Induction of ebolavirus cross-species immunity using retrovirus-like particles bearing the Ebola virus glycoprotein lacking the mucin-like domain

Abstract

Background: The genus Ebolavirus includes five distinct viruses. Four of these viruses cause hemorrhagic fever in humans. Currently there are no licensed vaccines for any of them; however, several vaccines are under development. Ebola virus envelope glycoprotein (GP 1,2) is highly immunogenic, but antibodies frequently arise against its least conserved mucin-like domain (MLD). We hypothesized that immunization with MLD-deleted GP 1,2(GPMLD) would induce cross-species immunity by making more conserved regions accessible to the immune system. Methods. To test this hypothesis, mice were immunized with retrovirus-like particles (retroVLPs) bearing Ebola virus GPMLD, DNA plasmids (plasmo-retroVLP) that can produce such retroVLPs in vivo, or plasmo-retroVLP followed by retroVLPs. Results: Cross-species neutralizing antibody and GP 1,2-specific cellular immune responses were successfully induced. Conclusion: Our findings suggest that GPMLD presented through retroVLPs may provide a strategy for development of a vaccine against multiple ebolaviruses. Similar vaccination strategies may be adopted for other viruses whose envelope proteins contain highly variable regions that may mask more conserved domains from the immune system. © 2012 Ou et al; BioMed Central Ltd.