DGAT1 inhibits retinol-dependent regulatory T cell formation and mediates autoimmune encephalomyelitis.

The balance of effector versus regulatory T cells (Tregs) controls inflammation in numerous settings, including multiple sclerosis (MS). Here we show that memory phenotype CD4 T cells infiltrating the central nervous system during experimental autoimmune encephalomyelitis (EAE), a widely studied animal model of MS, expressed high levels of mRNA for encoding diacylglycerol-O-acyltransferase-1 (DGAT1), an enzyme that catalyzes triglyceride synthesis and retinyl ester formation. DGAT1 inhibition or deficiency attenuated EAE, with associated enhanced Treg frequency; and encephalitogenic, DGAT1 in vitro-polarized Th17 cells were poor inducers of EAE in adoptive recipients.