Aortic recruitment of blood lymphocytes is most pronounced in early stages of lesion formation in apolipoprotein-E-deficient mice

Lymphocyte accumulation in the arterial intima affects development of atherosclerotic lesions. We studied the kinetics of lymphocyte accumulation in the arterial wall by injecting lymphocytes from male LacZ transgenic mice into female apolipoprotein-E-deficient mice. Recipient mouse aortas were removed and separated into lesioned and non-lesioned parts 2, 24, 48, or 72 h later. The accumulation of donor lymphocytes was quantified with real-time PCR of donor lymphocyte-specific genes. The accumulation of lymphocytes in the lesioned parts of aorta decreased with increasing lesion severity (r=−0.74, P=0.0005, n=18). Moreover, the accumulation of lymphocytes in the lesioned part of aorta was larger (392±108%, P=0.016) compared with the accumulation in the non-lesioned part in mice with mild atherosclerosis, whereas it was smaller (58±19%, P<0.01) compared with the accumulation in the non-lesioned part in mice with severe atherosclerosis. The results suggest that aortic recruitment of blood lymphocytes is most pronounced in early stages of lesion formation.