Astrocytes go into presenter mode.

Astrocytes are glial cells important for neuronal health, but their functions in CNS immunopathology are less understood. In a recent issue of Nature, Lee et al. report that CD40 engagement and proinflammatory cytokines promote lipid droplet accumulation in astrocytes and subsequent antigen presentation, boosting pathogenic CD4+ T cell responses during experimental autoimmune encephalomyelitis.