Edwardsiella tarda TraT is an anti-complement factor and a cellular infection promoter

Edwardsiella tarda TraT promotes cellular infection and serves as an anti-complement factor, shedding light on the mechanisms of E. tarda's strong evasion of killing by the host. Edwardsiella tarda is a well-known bacterial pathogen with a broad range of host, including fish, amphibians, and mammals. One eminent virulence feature of E. tarda is its strong ability to resist the killing of host serum complement, but the involving mechanism is unclear. In this report, we identified E. tarda TraT as a key player in both complement resistance and cellular invasion. TraT, a surface-localized protein, bound and recruited complement factor H onto E. tarda, whereby inhibiting complement activation via the alternative pathway. TraT also interacted with host CD46 in a specific complement control protein domain-dependent manner, whereby facilitating the cellular infection and tissue dissemination of E. tarda. Thus, by acting as an anti-complement factor and a cellular infection promoter, TraT makes an important contribution to the complement evasion and systemic infection of E. tarda. These results add insights into the pathogen-host interaction mechanism during E. tarda infection.

Automated summary

This study reveals the important role of E. tarda TraT in complement resistance and cellular invasion, providing insights into its strong evasion mechanisms.