Figure 2.

The pHCE cells undergo NLRP1 dependent pyroptosis. (A) Schematic of the related NLRP1 and CARD8 proteins with their subdomains and sites of autoprocessing labeled. Potent DPP8/9 inhibitors, including VbP, activate both NLRP1 and CARD8. (B–D) pHCE cells were treated with VbP (10 µM) and the selective CARD8 activator CQ31 (10 µM) for 18 hours before LDH B and cytokine C release were measured, and cellular contents assessed by immunoblotting D. Asterisk (*) indicates nonspecific band. (E–H) The pHCE cells were transfected with the NLRP1-selective activator, poly(I:C) (200 ng) or VbP (10 µM) for 6 hours. Pyroptosis was monitored by cytokine secretion to F, immunoblotting of cellular lysates G, and LDH release H. (I) Summary of NLRP1 versus CARD8 dependence in pHCE cells. Data are mean ± SEM from n = 3 donors. **P < 0.01, *P < 0.05, ns = not significant by 1-way ANOVA with Dunnett multiple comparison correction. FL = full length; NT = N-terminal.