title: IL7Rα contributes to experimental autoimmune encephalomyelitis through altered T cell responses and nonhematopoietic cell lineages.
abstract: A mutation in the IL7Rα locus has been identified as a risk factor for multiple sclerosis (MS), a neurodegenerative autoimmune disease characterized by inflammation, demyelination, and axonal damage. IL7Rα has well documented roles in lymphocyte development and homeostasis, but its involvement in disease is largely understudied. In this study, we use the experimental autoimmune encephalomyelitis (EAE) model of MS to show that a less severe form of the disease results when IL7Rα expression is largely restricted to thymic tissue in IL7RTg(IL7R-/-) mice. Compared with wild-type (WT) mice, IL7RTg(IL7R-/-) mice exhibited reduced paralysis and myelin damage that correlated with dampened effector responses, namely decreased TNF production. Furthermore, treatment of diseased WT mice with neutralizing anti-IL7Rα Ab also resulted in significant improvement of EAE. In addition, chimeric mice were generated by bone marrow transplant to limit expression of IL7Rα to cells of either hematopoietic or nonhematopoietic origin. Mice lacking IL7Rα only on hematopoietic cells develop severe EAE, suggesting that IL7Rα expression in the nonhematopoietic compartment contributes to disease. Moreover, novel IL7Rα expression was identified on astrocytes and oligodendrocytes endogenous to the CNS. Chimeric mice that lack IL7Rα only on nonhematopoietic cells also develop severe EAE, which further supports the role of IL7Rα in T cell effector function. Conversely, mice that lack IL7Rα throughout both compartments are dramatically protected from disease. Taken together, these data indicate that multiple cell types use IL7Rα signaling in the development of EAE, and inhibition of this pathway should be considered as a new therapeutic avenue for MS.
authors.affiliation: Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.
authors.forename: Jessica J
authors.initials: JJ
authors.lastname: Ashbaugh
authors.forename: Roberta
authors.initials: R
authors.lastname: Brambilla
authors.forename: Shaffiat A
authors.initials: SA
authors.lastname: Karmally
authors.forename: Cecilia
authors.initials: C
authors.lastname: Cabello
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Malek
authors.forename: John R
authors.initials: JR
authors.lastname: Bethea
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000276:immunology; D016026:Bone Marrow Transplantation / Q000276:immunology; D019070:Cell Lineage; D002490:Central Nervous System / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology*; D005260:Female; D008213:Lymphocyte Activation / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009103:Multiple Sclerosis / Q000276:immunology; D009154:Mutation / Q000276:immunology; D009186:Myelin Sheath / Q000276:immunology; D009836:Oligodendroglia / Q000276:immunology; D020395:Receptors, Interleukin-7 / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D016207:Cytokines; D020395:Receptors, Interleukin-7; D014409:Tumor Necrosis Factor-alpha; C415350:interleukin-7 receptor, alpha chain