Occludin and collagen IV degradation mediated by the T9SS effector SspA contributes to blood –brain barrier damage in ducks during Riemerella anatipestifer infection

In this study, we showed that obvious clinical symptoms, an increase in blood ‒brain barrier (BBB) permeability, and the accumulation of inflammatory cytokines occurred after intravenous infection with the Yb2 strain but not the mutant strain Yb2ΔsspA, indicating that Yb2 infection can lead to cerebrovascular dysfunction and that the type IX secretion system (T9SS) effecto r SspA plays a critical role in this pathological process. In addition, we showed that Yb2 infection led to rapid degradation of occludin (a tight junction protein) and collagen IV (a basement membrane protein), which contributed to endothelial barrier disruption. The interaction between SspA and oc cludin was confirmed by coimmunoprecipitation. Furthermore, we found that SspA was the main enzyme mediating occludin and collagen IV degradation. These data indicate thatR. anatipestifer SspA mediates occludin and collagen IV degradation, which functions in BBB disruption inR. anatipestifer-infected ducks. These findings establish the molecular mechanisms by whichR. anatipestifer targets duckling endothelial cell junctions and provide new perspectives for the treatment and prevention ofR. anatipestifer infection.
Source: Veterinary Research - Category: Veterinary Research Source Type: research