Inflammasome components are necessary for B. burgdorferi-induced IL-1β. (A) 3 × 10^6 Bone marrow-derived macrophages (BMDMs) from wild-type (WT), NLRP3-, ASC-, and caspase-1 gene-deficient mice were stimulated for 24 hours with or without 1 × 10^6 B. burgdorferi with adenosine triphosphate (ATP) (3 mM) for 30 minutes. Cleaved caspase-1 was detected by Western blotting using antibodies to detect the inactive caspase-1 (p45) or active caspase-1 (p20). (B) IL-1β protein levels in the supernatant expressed in picograms per milliliter after BMDM exposure for 24 hours to B. burgdorferi, using WT, NLRP3-, ASC-, or caspase-1 gene-deficient mice. BMDMs are isolated from at least five animals per group, protein measurements were performed in duplicates. (C) IL-2 protein levels in nanograms per mL after BMDM stimulation with medium (Med), or 5 × 10^6 B. burgdorferi per mL for 24 hours, using cells from different knockout mice. ASC, apoptosis-associated speck-like protein containing a caspase recruitment domain (CARD); NLRP3, nucleotide oligomerization domain (NOD)-like receptor P3.
Oosting et al. Arthritis Research & Therapy 2012 14:R247 doi:10.1186/ar4090