Cutting edge: Both activating and inhibitory Fc receptors expressed on mast cells regulate experimental allergic encephalomyelitis disease severity

Mast cell-deficient mice (W/W-v) exhibit significantly reduced severity of experimental allergic encephalomyelitis (EAE), a murine model of multiple sclerosis. In this study, the contribution of FcR-mediated mast cell activation to disease was examined. W/W-v mice were reconstituted i.v. with bone marrow-derived mast cells (BMMCs) from wild-type mice or those lacking functional FcRs. Eight weeks later, EAE was induced by immunization with the myelin oligodendrocyte glycoprotein 35-55 peptide. Disease scores were analyzed in reconstituted mice and compared with age-matched W/W-v mice and wild-type litter-mates. Mice reconstituted with FcRgamma(-/-) BMMCs or FcgammaRIII(-/-) BMMCs exhibited less severe clinical symptoms similar to W/W-v controls, while reconstitution with FcRIIB(-/-) BMMCs resulted in disease significantly more severe than wild-type controls. Notably, mice reconstituted with FcgammaRIII(-/-) BMMC exhibit a relapsing-remitting course of disease. These data demonstrate that both activating and inhibitory FcRs expressed on mast cells influence the course of EAE. The Journal of Immunology, 2003. .