Glatiramer acetate treatment negatively regulates type I interferon signaling Nicolas Molnarfi, PhD* ABSTRACT ’ Thomas Prod homme, Objective: Glatiramer acetate (GA; Copaxone), a disease-modifying therapy for multiple sclerosis (MS), PhD* promotes development of anti-inflammatory (M2, type II) monocytes that can direct differentiation of Ulf Schulze-Topphoff, regulatory T cells. We investigated the innate immune signaling pathways that participate in GA- PhD mediated M2 monocyte polarization. Collin M. Spencer, BS Methods: Monocytes were isolated from myeloid differentiation primary response gene 88 (MyD88)– Martin S. Weber, MD deficient, Toll-IL-1 receptor domain–containing adaptor inducing interferon (IFN)–b (TRIF)–deficient, IFN-a/b Juan C. Patarroyo, BS receptor subunit 1 (IFNAR1)–deficient, and wild-type (WT) mice and human peripheral blood. GA-treated Patrice H. Lalive, MD monocytes were stimulated with Toll-like receptor ligands, then evaluated for activation of kinases and Scott S. Zamvil, MD, transcription factors involved in innate immunity, and secretion of proinflammatory cytokines. GA-treated PhD mice were evaluated for cytokine secretion and susceptibility to experimental autoimmune encephalomyelitis. Results: GA-mediated inhibition of proinflammatory cytokine production by monocytes occurred inde- pendently of MyD88 and nuclear factor–kB, but was blocked by TRIF deficiency. Furthermore, GA did Correspondence to Dr. Zamvil: not provide clinical benefit in TRIF-deficient mice. GA inhibited activation of p38 mitogen-activated
[email protected] protein kinase, an upstream regulator of activating transcription factor (ATF)–2, and c-Jun N-terminal kinase 1, which regulates IFN regulatory factor 3 (IRF3). Consequently, nuclear translocation of ATF-2 and IRF3, components of the IFN-b enhanceosome, was impaired.