody responses to T-dependent antigens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibody Formation / immunology
  • B-Lymphocytes / immunology*
  • CD40 Ligand
  • Cell Division
  • Clone Cells
  • Humans
  • Lymphocyte Activation
  • Membrane Glycoproteins / immunology*
  • T-Lymphocytes / immunology*


  • Membrane Glycoproteins
  • CD40 Ligand