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Updated: Oct 4, 2025
Flow Cytometry Analysis of Immune Cells Within Murine Aortas
Published on: July 1, 2011
Differences in local immune cell landscape between Q fever and atherosclerotic abdominal aortic aneurysms identified
Kimberley R G Cortenbach1, Alexander H J Staal1, Teske Schoffelen2
1Department of Tumor Immunology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands.
Background:
Chronic Q fever is a zoonosis caused by the bacterium Coxiella burnetii which can manifest as infection of an abdominal aortic aneurysm (AAA). Antibiotic therapy often fails, resulting in severe morbidity and high mortality. Whereas previous studies have focused on inflammatory processes in blood, the aim of this study was to investigate local inflammation in aortic tissue.
Methods:
Multiplex immunohistochemistry was used to investigate local inflammation in Q fever AAAs compared to atherosclerotic AAAs in aorta tissue specimen. Two six-plex panels were used to study both the innate and adaptive immune systems.
Results:
Q fever AAAs and atherosclerotic AAAs contained similar numbers of CD68+ macrophages and CD3+ T cells. However, in Q fever AAAs, the number of CD68+CD206+ M2 macrophages was increased, while expression of GM-CSF was decreased compared to atherosclerotic AAAs. Furthermore, Q fever AAAs showed an increase in both the number of CD8+ cytotoxic T cells and CD3+CD8-FoxP3+ regulatory T cells. Finally, Q fever AAAs did not contain any well-defined granulomas.
Conclusions:
These findings demonstrate that despite the presence of pro-inflammatory effector cells, persistent local infection with C. burnetii is associated with an immune-suppressed microenvironment.
Funding:
This work was supported by SCAN consortium: European Research Area - CardioVascualar Diseases (ERA-CVD) grant [JTC2017-044] and TTW-NWO open technology grant [STW-14716].
Insights
Chronic Q fever infection of abdominal aortic aneurysms (AAAs) involves a local immune-suppressed microenvironment, despite the presence of inflammatory cells. This finding is crucial for understanding treatment resistance in Q fever AAA.
Area of Science:
- Cardiovascular Research
- Infectious Diseases
- Immunology
Background:
- Chronic Q fever, caused by *Coxiella burnetii*, can infect abdominal aortic aneurysms (AAAs).
- Current antibiotic therapies for Q fever AAAs have limited success, leading to significant morbidity and mortality.
- Previous research focused on systemic inflammation, necessitating investigation into local aortic tissue responses.
Purpose of the Study:
- To investigate the local inflammatory environment within aortic tissue affected by Q fever abdominal aortic aneurysms (AAAs).
- To compare the immune cell infiltrate and cytokine expression in Q fever AAAs versus atherosclerotic AAAs.
Main Methods:
- Multiplex immunohistochemistry was employed on aortic tissue specimens.
- Two six-plex antibody panels were utilized to analyze both innate and adaptive immune system components.
- Q fever AAAs were compared directly with atherosclerotic AAAs.
Main Results:
- Both Q fever and atherosclerotic AAAs showed comparable levels of CD68+ macrophages and CD3+ T cells.
- Q fever AAAs exhibited an increase in CD68+CD206+ M2 macrophages and a decrease in GM-CSF expression.
- An elevation in CD8+ cytotoxic T cells and CD3+CD8-FoxP3+ regulatory T cells was observed in Q fever AAAs, which lacked well-defined granulomas.
Conclusions:
- Persistent *Coxiella burnetii* infection in AAAs is associated with an immune-suppressed local microenvironment.
- The findings highlight a complex immune response within Q fever AAAs, characterized by specific immune cell populations.
- Understanding this local immune milieu is critical for developing effective therapeutic strategies against Q fever AAAs.
