The effect of lentinan on production of interleukin-1 by human monocytes.

Activated human monocytes produce a monokine, interleukin-1 (IL-1) which can amplify the immune response by inducing antigen specific T cells to elaborate T cell growth factor, or interleukin-2, which in turn causes T cells to proliferate. The immune adjuvant lentinan has been shown in this study to augment IL-1 production by human monocytes. Stimulation of IL-1 by lentinan was seen as early as 5 hr, with some effect as late as 60 hr. Optimal effects were seen with very low concentrations, around 0.1 micrograms/ml. Lentinan was also able to stimulate IL-1 production by the leukemic cell line, K-562. The data reported here suggest that the previously reported adjuvant effects of lentinan may in part be mediated via its ability to stimulate IL-1 production.