Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2012 Aug 31;30(40):5830-8.
doi: 10.1016/j.vaccine.2012.07.033. Epub 2012 Jul 24.

Heightened adaptive immune responses following vaccination with a temperature-sensitive, live-attenuated influenza virus compared to adjuvanted, whole-inactivated virus in pigs

Crystal L Loving  1 , Amy L Vincent, Lindomar Pena, Daniel R Perez
Affiliations
Comparative Study

Heightened adaptive immune responses following vaccination with a temperature-sensitive, live-attenuated influenza virus compared to adjuvanted, whole-inactivated virus in pigs

Crystal L Loving et al. Vaccine. .

Abstract

In the United States there are currently two influenza vaccine platforms approved for use in humans-conventional inactivated virus and live-attenuated influenza virus (LAIV). One of the major challenges for influenza A virus (IAV) vaccination is designing a platform that provides protection across strains. Pandemic H1N1 (pH1N1) IAV swept the globe in 2009 and crossed the species barrier, infecting swine in several countries. Pigs are a natural host for IAV and serve as a model for evaluating immune responses following vaccination and challenge. Recently, a temperature-sensitive (ts) LAIV was developed by introducing modifications in the polymerase genes of a swine-like triple reassortant (tr) virus and when paired with pandemic HA and NA, provided sterilizing immunity upon intratracheal challenge with virulent pH1N1 virus. The utility of a ts LAIV is expanded in this report to show vaccination of pigs induced a cell-mediated immune response characterized by an increased number of antigen-specific IFN-secreting cells and expanded T cell populations when compared to pigs vaccinated with a whole inactivated virus (WIV) vaccine. Following challenge, there was a significant increase in the percentage of proliferating lymphocytes in the LAIV group compared to the WIV group following restimulation with pH1N1 in vitro. Also, there was an increase in the percentage of CD4/CD8 double-positive memory T cells in LAIV vaccinated pigs compared to WIV vaccinated pigs. Hemagglutination inhibition and serum neutralization titers were significantly higher in the LAIV-vaccinated pigs compared to the WIV vaccinated pigs following the initial dose of vaccine. Taken together, these results indicate the ts LAIV vaccine, generated from a triple reassortant IAV, elicits greater cell-mediated and humoral immune responses in pigs.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Ca/04-specific serum antibody responses following vaccination with live-attenuated influenza virus (LAIV) or whole-inactivated influenza virus (WIV). Pigs were bled the day of boosting (pre-boost), prior to challenge (post-boost), and 5 days post-challenge for evaluating Ca/04-specific A) hemagglutination inhibition (HI) titers, B) virus serum neutralization (SN) titers, and C) IgG and D) IgA levels to whole virus. HI and SN titers were log2 converted and reported as the geometric mean ± SEM. Negative HI reactions are at the minimal level of detection (10), denoted by the dotted line. Antibody isotype data is expressed as the mean ± SEM optical density (OD) for 10 pigs per treatment group. A one-way analysis of variance with a Tukey’s post-test was used for statistical analysis and p-values <0.05 are indicated with connecting bars.
Figure 2
Figure 2
Recall responses to Ca/04 following vaccination. The number of antigen-specific IFN-γ secreting cells (SC) elicited following vaccination with live-attenuated influenza virus (LAIV), whole-inactivated virus (WIV), or cell-culture media (NV). Pigs were given 2 doses of vaccine and peripheral blood mononuclear cells isolated immediately A) prior to challenge or B) five days post-challenge. Cells were restimulated as described in Materials and Methods for each assay. Results are reported as the average number of spots in UV-Ca/04 stimulated wells minus the average number of spots in the media-only wells. The results are the mean ± SEM for each group. A one-way analysis of variance with a Tukey’s post-test was used for statistical analysis and p-values <0.05 are indicated with connecting bars.
Figure 3
Figure 3
Expansion of CD4+/CD8+ double-positive memory cells following challenge in pigs vaccinated with LAIV. Peripheral blood mononuclear cells were collected from pigs following prime-boost vaccination with live-attenuated influenza virus (LAIV), whole-inactivated virus (WIV), or cell-culture media (NV) 5 days following pH1N1 intratracheal challenge (Ch) or non-challenge controls (NC). PBMCs were labeled with PKH67 and restimulated for five days in vitro with UV-Ca/04 or mock media and the A) percent proliferation and the percent of B) CD4+CD8− C) CD4−CD8+ and D) CD4+/CD8+ double positive cells determined using flow cytometry. Phenotypic data is expressed as the percentage of cells detected in wells following UV-Ca/04 exposure minus wells given media alone. For proliferation, a student’s t-test was used for statistical analysis of UV-Ca/04 stimulated compared to media alone and for phenotypic data a one-way analysis of variance with a Tukey’s post-test was used and p-values <0.05 are indicated with a connecting bar or asterisk.
Figure 4
Figure 4
Levels of IL-2 and IFN-γ in the lung lavage of pigs previously vaccinated with live-attenuated influenza virus (LAIV), whole-inactivated virus (WIV), or mock-vaccinated (NV) collected 5 days after pH1N1 challenge (Ca/04) or mock challenge (NC). The results are expressed as the mean ± SEM for each group.
Figure 5
Figure 5
Levels of Ca/04-specific antibody in the lung lavage of pigs previously vaccinated with live-attenuated influenza virus (LAIV), whole-inactivated virus (WIV), or mock-vaccinated (NV) 5 days after pH1N1 challenge (Ca/04). Lung lavage was collected on day 5 following challenge and assayed for A) IgG and B) IgA levels specific to Ca/04 virus and C) Ca/04 neutralization titer. Neutralization titers were log2 converted and reported as the geometric mean ± SEM. Antibody isotype data is expressed as the mean ± SEM optical density (OD) for 10 pigs per treatment group. A one-way analysis of variance with a Tukey’s post-test was used for statistical analysis and p-values <0.05 are indicated with connecting bars.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Vincent AL, Ma W, Lager KM, Janke BH, Richt JA. Swine influenza viruses a North American perspective. Adv Virus Res. 2008;72:127–54. - PubMed
    1. Zhou NN, Senne DA, Landgraf JS, Swenson SL, Erickson G, Rossow K, et al. Genetic reassortment of avian, swine, and human influenza A viruses in American pigs. Journal of virology. 1999 Oct;73(10):8851–6. - PMC - PubMed
    1. Lorusso A, Vincent AL, Harland ML, Alt D, Bayles DO, Swenson SL, et al. Genetic and antigenic characterization of H1 influenza viruses from United States swine from 2008. The Journal of general virology. 2011 Apr;92(Pt 4):919–30. - PMC - PubMed
    1. Vincent AL, Ma W, Lager KM, Gramer MR, Richt JA, Janke BH. Characterization of a newly emerged genetic cluster of H1N1 and H1N2 swine influenza virus in the United States. Virus genes. 2009 Jul 14; - PubMed
    1. Dawood FS, Jain S, Finelli L, Shaw MW, Lindstrom S, Garten RJ, et al. Emergence of a novel swine-origin influenza A (H1N1) virus in humans. The New England journal of medicine. 2009 Jun 18;360(25):2605–15. - PubMed

Publication types

MeSH terms

  NODES
admin 1
Note 1
twitter 2