Design of Hyperglycosylated Zika Virus E Proteins that Focus Antibody Recognition on the Complex E Dimer Epitope

Zika virus (ZIKV) and dengue virus serotypes 1-4 (DENV1-4) are flaviviruses spread by Aedes mosquitoes. ZIKV infection can cause Guillain-Barré syndrome and microcephaly, while severe dengue can lead to hemorrhagic fever and death. DENV infection of ZIKV-immune individuals is linked to severe clinical outcomes due to antibody-dependent enhancement (ADE) of infection. Thus, the development of broadly protective vaccines is an important objective. We focus on the E dimer epitope (EDE) of ZIKV, which is targeted by broadly neutralizing antibodies that protect against ZIKV and DENV1-4. We engineered ZIKV E dimer variants containing non-native asparagine-linked glycosylation sites to block antibody responses to regions outside the EDE using a structure-based iterative design approach. One candidate, SC30m53, bound EDE mAbs but not other mAbs and induced a potently neutralizing response against ZIKV and moderately cross-neutralizing responses against DENV1-3 in mice. These findings suggest that hyperglycosylation provides a promising approach to focusing the immune response on key epitopes.