Quantitative analysis of the antigen-specific IFNgamma+ T cell-mediated immune response in conventional outbred pigs: kinetics and duration of the DNA-induced IFNgamma+ CD8+ T cell response.
It is now well established that antigen-specific CD8(+) T cells play a major role in vaccine-induced immunity against intracellular pathogens and tumor cells. The detection of these immune cells in outbred animals has been hampered mainly by the need to generate individual autologous antigen-presenting cells (APCs) due to the high degree of polymorphism of the major histocompatibility complex (MHC) Class I loci. We used individually derived immature porcine dendritic cells infected with a pox-based recombinant viral vector to ex vivo stimulate PBMCs from vaccinated conventional pigs. The frequencies of antigen-specific T cells was determined by the number of IFNgamma-secreting cells in a quantitative enzyme-linked immune spot (ELISPOT) assay. Using this approach we were able to rank different pseudorabies virus (PRV) vaccines strategies for their ability to prime viral-specific IFNgamma(+) T cells. Plasmid DNA has recently emerged as a promising tool with multiple applications in the field of infectious diseases, allergy and cancer. We showed for the first time in this study that DNA immunization induced a long-lived antigen-specific IFNgamma(+) T cells response in conventional pigs. Additional studies allowed us to show that these virus-specific IFNgamma(+) responding cells detected in this ELISPOT assay were MHC-restricted and comprised in the CD8alpha(bright) pig T cell subset. These new data confirm the usefulness of DNA vaccines to control diseases requiring cellular immunity in pigs.
Laval
F
F
Discovery Research, Merial, 254 Rue Marcel Mérieux, BP 7009, 63342 Lyon Cedex 07, France.
Paillot
R
R
Bollard
S
S
Fischer
L
L
Audonnet
J-C
JC
Andreoni
C
C
Juillard
V
V
D000818:Animals; D021461:Animals, Outbred Strains; D000956:Antigens, Viral / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D004247:DNA / Q000276:immunology; D005260:Female; D016130:Immunophenotyping; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology*; D008285:Major Histocompatibility Complex / Q000276:immunology; D008297:Male; D011557:Pseudorabies / Q000276:immunology; D022421:Pseudorabies Vaccines / Q000008:administration & dosage / Q000276:immunology; D013552:Swine / Q000276:immunology* / Q000821:virology; D014613:Vaccines, Attenuated / Q000276:immunology; D019444:Vaccines, DNA / Q000276:immunology*; D022223:Vaccines, Subunit / Q000276:immunology
D000956:Antigens, Viral; D022421:Pseudorabies Vaccines; D014613:Vaccines, Attenuated; D019444:Vaccines, DNA; D022223:Vaccines, Subunit; D007371:Interferon-gamma; D004247:DNA