Our initial experiment did not detect any significant cytokine production in B cells, so we replicated the experiment using monocytes. Monocytes are known to produce numerous cytokines including IL-6, TNF-α and MIP-1α, and this experiment was no exception. After overnight culture, the levels of MIP-1α produced were off the charts, beyond the upper limit of the assay. There was little IFNγ, IL-10 or IL-12, but IL-6 and TNF-α gave a useful measure of the activity of the compounds.
Figure 1 shows the differences in IL-6 production following culture for four of the compounds tested. Each compound in the panel activated cytokine production by monocytes, but compound 1 was less potent than the others. IL-6 production was highest at the highest concentration, 30 µM. Compounds 2 and 4 were most active at the lowest concentration, and compound 18 had peak activity at concentrations above 1 µM but below 30 µM.