Yersinia ruckeri strain SC09 disrupts proinflammatory activation via Toll/IL-1 receptor-containing protein STIR-3. Issue 99 (April 2020)

• Record Type: Journal Article
• Authors: Liu, Tao; Li, Liangyu; Wei, Wenyan; Wang, Kaiyu; Yang, Qian; Wang, Erlong
• Is Part Of: Fish & shellfish immunology. Issue 99(2020)
• Page Start: 424
• Page End: 434
• Publication Date: 2020-04
• Subjects: Yersinia ruckeri -- STIR-3 -- MyD88 -- Immune evasion -- Secretion; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2020.02.035
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Virulent pathogenic microorganisms often enhance their infectivity through immune evasion mechanisms. Our research on the integrative and conjugative element (ICE(r2)) of the virulent fish pathogen Yersinia ruckeri SC09 led to the identification of genes related to immune evasion (designated stir-1, stir-2, stir-3 and stir-4 ), among which stir-1 and stir-2 were determined as the key contributors to bacterial toxicity and immune evasion. Here, we further examined the ability of stir-3 to mediate immune evasion based on detailed bioinformatic analysis of ICE(r2) from Y. ruckeri SC09. Interactions among the translated STIR-1, STIR-2, STIR-3 and STIR-4 proteins in the secretory process were additionally explored. STIR-3 was positively correlated with bacterial toxicity and inhibited host toll-like receptor (TLR) signaling by interacting with MyD88, thereby facilitating bacterial survival in host cells. Importantly, our data showed co-secretion of STIR-1, STIR-2 and STIR-3 as a complex, with secretion failure occurring in the absence of any one of these proteins. While stir-1, stir-2, stir-3 and stir-4 genes werespecific to Y. ruckeri SC09, the ICE(r2) region where these genes were located is a mobile component widely distributed in bacteria. Therefore, the potential transmission risk of these immune evasion genes requires further research attention. Highlights: STIR-3 is a virulence factor of the fish pathogen Yersinia ruckeri SC09 strain. STIR-3 mediates inhibition of Toll-like receptor signaling during infection. The TIR domain-containing protein STIR-3 enables interaction with TLR adaptor MyD88. STIR-3 is co-secreted with STIR-1 and STIR-2. ICE(r2) where the STIRs located is widely distributed in bacteria.