A Synthetic Biology Strategy: Genetic and Metabolic Orthogonality for Overcoming the Immunogenicity of Therapeutic Proteins

Abstract

With the widespread application of therapeutic protein drugs, numerous issues associated with these medications have been increasingly serious. The most prevalent one is immunogenicity, that is antigens stimulate an immune response in the body. It would limit efficacy and safety. To overcome this challenge, this paper built a dual orthogonal system via synthetic biology to reduce protein drug immunogenicity without interfering with host cellular functions. It includes both genetic and metabolic orthogonality. Codon reprogramming was employed to mask drug immunogenic epitopes for concealing immune recognition sites, enabling the drug to achieve “molecular invisibility” in the body. Furthermore, by reconstructing glycosylation to modify non-human glycans and establishing a human glycan synthesis pathway, the potential for immunogenicity caused by xenogeneic glycans was reduced. Using insulin as a model, this strategy produced modified molecules capable of evading MHC-II binding and antibody-mediated neutralization. The dual orthogonal framework therefore offers a promising route to generate therapeutic proteins that are functionally active yet immunologically “invisible”. Besides insulin, this approach also can be extended to other biotherapeutics. Taken these, this finding establish safer, de-immunized therapeutic proteins through synthetic biology contributing to the future of biologic drug design and personalized therapy.