Fig. 5.

Production of IFN-γ by cultured murine spleen cells from methotrexate (MTX)-treated mice. Tumour necrosis factor (TNF) knockout(ko) and TNF transgenic (tg) mice were treated three times a week with PBS or indicated amounts of MTX for a period of 30 days. Spleen cells were isolated after 30 days and stimulated for 48 h with anti-CD3/CD28, phorbol myristate acetate (PMA) and lipopolysaccharide (LPS). Culture supernatants were taken after 48 h and cytokine concentrations were assessed by ELISA. Data represent mean values of duplicate measurements from one representative experiment. IFN-γ baseline level in uninjected transgenic mice was 43 000 pg/ml.