Autocrine models of B-lymphocyte growth. II. Interleukin-1 supports the proliferation of transformed lymphoblasts but not the stimulation of resting B cells triggered through their receptors for antigen.

Purified, monocyte-derived interleukin-1 (IL-1) was found to provide growth support for Epstein-Barr virus (EBV) transformed B-lymphocytes seeded at densities below which their own autostimulatory factors were limiting. By contrast, highly purified resting B cells triggered via their receptors for antigen failed to respond to identical preparations of IL-1 by DNA synthesis. That successful priming of the B cells had occurred was evidenced by a transient rise in RNA synthesis and the ability of the cells to respond to T-cell supernatants by DNA synthesis. The findings indicate that while IL-1 might perform an autostimulatory function in B lymphocyte proliferation it is not by itself sufficient to provide growth support for resting B cells activated through their receptors for antigen. The implications of these observations for autocrine models of B-cell growth are discussed.