Cytokine production in short-term peptide-specific T-cell lines from patients with juvenile idiopathic arthritis (JIA). Short-term peptide-specific T-cell lines were generated from peripheral blood mononuclear cells of five patients with polyarticular JIA. After 14 days of culture, supernatants were taken for multiplex cytokine analysis and cells were stained for fluorescence-activated cell sorting (FACS) analysis. The aggrecan peptide induced significant production of interferon-γ (IFN-γ)/interleukin (IL)-17 and inhibition of IL-10 production (p < 0.05). The matrix metalloproteinase (MMP)-3 peptide induced significant production of IFN-γ. FACS analysis confirmed the presence of activated T cells. Asterisks indicate significant difference.