title: Discovery of selective small-molecule CD80 inhibitors.
abstract: Protein-protein interactions are widely found in biological systems controlling diverse cellular events. Because these interactions are implicated in many diseases such as autoimmunity and cancer, regulation of protein-protein interactions provides ideal targets for drug intervention. The CD80-CD28 costimulatory pathway plays a critical role in regulation of the immune response and thus constitutes an attractive target for therapeutic manipulation of autoimmune diseases. The objective of this study is to identify small compounds disrupting these pivotal protein-protein interactions. Compounds that specifically blocked binding of CD80 to CD28 were identified using a strategy involving a cell-based scintillation proximity assay as the initial step. Secondary screening (e.g., by analyzing the direct binding of these compounds to the target immobilized on a biosensor surface) revealed that these compounds are highly selective CD80 binders. Screening of structurally related derivatives led to the identification of the chemical features required for inhibition of the CD80-CD28 interaction. In addition, the optimization process led to a 10-fold increase in binding affinity of the CD80 inhibitors. Using this approach, the authors identify low-molecular-weight compounds that specifically and with high potency inhibit the interaction between CD80 and CD28. These compounds serve as promising starting points for further development of CD80 inhibitors as potential immunomodulatory drugs.
authors: Active Biotech Research AB, Lund, Sweden.
authors: Kristina
authors: K
authors: Uvebrant
authors: Dorthe
authors: D
authors: da Graça Thrige
authors: Anna
authors: A
authors: Rosén
authors: Mats
authors: M
authors: Akesson
authors: Helena
authors: H
authors: Berg
authors: Björn
authors: B
authors: Walse
authors: Per
authors: P
authors: Björk
mesh_terms: D000818:Animals; D018122:B7-1 Antigen / Q000378:metabolism*; D001667:Binding, Competitive; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D015195:Drug Design; D006041:Goats; D006801:Humans; D051379:Mice; D011485:Protein Binding; D025941:Protein Interaction Mapping; D011817:Rabbits
chemical_list: D018122:B7-1 Antigen