Epitope map of HSV-specific mAbs that target the viral entry mediator gD. (A) Linear representation of the gD extracellular domain with the HVEM binding domain (yellow) and Nectin domains (black). UB-621 is a clinical-grade product of the E317 clone. The exact contact residues of HSV8 are not known, but shown is an approximation based on reactivity against gD residues 235–275. (B) The space-filling structure of truncated gD (gD285; PDB accession no. 1JMA), with cell receptor binding domains and mAb epitopes denoted by specific colors shown in A, as follows: red = CH42, pink = CH43, blue = E317/UB-621, purple = HSV8. Residues (P14, A21, Q27, R130, D215, R222) are numbered as points of reference.