Design of high-affinity binders to immune modulating receptors for cancer immunotherapy
Wei Yang, Derrick R. Hicks, Agnidipta Ghosh, Tristin A. Schwartze, Brian Coventry, Inna Goreshnik, Aza Allen, Samer Halabiya, Chan Johng Kim, Cynthia S. Hinck, David Lee, Asim K. Bera, Zhe Li, Yujia Wang, Thomas Schlichthaerle, Longxing Cao, Buwei Huang, Sarah Garrett, Stacey Gerben, Stephen Rettie, Piper Heine, Analisa Murray, Natasha I. Edman, Lauren Carter, Lance Stewart, Steven C. Almo, Andrew P. Hinck, David Baker
Abstract
Immune receptors have emerged as critical therapeutic targets for cancer immunotherapy. Designed protein binders can have high affinity, modularity, and stability and hence could be attractive components of protein therapeutics directed against these receptors, but traditional Rosetta based protein binder methods using small globular scaffolds have difficulty achieving high affinity on convex targets. Here we describe the development of helical concave scaffolds tailored to the convex target sites typically involved in immune receptor interactions. We employed these scaffolds to design proteins that bind to TGFβRII, CTLA-4, and PD-L1, achieving low nanomolar to picomolar affinities and potent biological activity following experimental optimization. Co-crystal structures of the TGFβRII and CTLA-4 binders in complex with their respective receptors closely match the design models. These designs should have considerable utility for downstream therapeutic applications.