Purpose: A shear stress-induced atherosclerosis mouse model was characterized for its expression of inflammation markers with focus on CD80. With this model, we evaluated two positron emission tomography (PET) radiotracers targeting CD80 as well as 2-deoxy-2-[18F]fluoro-D-mannose ([18F]FDM) in comparison with 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG).
Procedure: A flow constrictive cuff implanted around the common carotid artery in apolipoprotein E knockout mice resulted in plaque formation. CD80 expression levels and plaque histopathology were evaluated. Serial PET/X-ray computed tomography scans were performed to follow inflammation.
Results: Plaque formation with increased levels of CD80 was observed. Histologically, plaques presented macrophage-rich and large necrotic areas covered by a thin fibrous cap. Of the CD80-specific tracers, one displayed an increased uptake in plaques by PET. Both [18F]FDG and [18F]FDM accumulated in atherosclerotic plaques.
Conclusion: This mouse model presented, similar to humans, an increased expression of CD80 which renders it suitable for non-invasively targeting CD80-positive immune cells and evaluating CD80-specific radiotracers.
Keywords: ApoE KO; Atherosclerosis; CD80; Plaque inflammation; Positron emission tomography; Shear stress; [18F]FDG.