Vaccine-induced T cell-mediated immunity plays a critical role in early protection against pseudorabies virus (suid herpes virus type 1) infection in pigs.
The aim of our study was to evaluate the relative importance of antibody and T cell-mediated immunity in protection against pseudorabies virus (suid herpes virus type 1) infection in pigs. We induced different levels of immune responses by using: (1) a modified live vaccine; (2) the same modified live vaccine with an oil-in-water (o/w) adjuvant; (3) an inactivated vaccine; and (4) the same inactivated vaccine with an o/w adjuvant. Subsequently, we challenged pigs with virulent pseudorabies virus (PRV). We demonstrated that best-protected pigs stood out by maintaining strong T cell-mediated immune (CMI) responses after challenge. Of the immune parameters tested, protection against virus shedding was correlated best with the magnitude of the IFN-gamma response of in vitro re-stimulated peripheral blood mononuclear cells (PBMC) with an additional role for PRV-specific IgG2 antibodies. The use of an o/w adjuvant resulted in higher antibody and CMI responses, in particular with an increased frequency of memory T helper blast cells of in vitro re-stimulated PBMC. However, this adjuvant-induced enhancement of the immune response had a limited additional effect on the efficacy of inactivated vaccines. This study suggests a major contribution of the CMI response in early protection against PRV infection and that PRV-induced IFN-gamma responses may serve as a suitable indicator for assessing the immune status of vaccinated pigs.
van Rooij
E M A
EM
Central Institute for Animal Disease Control, CIDC-Lelystad, P.O. Box 2004, 8203 AA Lelystad, The Netherlands. eugene.vanrooij@wur.nl
de Bruin
M G M
MG
de Visser
Y E
YE
Middel
W G J
WG
Boersma
W J A
WJ
Bianchi
A T J
AT
D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D002455:Cell Division / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005434:Flow Cytometry / Q000662:veterinary; D011558:Herpesvirus 1, Suid / Q000276:immunology*; D007132:Immunoglobulin Isotypes / Q000276:immunology; D016130:Immunophenotyping / Q000662:veterinary; D007371:Interferon-gamma / Q000276:immunology; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology; D009500:Neutralization Tests / Q000662:veterinary; D011557:Pseudorabies / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D022421:Pseudorabies Vaccines / Q000276:immunology*; D011897:Random Allocation; D013047:Specific Pathogen-Free Organisms; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000517:prevention & control / Q000821:virology*; D014611:Vaccination / Q000662:veterinary*; D014613:Vaccines, Attenuated / Q000276:immunology / Q000592:standards; D015164:Vaccines, Inactivated / Q000276:immunology / Q000592:standards
D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D007132:Immunoglobulin Isotypes; D022421:Pseudorabies Vaccines; D014613:Vaccines, Attenuated; D015164:Vaccines, Inactivated; D007371:Interferon-gamma