Cleavage of NLRP1B is sufficient to promote inflammasome activation.

<p>A) 293T cells were transfected with WT, TEV-site2 or TEV-site1 GFP-HA-NLRP1B along with empty vector, TEV expression vector, or a LF expression plasmids. In all conditions cells were also co-transfected with <i>Casp1</i> and <i>Il1b</i> expression vectors. Cleavage of GFP-HA-NLRP1B and IL-1β was determined 24 h post transfection. B) Immortalized B6 macrophages were transduced with a retrovirus encoding the indicated GFP-HA-NLRP1B form followed by a sequential transduction with a TEV-expression retrovirus co-expressing THY1.1. Percent transduction was determined by measuring expression of the respective retroviral integration markers (GFP and anti-THY1.1-PE-Cy7) by flow cytometry, and are expressed in relative fluorescent units (RFU). The numbers within each quadrant represent the percentage of live cells within the respective quadrant. C) RAW264.7 macrophages were transduced with GFP-HA-NLRP1B and a Tet-On construct expressing the indicated gene. Cells were treated with 5 µg/ml doxycycline for 20 h and supernatants were assayed for LDH release. D) 293T cells were transfected with empty vector, FL-NLRP1B-HA, the truncated NLRP1B-HA, or ΔLRR HA-NLRP1B, along with <i>Casp1</i> and <i>Il1b</i> and assayed by immunoblotting.