The Discovery and Characterization of an Interleukin 6 Cytokine Family Antagonist Protein from A Marine Sponge, Callyspongia sp.

The process of drug discovery in the pharmaceutical industry often begins with the setting up of a bioassay whereby many thousands of synthetic compounds, or less characterized substances such as natural product extracts, may be screened in high throughput mode. During the early 1990s, we started a search using this approach for inhibitors of the cytokine Interleukin 6 (IL-6). One of the sources for screening was extracts of marine organisms provided to the former Ciba-Geigy organization by Harbor Branch Oceanographic Institute (HBOI). This chapter describes the finding of activity inhibiting IL-6 function from an extract of the marine sponge Callyspongia sp., and work which was carried out during the effort to characterize this activity more fully.