<i>In Vitro</i> Assessment of Putative PD-1/PD-L1 Inhibitors: Suggestions of an Alternative Mode of Action
作者:Derek J. Blevins、Ronan Hanley、Trevor Bolduc、David A. Powell、Michael Gignac、Kayleigh Walker、Mark D. Carr、Fraser Hof、Jeremy E. Wulff
DOI:10.1021/acsmedchemlett.9b00221
日期:2019.8.8
The programmed cell death protein 1 (PD-1) signaling axis is among the most important therapeutic targets in modern oncology. Aurigene Discovery Technologies Ltd. (Aurigene) has patented a series of peptidomimetic small molecules derived from the PD-1 protein sequence for use in targeting the interaction between PD-1 and its ligand, PD-L1. We evaluated three of Aurigenes most potent compounds in SPR binding assays. Our results showed that these compounds-each of which is known to be potently effective in a splenocyte recovery assay-do not directly inhibit the PD-1/PD-L1 interaction nor do they appear to bind to either of the constituent proteins, indicating that another mechanism is at play. As a result of these studies and upon consideration of structural features within the PD-1/PD-L1 complex, we hypothesize that the Aurigene molecules may interact with a currently unknown protein capable of regulating the PD-1 axis.