Grant: Master's Award: Canada Graduate Scholarships

Pyroptosis, one of several inflammatory types of programmed cell death, is induced after activation of an inflammasome which ultimately results in pore formation and cell lysis. It was previously thought that liver cirrhosis associated with hepatitis C virus (HCV) was due to caspase-3 mediated apoptosis (non-inflammatory). However, it has recently been shown that both apoptosis and pyroptosis occur in cultured human hepatocyte-like cells infected with HCV as well as uninfected bystander cells. Scientists are unsure whether pyroptosis is beneficial to the virus or an innate anti-viral response benefiting the host. The current research aims to validate use of antibodies for universal inflammasome components (ASC and Nlrp3) for immunofluorescence and Flow Cytometry and then to separate infected and uninfected cells based on which programmed cell death pathway is utilized. Sorted populations will be analyzed by RNA sequencing to examine differential gene expression. Then the goal will be to detect entire inflammasome complexes in cells undergoing pyroptosis and to determine whether complexes are released from dying cells. By using an Nlrp3 inhibitor and monitoring virus replication, the benefit or detriment of pyroptosis to the virus will be examined. Presence of inflammasome components in infected and uninfected hepatocytes derived from HCV-infected cryopreserved humanized mouse liver and HCV-infected human liver will be analyzed. The in vivo relevance of pyroptosis on the woodchuck hepatitis model of HBV infection will be considered as well. Results will aid in understanding mechanisms of innate immune response to viral infections and could assist in development of immune-based therapies to treat virus-induced diseases.