The Power of Three: Nanomaterials for Natural Killer (NK) Cell Immunoengineering Maximize Their Potency If They Exploit Multireceptor Stimulation.

Many emerging cancer treatments are immunotherapies that modulate Natural Killer- (NK) or T cell activation, posing a challenge to develop immunoengineering nanomaterials that improve on the performance of molecular reagents. In physiological activation, multiple immunoreceptors signal in consort, however current biomaterials do not replicate this. Here, we create for the first time NK cell activating bionanomaterials that stimulate >2 immunoreceptors. We exploit nanoclusters of monoclonal antibodies (mAb), templated by nanoscale graphene oxide sheets (NGO) (∼75 nm size). To inform nanoreagent design, we first investigated a model system of planar substrates with anchored mAb. Combining mAb that stimulate 3 NK cell activating receptors (αNKP46 + αNKG2D + αDNAM-1), activated NK cells more potently than any single receptor or pair. Applying this insight, we created an NGO-mAb nanocluster that combined three distinct mAb: NGO-mAb(αNKP46 + αNKG2D + αDNAM-1). This construct was potent and outperformed single-receptor-simulating nanoclusters, activating nearly twice as many NK cells as NGO-mAb(αNKP46) at a similar mAb dose, or delivering similar activation at 10x lower dosage. Furthermore, NGO-mAb were more potent than planar substrates for both single- and triple-mAb stimulation. Our results imply a new concept for immunoengineering biomaterials: both nanoclustering and multi-receptor stimulation should be incorporated for maximum effect. This article is protected by copyright. All rights reserved.