1
|
Scheithauer L, Thiem S, Schmelz S, Dellmann A, Büssow K, Brouwer RMHJ, Ünal CM, Blankenfeldt W, Steinert M. Zinc metalloprotease ProA of Legionella pneumophila increases alveolar septal thickness in human lung tissue explants by collagen IV degradation. Cell Microbiol 2021; 23:e13313. [PMID: 33491325 DOI: 10.1111/cmi.13313] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 01/25/2023]
Abstract
ProA is a secreted zinc metalloprotease of Legionella pneumophila causing lung damage in animal models of Legionnaires' disease. Here we demonstrate that ProA promotes infection of human lung tissue explants (HLTEs) and dissect the contribution to cell type specific replication and extracellular virulence mechanisms. For the first time, we reveal that co-incubation of HLTEs with purified ProA causes a significant increase of the alveolar septal thickness. This destruction of connective tissue fibres was further substantiated by collagen IV degradation assays. The moderate attenuation of a proA-negative mutant in A549 epithelial cells and THP-1 macrophages suggests that effects of ProA in tissue mainly result from extracellular activity. Correspondingly, ProA contributes to dissemination and serum resistance of the pathogen, which further expands the versatile substrate spectrum of this thermolysin-like protease. The crystal structure of ProA at 1.48 Å resolution showed high congruence to pseudolysin of Pseudomonas aeruginosa, but revealed deviations in flexible loops, the substrate binding pocket S1 ' and the repertoire of cofactors, by which ProA can be distinguished from respective homologues. In sum, this work specified virulence features of ProA at different organisational levels by zooming in from histopathological effects in human lung tissue to atomic details of the protease substrate determination.
Collapse
Affiliation(s)
- Lina Scheithauer
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Stefanie Thiem
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Stefan Schmelz
- Structure and Function of Proteins, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Ansgar Dellmann
- Institut für Pathologie, Städtisches Klinikum Braunschweig gGmbH, Braunschweig, Germany
| | - Konrad Büssow
- Structure and Function of Proteins, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - René M H J Brouwer
- Herz-, Thorax-, Gefäßchirurgie, Städtisches Klinikum Braunschweig gGmbH, Braunschweig, Germany.,Institut für Psychologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Can M Ünal
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany.,Fen Fakültesi, Turkish-German University, Istanbul, Turkey
| | - Wulf Blankenfeldt
- Structure and Function of Proteins, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany.,Institut für Biochemie, Biotechnologie und Bioinformatik, Technische Universität Braunschweig, Braunschweig, Germany
| | - Michael Steinert
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| |
Collapse
|
2
|
Rasch J, Ünal CM, Klages A, Karsli Ü, Heinsohn N, Brouwer RMHJ, Richter M, Dellmann A, Steinert M. Peptidyl-Prolyl- cis/ trans-Isomerases Mip and PpiB of Legionella pneumophila Contribute to Surface Translocation, Growth at Suboptimal Temperature, and Infection. Infect Immun 2019; 87:e00939-17. [PMID: 30323027 DOI: 10.1128/IAI.00939-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 09/12/2018] [Indexed: 12/31/2022] Open
Abstract
The gammaproteobacterium Legionella pneumophila is the causative agent of Legionnaires' disease, an atypical pneumonia that manifests itself with severe lung damage. L. pneumophila, a common inhabitant of freshwater environments, replicates in free-living amoebae and persists in biofilms in natural and man-made water systems. Its environmental versatility is reflected in its ability to survive and grow within a broad temperature range as well as its capability to colonize and infect a wide range of hosts, including protozoa and humans. Peptidyl-prolyl-cis/trans-isomerases (PPIases) are multifunctional proteins that are mainly involved in protein folding and secretion in bacteria. In L. pneumophila the surface-associated PPIase Mip was shown to facilitate the establishment of the intracellular infection cycle in its early stages. The cytoplasmic PpiB was shown to promote cold tolerance. Here, we set out to analyze the interrelationship of these two relevant PPIases in the context of environmental fitness and infection. We demonstrate that the PPIases Mip and PpiB are important for surfactant-dependent sliding motility and adaptation to suboptimal temperatures, features that contribute to the environmental fitness of L. pneumophila Furthermore, they contribute to infection of the natural host Acanthamoeba castellanii as well as human macrophages and human explanted lung tissue. These effects were additive in the case of sliding motility or synergistic in the case of temperature tolerance and infection, as assessed by the behavior of the double mutant. Accordingly, we propose that Mip and PpiB are virulence modulators of L. pneumophila with compensatory action and pleiotropic effects.
Collapse
|
3
|
Hoppe J, Ünal CM, Thiem S, Grimpe L, Goldmann T, Gaßler N, Richter M, Shevchuk O, Steinert M. PilY1 Promotes Legionella pneumophila Infection of Human Lung Tissue Explants and Contributes to Bacterial Adhesion, Host Cell Invasion, and Twitching Motility. Front Cell Infect Microbiol 2017; 7:63. [PMID: 28326293 PMCID: PMC5339237 DOI: 10.3389/fcimb.2017.00063] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 02/20/2017] [Indexed: 11/13/2022] Open
Abstract
Legionnaires' disease is an acute fibrinopurulent pneumonia. During infection Legionella pneumophila adheres to the alveolar lining and replicates intracellularly within recruited macrophages. Here we provide a sequence and domain composition analysis of the L. pneumophila PilY1 protein, which has a high homology to PilY1 of Pseudomonas aeruginosa. PilY1 proteins of both pathogens contain a von Willebrand factor A (vWFa) and a C-terminal PilY domain. Using cellular fractionation, we assigned the L. pneumophila PilY1 as an outer membrane protein that is only expressed during the transmissive stationary growth phase. PilY1 contributes to infection of human lung tissue explants (HLTEs). A detailed analysis using THP-1 macrophages and A549 lung epithelial cells revealed that this contribution is due to multiple effects depending on host cell type. Deletion of PilY1 resulted in a lower replication rate in THP-1 macrophages but not in A549 cells. Further on, adhesion to THP-1 macrophages and A549 epithelial cells was decreased. Additionally, the invasion into non-phagocytic A549 epithelial cells was drastically reduced when PilY1 was absent. Complementation variants of a PilY1-negative mutant revealed that the C-terminal PilY domain is essential for restoring the wild type phenotype in adhesion, while the putatively mechanosensitive vWFa domain facilitates invasion into non-phagocytic cells. Since PilY1 also promotes twitching motility of L. pneumophila, we discuss the putative contribution of this newly described virulence factor for bacterial dissemination within infected lung tissue.
Collapse
Affiliation(s)
- Julia Hoppe
- Institut für Mikrobiologie, Technische Universität Braunschweig Braunschweig, Germany
| | - Can M Ünal
- Institut für Mikrobiologie, Technische Universität Braunschweig Braunschweig, Germany
| | - Stefanie Thiem
- Institut für Mikrobiologie, Technische Universität Braunschweig Braunschweig, Germany
| | - Louisa Grimpe
- Institut für Mikrobiologie, Technische Universität Braunschweig Braunschweig, Germany
| | - Torsten Goldmann
- Pathology of the University Hospital of Lübeck and the Leibniz Research CenterBorstel, Germany; Airway Research Center North (ARCN), Member of the German Center for Lung ResearchBorstel, Germany
| | - Nikolaus Gaßler
- Institut für Pathologie, Klinikum Braunschweig Braunschweig, Germany
| | | | - Olga Shevchuk
- Center for Proteomics, University of Rijeka Rijeka, Croatia
| | - Michael Steinert
- Institut für Mikrobiologie, Technische Universität BraunschweigBraunschweig, Germany; Helmholtz Center for Infection ResearchBraunschweig, Germany
| |
Collapse
|