Abstract General Information

Title

Effect of dimethyl fumarate and monomethyl fumarate in vitro on the profile of myeloid dendritic cells in EAE

Abstract

Introduction: Dimethyl fumarate (DMF; Tecfidera, Biogen) is an oral medication utilized to treat Relapsing- Remitting Multiple Sclerosis (MS), being associated with reduced disease activity in MS patients. DMF is converted into its active form, the monomethyl fumarate (MMF), by dendritic cells (DCs) of the gut. However, the mechanisms of action of DMF are not fully understood.

Objective: To analyze the effect of DMF and MMF on the in vitro generation of dendritic cells.

Methods: DCs were generated from bone marrow precursors extracted from femurs and tibias of C57BL/6J mice. Red blood cells were lysed and cells were cultured for 12 days in RPMI medium with 10% fetal bovine serum, 10ng/ml GM-CSF, 1% antibiotic and 1% L-glutamine. From day 2 of culture, part of the cells received DMF at a concentration of 70uM, another group received MMF at a concentration of 50uM, and another group did not receive any treatment. The medium was changed every 2 days or sooner if necessary. After 12 days, the immature DCs were be induced to maturation with LPS (5ng/ml, for 24h). Cells were then destinated to flow cytometry and qPCR analysis.

Results. Both forms do not alter the proportion between CD11b+ and CD11c+ DC's. Additionally, they do not modify the expression of auxiliary factors CD80, CD86 and MHC II in CD11c+ and CD11b+CD11c+ DCs. However, it was observed that DMF and MMF increase the expression of CD80, CD86 and MHC II in CD11b+ DCs. Cytokine expression is modulated by the treatment with MMF.

Conclusions. Although preliminary, our results suggest that MMF acts, at least in part, inducing a tolerogenic profile characterized by the expression of CD11b in DCs, to the detriment of the immunogenic profile, characterized by the expression of CD11c. Thus, more Treg cells would be generated, which would attenuate MS in mices.