Atherosclerosis is the most common pathological change in the walls of arteries. It can lead to dysfunctions of the endothelium, to inflammations, and to deposits in vascular walls. If such plaques constrict blood vessels, they can cause circulatory disorders. And if the plaques rupture and trigger blood clots, the patient can suffer a heart attack or stroke.“Although T cells have been detected in atherosclerosis, immune tolerance dysfunction has remained unexplored as a disease driver,” says IPEK scientist Professor Andreas Habenicht . “Scientists have discussed the hypothesis that it could be an autoimmune disease for decades."Now his team has managed to prove the conjecture with a mouse model of atherosclerosis, but also with data from human plaques. IPEK PhD student Zhihua Wang contributed as lead author, together with Prof. Changjun Yin from Sun Yat-sen University in Guangzhou, China, as senior author, and Professor Klaus Ley from Georgia Institute for Immunology in the United States. “In the paper, we show for the first time that, with a very high degree of probability, atherosclerosis in late, clinically relevant stages is a T lymphocyte-dependent autoimmune disease,” explains Habenicht. "This applies", he adds, "to all three major T lymphocyte subpopulations, namely to CD4, CD8, and regulatory T cells".