Fig. 6. TNFR2 stimulation does not sensitize PC60 R1R2 cells for a subsequent TNFR1-mediated apoptotic signal. (A) PC60 R1R2 cells, preincubated for 14 hours in medium or medium containing 500 ng/ml of the TNFR2-specific mutein D143NA145R were stimulated with 100 ng/ml hTNF, the TNFR1 specific mutein R32WS86T (500 ng/ml) or a combination of both receptor specific muteins. (B) Cells preincubated as in A were exposed to a dilution range of hTNF as indicated. (C) Western blot, revealed with anti-TRAF2, of lysates of PC60 R1R2 cells that were treated for 14 hours with hTNF (100 ng/ml) or its receptor specific muteins (500 ng/ml).