IL-18 binding protein (IL-18BP) in inflammatory diseases

#The contents of the electronic sequence listing (VOSS_0200US_CON_ST25.txt”; Size is 97,780 bytes and it was created on Aug. 3, 2020) is herein incorporated by reference in its entirety.

#The present invention provides means and methods for treating Interleukin 18 (IL-18)-associated diseases and disorders. In particular, the present invention discloses antibodies specific for free IL-18 and IL-18 Binding Protein (IL-18BP) for use in such treatments and for the diagnosis of the indications.

#Interleukin-18 (IL-18), also known as interferon-gamma inducing factor is a cytokine, which is produced by activated macrophages, Kupffer cells and other cells. IL-18 binds to the IL-18 receptor and induces cell-mediated immunity. Defects (e.g. knock-out) of the IL-18 cytokine receptor or IL-18 cytokine lead to impaired natural killer (NK) cells activity and TH1 responses. Apart from its physiological role, IL-18 may also induce severe inflammatory disorders. For the purpose of early diagnosis of such disorders it therefore would be necessary to quantify the levels of free IL-18 in body fluids of a subject, expected to have such a disorder.

#FIG. 1: Comparison of total and free IL-18 in individual sepsis patients. Adapted from Novick et al 2001. The level of free IL-18 (closed circles) in sera of sepsis patients upon admission was calculated based on the concentration of total IL-18 (open circles) and IL-18BPa, taking into account a 1:1 complex of IL-18 and IL-18BPa and a calculated KD of 400 pM. Each vertical line links total and free IL-18 in an individual serum sample. The above ELISA assays are performed with the pair of antibodies developed by Taniguchi et al 1997 1, namely antibodies 125-2H as primary/capture antibody and 159-12B as secondary/developing antibody.

#FIG. 2: Detection of total IL-18 with antibodies 125-2H and 159-12B. The data indicates that both antibodies quantify total IL-18.

#FIG. 3: Titration of 400 pg/ml IL-18 as a function of IL-18BP level

#SEQ ID NO 1: IL-18 Epitope 1: Tyr-Phe-Gly-Lys-Leu-Glu-Ser-Lys-Leu-Ser-Val-Ile-Arg-Asn

#SEQ ID NO 2: IL-18 Epitope 2: Phe-Ile-Ile-Ser-Met-Tyr-Lys-Asp-Ser-Gln-Pro-Arg-Gly-Met-Ala-Val-Thre-Ile-Ser-Val-Lys

#SEQ ID NO 3: IL-18 Epitope 3: Glu-Met-Asn-Pro-Pro-Asp-Asn-Ile-Lys-Asp-Thr-Lys-Ser-Asp-Ile-Ile-Phe