Interferon-Beta treatment differentially alters TLR2 and TLR4-dependent cytokine production in multiple sclerosis patients

Abstract

Objective: Multiple sclerosis (MS) is a multifactorial chronic disease that affects the central nervous system (CNS). Toll-like receptors (TLRs) play a central role in cytokine production after pathogen- and danger-associated molecular patterns (PAMPs and DAMPs) and contribute to CNS damage in MS patients. Here, we evaluated the effects of interferon (IFN)-β treatment in TLR2 and TLR4-dependent cytokine production and mRNA expression in whole-blood cell cultures from MS patients. Methods: We evaluated cytokine production by ELISA from whole-blood cell culture supernatants and mRNA expression by real-time polymerase chain reaction in peripheral blood mononuclear cells (PBMCs). Results: In patients treated with IFN-β, tumor necrosis factor (TNF)-α production after exposure to TLR2 agonist (Pam3Cys) was lower than in healthy controls and untreated MS patients. However, IFN-β treatment had no significant effect on TNF-α production after TLR4 agonist (LPS) stimulation. On the other hand, interleukin (IL)-10 production was increased in TLR4- but not in TLR2-stimulated whole-blood cell culture from MS patients under IFN-β treatment when compared to the controls. No differences in TNF-α or IL-10 mRNA expression in PBMCs from healthy controls and untreated or treated MS patients were detected, although PBMCs from treated patients presented higher levels of IL-32γ mRNA than those from controls. Conclusions: Our data suggest that IFN-β treatment alters the TLR-dependent immune response of PBMCs from MS patients. This may contribute to the beneficial effects of IFN-β treatment.