Detection of novel carbohydrate binding activity of interleukin-1

Tamm-Horsfall glycoprotein (THGP) and the oligosaccharide fraction liberate d from THGP by hydrazinolysis inhibited tetanus toroid-induced T cell proli feration. Intact THGP showed approximately 100-fold more inhibitory activit y than the free oligosaccharides. After fractionating the oligosaccharides by anion-exchange column chromatography, the inhibitory activity could be d etected in a sialidase-resistant acidic oligosaccharide fraction (fraction AR). The inhibitory activity of fraction AR was not observed when the fract ion was added to the T cell culture medium 24 h after the addition of tetan us toroid. Increased concentration of interleukin (IL) 1 beta and decreased concentration of IL-2 were observed in the T cell culture medium after the addition of fraction AR. The oligosaccharides in fraction AR also inhibite d the growth of an IL-1-dependent cell line, D10-G4. These results strongly suggested that the oligosaccharides in fraction AR bind to IL-1 beta and s uppress its cytokine activity. IL-1 beta actually bound to the fraction AR immobilized on an amino-bonded thin layer plate. Fractionation of the oligo saccharides indicated that only oligosaccharides containing an N-acetylgala ctosamine residue and a sulfate residue bound specifically to IL-1 beta. Re moval of either the sulfate residue or the N-acetylgalactosamine residue fr om the oligosaccharides abolished both the proliferation-inhibition and IL- 1 beta binding activities. Since IL-1 beta did not bind to thyroid-stimulat ing hormone, which has the sulfate group at C-4 of the N-acetylgalactosamin e residue in its N-linked sugar chains, the binding of IL-1 beta toward oli gosaccharides in fraction AR was considered to be highly specific.