Screening assay for modulators of interaction between interleukin-12 and/or -23 with their receptors

Kit for identifying an agent that modulates the interaction of interleukin-23 and/or interleukin-12 with a corresponding receptor comprising

• a) interleukin-23 and/or interleukin-12,
• b) the interleukin-23 p19 receptor and/or the interleukin-12 p40 receptor,
• c) optionally detection means,
• d) instructions for use of said kit, and
• e) optionally a solid phase.

Method for determining whether a receptor is specific for interleukin-23 or interleukin-12 or both or none, comprising

• a) providing a receptor,
• b) contacting interleukin-23 with the receptor of step a) for a sufficient period of time so that a complex between said interleukin and said receptor can be formed,
• c) contacting interleukin-12 with the receptor of step a) for a sufficient period of time so that a complex between said interleukin and said receptor can be formed,
• d) optionally separating the complex formed in step b) and/or c) from uncomplexed fractions,
• e) detecting the complex formed in step b) and/or in step c) with detection means,
• f) determining whether the receptor is
• specific for interleukin-23, which is the case if a complex formation of step b) and no complex formation of step c) is detected, or
• specific for interleukin-12, which is the case if a complex formation of step c) and no complex formation of step b) is detected, or
• specific for both interleukin-23 and interleukin-12, which is the case if a complex formation of step b), and a complex formation of step c) is detected, or
• unspecific for interleukin-23 and interleukin-12, which is the case if no complex formation of step b), and no complex formation of step c) is detected.