Characterization of Caspase 1 Substrate Specificity Utilizing Luminescent Reporter Constructs

Inflammation is the bodies first response to defend itself against foreign pathogens and damage. Cellular sensors are constantly monitoring the body and checking for homeostatic disruption. Microbial pathogens and tissue damage are sensed by pattern recognition receptors (PRRs), which sense pathogen associated molecular patterns and damage associated molecular patterns, termed PAMPs and DAMPs respectively. Within the family of PRRs are sensors that can induce the formation of the multi-protein complex termed the inflammasome following activation. the inflammasome complex is a molecular platform for which caspase 1, a cysteine protease, is incorporated and is responsible for the maturation of pro-inflammatory cytokines such as IL-1B and IL-18. These mature cytokines are then released from the cell and act via endocrine and paracrine signaling to generate an inflammatory environment. Among these cytokines, other cellular substrates are targeted and cleaved by active caspase 1, such as the protein gasdermin D. Cleavage of gasdermin D can lead to a form of programmed cell death termed pyroptosis, a highly inflammatory cell death. upon activation, gasdermin D self oligomerizes creating a pore in the cell wall. This allows for the secretion of massive amounts of inflammatory cytokines as well as an influx of water into the cell leading to eventual cell death