Abstract
This study demonstrates that intact antibodies specific for mu, delta, or light chains when coupled to Sepharose are effective in delivering proliferative signals to B cells. Furthermore, using Sepharose-coupled anti-delta antibodies, we have shown that hybridoma anti-delta (that is not active as soluble protein) is as effective as rabbit anti-delta in activating murine B cells. However, antibodies directed against two other surface molecules, I-A and H-2K, were not mitogenic. Thus, sIgM and sIgD are comparable in their ability to transmit a proliferative signal to the B cell and sIg seems to play a unique role in this regard.