Immunity raises cholesterol

Our immune system is trying to give us a heart attack. Findings from James Lo, Yugang Wang, Godfrey Getz, Yang-Xin Fu (University of Chicago, IL), and colleagues reveal that T cells hinder the liver's ability to remove cholesterol from the blood.

The immune system and the liver were previously linked by a mouse model of inflammation that causes the animals to have enlarged livers. These mice express high levels of proinflammatory molecules called LIGHT and LT on their T cells. The authors now find that LIGHT-expressing T cells bump up triglyceride and cholesterol levels in the mouse bloodstream.

These lipids are normally broken down by the liver. But T cells carrying LIGHT caused liver cells to make less hepatic lipase, which hydrolyzes triglycerides and phospholipids. Interfering with LIGHT's ability to bind to its LTβR...