A lung-on-chip model of early M. tuberculosis infection reveals an essential role for alveolar epithelial cells in controlling bacterial growth

  1. Vivek V Thacker  Is a corresponding author
  2. Neeraj Dhar
  3. Kunal Sharma
  4. Riccardo Barrile
  5. Katia Karalis
  6. John D McKinney  Is a corresponding author
  1. Swiss Federal Institute of Technology in Lausanne (EPFL), Switzerland
  2. University of Cincinnati, United States
  3. Emulate Inc, United States

Abstract

We establish a murine lung-on-chip infection model and use time-lapse imaging to reveal the dynamics of host-Mycobacterium tuberculosis interactions at an air-liquid interface with a spatiotemporal resolution unattainable in animal models and to probe the direct role of pulmonary surfactant in early infection. Surfactant deficiency results in rapid and uncontrolled bacterial growth in both macrophages and alveolar epithelial cells. In contrast, under normal surfactant levels, a significant fraction of intracellular bacteria are non-growing. The surfactant-deficient phenotype is rescued by exogenous addition of surfactant replacement formulations, which have no effect on bacterial viability in the absence of host cells. Surfactant partially removes virulence-associated lipids and proteins from the bacterial cell surface. Consistent with this mechanism, the attenuation of bacteria lacking the ESX-1 secretion system is independent of surfactant levels. These findings may partly explain why smokers and elderly persons with compromised surfactant function are at increased risk of developing active tuberculosis.

Data availability

Figures in the main text include all the data for bacterial growth rates within the scatter plots, and all the data for qRT-PCR measurements and quantification of lamellar body size, number, and volume. A summary of the code used to calculate growth rates is included in the Materials and Methods. Annotated code used for data analysis written in Matlab, raw data for bacterial fluorescence intensity over time that was used to calculate growth rates, and image stacks related to Fig. 1, Fig. 1 - figure supplement 3 and Fig. 2 - figure supplement 1is available on Zenodo under DOI 10.5281/zenodo.4266198.

The following data sets were generated

Article and author information

Author details

  1. Vivek V Thacker

    School of Life Sciences, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland
    For correspondence
    vivekvthacker@gmail.com
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1681-627X
  2. Neeraj Dhar

    School of Life Sciences, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5887-8137
  3. Kunal Sharma

    School of Life Sciences, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland
    Competing interests
    No competing interests declared.
  4. Riccardo Barrile

    Department of Biomedical Engineering, University of Cincinnati, Cincinnati, United States
    Competing interests
    Riccardo Barrile, Riccardo Barrile was affiliated with Emulate Inc for a portion of the duration of this study. The author has no financial interests to declare..
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7301-3959
  5. Katia Karalis

    Research and Development, Emulate Inc, Boston, United States
    Competing interests
    Katia Karalis, Katia Karalis is affiliated with Emulate Inc,. The author has no financial interests to declare..
  6. John D McKinney

    School of Life Sciences, Swiss Federal Institute of Technology in Lausanne (EPFL), Lausanne, Switzerland
    For correspondence
    john.mckinney@epfl.ch
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0557-3479

Funding

Human Frontier Science Program (Long-Term Fellowship,LT000231/2016-L)

  • Vivek V Thacker

European Molecular Biology Organization (Long-Term Fellowship,921-2015)

  • Vivek V Thacker

Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (Project Funding,310030B_176397)

  • John D McKinney

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Christina L Stallings, Washington University School of Medicine, United States

Ethics

Animal experimentation: Animal protocols were reviewed and approved by EPFL's Chief Veterinarian, by the Service de la Consommation et des Affaires Vétérinaires of the Canton of Vaud, and by the Swiss Office Vétérinaire Fédéral (License Number VD 3434 for experiments involving organ collection and License Number VD 3472 for experiments involving infection with Mycobacterium tuberculosis)

Version history

  1. Received: June 12, 2020
  2. Accepted: November 10, 2020
  3. Accepted Manuscript published: November 24, 2020 (version 1)
  4. Accepted Manuscript updated: November 27, 2020 (version 2)
  5. Version of Record published: December 14, 2020 (version 3)

Copyright

© 2020, Thacker et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Vivek V Thacker
  2. Neeraj Dhar
  3. Kunal Sharma
  4. Riccardo Barrile
  5. Katia Karalis
  6. John D McKinney
(2020)
A lung-on-chip model of early M. tuberculosis infection reveals an essential role for alveolar epithelial cells in controlling bacterial growth
eLife 9:e59961.
https://doi.org/10.7554/eLife.59961

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https://doi.org/10.7554/eLife.59961

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