T cells tamed by statins

Cholesterol-lowering statin drugs, such as Lipitor and Zocor, have a fortuitous side effect: they ease T cell–driven autoimmune diseases such as multiple sclerosis (MS) and rheumatoid arthritis (RA). On page 401, Dunn and colleagues show that statins curb T cell activation by robbing the cells of isoprenoids, lipid intermediates formed during cholesterol biosynthesis.

The ability of statins to inhibit T cell proliferation has been appreciated for over a decade, but the mechanism was never fully understood. More recently, these drugs were shown to inhibit inflammatory T helper (Th)-1 responses and instead promote Th2 responses—a shift that protects mice against Th1-driven diseases such as RA and experimental autoimmune encephalomyelitis (EAE), a mouse model of MS.

A study in 2002 was the first to attribute the protective effect of statins in...