Cryptococcus neoformans Secretes Small Molecules That Inhibit IL-1β Inflammasome-Dependent Secretion

Figure 5

1 kDa CM35 inhibition characteristics indicate a small, polar molecule that does not derive from a polysaccharide origin. (a) BMMs were stimulated with LPS (500 ng/ml) and nigericin (20 μM), with or without 1 kDa CM35 fractioned by water affinity or autoclaved (10% ) overnight (18 h). (b, c) BMMs were stimulated with LPS (500 ng/ml) and nigericin (20 μM), with or without potential inhibitor (10% ) overnight (18 h). Polysaccharides (200ug/mL) extracted from the (c) capsule or secreted in (d) minimal medium were used as inhibitors. (d, e) BMMs were stimulated with LPS (500 ng/ml) and/or nigericin (20 μM), with or without possible inhibitor (10% ) overnight (18 h). Conditioned medium and minimal media (1 kDa CM35, 1 kDa CMCAP, and MM) were treated for GXM depletion utilizing capture ELISA and used as inhibitors (10% ) (e). GXM recovered from ELISA was mixed with 1 kDa CM35 and utilized as an inhibitor (10% ) (f). Supernatants were recovered after stimuli and IL-1β secretion was quantified using ELISA. Statistical analysis was performed by one-way ANOVA, where ns: not significant; ; ; . Comparisons were made with the (a) 1 kDa CM35-treated group or the (b, c) positive control group (LPS+nigericin).

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