Pyroptosis Antibody Sampler Kit

Background

Pyroptosis is a regulated pathway of cell death with morphological features of necrosis, including cell swelling, plasma membrane pore formation, and engagement of an inflammatory response with the release of a number of damage-associated molecular patterns (DAMPs), such as HMGB1 and inflammatory cytokines like IL-1β and IL-18 (1,2). Pyroptosis is generally induced in cells of the innate immune system, such as monocytes, macrophages, and dendritic cells in the presence of pathogen-associated molecular patterns (PAMPs) expressed on microbial pathogens or by cell-derived DAMPs. It is induced through assembly of inflammasomes triggering proteolytic activation of caspase-1 which then cleaves inflammatory cytokines like IL-1β and IL-18 to their mature forms (3). A critical feature of pyroptosis is the cleavage of Gasdermin D by caspase-1 and mouse caspase-11 (or human caspase-4/5) (4-6). Upon cleavage, the N-terminal fragment of Gasdermin D oligomerizes to form a pore, allowing secretion of inflammatory DAMPs and cytokines. Canonical inflammasome assembly typically consists of a cytosolic-pattern recognition receptor (PPR; a nucleotide binding domain and leucine-rich repeat [NLR] or AIM2-like family members), an adaptor protein (ASC/TMS1), and pro-caspase-1. Distinct inflammasome complexes can recognize distinct PAMPs and DAMPs to trigger pyroptosis. The best characterized pathway triggered by the NLR, NLRP3, occurs through a two-step process. The first step is a priming signal, NF-κB is activated to induce the expression of a number of inflammasome components including NLRP3, pro-IL-1β, and pro-IL-18. In the second activation step, caspase-1 is activated and Gasdermin D and cytokines are proteolytically activated. In a non-canonical pathway, caspase-4 and caspase-5 can directly trigger Gasdermin D cleavage in monocytes following LPS stimulation (5,7).