A trivalent vaccine candidate against hepatitis E virus, norovirus, and astrovirus

Abstract

Hepatitis E virus (HEV), norovirus (NoV), and astrovirus (AstV) are enterically-transmitted viral pathogens causing epidemic or endemic hepatitis (HEV) and gastroenteritis (NoV and AstV) respectively in humans, leading to significant morbidity and mortality worldwide. While a recombinant subunit vaccine against HEVs is available in China, there is no commercial vaccine or antiviral against NoV or AstV. We report here our development of a trivalent vaccine against the three viral pathogens through our new polymer vaccine technology. All HEV, NoV, and AstV are non-enveloped RNA viruses covered by a protein capsid, featuring surface protruding (P) proteins that are responsible for virus–host interaction. These dimeric P protein selicit neutralizing antibody and are good targets for subunit vaccine development. The trivalent subunit vaccine was developed by fusion of the dimeric P domains of the three viruses together that formed tetramers. This trivalent vaccine elicited significantly higher antibody responses in mice against all three P domains than those induced by a mixture of the three free P domains (mixed vaccine). Furthermore, the post-immune antisera of the trivalent vaccine showed significantly higher neutralizing titers against HEV infection in cell culture and higher blocking activity on NoV binding to HBGA ligands than those of the post-immune antisera of the mixed vaccine. Thus, the trivalent vaccine is a promising vaccine candidate against HEV, NoV, and AstV.

Bioengineered Norovirus S60 Nanoparticles as a Multifunctional Vaccine Platform

“…These DNA constructs were made by introductions of other two (V 57 C/M 140 C), three (V 57 C/Q 58 C/S 136 C), or four (V 57 C/Q 58 C/S 136 C/M 140 C) mutations to the expression construct of the S R69A -VP8* chimeric proteins through site-directed mutagenesis. In addition, plasmid DNA constructs for other S R69A/V57C/Q58C/S136C -based chimeric particles displaying antigens of various pathogens, including a) the VP8* antigen of the murine RV EDIM (epizootic diarrhea of infant mice) strain; 49 b) the full-length RV VP8* antigen of human RV (strain BM14113); c) the surface TSR antigen of the circumsporozoite protein (CZP) (GenBank AC#:CAB38998, residues 309–375) of Plasmodium falciparum parasite 3D7 strain; 50 d) the H7 HA1 antigen (the receptor binding domain) of influenza A virus; and e) the P domain antigens of hepatitis E viruses, 51–53 were constructed using the construct of S R69A/V57C/Q58C/S136C -VP8* chimeric proteins as the starting construct, in which the RV VP8*-encoding sequences were replaced with those encoding the corresponding antigens.…”

Evidence for an unknown agent antigenically related to the hepatitis E virus in dairy cows in the United States

“…A subclone of the Huh7 human liver cell line, Huh7‐S10‐3, was used to propagate the genotype 3 human HEV Kernow P6 strain . Human hepatocellular carcinoma cells HepG2/C3A (ATCC, Manassas, VA) were maintained in Dulbecco's modified Eagle medium (DMEM, ThermoFisher Scientific, Ontario, Canada) with 10% fetal bovine serum on collagen‐coated flasks and were used for all in vitro infectivity assays as described previously on selected bovine sera that were tested positive by ELISA. Briefly, the genotype 3 HEV Kernow P6 virus stock was incubated in duplicate with phosphate‐buffered saline (PBS) as the negative control, Chimp 1313 hyperimmune anti‐HEV serum as the positive control, or selected bovine serum samples at 1:10, 1:100, and 1:1000 dilutions.…”

Saliva as a source of reagent to study human susceptibility to avian influenza H7N9 virus infection

“…A Hisx6 tag was fused to the end of the H7 HA1 for purification purpose. Both proteins were expressed in E. coli as described elsewhere 23 , 24 .…”