E Peelen1, A-H Muris1, J Damoiseaux2, S Knippenberg1, K Broens3, J Smolders4, J W Cohen Tervaert5, R Hupperts6, M Thewissen7. 1. School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands; Academic MS Center Limburg, Department of Neurology, Orbis Medical Center, Sittard, The Netherlands; Department of Internal Medicine, Division of Clinical and Experimental Immunology, Maastricht University Medical Center, Maastricht, The Netherlands. 2. Central Diagnostic Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands. Electronic address: jan.damoiseaux@mumc.nl. 3. Department of Clinical Chemistry and Hematology, Orbis Medical Center, Sittard, The Netherlands. 4. School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands. 5. Maastricht University Medical Center, Maastricht, The Netherlands. 6. School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, The Netherlands; Academic MS Center Limburg, Department of Neurology, Orbis Medical Center, Sittard, The Netherlands. 7. Department of Internal Medicine, Division of Clinical and Experimental Immunology, Maastricht University Medical Center, Maastricht, The Netherlands.
Abstract
BACKGROUND/ OBJECTIVE: Data from animal models of MS suggest that GM-CSF(+)CD4(+)T cells are pathogenic cells. Therefore, GM-CSF production by CD4(+)T cells of MS patients and their susceptibility to regulatory mechanisms were investigated. METHODS: Intracellular flowcytometry was performed to determine the GM-CSF(+)CD4(+)T cell fraction in PBMC and CSF of MS patients and controls. The effect of regulatory T cells (Tregs) on GM-CSF production by CD4(+)T cells was studied in MS patients using a proliferation-suppression assay. Finally, GM-CSF(+)CD4(+)T cell fraction and GM-CSF protein levels in supernatant were assessed in anti-CD3-stimulated CD4(+)T cell cultures derived from healthy controls and MS patients, in the presence or absence of the active vitamin D metabolite calcitriol. RESULTS: The GM-CSF(+)CD4(+)T cell fraction in the peripheral blood did not differ between controls and MS patients. This T cell population could also be detected in the CSF of both subjects with MS as well as subjects with another diagnosis. In the CSF, it comprised a significant fraction of the T cell population. Upon in vitro stimulation of PBMC with anti-CD3 antibody, no differences were observed in GM-CSF(+)CD4(+)T cell frequencies. GM-CSF secretion was susceptible to regulation by Treg and vitamin D. Suppression of GM-CSF secretion by vitamin D was reduced in MS patients. CONCLUSIONS: Our study showed no elevation in GM-CSF(+)CD4(+)T cell fractions in MS patients compared to controls. Furthermore, GM-CSF secretion was prone to regulation by Treg and vitamin D, the latter being less effective in MS patients.
BACKGROUND/ OBJECTIVE: Data from animal models of MS suggest that GM-CSF(+)CD4(+)T cells are pathogenic cells. Therefore, GM-CSF production by CD4(+)T cells of MSpatients and their susceptibility to regulatory mechanisms were investigated. METHODS: Intracellular flowcytometry was performed to determine the GM-CSF(+)CD4(+)T cell fraction in PBMC and CSF of MSpatients and controls. The effect of regulatory T cells (Tregs) on GM-CSF production by CD4(+)T cells was studied in MSpatients using a proliferation-suppression assay. Finally, GM-CSF(+)CD4(+)T cell fraction and GM-CSF protein levels in supernatant were assessed in anti-CD3-stimulated CD4(+)T cell cultures derived from healthy controls and MSpatients, in the presence or absence of the active vitamin D metabolite calcitriol. RESULTS: The GM-CSF(+)CD4(+)T cell fraction in the peripheral blood did not differ between controls and MSpatients. This T cell population could also be detected in the CSF of both subjects with MS as well as subjects with another diagnosis. In the CSF, it comprised a significant fraction of the T cell population. Upon in vitro stimulation of PBMC with anti-CD3 antibody, no differences were observed in GM-CSF(+)CD4(+)T cell frequencies. GM-CSF secretion was susceptible to regulation by Treg and vitamin D. Suppression of GM-CSF secretion by vitamin D was reduced in MSpatients. CONCLUSIONS: Our study showed no elevation in GM-CSF(+)CD4(+)T cell fractions in MSpatients compared to controls. Furthermore, GM-CSF secretion was prone to regulation by Treg and vitamin D, the latter being less effective in MSpatients.
Authors: Anderson P Jones; Stephanie Trend; Scott N Byrne; Marzena J Fabis-Pedrini; Sian Geldenhuys; David Nolan; David R Booth; William M Carroll; Robyn M Lucas; Allan G Kermode; Prue H Hart Journal: Clin Transl Immunology Date: 2017-05-26