Increased atherosclerosis in rabbits immunized with endothelial cells

Area of Science:

• Cardiovascular Science
• Immunology
• Atherosclerosis Research

Background:

• Atherosclerosis is a complex cardiovascular disease.
• The role of immune responses in atherosclerosis is not fully understood.
• Endothelial cells play a critical role in vascular health.

Purpose of the Study:

• To investigate the impact of immunization with endothelial cells on atherosclerosis development in rabbits.
• To determine if immune responses against endothelial cells contribute to aortic lesion formation.
• To explore the relationship between immune responses, plasma cholesterol levels, and atherosclerosis.

Main Methods:

• Rabbits were fed either a normal or cholesterol-supplemented diet.
• Animals were immunized with cultured endothelial cells from bovine or human aorta.
• Aortic lesions were quantified microscopically and macroscopically.
• Cell-mediated and humoral immune responses were assessed.
• Plasma cholesterol levels were measured.

Main Results:

• Immunization with endothelial cells significantly increased aortic atherosclerosis in cholesterol-fed rabbits.
• Lesion severity was notably higher in the abdominal aorta (4-7 times) and thoracic aorta (2.5-5 times) of immunized animals.
• Immunized rabbits showed reduced plasma cholesterol levels compared to controls (770 vs. 1595 mg/dl).
• Strong cell-mediated and humoral immune responses were observed, with cross-reactivity against human and bovine cells.

Conclusions:

• Specific antibodies and cell-mediated immunity against endothelial cells enhance atherosclerosis.
• The development of atherosclerosis in this model is driven by immune mechanisms rather than solely by hypercholesterolemia.
• These findings highlight the potential involvement of autoimmune processes in the pathogenesis of atherosclerosis.