Quantifying Protein Levels by Immunoblotting

Protein levels were measured by immunoblot analysis following a previous protocol 26 (link). Tissues and cells were lysed in 1×RIPA lysis buffer (Abcam, #ab156034). After boiling with Laemmli SDS sample buffer (Sigma-Aldrich, #S3401), equal amount of total cell lysate of each sample was loaded onto 10% SDS-PAGE gels, followed by transfer to polyvinylidene difluoride (PVDF) membranes (Thermo Fisher Scientific, #LC2002). The immunoblots were then probed with primary antibodies including anti-HDAC1 (Abcam, #ab53091), anti-FOXP3 (Abcam, #ab450), anti-CtBP2 (BD Biosciences, San Jose, CA, USA, #612044), anti-NLRP1 (Biolegend, San Diego, CA, USA, #a679802), anti-Caspase-1 (Santa Cruz Biotechnology, Dallas, TX, USA, #sc-56036), and anti-GAPDH (Santa Cruz Biotechnology, #47724). Protein signals were recorded using enhanced chemiluminescence reagents (GE Healthcare Life Sciences, Piscataway, NJ, USA, #RPN2232).