10.26249/FK2/NPX7DUPollmann, ChristophChristophPollmann0000-0002-1473-0288Osnabrück UniversityosnaData2024Medicine, Health and Life SciencesPollmann, ChristophChristophPollmannOsnabrück University2024-08-302024-08-30https://omero.cellnanos.uni-osnabrueck.de/webclient/?show=project-157071.0CC0 WaiverExcessive cytokine signaling resulting from dysregulation of a cytokine or its receptor can be a main driver of cancer, autoimmune or hematopoietic disorders. Here we leverage protein design to create tailored cytokine receptor blockers with idealized properties. Specifically, we aimed to tackle the granulocyte-colony stimulating factor receptor (G-CSFR), a mediator of different types of leukemia and autoinflammatory diseases. By modifying designed G-CSFR binders, we engineered hyper-stable proteins that function as nanomolar signaling antagonists. X-ray crystallography showed atomic-level agreement with the experimental structure of an exemplary design. Furthermore, the most potent design blocks G-CSFR in acute myeloid leukemia cells and primary hematopoietic stem cells. Thus, the resulting designs can be used for inhibiting or homing to G-CSFR-expressing cells. Our work also demonstrates that designed cytokine mimics can be used to derive non-activating variants for tackling a range of cytokine receptors.