Tumor necrosis factor alpha receptor pathway (TNFα pathway (sometimes abbreviated as TNF pathway or TNFα signaling))

Tumor necrosis factor alpha is a pro-inflammatory cytokine produced mainly by activated macrophages but also by other immune cells such as T cells, B cells, dendritic cells, fibroblasts, and keratinocytes. It plays a central role in mediating inflammation through binding to two main cell surface receptors—tumor necrosis factor receptor 1 (TNFR1/p55) and tumor necrosis factor receptor 2 (TNFR2/p75). Activation of these receptors triggers complex intracellular signaling cascades that can result in cell survival via NF-kappaB activation or programmed cell death via caspase activation. The balance between these outcomes is tightly regulated but can be disrupted during chronic inflammation or autoimmune disease. Therapeutic targeting has focused on neutralizing circulating tumor necrosis factor alpha using monoclonal antibodies such as infliximab and adalimumab; fusion proteins like etanercept act as decoy receptors. These drugs are approved for several inflammatory conditions including rheumatoid arthritis, Crohn’s disease, ulcerative colitis, psoriasis, ankylosing spondylitis, hidradenitis suppurativa, uveitis, juvenile idiopathic arthritis among others. However their use carries risks including increased susceptibility to infections. Recent research aims at selectively modulating individual pathways—such as inhibiting only the pro-inflammatory activities mediated by TNFR1 while sparing regulatory functions mediated by TNFR2—to improve safety profiles while maintaining efficacy.

Other names

Tumor necrosis factor alpha signalingTNF-alpha signalingTNF signalingTumor necrosis factor receptor 1/2 (TNFR1/TNFR2) pathways

– Neutralization of tumor necrosis factor alpha by monoclonal antibodies or fusion proteins to prevent its binding to receptors and downstream pro-inflammatory effects – Selective antagonism of TNFR1 or agonism of TNFR2 for more targeted modulation in development/preclinical stages