Tumor necrosis factor (transmembrane form) (tmTNF-α)

Tumor necrosis factor (TNF) is a pleiotropic cytokine initially synthesized as a 26 kDa type II transmembrane protein (tmTNF-α) that is expressed on the surface of activated macrophages, lymphocytes, and other immune cells (UniProt P01375). While tmTNF-α can be proteolytically cleaved by the TNF-alpha converting enzyme (TACE) to release a 17 kDa soluble form (sTNF-α), the membrane-bound form remains biologically active and mediates juxtacrine signaling through interaction with TNF receptors (TNFR1 and TNFR2) on adjacent cells (PubMed 23812099). Beyond its role as a ligand, tmTNF-α also functions as a receptor that transmits reverse signals into the cell upon binding by its receptors or therapeutic antibodies, influencing cellular activation and cytokine production (PubMed 11015595). In many chronic inflammatory diseases, such as rheumatoid arthritis and Crohn's disease, tmTNF-α plays a critical role in maintaining local inflammation and tissue damage. Therapeutic monoclonal antibodies like infliximab and adalimumab target both soluble and transmembrane TNF-α, often inducing apoptosis or regulatory effects in tmTNF-expressing cells, which contributes to their clinical efficacy compared to agents that primarily target the soluble form (PubMed 16216894).

Other names

Membrane-bound TNF-alphamTNF-alphaPro-tumor necrosis factor-alphaTNF-alpha precursorSurface TNF-alpha

Neutralization of TNF-alpha signaling by preventing binding to TNFR1 and TNFR2; induction of antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against cells expressing tmTNF-alpha; and induction of reverse signaling which can lead to apoptosis or suppression of cytokine production in the target cell (PubMed 23812099, PubMed 11015595).