Interleukin-2 does not induce murine B cells to secrete Ig.

We previously defined two T cell-derived lymphokines, BDCF mu and BCDF gama, which induce B cell differentiation in the absence of IL 2. Although these studies indicated that IL 2 was not required to induce Ig secretion, the effect of IL 2 on B cell differentiation was not established. In the present studies we have assessed the ability of purified IL 2 to induce IgM or IgG secretion. Our results demonstrate that IL 2 does not induce IgM secretion by BCL1 tumor cells, nor does it enhance BCDF mu-induced IgM secretion by these cells. Similarly, IL 2 had no effect on LPS or BCDF gamma-induced IgG secretion by normal B cells. Thus, we conclude that IL 2 does not act directly on B cells to induce differentiation.