FIG. 6.

Diagram illustrating potential interactions of TNF antagonists with relevant TNF superfamily members. sTNFR1 and anti-TNF MAb can bind soluble or membrane-bound TNF. PEGylated monomeric sTNFR1, which was used in several of the studies reported here, does not bind LT, and the anti-TNF MAb binds both sTNF and mTNF but not LT. Thus, the only potential side effect in using sTNFR1 and anti-TNF MAb for in vivo neutralization of TNF is reverse signaling via mTNF. In contrast, siTNF specifically down-regulates TNF but does not interact with other TNF superfamily member ligands or receptors.