Development of a human interleukin-6 receptor antagonist.
1994; Elsevier BV; Volume: 269; Issue: 1 Linguagem: Inglês
10.1016/s0021-9258(17)42317-9
ISSN1083-351X
AutoresJust P. J. Brakenhoff, Floris D. de Hon, Véronique Fontaine, Edwin ten Boekel, Heidi Schooltink, Stefan Rose‐John, Peter C. Heinrich, J. Content, L Aarden,
Tópico(s)Synthesis and Reactions of Organic Compounds
Resumoof Autoimmune ~~s e u s e s , Central to^ of the ~e t h e r ~a n ~ Red Cross Blood ~a n s ~s ~o n Service, Ams~erdam 1066 CX, The Nether~unds, the ~~n s ~i ~u t Pasteur du ~~~~n t , ~~e ~l e s 1180, B e ~~u m , and the Nnstitut f i r Biochemie der ~heinisch Wes~ful~schen ~c h n ~c h e n ~~h s c h u ~ Aaehen, Aaehen ~-5 ~~, GermanyNeutralizing monoclonal antibodies specific for human interleukin-6 fIL-6) bind two distinct sites on the IL6 protein (sites I and X).Their interference with IL-6 receptor binding suggested that site I is a receptor-binding site of KL-6, whereas site I1 is important for signal transduction.Mutagenesis of site I1 could therefore result in the isolation of IL-6 receptor antagonists.To test this hypothesis, a panel of IL-6 mutant proteins was constructed that did not bind to a site 11-specific mono- clonal antibody.One such site 11 mutant protein (with double su~titution of Gln-180 with Glu and Thr-183 with Pro) was found to be an antagonist of human IL-6.It was inactive on human CESS cells, weakly active on human HepG2 cells, but active on mouse B9 cells.It could specifically antagonize the activity of wild-type EL-6 on CESS and HepG2 cells.The binding affinity of this variant for the 80-kDa KL-6 receptor wae similar to that of wild-type IL-6.High affinity binding to CESS cells, however, was abolished, suggesting that the mutant protein is inactive because the complex of the 80m a IL-6 receptor and the mutant protein cannot associate with the signal transducer gp130.The human IL-6 antagonist protein may be potentidly useful as a therapeutic agent, Interleukin-6 (IL-6)1 is a multifixnctional cytokine playing a central role in host defense mechanisms (for reviews, see Refs.1-3).IL-6 exerts its multiple activities through interaction with specific receptors on the surface of target cells (4,5).The c D N h for two receptor chains have been cloned and code for transmembrane glycoproteins of 80 and 130 kDa (gp130) (6,7), which both belong to the large cytokine receptor superfamily (8-10).The 80-kDa IL-6 receptor (IL-6R) binds IL-6 with low affinity ( & --1 nM) without triggering a signal (11).The IL-6.80-kDa EL-6R complex s~bsequent~y associates with gp130, which then transduces the signal (7, 111.gp130 itself has no afEnity for IL-6 in solution, but stabilizes the IL-6.80-kDaIL-6R complex on the membrane, resulting in high affinity binding of IL-6 (& -10 PM) (7).Recently, it was found that gp130 is also a constituent of the receptors for leukemia inhibitory factor, oncostatin M, and ciliary neurotrophic factor (for erlands Foundation for Fundamental Research.The costs of
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