Transfer of CD4 + T Cells Aggravates Atherosclerosis in Immunodeficient Apolipoprotein E Knockout Mice

BACKGROUND: Atherosclerosis is associated with immune responses to oxidized lipoproteins and certain microorganisms, but the role of specific immunity has remained unclear. METHODS AND RESULTS: To study the role of immunity in atherosclerosis, we crossed atherosclerosis-prone apoE(-/-) mice with immunodeficient scid/scid mice. The offspring showed a 73% reduction in aortic fatty streak lesions when compared with immunocompetent apoE(-/-) mice. Transfer of CD4(+) T cells from apoE(-/-) to immunodeficient apoE(-/-)/scid/scid mice increased lesions by 164%. This was associated with the infiltration of transferred T cells into lesions, increased circulating interferon-gamma levels, and increased I-A expression in lesions. CONCLUSIONS: CD4(+) T cells carry disease-promoting immunity in atherosclerosis.