CD4 + CD25 + FoxP3 + T lymphocytes fail to suppress myelin basic protein-induced proliferation in patients with multiple sclerosis

Multiplesclerosis (MS) isanautoimmunedisorderdirectedagainst selfantigens of thecentral nervous system. CD4 + CD25 + FoxP3 + regulatory Tcell(Treg)mediatedsuppressionisanessentialmechanismofself-tolerance.Westudiedwhether changesinthesuppressivefunctionofamixture of CD25 high and CD25 intemediate expressing Treg cells in myelin basic protein (MBP)-induced proliferation occurred in untreated MS patients. SuppressionofMBP-inducedproliferationwasobservedin13outof29(45%)MSpatients;thiswassignificantly(pb0.05)lesscomparedwith17 outof19 (89%)healthy individuals. Relative Tregcounts was significantlyincreased inMS patients (mean±S.D.; 20±8%) compared withhealthy individuals (15±5%). These findings suggest that impaired Treg function may be involved in pathogenesis of MS. © 2006 Elsevier B.V. All rights reserved.