Bifunctional fusion protein targeting cd47 and pd-l1

Abstract

A bifunctional fusion protein targeting CD47 and PD-L1, which belongs to the field of biomedicine and solves the problems that anti-PD-1/PD-L1 treatment has poor effect on low immunogenic tumors and anti-CD47 treatment has poor targeting properties. The fusion protein consists of a CD47-binding moiety and a PD-L1-binding moiety linked by means of a disulfide bond, can block both the binding of CD47 to SIRPa and the binding of PD-L1 to PD-1, not only activating macrophage phagocytosis of tumor cells and promoting antigen presentation in innate immunity, but also promoting tumor-specific T cell activation in acquired immunity, and has lower hematological toxicity. The fusion protein has better anti-tumor efficacy and hematological safety than anti-PD-L1 or anti-CD47 therapy alone, and animals from which a tumor has disappeared after the treatment of the fusion protein produce immunity against re-inoculation of the same tumor cell.