Combined administration of synthetic RNA and a conventional vaccine improves immune responses and protection against foot-and-mouth disease virus in swine.
Foot-and-mouth disease virus (FMDV) is the causative agent of a highly contagious disease and a major concern in animal health worldwide. We have previously reported the use of RNA transcripts mimicking structural domains in the non-coding regions of the FMDV RNA as potent type-I interferon (IFN) inducers showing antiviral effect in vivo, as well as their immunomodulatory properties in combination with an FMD vaccine in mice. Here, we describe the enhancing effect of RNA delivery on the immunogenicity and protection induced by a suboptimal dose of a conventional FMD vaccine in pigs. Animals receiving the RNA developed earlier and higher levels of neutralizing antibodies against homologous and heterologous isolates, compared to those immunized with the vaccine alone, and had higher anti-FMDV titers at late times post-vaccination. RNA delivery also induced higher specific T-cell response and protection levels against FMDV challenge. Peripheral blood mononuclear cells from pigs inoculated with RNA and the vaccine had a higher IFN-γ specific response than those from pigs receiving the vaccine alone. When challenged with FMDV, all three animals immunized with the conventional vaccine developed antibodies to the non-structural viral proteins 3ABC and two of them developed severe signs of disease. In the group receiving the vaccine together with the RNA, two pigs were fully protected while one showed delayed and mild signs of disease. Our results support the immunomodulatory effect of these RNA molecules in natural hosts and suggest their potential use for improvement of FMD vaccines strategies.
CISA-INIA, Valdeolmos, 28130, Madrid, Spain. Electronic address: borrego@inia.es.
Belén
B
Borrego
CISA-INIA, Valdeolmos, 28130, Madrid, Spain. Electronic address: blanco@inia.es.
Esther
E
Blanco
Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Cantoblanco, 28049, Madrid, Spain. Electronic address: mrrodriguez@cbm.csic.es.
Miguel
M
Rodríguez Pulido
CISA-INIA, Valdeolmos, 28130, Madrid, Spain. Electronic address: fmateos@inia.es.
Francisco
F
Mateos
Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Cantoblanco, 28049, Madrid, Spain. Electronic address: lorenzo.gema@inia.es.
Gema
G
Lorenzo
Biogénesis Bagó S.A., Garín, B1619 IEA, Buenos Aires, Argentina. Electronic address: sabrina.cardillo@biogenesisbago.com.
Sabrina
S
Cardillo
Biogénesis Bagó S.A., Garín, B1619 IEA, Buenos Aires, Argentina. Electronic address: eliana.smitsaart@biogenesisbago.com.
Eliana
E
Smitsaart
Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Cantoblanco, 28049, Madrid, Spain. Electronic address: fsobrino@cbm.csic.es.
Francisco
F
Sobrino
Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Cantoblanco, 28049, Madrid, Spain. Electronic address: msaiz@cbm.csic.es.
Margarita
M
Sáiz
D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D005260:Female; D005536:Foot-and-Mouth Disease / Q000276:immunology* / Q000517:prevention & control*; D029544:Foot-and-Mouth Disease Virus / Q000235:genetics / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood; D007370:Interferon Type I / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D007700:Kinetics; D007963:Leukocytes, Mononuclear / Q000276:immunology; D012313:RNA / Q000008:administration & dosage* / Q000138:chemical synthesis / Q000276:immunology*; D058727:RNA, Small Untranslated; D013552:Swine; D013553:Swine Diseases / Q000517:prevention & control; D013601:T-Lymphocytes / Q000276:immunology; D014611:Vaccination; D017361:Viral Nonstructural Proteins / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
C109754:3ABC protein, virus; D000276:Adjuvants, Immunologic; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007370:Interferon Type I; D058727:RNA, Small Untranslated; D017361:Viral Nonstructural Proteins; D014765:Viral Vaccines; D012313:RNA; D007371:Interferon-gamma
FMD vaccines; Foot-and-mouth disease virus; Immunomodulatory molecules; Non-coding RNA; Vaccine adjuvants