Aktuelle Neurologie 2004; 31 - P464
DOI: 10.1055/s-2004-833325

CD4+CD25- effector T cells from healthy controls and MS patients do not differ in mRNA expression of IFN-γ, IL-2, and TNF-α

A Hug 1, J Haas 1, A Viehöver 1, B Fritz 1, B Storch-Hagenlocher 1, B Wildemann 1
  • 1(Heidelberg)

Relapsing remitting multiple sclerosis (RRMS) is supposed to be an inflammatory, demyelininating T cell mediated autoimmune disease of the central nervous system (CNS). A prerequisite for the induction of autoimmunity within the CNS is the priming and activation of self-reactive T cell clones in the periphery (blood, secondary lymphatic organs). One target for T cell activation within the T cell pool are resting, unactivated CD4+ T helper cells. Therefore we analyzed freshly isolated peripheral blood CD4+CD25- T effector cells (Teff) for mRNA expression profiles of T cell activation cytokines interferon gamma (IFN-γ), interleukin 2 (IL-2) and tumor necrosis factor alpha (TNF-α).

10 patients with RRMS with an acute relapse and 10 age matched controls were included in the study (mean age 32 years, mean disease duration 15 month). Patients were treatment nave. CD4+ T cells were negatively enriched from peripheral blood mononuclear cells (PBMC) and CD4+CD25high T regulatory cells were depleted via an CD25 antibody. Total RNA was isolated from 106 of the sorted CD4+CD25- Teff and reverse transcribed. Quantitative real time PCR was performed with primers and specific probes for IFN-γ, IL-2, TNF-α, and GAPDH. Relative expression levels were calculated by the 2 e(-delta delta Ct) method.

IFN-γ, IL-2, and TNF-α mRNA was barely detectable in freshly isolated Teff isolated from both study groups indicating very low numbers of activated T cells in MS patients with an acute relapse as well as in normal controls. Mean mRNA levels in Teff obtained from MS patients over the mean mRNA levels in Teff from healthy controls were 0.8 (IFN-γ), 1.6 (IL-2), and 1.6 (TNF-α).

Freshly isolated Teff from MS patients and healthy control individuals harbor very low numbers of activated T cells as demonstrated by mRNA expression of proinflammatory cytokines IFN-γ, IL-2, and TNF-α. Furthermore, there was no significant difference in mRNA expression of IFN-γ, IL-2, and TNF-α between the two study groups. An acute relapse in patients with RR-MS is not associated with a measurable increase of mRNA-expression of proinflammatory cytokines (IFN-γ, IL-2, TNF-α) in the whole Teff subset.