Dynamic and Heterogeneous Distribution of Trichomonasvirus Species in Trichomonas vaginalis

Trichomonasvirus (TVV) is a double-stranded RNA virus from the Pseudototiviridae family that exclusively infects Trichomonas vaginalis , the protozoan responsible for the most common non-viral sexually transmitted infection. Within the Trichomonasvirus genus, five distinct viral species have been identified, and intriguingly, a single T. vaginalis isolate can simultaneously harbor multiple TVV species. Previous studies have explored the impact of TVV infection on the physiology and virulence of T. vaginalis , yet findings remain inconsistent and often contradictory. We propose that these discrepancies stem from the heterogeneous intracellular distribution of TVV within individual cells of the same T. vaginalis isolate. To investigate this, we employed ultra-deep single-cell RNA sequencing and immunofluorescence assays to examine multiple T. vaginalis isolates. Our results revealed striking variability in the proportion of infected cells carrying the same viral species, even within a single isolate. The present study is the first to demonstrate the dynamic and non-uniform intracellular distribution of TVV at the single-cell level. These findings challenge previous assumptions and provide a new perspective on the intricate virus-host interactions between TVV and T. vaginalis , offering new avenues for further research into their complex relationship.