CXCR7 - Ligand Design/Evaluation (Margret Schottelius / Calogero D’Alessandria)

The development and optimization of CXCR-4 receptor ligands is one of our major research focusses. During the in vitro evaluation of new CXCR-4-targeting cyclopeptide ligands we encountered interesting effects, which can only be explained by interaction of the ligands with another receptor. Based on the fact, that the natural CXCR-4 ligand CXCL12 (SDF-1) also binds to the CXCR-7 receptor, and also on the closely interlocked function of CXCR-4 and CXCR-7, which has been documented in a variety of studies, we assume, that concomitant binding to CXCR-7 may play an important role in cellular binding of several of our ligands. The goal of our ongoing studies is to identifiy and to “separate” the contributions of CXCR-4 and CXCR-7 binding to total binding, along with the development of CXCR-7 specific radioligands.