Engineering antigen-specific tolerance to an artificial protein hydrogel

ABSTRACT Artificial protein hydrogels are an emerging class of biomaterials with numerous prospective applications in tissue engineering and regenerative medicine. These materials are likely to be immunogenic due their frequent incorporation of novel amino acid sequence domains, which often serve a functional role within the material itself. We engineered injectable “self” and “non-self” artificial protein hydrogels which were predicted to have divergent immune outcomes in vivo on the basis of their primary amino acid sequence. Following implantation in mouse, the non-self gels raised significantly higher anti-gel antibody titers than the corresponding self gels. Prophylactic administration of a fusion antibody targeting the non-self hydrogel epitopes to DEC-205, an endocytic receptor involved in T reg induction, fully suppressed the elevated antibody titer against the non-self gels. These results suggest that the clinical immune response to artificial protein biomaterials, including those that contain highly antigenic sequence domains, can be tuned through the induction of antigen-specific tolerance.