A Salmonella Typhi RNA thermosensor regulates virulence factors and innate immune evasion in response to host temperature

• DOI: 10.1371/journal.ppat.1009345
• Publication Date: 2021-03-02T18:49:58Z
• Authors: Susan M. Brewer; Christian Twitten...; Jens Kortmann; Sky W. Brubaker; Jared Honeycutt; Liliana Moura Massis; Trung H. M. Pham; Franz Narberhaus; Denise M. Monack
• Keywords: Flagellin; Virulence factor; TLR5; Salmonella enterica

Sensing and responding to environmental signals is critical for bacterial pathogens successfully infect persist within hosts. Many sense temperature as an indication they have entered a new host must alter their virulence factor expression evade immune detection. Using secondary structure prediction, we identified RNA thermosensor (RNAT) in the 5’ untranslated region (UTR) of tviA encoded by typhoid fever-causing bacterium Salmonella enterica serovar Typhi ( S . Typhi). Importantly, transcriptional regulator factors Vi capsule, flagellin, type III secretion system-1 expression. By introducing point mutations mRNA structure, demonstrate that UTR contains functional RNAT using vitro expression, probing, ribosome binding methods. Mutational inhibition causes aberrant leading enhanced innate responses during infection. In conclusion, show regulates through Our findings limiting inflammation RNAT-dependent regulation response body important Typhi’s “stealthy” pathogenesis.