SARS-CoV-2-derived RNA replicons as safe and effective vaccines
Abstract
A collection of RNA replicons (RRs) derived from severe acute respiratory syndrome 2 (SARS-CoV-2) for use in vaccine design was constructed by genetic engineering using bacterial artificial chromosomes. A replicon, which was deleted in six genes (3a, 3c, E, 6, 7a, and 7b) was selected. Cells infected with the RR vaccine candidate led to the formation of virus-like particles that, due to the failure of being secreted, increase vaccine safety, in contrast to the wild type virions. The replicon maintained the production of RNAs encoding at least proteins S, M, and N for several days. Intranasal immunization with the RR of transgenic mice, expressing human ACE2, elicited respiratory mucosal immunity. Immunization protected against challenge with SARS-CoV-2, inducing IgG, IgM, and IgA antibodies to the spike (S) protein, the receptor binding domain, N and M proteins, and cellular immune responses (CD4 + , CD8 + , and long-term memory T cells). Coinfection of cells with the RR vaccine and a full-length SARS-CoV-2 led to a significant inhibition of replication of full-length virus, increasing the safety of the RR vaccine. The RR vaccine induced a minor inflammatory reaction in the absence of major side effects and was stable at different temperatures. An updated RR expressing XBB.1.5 S protein elicited neutralizing antibodies against the homologous virus and provided full protection against recent SARS-CoV-2 variants.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (24)
Marta Villarejo-Torres
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Iván Nombela-Diaz
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Diego Muñóz-Santos
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Mercedes Ruiz-Yuste
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Ana Marchena-Pasero
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
María A. Rueda-Huélamo
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Jorge Ripoll-Gómez
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Pedro J. Sánchez-Cordón
Pathology Department, Centro de Investigaciones en Salud Animal, Instituto de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC)
Laura Fernandez del Ama
Pathology Department, Centro de Investigaciones en Salud Animal, Instituto de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC)
José M. Honrubia
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Javier Gutiérrez-Álvarez
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Jesús Hurtado-Tamayo
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Ricardo Requena-Platek
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
María Guzmán
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Jose M. Casasnovas
Department of Macromolecular Structures, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Juan F. García-Arriaza
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Patricia Perez
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Beatriz Martin-Jouve
Electron Microscopy Service, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Tania Matamoros
Electron Microscopy Facility, Molecular Biology Center (CBMSO-CSIC), Campus Universidad Autónoma de Madrid
Belén Pintado
Transgenesis and Gene Editing Unit, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Stanley Perlman
Isabel Sola
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Sonia Zuñiga
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid
Luis Enjuanes
Department of Molecular and Cell Biology, National Center of Biotechnology (CNB-CSIC), Darwin 3, Campus Universidad Autónoma de Madrid