A multiple comorbidities mouse lung infection model in ApoE‑deficient mice

Area of Science:

• Cardiovascular Science
• Infectious Disease Research
• Inflammation Biology

Background:

• Acute pneumonia involves intense inflammation, a key factor in atherosclerosis progression.
• Pre-existing atherosclerotic inflammation may influence pneumonia severity and risk.
• Understanding the interplay between infection and cardiovascular disease is crucial.

Purpose of the Study:

• To investigate respiratory and systemic inflammation in a murine model of atherosclerosis with pneumonia.
• To establish a reliable model for studying pneumonia in the context of cardiovascular disease.

Main Methods:

• Atherosclerotic C57Bl/6 ApoE-/- mice on a high-fat diet were inoculated with Streptococcus pneumoniae (TIGR4 strain).
• Lung inflammation was assessed using magnetic resonance imaging (MRI) and positron emission tomography (PET) up to 28 days post-inoculation.
• Systemic inflammation was evaluated via ELISA, Luminex assay, and real-time PCR.

Main Results:

• Pneumonia induction led to persistent lung inflammation, including infiltrate and consolidation, visible on MRI up to 28 days.
• Positron emission tomography revealed increased FDG uptake in lungs, indicating ongoing inflammation.
• Elevated inflammatory markers (IL-1β, IL-6, CCL3) and a pneumococcal-specific IgG response were observed.

Conclusions:

• The developed murine model effectively simulates pneumonia in an atherosclerotic setting, highlighting persistent inflammation.
• This model serves as a valuable tool for elucidating the link between infectious inflammation and cardiovascular disease risk.