Journal: Journal of Biological Chemistry

Article Title: Modulation of T Cell Cytokine Production by Interferon Regulatory Factor-4

doi: 10.1074/jbc.m205895200

Figure Lengend Snippet: FIG. 1. Early activation events in IRF-4-transfected cells. A, whole cell extracts were prepared from Jurkat cells stably transfected with either a control or an IRF-4 expression vector, electrophoresed on a 7% SDS-polyacrylamide gel, and then analyzed by Western blotting using an anti-IRF-4 antibody (upper panel). The blot was later stripped and reprobed with a -actin antibody (lower panel) to ensure for equal loading. Extracts from untransfected Jurkat cells and HUT 78 served, respectively, as negative and positive controls. B, Jurkat-transfected cells were either left unstimulated or were stimulated with PMA (50 ng/ml) and ionomycin (1 M) for 24 h. The cells were then harvested and stained with either a phycoerythrin-labeled anti-CD69 (upper panel) or a phycoerythrin-labeled anti-CD25 antibody (lower panel) and analyzed by flow cytometry. Filled histograms represent unstimulated cells, whereas empty histograms represent cells stimulated with PMA and ionomycin. Left panel, vector transfectants; right panel, IRF-4 transfec- tants. Not shown is staining with an isotype-matched control, which did not reveal any significant differences between control and IRF-4 transfectants.

Article Snippet: Cell Lines and Cultures—The Jurkat (human T cell leukemia) cell line was obtained from American Type Culture Collection (ATCC, Manassas, VA).

Techniques: Activation Assay, Transfection, Stable Transfection, Control, Expressing, Plasmid Preparation, Western Blot, Staining, Labeling, Flow Cytometry

Journal: Journal of Biological Chemistry

Article Title: Modulation of T Cell Cytokine Production by Interferon Regulatory Factor-4

doi: 10.1074/jbc.m205895200

Figure Lengend Snippet: FIG. 4. IRF-4 transactivates the human IL-2 and IL-4 promoters. Control and IRF-4 Jurkat-transfected cells were transiently transfected with a luciferase reporter construct driven either by the human IL-2 promoter (left panel) or the human IL-4 promoter (right panel). The transfected cells were equally split into two 2-ml aliquots and then incubated for 4 h in the presence or absence of PMA (50 ng/ml) and ionomycin (1 M). The data are presented relative to the activity of the reporter construct in unstimulated control cells, which was set to 1.0, as indicated in each experiment. Results show the mean S.E. of five (for the IL-2 promoter) and six (for the IL-4 promoter) independent experiments.

Article Snippet: Cell Lines and Cultures—The Jurkat (human T cell leukemia) cell line was obtained from American Type Culture Collection (ATCC, Manassas, VA).

Techniques: Control, Transfection, Luciferase, Construct, Incubation, Activity Assay

Journal: Journal of Biological Chemistry

Article Title: Modulation of T Cell Cytokine Production by Interferon Regulatory Factor-4

doi: 10.1074/jbc.m205895200

Figure Lengend Snippet: FIG. 6. IRF-4 can act as a transactivator of the P1-IRF element. Control and IRF-4 Jurkat cells were transfected with a luciferase re- porter construct driven by either an oligomerized P1-IRF wt or an oligomerized P1-IRFM3 element. The transfected cells were equally split into two 2-ml aliquots and then incubated for 4 h in the presence or absence of PMA (50 ng/ml) and ionomycin (1 M). The data are presented relative to the activity of the reporter construct in unstimu- lated control cells, which was set to 1.0, as indicated, in each experi- ment. Results show the mean S.E. of three independent experiments.

Article Snippet: Cell Lines and Cultures—The Jurkat (human T cell leukemia) cell line was obtained from American Type Culture Collection (ATCC, Manassas, VA).

Techniques: Control, Transfection, Luciferase, Construct, Incubation, Activity Assay

Journal: Journal of Biological Chemistry

Article Title: Modulation of T Cell Cytokine Production by Interferon Regulatory Factor-4

doi: 10.1074/jbc.m205895200

Figure Lengend Snippet: FIG. 7. IRF-4 cooperates with NFAT in driving T cell cytokine production. A, vector and IRF-4 Jurkat cells were co- transfected with a luciferase reporter con- struct driven by the human IL-4 promoter and either an NFATc1 expression vector or equivalent amounts of an empty vector. The transfected cells were equally split into two 2-ml aliquots and then incubated for 4 h in the presence or absence of PMA (50 ng/ml) and ionomycin (1 M). The data are presented relative to the activity of the reporter construct in vector control cells, which was set to 1.0, as indicated, in each experiment. Results show the mean S.E. of four independent experi- ments. B, control and IRF-4-transfected cells were either left unstimulated or stimulated with PMA and ionomycin as indicated in the legend to Fig. 2. Stimula- tions were conducted in the presence or absence of cyclosporin A (1 g/ml) or FK506 (10 ng/ml) as indicated. Superna- tants were then collected and analyzed for their cytokine content by ELISA. Data shown are representative of four inde- pendent experiments and performed on three independent sets of transfectants.

Article Snippet: Cell Lines and Cultures—The Jurkat (human T cell leukemia) cell line was obtained from American Type Culture Collection (ATCC, Manassas, VA).

Techniques: Plasmid Preparation, Transfection, Luciferase, Expressing, Incubation, Activity Assay, Construct, Control, Enzyme-linked Immunosorbent Assay