Myeloid cell-specific Irf5 deficiency stabilizes atherosclerotic plaques in Apoe mice.

Objective: Interferon regulatory factor (IRF) 5 is a transcription factor known for promoting M1 type macrophage polarization in vitro. Given the central role of inflammatory macrophages in promoting atherosclerotic plaque progression, we hypothesize that myeloid cell-specific deletion of IRF5 is protective against atherosclerosis.

Methods: Female ApoeLysmIrf5 and ApoeIrf5 mice were fed a high-cholesterol diet for three months.

A molecular intravascular ultrasound contrast agent allows detection of activated platelets on the surface of symptomatic human plaques.

Background And Aims: Activated platelets are amongst the most attractive imaging targets in atherosclerosis due to their important role in early processes of atherogenesis and thrombus formation. We developed a molecular intravascular ultrasound (IVUS) approach to detect activated platelets ex vivo on the surface of human plaques, using an IVUS system applied in clinical routine.

Methods: Human carotid endarterectomy specimens were obtained directly from the operating room and exposed to artificial arterial flow conditions for incubation with the contrast agent.

Immuno-magnetoliposomes targeting activated platelets as a potentially human-compatible MRI contrast agent for targeting atherothrombosis.

To detect unstable atherosclerotic plaques early and noninvasively would be of great clinical interest. Activated platelets are an interesting molecular target for detecting early lesions or unstable plaques. We therefore developed an MRI contrast agent consisting of magnetoliposomes (ML) linked to an antibody (anti-LIBS) specifically targeting the ligand-induced binding site of the activated GPIIb/IIIa receptor of platelets.