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TesG is a type I secretion effector of Pseudomonas aeruginosa that suppresses the host immune response during chronic infection


Pseudomonas aeruginosa is a versatile Gram-negative pathogen with intricate intracellular regulatory networks that enable it to adapt to and flourish in a variety of biotic and abiotic habitats. However, the mechanism permitting the persistent survival of P. aeruginosa within host tissues and causing chronic symptoms still remains largely elusive. By using in situ RNA sequencing, here we show that P. aeruginosa adopts different metabolic pathways and virulence repertoires to dominate the progression of acute and chronic lung infections. Notably, a virulence factor named TesG, which is controlled by the vital quorum-sensing system and secreted by the downstream type I secretion system, can suppress the host inflammatory response and facilitate the development of chronic lung infection. Mechanically, TesG can enter the intracellular compartment of macrophages through clathrin-mediated endocytosis, competitively inhibit the activity of eukaryotic small GTPase and thus suppress subsequent neutrophil influx, cell cytoskeletal rearrangement of macrophages and the secretion of cytokines and chemokines. Therefore, the identification of TesG in this study reveals a type I secretion apparatus of P. aeruginosa that functions during the host–pathogen interaction, and may open an avenue for the further mechanistic study of chronic respiratory diseases and the development of antibacterial therapy.

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Data availability

Large screening datasets are provided in the Supplementary Information. The RNA-Seq data for P. aeruginosa PAO1 are deposited in the NCBI database under accession numbers SRX2662725, SRX2662726, SRX2662727 and SRX2662728. Additional data that support the findings of this study are available from the corresponding author X. Zhou upon request.

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This work is supported by the National Natural Science Foundation of China (no. 31700111 to K.Z., no. 81302371 and no. 81672675 to Jing Li, no. 81202324 to X. Zhou and no. 31570534 to X. Zhang), the Excellent Young Scientist Foundation of Sichuan University (no. 2017SCU04A16 to X. Zhou), the Innovative Spark Foundation of Sichuan University (no. 2018SCUH0032 to X. Zhou) and the National Major Scientific and Technological Special Project for ‘Significant New Drugs Development’ (no. 2018ZX09201018-013 to X. Zhou).

Author information

K.Z., W.L., Jing Li, T.M., K.W., Y.Y., J.S.L, R.X., T.H., Y. Zhang, Y. Zhou, N.H., W.W., Z.W., J.Z., X. Zhang and X. Zhou performed and analysed the experiments. K.Z., W.L., B.Y. and X. Zhang performed the bioinformatics analyses. K.Z., X. Zhang and X. Zhou contributed to study design and data analysis. K.Z. and X. Zhou wrote the manuscript. Z.Z., Jiong Li and Y.-Q.W. provided critical resources and acquired data. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing interests.

Correspondence to Xiuyue Zhang or Xikun Zhou.

Supplementary information

  1. Supplementary Information

    Supplementary Figures 1–14, Supplementary Table 1, Supplementary Table 5, Supplementary References, uncropped blots.

  2. Reporting Summary

  3. Supplementary Table 2

    Significantly upregulated genes of PAO1 during acute lung infection.

  4. Supplementary Table 3

    Significantly upregulated genes of PAO1 during chronic lung infection.

  5. Supplementary Table 4

    Significance ranking of upregulated operons of PAO1 during lung infections.

  6. Supplementary Table 6

    Mass spectrometry analysis of proteins included exclusively in TesG group.

  7. Supplementary Table 7

    Small GTPase superfamily proteins included exclusively in TesG group.

  8. Supplementary Table 8

    Strains, plasmids and primers used in this study.

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Fig. 1: Establishment of the P. aeruginosa chronic lung infection model and in situ RNA-Seq analyses.
Fig. 2: TesG is mainly expressed during chronic infection and secreted by the downstream Tes-T1SS under rhl-QS regulation.
Fig. 3: TesG suppresses neutrophil influx responses to PAO1 infection.
Fig. 4: TesG induces behavioural alterations in MH-S macrophages.
Fig. 5: TesG suppresses RhoA activation.
Fig. 6: RhoA plays a role in mediating P. aeruginosa infection-induced inflammatory responses.