Tumour necrosis factor-alpha interacts with biglycan and decorin.

Several interactions of cytokines with extracellular matrix molecules are mediated by proteoglycans, such as biglycan and decorin. Using surface plasmon resonance, we show for the first time that tumour necrosis factor-alpha (TNF-alpha) binds to both biglycan and decorin with K(d)s of 0.81 microM and 1.23 microM respectively, a binding that was confirmed by Scatchard plots using a solid phase assay. Binding occurs preferentially via the core protein, shown by lower K(d)s, 0.26 microM and 0.81 microM for biglycan and decorin respectively. There was also binding to dermatan sulphate, with a K(d) of 10.53 microM. The function of this interaction between TNF-alpha and biglycan and decorin is not known, but we suggest that the differential localisation of the proteoglycans enables the cytokines to be immobilised in different environments.