Figure 6.

 TNFR2 can enhance TNFR1 sensitivity and induces TRAF2 degradation. (A) 293 cells were transfected with the indicated CD28 chimeric vectors (1 μg), along with a GFP vector (100 ng), exactly as described in the legend to Fig. 1. Transfectants were stimulated with TNF-α (200 U/ml) and cell viability was determined by DAPI staining and fluorescence microscopy as described in Materials and Methods. (B) 293 cells were transfected with the TRAF2 expression vector along with the indicated chimeric vectors. Twelve hours following transfection, cells were either mock treated or treated with human TNF-α (200 U/ml) as indicated. Cells were harvested 24 hr following transfection, standardized by protein content and TRAF2 was detected by immunoblot analysis as described in Materials and Methods.