Lane, P.; Brocker, Thomas; Hubele, S.; Padovan, E.; Lanzavecchia, A.; McConnell, F.
Soluble CD40 ligand can replace the normal T cell-derived CD40 ligand signal to B cells in T cell-dependent activation.
In: Journal of Experimental Medicine, Vol. 177, No. 4: pp. 1209-1213
We have constructed a soluble chimeric fusion protein between the mouse CD8 alpha chain and the mouse CD40 T cell ligand. This protein binds to both human and mouse B cells. By itself it induced a modest degree of B cell proliferation, but together with anti-immunoglobulin (anti-Ig) antibody it greatly stimulated B cell proliferation, as determined by both [3H]thymidine uptake and increase in cell numbers. These data are evidence that the CD40 ligand on T cells provides a signal that drives B cell proliferation. This signal is synergistic with that delivered by anti-Ig antibody.