CD4⁺ T-cell proliferation and cytokine expression in response to myelin basic protein (MBP) and tetanus toxoid (TT) <i>ex vivo</i>.

To assess antigen-induced CD4+ T-cell proliferation we incubated CFSE labeled peripheral blood mononuclear cells (PBMCs) from untreated and natalizumab treated MS patients with myelin basic protein and tetanus toxoid for 7 days. Using flow-cytometry CD4+ T-cell proliferation was assessed as the percentage of CFSE diluted cells within the CD4+ T-cell proliferation. After activation with phorbol 12-myristate 13-acetate and staining of intracellular cytokines the percentage of cytokine expressing cells within the proliferating CD8− T-cell population was determined by flow-cytometry. Data are given as median with interquartile range in the parenthesis. There were no significant differences in antigen-specific CD4+ T-cell reactivity between untreated and natalizumab treated MS patients using Mann-Whitney U Test with a level of significance p<0.01. IL = interleukin; IFN = interferon; TNF-α = tumor necrosis factor-α.