DNA immunization with plasmids encoding fusion and nucleocapsid proteins of bovine respiratory syncytial virus induces a strong cell-mediated immunity and protects calves against challenge.
Respiratory syncytial viruses (RSV) are one of the most important respiratory pathogens of humans and cattle, and there is currently no safe and effective vaccine prophylaxis. In this study, we designed two codon-optimized plasmids encoding the bovine RSV fusion (F) and nucleocapsid (N) proteins and assessed their immunogenicity in young calves. Two administrations of both plasmids elicited low antibody levels but primed a strong cell-mediated immunity characterized by lymphoproliferative response and gamma interferon production in vitro and in vivo. Interestingly, this strong cellular response drastically reduced viral replication, clinical signs, and pulmonary lesions after a highly virulent challenge. Moreover, calves that were further vaccinated with a killed-virus vaccine developed high levels of neutralizing antibody and were fully protected following challenge. These results indicate that DNA vaccination could be a promising alternative to the classical vaccines against RSV in cattle and could therefore open perspectives for vaccinating young infants.
Boxus
Mathieu
M
Biologie Cellulaire et Moléculaire, Faculté des Sciences Agronomiques, 5030 Gembloux, Belgium. boxus.m@fsagx.ac.be
Tignon
Marylène
M
Roels
Stefan
S
Toussaint
Jean-François
JF
Walravens
Karl
K
Benoit
Marie-Ange
MA
Coppe
Philippe
P
Letesson
Jean-Jacques
JJ
Letellier
Carine
C
Kerkhofs
Pierre
P
D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D019556:COS Cells; D002417:Cattle; D002418:Cattle Diseases / Q000235:genetics / Q000276:immunology / Q000517:prevention & control*; D002522:Chlorocebus aethiops; D007111:Immunity, Cellular / Q000187:drug effects; D007371:Interferon-gamma / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D019590:Nucleocapsid Proteins / Q000235:genetics / Q000276:immunology*; D018357:Respiratory Syncytial Virus Infections / Q000235:genetics / Q000276:immunology / Q000517:prevention & control* / Q000662:veterinary*; D018112:Respiratory Syncytial Virus, Bovine / Q000235:genetics / Q000276:immunology*; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D014709:Vero Cells; D014760:Viral Fusion Proteins / Q000235:genetics / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology* / Q000494:pharmacology
D000914:Antibodies, Viral; D019590:Nucleocapsid Proteins; D019444:Vaccines, DNA; D014760:Viral Fusion Proteins; D014765:Viral Vaccines; D007371:Interferon-gamma