In vitro bioactivity of the scR1antTNFs through TNFR1 and TNFR2. Agonistic (A) and antagonistic (B) activities of R1antTNF (closed squares), scR1antTNF-L1 (closed circles), scR1antTNF-L2 (open squares), and scR1antTNF-L3 (open circles) through TNFR1 were confirmed by LM cell assay. The activity of WT-TNF (closed diamonds) was used as a control. C, agonistic activity through TNFR2 was evaluated by cell death of hTNFR2/mFas preadipocytes. D, caspase-3 activation induced by serially diluted WT-TNF, R1antTNF, or scR1antTNFs (1, 10, and 100 ng/ml) using A673 cells was measured with Ac-DEVD-p-nitroanilide. All error bars represent S.D.; n = 3.