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.

Identification of a Newly Conserved SLA-II Epitope in a Structural Protein of Swine Influenza Virus

“…Babraham's pigs were used as model to identify T cells epitopes because their syngeneic MHC loci which aids identification of SLA restriction of the identified epitopes. Previous studies demonstrated that immunization strategies based on the administration of whole inactive virus (WIV) formulated with adjuvant in pigs were able to produce an IFNγ or proliferative cell mediated response in peripheral blood involving T helper subsets (8,16,24). Moreover, the generated immunity was also able to respond to heterologous IAV strains (24).…”

Intraepithelial T Cells Diverge by Intestinal Location as Pigs Age

“…Immediately prior to euthanasia, ∼8 mL of whole blood was collected from each animal into a sodium citrate cell-preparation tube (CPT; BD Biosciences). Samples were transported to the lab at RT and processed using manufacturer's recommendations as previously described (42). HBSS was used to wash and resuspend cells.…”

Randomized Controlled Parallel-Design Clinical Study of the Efficacy and Safety of Intranasal Interferon gamma in Treatment of Influenza-Like Infections

“…This significantly complicates the quick data collection necessary to make an effective vaccine; therefore, vaccination can rarely protect people. (12)(13)(14) Another challenge is that alongside the influenza viruses, so-called «imitators» (the viruses of parainfluenza, adenoviruses, respiratory syncytial virus (RSV), coronavirus, etc.) could be a reason for acute respiratory tract disease.…”