Hyperresponsiveness of Corticoid-Resistant Th17/Tc-17 Cells to TLR-2 and TLR-4 Ligands is a Feature of Multiple Sclerosis Patients at Higher Risk of Therapy Failure

Abstract

Joana Hygino,1,* Marisa C Sales,2,* Priscila M Sacramento,1 Taissa M Kasahara,3 Júlio César Costa da Silva,3 Rafaela Bilhão,3 Regis M Andrade,4 Cláudia Cristina Ferreira Vasconcelos,1 Cleonice AM Bento1,3– 5 1Post-Graduate Program in Neurology, Federal University of the State of Rio de Janeiro, Rio de Janeiro City, Brazil; 2Post-Graduate Program in Microbiology, University of the State of Rio de Janeiro, Rio de Janeiro City, Brazil; 3Post-graduate Program in Molecular and Cellular Biology, Federal University of the State of Rio de Janeiro, Rio de Janeiro City, Brazil; 4Department of General Medicine, Federal University of the State of Rio de Janeiro, Rio de Janeiro City, Brazil; 5Department of Microbiology and Parasitology, Federal University of the State of Rio de Janeiro, Rio de Janeiro City, Brazil*These authors contributed equally to this workCorrespondence: Cleonice AM Bento, Department of Microbiology and Parasitology, Federal University of the State of Rio de Janeiro, Frei Caneca 94, 20.261-040, Rio de Janeiro, RJ, Brazil, Tel/Fax + 55-21-2531-7906, Email [email protected]: The presence of T cells expressing TLR-2 and TLR-4 has been associated with relapsing-remitting multiple sclerosis (RRMS) pathogenesis. Here, we evaluated whether the effectiveness of DMT in controlling clinical activity of the disease would be associated with modulation of proportion of TLRs+ T cells.Patients and Methods: Whole peripheral blood mononuclear cells, purified CD4+ and CD8+ T cells from RRMS patients were cultured with different stimuli. The frequency of IL-17-secreting CD4+ and CD8+ T cells positive for TLR-2 and TLR-4 was determined by flow cytometry. The cytokine profile of these T cells following TLR-2 and TLR-4 stimulation was determined by Multiplex. Some of these T cell cultures were treated with hydrocortisone. The levels of LPS-binding protein (LBP) were dosed by ELISA. Clinical (occurrence of relapses) and radiological (number of active brain lesions) activity were evaluated during the 1-year follow-up.Results: Despite DMT, high intensity of TLR-2 and TLR-4 expression on (CD4+ and CD8+) T-cells, as well as the frequency of IL-17-secreting (CD4+ and CD8+) T-cells, are predictive of future RRMS relapses. Moreover, higher cytokine production related to Th17/Tc-17 phenotypes in response to TLR-2 and TLR-4 agonists was observed in DMT-treated patients and displayed an elevated number of brain lesions. The hyperresponsiveness of MS-derived T-cells to TLR-2 and TLR-4 ligands, with high levels of IL-1β, IL-6, IL-17, IFN-γ and GM-CSF in response to both TLR agonists, positively correlated with plasma LBP levels. Interestingly, corticoid was less efficient in reducing Th17 and Tc-17 cytokine production induced by TLR-2 and TLR-4 ligands in DMT-treated patients who relapsed during follow-up.Conclusion: Collectively, the data suggested that persistence of circulating Th17 and Tc17 cells expressing elevated levels of functional TLR-2 and TLR-4 could indicate high disease activity and lower therapeutic efficacy in RRMS patients.Keywords: multiple sclerosis, toll-like receptors, T cells, Th17, LPS-binding protein

Keywords

• multiple sclerosis
• toll-like receptors
• t cells
• th17
• lps-binding protein