Abstract: The present application provides a fusion protein, a method for preparing such fusion proteins and use thereof. The fusion protein comprises a Fab fragment capable of binding specifically to 4-lBB molecules and comprises CD40L capable of binding specifically to CD40 molecules; the N-terminus of the first CD40L is connected to the C-terminus of the light chain or heavy chain of the Fab fragment by means of a first peptide linker. The fusion protein of the CD137 antibody and CD40L of the present application is capable of binding specifically to CD40, has the effects of inducing dendritic cell maturation, activating lymphocytes, etc., and can be used for treating tumors and immune-related diseases; Meanwhile, the fusion protein of the CD137 antibody and CD40L can target 4-lBB and activate the signal transduction pathway of 4-lBB to enhance immune responses.

Abstract: The present application provides a fusion protein, containing: an anti-CD137 antibody capable of specifically binding to a CD137 molecule or an antigen binding fragment thereof; an anti-CD3 antibody capable of specifically binding to a CD3 molecule or an antigen binding fragment thereof; and a first peptide linker and a second peptide linker. The present application also provides a nucleic acid encoding the fusion protein, an expression vector containing the nucleic acid, a host cell containing the nucleic acid or the expression vector, a method for preparing the fusion protein, a pharmaceutical composition containing the fusion protein, and a use of the fusion protein.