Pre-clinical evaluation of bifunctional SIRPα-antibody fusion proteins for the treatment of acute myeloid leukemia

Abstract

Background: 4-1BB (CD137; TNFRSF9) binds 4-1BBL, which triggers subsequent proliferation and activation of immune cells, T and NK cells in particular. We designed and generated PVR-4-1BBL, a hexameric protein of 4-1BBL fused to PVR (CD155), the major ligand for TIGIT that marks exhausted T cells. This fusion protein efficiently bind to its targets TIGIT and 4-1BB on cells as well as in soluble form.