Nogo receptor 1 is a novel class of NK cell inhibitory receptor to destabilize synapse by regulating actin dynamics

Abstract The formation of immunological synapse (IS) is essential for natural killer (NK) cells to eliminate target cells. Although elucidation of the overall characteristics and formation processes of IS is ongoing, the mechanisms for regulating the stability of IS by cytoskeleton remain to be understood. The current study reports that Nogo receptor 1 (NgR1) plays a key role in modulating NK cell-mediated killing by destabilization of IS formation. NgR1 deficiency or blockade results in improved tumor control of NK cells by enhancing NK-to-target cell contact stability and regulating F-actin dynamics during IS formation. Clinically, patients with a tumor expressing abundant NgR1 ligand showed poor prognosis despite high levels of NK cell infiltration. Thus, our study identifies NgR1 as an immune checkpoint involved in IS formation and reveals a potential approach to improve the killing effect of NK cells in cancer immunotherapy.