A CH3 region connects the two diabodies that make up Recombinant Anti-Ad fiber knob x Anti-CEA Bispecific Antibody (Diabody-CH3), a fusion protein. Anti-Ad fiber knob and anti-CEA antibodies are the two scFvs with short linkers in a diabody. An inter-chain pairing is formed by the VH and VL domains. The diabody, which has distinct specificities, is fused to every CH3 chain, resulting in valency for 2+2 antigen binding and prolonging the BsAb’s half-life. Adenoviral vectors can be retargeted to tumor cells by this BsAb. It can be applied in cancer gene therapy to introduce a therapeutic gene into tumor cells with the goal of destroying cancer cells in a targeted and effective manner.
