An Immunological Wildfire: Trichomonas vaginalis sparks pyroptosis in ectocervical cells 2257413

Abstract Introduction Trichomonas vaginalis (Tv) is a eukaryotic parasite that causes the most common sexually transmitted infection, trichomoniasis. Increased inflammation during Tv infection is predicted to drive comorbidities like cervical cancer, but the underlying inflammatory mechanism at play is unclear. Pyroptosis is a form of cell death that releases proinflammatory cytokines. It involves caspase-1 cleavage of Interleukin-1β (IL-1β) cytokine and gasdermin D (GSDMD), which generates a gasdermin N-terminal fragment (GSDMD-NT). GSDMD-NT oligomerization forms pores on the cell membrane, prompting cytokine release and cellular rupture. We hypothesize that Tv damages ectocervical epithelial cells (Ect1) via GSDMD-mediated pyroptosis. Methods To test whether Tv induces GSDMD-mediated pyroptosis, we generated Ect1 GSDMD-knockout (GSDMD KO) cells and measured cytolysis via lactate dehydrogenase assay. Furthermore, we assayed Ect1 GSDMD KO and WT cell supernatants for differential release of proinflammatory cytokines via enzyme-linked immunosorbent assay (ELISA). In parallel, we sought to identify additional microenvironment-altering proteins released via GSDMD pores during Tv-induced pyroptosis using quantitative proteomics and western blot analysis. Results Upon Tv infection, we noted a striking 25% decrease in cytolysis of GSDMD KO cells compared to WT. Furthermore, cell supernatant analysis via ELISA showed a dramatic 53% decrease in IL-1β and a 25% decrease in IL-18 cytokine release in GSDMD KO cells compared to WT. Finally, quantitative proteomics demonstrated the selective release of potential microenvironment-altering proteins via GSDMD-NT pores. We further validated the differential release of these proteins via western blots. Conclusion Collectively, we show that Tv triggers GSDMD-mediated pyroptosis in Ect1 cells. To our knowledge, this is the first evidence showing that Tv triggers pyroptosis in Ect1 cells and that female reproductive tract cells, not just immune cells, can undergo robust pyroptosis. Funding Source Rees-Stealy Research Foundation Fellowship Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)