Integrated evaluation of lung disease in single animals

• Type of Material: Article
• Authors: Pratyusha Mandal, Emory University; John Lyons, Emory University; Eileen Burd, Emory University; Michael Koval, Emory University; Edward Mocarski, Emory University; Craig Coopersmith, Emory University
• Language: English
• Date: 2021-07-08
• Publisher: PUBLIC LIBRARY SCIENCE
• Publication Version: Final Published Version
• Copyright Statement: © 2021 Mandal et al
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1371/journal.pone.0246270
• Title of Journal or Parent Work: PLOS ONE
• Volume: 16
• Issue: 7
• Start Page: e0246270
• End Page: e0246270
• Grant/Funding Information: National Institute of General Medical Sciences (NIGMS) R01-GM072808, T32GM095442 to CMC; NIGMS F32-GM117895 to JDL, National Institute on Alcohol Abuse and Alcoholism (NIAAA) R01-AA025854 to MKH; National Institute of Allergy and Infectious Disease (NIAID) R01-AI020211 to ESM and R21-AI142507 to ESM, CF@LANTA Director’s Fund to PM.
• Keywords: APOPTOSIS; PATHOGENESIS; INJURY; SURVIVAL; Multidisciplinary Sciences; INFLAMMATION; Science & Technology; Science & Technology - Other Topics; MURINE MODEL; FIBROSIS; ASTHMA
• Research Categories: Biology, Microbiology; Health Sciences, Pathology; Health Sciences, Immunology

Abstract

During infectious disease, pathogen load drives inflammation and immune response that together contribute to tissue injury often resulting in organ dysfunction. Pulmonary failure in SARS-CoV2-infected hospitalized COVID-19 patients is one such prominent example. Intervention strategies require characterization of the host-pathogen interaction by accurately assessing all of the above-mentioned disease parameters. To study infection in intact mammals, mice are often used as essential genetic models. Due to humane concerns, there is a constant unmet demand to develop studies that reduce the number of mice utilized while generating objective data. Here, we describe an integrated method of evaluating lung inflammation in mice infected with Pseudomonas aeruginosa or murine gammaherpesvirus (MHV)-68. This method conserves animal resources while permitting evaluation of disease mechanisms in both infection settings. Lungs from a single euthanized mouse were used for two purposes-biological assays to determine inflammation and infection load, as well as histology to evaluate tissue architecture. For this concurrent assessment of multiple parameters from a single euthanized mouse, we limit in-situ formalin fixation to the right lung of the cadaver. The unfixed left lung is collected immediately and divided into several segments for biological assays including determination of pathogen titer, assessment of infection-driven cytokine levels and appearance of cell death markers. In situ fixed right lung was then processed for histological determination of tissue injury and confirmation of infection-driven cell death patterns. This method reduces overall animal use and minimizes inter-animal variability that results from sacrificing different animals for different types of assays. The technique can be applied to any lung disease study in mice or other mammals.