Dendritic cells derived from patients with multiple sclerosis show high CD1a and low CD86 expression

Dendritic cells (DC) are important antigen presenting cells (APC) and play a major role in initiating and orchestrating immune responses by priming T cells. Little is known about involvement of DC in multiple sclerosis (MS), where auto-aggressive T cells against myelin autoantigens are considered to contribute to inflammation and demyelination in the central nervous system. In this study, we compared phenotype and cytokine secretion of DC from patients with MS, other neurological diseases (OND) and healthy subjects. DC were generated from blood adherent mononuclear cells (MNC) by culture for 7 days with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4). The yield and morphology of DC were similar in MS patients and controls. In both, the DC phenotype was that of immature myeloid lineage, comprising CD1a+ and CD11c+. The proportion of CD1a+ DC, being important for presentation of lipid antigens to T cells, was higher in MS patients compared to controls. The proportion of CD86+ DC, a co-stimulatory molecule that is assumed to promote Th2 differentiation, was low in MS. Low proportions of CD86+ DC were only observed in untreated MS patients but not in patients treated with IFN-beta. Production of IL-10 and IL-12 p40 by DC did not differ in MS patients and controls. These findings indicate that alterations of functionally important surface molecules on DC are associated with MS.