Assays for inhibitors of leukocyte adhesion

Abstract

The present invention provides novel assays for determining the ability of a test compound to inhibit intercellular adhesion mediated by a selectin receptor, such as the LHR. The assay involves coating a surface of a solid substrate with an antibody which specifically binds a selectin ligand. Preferred are antibodies against GlyCAM-1 which is a natural biological ligand for L-Selectin and also binds to P-Selectin and E-Selectin. A compound such as GlyCAM-1 is then bound to the antibodies. The test compound mixture putatively containing a selectin ligand is then brought into contact with a chimeric molecule. The test mixture might include any compound which might block or hinder binding between a selectin receptor and the ligand bound to the antibody. The chimeric molecule is comprised of an immunoglobulin bound to a selectin receptor and is introduced under conditions such that the selectin receptor portion of the chimeric molecule will bind to the selectin ligand bound to the antibodies on the surface if such binding is not blocked by the test compound. Bound chimeric molecules can be detected in a variety of ways such as by a conjugate compound of an anti-immunoglobulin antibody bound to enzyme such as alkaline phosphatase for the generation of color. Any test compounds which bind to the selectin receptor and block finding can be isolated, analyzed and identified.