Abstract
Programmed cell death protein-1 (PD-1) expressed on activated T cells inhibits T cell function and proliferation to prevent an excessive immune response, and disease can result if this delicate balance is shifted in either direction. Tumor cells often take advantage of this pathway by overexpressing the PD-1 ligand PD-L1 to evade destruction by the immune system. Alternatively, if there is a decrease in function of the PD-1 pathway, unchecked activation of the immune system and autoimmunity can result. Using a combination of computation and experiment, we designed a hyperstable 40-residue miniprotein, PD-MP1, that specifically binds murine and human PD-1 at the PD-L1 interface with a Kd of ∼100 nM. The apo crystal structure shows that the binder folds as designed with a backbone RMSD of 1.3 Å to the design model. Trimerization of PD-MP1 resulted in a PD-1 agonist that strongly inhibits murine T cell activation. This small, hyperstable PD-1 binding protein was computationally designed with an all-beta interface, and the trimeric agonist could contribute to treatments for autoimmune and inflammatory diseases.
| Original language | English (US) |
|---|---|
| Article number | e2102164118 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 118 |
| Issue number | 29 |
| DOIs | |
| State | Published - Jul 20 2021 |
Funding
ACKNOWLEDGMENTS. We want to thank Steve Almo at the Albert Einstein College of Medicine for his gift of mPD-1 protein at the start of this project. Christy Tinberg and Songyu Wang from Amgen tested stability of molecules prior to the functional assays. This project was supported by a grant from the NIH (Grant 5U01GM094665) and Amgen Research. C.M.B. received support from a generous gift from Rocky and Genie Higgins. G.J.R. was funded as a Merck Fellow of the Life Sciences Research Foundation. M.J.B. was supported by the Institute for Protein Design (IPD) Launch Matching Fund. A.F. was funded by the NIH (Grant R01GM092802). L.C. was funded through a grant from the Bill and Melinda Gates Foundation (Grant OPP1156262 AM03). I.G. was supported by the Open Philanthropy Project Improving Protein Design Fund and the Nordstrom Barrier Institute for Protein Design Directors Fund. A.K. was funded by a gift from Silicon Valley Community. C.J.M. was supported by Bill and Melinda Gates Foundation Grant OPP1156262 and Amgen. F.D. was funded by the NIH (Grant R01GM123089).
Keywords
- Protein design | PD-1 | autoimmunity | immunotherapy
ASJC Scopus subject areas
- General
