title: Factors affecting induction of peripheral IFN-γ recall response to influenza A virus vaccination in pigs.
abstract: While T cell contribution to IAV immunity is appreciated, data comparing methods to evaluate IFN-γ production by IAV-specific T cells elicited following vaccination is limited. To understand the differential immunogenicity between live-attenuated influenza virus (LAIV) and whole-inactivated virus (WIV) vaccines in relation to induction of peripheral T cell responses, ELISpot and ELISA were used to assess IFN-γ production by peripheral lymphocytes following antigen restimulation. Following restimulation, peripheral blood lymphocytes from WIV-vaccinated pigs had a greater quantity of IFN-γ secreting cells (SC) and IFN-γ secreted compared to LAIV vaccinated and non-vaccinated (NV) pigs. Pig age at time of WIV vaccination significantly impacted peripheral IAV-specific IFN-γ recall response, as did the inclusion of adjuvant in the WIV vaccine. Collectively, these data indicate that peripheral IAV-specific IFN-γ recall responses are not predictive of LAIV vaccination status, thus, are unlikely to be a useful surrogate for evaluating LAIV immunogenicity and predicting cross-protection. However, these data suggest that the evaluation of peripheral IFN-γ recall responses may be useful for identifying factors, such as animal age or vaccine formulation, that may impact parenterally-delivered WIV vaccine immunogenicity. Overall, results did not differ based upon the assay used to evaluate IFN-γ recall responses. Therefore, either ELISpot or ELISA could serve as a measure for evaluating IAV-specific IFN-γ cell-mediated immune responses in swine.
authors.affiliation: USDA, ARS, National Animal Disease Center, United States.
authors.forename: Zahra F
authors.initials: ZF
authors.lastname: Olson
authors.affiliation: USDA, ARS, National Animal Disease Center, United States; Iowa State University, Ames, IA, United States.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Sandbulte
authors.affiliation: USDA, ARS, National Animal Disease Center, United States.
authors.forename: Carine Kunzler
authors.initials: CK
authors.lastname: Souza
authors.affiliation: Department of Veterinary Medicine, University of Maryland, College Park, United States; Virginia-Maryland Regional College of Veterinary Medicine, College Park, MD, United States.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Perez
authors.affiliation: USDA, ARS, National Animal Disease Center, United States.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Vincent
authors.affiliation: USDA, ARS, National Animal Disease Center, United States. Electronic address: Crystal.loving@ars.usda.gov.
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Loving
mesh_terms: D000818:Animals; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D007111:Immunity, Cellular; D000071497:Immunogenicity, Vaccine; D009980:Influenza A virus / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D007371:Interferon-gamma / Q000378:metabolism*; D061985:Madin Darby Canine Kidney Cells; D013552:Swine; D014613:Vaccines, Attenuated / Q000276:immunology; D015164:Vaccines, Inactivated / Q000276:immunology
chemical_list: D007252:Influenza Vaccines; D014613:Vaccines, Attenuated; D015164:Vaccines, Inactivated; D007371:Interferon-gamma
keywords: Cell-mediated immunity; IFN-gamma; Immune; Influenza; Porcine; Vaccine