Rational design of next-generation filovirus vaccines combining glycoprotein stabilization and nanoparticle display with glycan modification

Filoviruses pose a significant threat to human health due to frequent outbreaks and high mortality. Although two vector-based vaccines are available for Ebola virus, a broadly protective filovirus vaccine remains elusive. Here, we evaluate a general strategy for stabilizing glycoproteins (GP) from Ebola, Sudan, and Bundibugyo orthoebolaviruses, as well as Ravn orthomarburgvirus. A 3.2 Å crystal structure provides atomic-level details of the redesigned Ebola virus GP, while cryo-electron microscopy reveals how a pan-orthoebolavirus neutralizing antibody targets a conserved site on the stabilized Sudan virus GP (3.13 Å resolution), along with a low-resolution model of antibody-bound Ravn virus GP. A self-assembling protein nanoparticle (SApNP), I3-01v9, is redesigned at the N terminus to enable optimal surface display of filovirus GP trimers. Following detailed in vitro characterization, we examine the lymph node dynamics of Sudan virus GP and GP-presenting SApNPs in mice. Compared with the soluble trimer, SApNPs exhibit ~112-fold longer retention in lymph node follicles, up to 28-fold greater presentation on follicular dendritic cell dendrites, and up to 3-fold stronger germinal center reactions. Functional antibody responses induced by filovirus GP trimers and SApNPs bearing wild-type or modified glycans are assessed in mice. This study provides a foundation for next-generation filovirus vaccine development. There are limited vaccines available for Ebola virus and none for broad protection from filoviruses. Here, the authors rationally design vaccines using nanoparticles and stabilized Ebola virus and other filovirus glycoproteins, characterize antibody epitopes and profile lymph node and antibody responses in mice.