ACCELERATED ATHEROSCLEROSIS IN HYPERLIPIDEMIC C57BL 6 MICE TREATED WITH CYCLOSPORINE-A/

We and others have demonstrated that T lymphocytes are prominent compo nents of atherosclerotic lesions. We hypothesized that if T cells were necessary for the development of atherosclerosis it would be possible to demonstrate its prevention or retardation in T-cell-suppressed mic e. To test this hypothesis, CyA, a potent suppressor of T-cell activat ion, was used to treat C57BL/6 mice under-going lipid hyperalimentatio n. Mice receiving normal mouse chow were completely free of atheroscle rotic lesions. In mice receiving the atherogenic diet plus control oil injections, lesions of the aorta and corona arteries were observed at 135 days and increased progressively in area until 310 days. Somewhat surprisingly, mice given the atherogenic diet plus CyA injections dis played even larger lesions at all three observed time intervals. Altho ugh CyA did suppress T-cell reactivity sufficiently to obtain the expe cted prolongation of skin allografts, it did not suppress the developm ent or progression of atherosclerotic lesions.