Structure-based design of antibodies targeting the EBNA1 DNA-binding domain to block Epstein-Barr virus latent infection and tumor growth.

The Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is critically involved in maintaining episomes during latent infection and promoting tumorigenesis. The development of an epitope-specific monoclonal antibody (mAb) for EBNA1 holds great promise due to its high affinity and specificity, offering a new and innovative approach for the treatment of EBV-related diseases. In this proof-of-concept study, we employed a structure-based design strategy to create three unique immunogens specifically targeting the DNA binding state of the EBNA1 DBD. By immunizing mice, we successfully generated a mAb, named 5E2-12, which selectively targets the DNA binding interface of EBNA1. The 5E2-12 mAb effectively disrupts the interaction between EBNA1 and DNA binding, resulting in reduced proliferation of EBV-positive cells and inhibition of xenograft tumor growth in both cellular assays and mouse tumor models. These findings open up new avenues for the development of innovative biological macromolecular drugs that specifically target EBNA1 and provide potential for clinical therapy options for early-stage EBV-positive tumors. The epitope-specific mAb approach demonstrates novelty and innovation in tackling EBV-related diseases and may have broad implications for precision medicine strategies in the field of viral-associated cancers.