Patent ID: 7208148

Claim:
A chemically modified cytokine of formula: Cy-(X—R) n wherein Cy represents a native cytokine having toxic biological properties and being selected from the group consisting of interferon-α (IFNα), interferon-γ (IFNγ), interleukin-1 (IL1), interleukin-4 (IL4), interleukin-6 (IL6), interleukin-10 (IL10), and interleukin-13 (IL13), —(XR) represents a chemically-reactive function of an amino acid contained in said cytokine where X represents an NH group or a sulphur atom, n represents an integer from 1 to 70, and R is either: (i) a carboxymethylated, carboxamide, N-alkylmaleimde, thionitrobenzoic group or a radical formed by reaction of a thiol function with ammonium 4-chloro-7-sulphobenzofurazane, N(iodoethyl)-trifluroacetamide or N-(6-(7-amino-4-methylcoumarin-3-acetamido) hexyl)-3′-(2′-pyridyldithio) propionamide; or (ii) a radical formed by reaction of an amino function with ethylacetimidate, an anhydride, 2-iminothiolane-HCl, N-succinimidyl S-acetylthioacetate, sulphosuccinimidyl-actetate, sulphosuccinimidyl-4-0-(4-4′-dimethoxytrityl)butyrate, succinimidyl 7-amino -4-methlcoumarin-3-acetate, sulphosuccinimidyl 7-amino-4methylcoumarin-3-acetate or phenylglyoxal, said chemically modified cytokine elicits antibodies which neutralize or block said native cytokine and at the same time bring about the loss of at least 90% of the toxic biological properties of said native cytokine.