Digital Image Analyses on Whole-Lung Slides in Mouse Models of Acute Pneumonia

Am J Respir Cell Mol Biol. 2018 Apr;58(4):440-448. doi: 10.1165/rcmb.2017-0337MA.


Descriptive histopathology of mouse models of pneumonia is essential in assessing the outcome of infections, molecular manipulations, or therapies in the context of whole lungs. Quantitative comparisons between experimental groups, however, have been limited to laborious stereology or ill-defined scoring systems that depend on the subjectivity of a more or less experienced observer. Here, we introduce self-learning digital image analyses that allow us to transform optical information from whole mouse lung sections into statistically testable data. A pattern-recognition-based software and a nuclear count algorithm were adopted to quantify user-defined pathologies from whole slide scans of lungs infected with Streptococcus pneumoniae or influenza A virus compared with PBS-challenged lungs. The readout parameters "relative area affected" and "nuclear counts per area" are proposed as relevant criteria for the quantification of lesions from hematoxylin and eosin-stained sections, also allowing for the generation of a heat map of, for example, immune cell infiltrates with anatomical assignments across entire lung sections. Moreover, when combined with immunohistochemical labeling of marker proteins, both approaches are useful for the identification and counting of, for example, immune cell populations, as validated here by direct comparisons with flow cytometry data. The solutions can easily and flexibly be adjusted to specificities of different models or pathogens. Automated digital analyses of whole mouse lung sections may set a new standard for the user-defined, high-throughput comparative quantification of histological and immunohistochemical images. Still, our algorithms established here are only a start, and need to be tested in additional studies and other applications in the future.

Keywords: histology; infection; lung; mouse; scoring.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Algorithms*
  • Animals
  • Automation, Laboratory
  • Cytological Techniques*
  • Disease Models, Animal
  • Image Interpretation, Computer-Assisted / methods*
  • Influenza A virus / pathogenicity
  • Lung / microbiology
  • Lung / pathology*
  • Lung / virology
  • Mice
  • Orthomyxoviridae Infections / pathology*
  • Orthomyxoviridae Infections / virology
  • Pattern Recognition, Automated
  • Pneumonia, Pneumococcal / microbiology
  • Pneumonia, Pneumococcal / pathology*
  • Pneumonia, Viral / pathology*
  • Pneumonia, Viral / virology
  • Predictive Value of Tests
  • Software
  • Streptococcus pneumoniae / pathogenicity