Seeing a Mycobacterium-Infected Cell in Nanoscale 3D: Correlative Imaging by Light Microscopy and FIB/SEM Tomography

PLoS One. 2015 Sep 25;10(9):e0134644. doi: 10.1371/journal.pone.0134644. eCollection 2015.

Abstract

Mycobacteria pose a threat to the world health today, with pathogenic and opportunistic bacteria causing tuberculosis and non-tuberculous disease in large parts of the population. Much is still unknown about the interplay between bacteria and host during infection and disease, and more research is needed to meet the challenge of drug resistance and inefficient vaccines. This work establishes a reliable and reproducible method for performing correlative imaging of human macrophages infected with mycobacteria at an ultra-high resolution and in 3D. Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM) tomography is applied, together with confocal fluorescence microscopy for localization of appropriately infected cells. The method is based on an Aclar poly(chloro-tri-fluoro)ethylene substrate, micropatterned into an advantageous geometry by a simple thermomoulding process. The platform increases the throughput and quality of FIB/SEM tomography analyses, and was successfully applied to detail the intracellular environment of a whole mycobacterium-infected macrophage in 3D.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electron Microscope Tomography
  • Humans
  • Image Processing, Computer-Assisted
  • Imaging, Three-Dimensional*
  • Leukocytes, Mononuclear / microbiology*
  • Leukocytes, Mononuclear / pathology*
  • Leukocytes, Mononuclear / ultrastructure
  • Macrophages / microbiology
  • Macrophages / pathology
  • Macrophages / ultrastructure
  • Microscopy, Confocal
  • Microscopy, Electron, Scanning
  • Mycobacterium* / physiology

Grants and funding

This work was supported by the Research Council of Norway through its Centres of Excellence funding scheme, project number 223255/F50, and through support to the Norwegian Micro- and Nano-Fabrication Facility, NorFab, project number 197411/V30; http://www.forskningsradet.no/en/Home_page/1177315753906. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.