RNA-seq for AnvM

Pseudomonas aeruginosa is one of the most common pathogens in hospital-acquired infection, which is tightly controlled by a multi-layered regulatory network including quorum sensing system (QS), type VI secretion system (T6SS) and resistance to host immunity. In the present study, we found that a PA3880 gene, which encodes an unknown protein, acted as a regulator of anaerobic metabolism, response to oxidative stress and virulence in P. aeruginosa. More than thirty PA3880 homologs were found in other bacterial genomes, indicating that PA3880 was widely distributed in bacterial kingdom with a conserved function. Deletion of PA3880 gene changed expression of more than seven hundred genes, including a group of virulence genes under both aerobic and anaerobic conditions. To further study the mechanisms of PA3880-mediated regulation on virulence, we utilized bacterial two-hybrid assay and found that PA3880 protein directly interacted with QS regulator MvfR and anaerobic regulator Anr. Loss of PA3880 protein significantly blunted the pathogenicity of P. aeruginosa, resulting in increased survival, decreased bacterial burdens, muffled inflammatory response, and less lung injuries in mice. Mechanistically, we identified that Cys44 was a critical site for full function of PA3880 to influence alveolar macrophage phagocytosis and bacterial clearance. We also found that AnvM directly interacted with host receptors TLR2 and TLR5, which might lead to activation of host immune response. Hence, we named PA3880 as anvM (anaerobic and virulence modulator). The present characterization of anvM will help to uncover new targets and strategies to treat P. aeruginosa infections. Overall design: RNA-seq for AnvM