Fig. 4

Immunohistochemistry with postmortem sections from MS and normal human brains. a Immunohistochemistry reveals FR-β expression in normal-appearing white matter from a patient with secondary progressive MS (left) but not in the white matter from a normal brain (right). b Moderate FR-β expression is observed in the normal-appearing gray matter from a patient with secondary progressive MS (left) but not in a normal brain (right). c Chronic inactive lesions display minimal or no FR-β expression. d FR-β-immunoreactive macrophages border chronic active plaques. Immunofluorescence staining reveals that FR-β colocalizes with CD68 (e), iNOS (f), and MRC-1 (g) in normal-appearing white matter from a patient with secondary progressive MS (left) but not in the white matter of a normal brain (right). Scale bars, 50 μm. Red arrows indicate FR-β positivity, and white arrows indicate colocalization of FR-β and CD68, iNOS, or MRC-1