Date of Award
8-20-2024
Degree Type
Thesis
Degree Name
Master of Science (MS)
Department
Microbiology and Immunology
First Advisor
Alan Wolfe
Abstract
Urinary tract infections are one of the most common bacterial infections, historically implicating Escherichia coli as the causative pathogen. However, it is now known that there are a variety of bacteria that exist within the urinary tract, acting as either beneficial uroprotectives or opportunistic uropathogens. Furthermore, there are significant gaps in our understanding as to how these bacteria interact with the urothelium and what role each plays in maintaining or disrupting homeostasis. Research has shown that Toll-like receptor 4 (TLR4) signaling and Nod-like Receptor Protein 3 play a role in inflammasome activation during infection, triggering caspase-1 activation and inducing release of pyroptotic-inducing proteins and inflammatory cytokines. However, little is known about how this inflammatory process is induced in the urinary tract. Urothelial cells are constantly exposed to the passage of urine and have developed an innate immune response to combat potential pathogens in urine. These cells express specific pattern recognition receptors (PRRs) to sense pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) from neighboring cells. These signals can trigger the formation of the inflammasome complex and activate caspase-1. Measuring this transient inflammatory response can be difficult, as various techniques such as ELISA or Western Blotting have limitations. The purpose of this study is to develop a reporter model to screen for caspase-1 activation and inflammatory pathways in the urinary tract in response to urinary microbes. Using a human urothelial cell line (hURO18H7) transduced with a caspase-1 biosensor with a circularly permuted luciferase construct, a viable reporter line was established and used for infection with urinary isolates. Preliminary results have shown increased luciferase activity in response to uropathogenic bacteria such as E. coli, compared to uroprotective bacteria such as members of certain Lactobacillus species. Using a human cell line model expressing this biosensor, we can track inflammatory responses induced by a wide array of suspected uropathogenic or uroprotective bacteria, elucidating the interactions between the protective layer of the urinary system and the bacteria that it harbors.
Recommended Citation
Kesav, Nikita Riya, "Development of a Urothelial Cell Line Expressing a Caspase-1 Biosensor to Measure Cellular Inflammatory Responses to Potential Uropathogens" (2024). Master's Theses. 4529.
https://ecommons.luc.edu/luc_theses/4529
