title: Exosomal vaccines containing the S protein of the SARS coronavirus induce high levels of neutralizing antibodies.
abstract: Infection with the SARS-associated coronavirus (SARS-CoV) induces an atypical pulmonary disease with a high lethality rate. Although the initial SARS epidemic was contained, sporadic outbreaks of the disease still occur, suggesting a continuous need for a vaccine against this virus. We therefore explored exosome-based vaccines containing the spike S proteins of SARS-CoV. S-containing exosomes were obtained by replacing the transmembrane and cytoplasmic domains of the S protein by those of VSV-G. The immunogenicity and efficacy of the S-containing exosomes were tested in mice and compared to an adenoviral vector vaccine expressing the S protein. Both, S-containing exosomes and the adenoviral vector vaccine induced neutralizing antibody titers. After priming with the SARS-S exosomal vaccine and boosting with the adenoviral vector the neutralizing antibody titers exceeded those observed in the convalescent serum of a SARS patient. Both approaches were effective in a SARS-S-expressing tumor challenge model and thus warrant further investigation.
authors.affiliation: Department of Molecular and Medical Virology, Ruhr-University Bochum, D-44780 Bochum, Germany. Seraphin.Kuate@rub.de
authors.forename: Seraphin
authors.initials: S
authors.lastname: Kuate
authors.forename: Jindrich
authors.initials: J
authors.lastname: Cinatl
authors.forename: Hans Wilhelm
authors.initials: HW
authors.lastname: Doerr
authors.forename: Klaus
authors.initials: K
authors.lastname: Uberla
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002460:Cell Line; D002522:Chlorocebus aethiops; D004195:Disease Models, Animal; D006801:Humans; D007117:Immunization, Secondary; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D023421:Models, Animal; D009369:Neoplasms / Q000276:immunology / Q000473:pathology; D009500:Neutralization Tests; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D045473:Severe acute respiratory syndrome-related coronavirus / Q000276:immunology*; D064370:Spike Glycoprotein, Coronavirus; D022161:Transport Vesicles / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D008562:Membrane Glycoproteins; D011993:Recombinant Fusion Proteins; D064370:Spike Glycoprotein, Coronavirus; D014614:Vaccines, Synthetic; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus