An interferon-β-resistant and NLRP3 inflammasome–independent subtype of EAE with neuronal damage

Experimental autoimmune encephalomyelitis can be induced by strong activation of innate immunity. This subtype of EAE is resistant to interferon (IFN)-β treatment and is NLRP3 inflammasome independent. Its development is dependent upon lymphotoxin-β receptor LTβR and CXCR2, and can be inhibited by blocking these receptors. The IFNβ-resistant EAE subtype is characterized by minimal remission and neuronal damage induced by semaphorin-6B on CD4+ T cells. Inflammation induced by innate immunity influences the development of T cell–mediated autoimmunity in multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). We found that strong activation of innate immunity induced Nod-like receptor protein 3 (NLRP3) inflammasome–independent and interferon-β (IFNβ)-resistant EAE (termed type B EAE), whereas EAE induced by weak activation of innate immunity requires the NLRP3 inflammasome and is sensitive to IFNβ treatment. Instead, an alternative inflammatory mechanism, including membrane-bound lymphotoxin-β receptor (LTβR) and CXC chemokine receptor 2 (CXCR2), is involved in type B EAE development, and type B EAE is ameliorated by antagonizing these receptors. Relative expression of Ltbr and Cxcr2 genes was indeed enhanced in patients with IFNβ-resistant multiple sclerosis. Remission was minimal in type B EAE due to neuronal damages induced by semaphorin 6B upregulation on CD4+ T cells. Our data reveal a new inflammatory mechanism by which an IFNβ-resistant EAE subtype develops.