MOLECULES

Full name: Tumor necrosis factor

Aliases: DIF, TNFA, TNFSF2, TNLG1F, and TNF-α^1,2

Size: 26 kDa membrane-bound form; 17 kDa soluble form^1,3

Family: TNF family (TNF-α, TNF-β, CD40 ligand, Fas ligand, TRAIL, and LIGHT)⁴

Receptors: TNFR1 and TNFR2¹

Major cellular sources: Activated macrophages, monocytes, CD4+ T cells, B cells, neutrophils, NK, and mast cells¹

Major cellular targets: Nucleated cells¹

Disease states associated with: Psoriasis, psoriatic arthritis, rheumatoid arthritis, juvenile arthritis, ankylosing spondylitis, inflammatory bowel disease, systemic lupus erythematosus, and allergic diseases (asthma, allergic rhinitis, and atopic dermatitis)²

Major physiologic functions:

• TNF is a pleiotropic cytokine involved in host defense, tumor lysis, apoptosis, and inflammation.^1,4
• TNF has two roles in the regulation of immune responses: as a pro-inflammatory mediator, initiating a strong inflammatory response, and as an immunosuppressive mediator, inhibiting the development of autoimmune diseases and tumorigenesis and limiting the extent and duration of inflammatory processes.¹
• TNF stimulates a cascade of pro-inflammatory cytokines, chemokines, integrins, and adhesion molecules to attract leukocytes to the sites of inflammation.^5,6
• TNF promotes angiogenesis and contributes to bone erosion.^5,7

CD: cluster of differentiation; DIF: Dorsal-related immunity factor; LIGHT: homologous to lymphotoxins, exhibits inducible expression, and competes with herpes simplex virus (HSV) glycoprotein D for herpesvirus entry mediator (HVEM), a receptor expressed by T lymphocytes; NK: natural killer; TNFR: TNF receptor; TNFSF: TNF superfamily; TNLG1F: tumor necrosis factor ligand 1F; TRAIL: TNF-related apoptosis-inducing ligand.