NF-κB signaling and cell-fate decision induced by a fast-dissociating tumor necrosis factor mutant.

Tumor necrosis factor (TNF) is a pluripotent inflammatory cytokine that can induce both the pro-survival nuclear factor kappa B (NF-κB) pathway and the pro-apoptotic caspase pathway. Selectively activating only one of the two pathways remains challenging. We used TNF mutants with different receptor binding kinetics to study their effects on NF-κB signaling dynamics and cell apoptosis. A TNF mutant, R1antTNF, which binds to TNFR1 with increased association and dissociation rates, induced NF-κB signaling with shorter response time and first peak duration. The short nuclear stay of NF-κB led to biased activation of downstream genes, favoring the fast response ones. At the same time, R1antTNF retains pro-apoptotic activity. At 10 ng/ml, R1antTNF selectively activated the pro-apoptotic pathway rather than the pro-survival NF-κB pathway. Our study provides a new example for the emerging evidence that ligand-receptor binding kinetics play a key role in the selective activation of downstream pathways, which deserves more attention in future drug discovery and disease studies.