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
. 2014 Oct:27:37-43.
doi: 10.1016/j.ijid.2014.05.016. Epub 2014 Aug 27.

T-cell-mediated cross-strain protective immunity elicited by prime-boost vaccination with a live attenuated influenza vaccine

Junwei Li  1 , Maria T Arévalo  1 , Yanping Chen  1 , Shan Chen  1 , Mingtao Zeng  2
Affiliations

T-cell-mediated cross-strain protective immunity elicited by prime-boost vaccination with a live attenuated influenza vaccine

Junwei Li et al. Int J Infect Dis. 2014 Oct.

Abstract

Background: Antigenic drift and shift of influenza viruses require frequent reformulation of influenza vaccines. In addition, seasonal influenza vaccines are often mismatched to the epidemic influenza strains. This stresses the need for a universal influenza vaccine.

Methods: BALB/c mice were vaccinated with the trivalent live attenuated (LAIV; FluMist) or inactivated (TIV; FluZone) influenza vaccines and challenged with PR8 (H1N1), FM/47 (H1N1), or HK/68 (H3N2) influenza virus. Cytokines and antibody responses were tested by ELISA. Furthermore, different LAIV dosages were applied in BALB/c mice. LAIV vaccinated mice were also depleted of T-cells and challenged with PR8 virus.

Results: LAIV induced significant protection against challenge with the non-vaccine strain PR8 influenza virus. Furthermore, protective immunity against PR8 was dose-dependent. Of note, interleukin 2 and interferon gamma cytokine secretion in the lung alveolar fluid were significantly elevated in mice vaccinated with LAIV. Moreover, T-cell depletion of LAIV vaccinated mice compromised protection, indicating that T-cell-mediated immunity is required. In contrast, passive transfer of sera from mice vaccinated with LAIV into naïve mice failed to protect against PR8 challenge. Neutralization assays in vitro confirmed that LAIV did not induce cross-strain neutralizing antibodies against PR8 virus. Finally, we showed that three doses of LAIV also provided protection against challenge with two additional heterologous viruses, FM/47 and HK/68.

Conclusions: These results support the potential use of the LAIV as a universal influenza vaccine under a prime-boost vaccination regimen.

Keywords: Cross-strain protective immunity; Heterologous influenza viruses; Live attenuated influenza vaccine; Prime–boost vaccination; T-cell-mediated immunity; Trivalent inactivated influenza vaccine.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Intranasal vaccination with FluMist induced heterologous protection. Groups of mice were vaccinated with 10 μl FluMist in 40 μl PBS (in a total volume of 50 μl) or 55 μl FluZone, and then boosted at day 28 post-vaccination with the same dose of FluMist or FluZone. Unless otherwise noted, FluMist and FluZone were administered are per manufacturer's indication, intranasally and intramuscularly, respectively. In one group (marked with ‘i.m.’), mice were primed and boosted via intramuscular injections of 10 μl FluMist in 40 μl PBS; in another group, mice (marked with ‘i.n.’) were primed and boosted with 55 μl FluZone intranasally. Mice in the negative control group were inoculated intranasally with 50 μl PBS. At 42 days post-vaccination, mice were lethally challenged with 100 × LD50 PR8 (H1N1) influenza virus. (A) Mouse weight change; the weights of mice in the FluMist + FluMist group decreased less than weights in other groups (p < 0.001). (B) Mouse survival rates by different vaccination regimens. (n = 8 in each group.)
Figure 2
Figure 2
Measurement of anti-influenza IgG in sera and IgA in lung alveolar fluid by ELISA. (A) Mice were primed with 10 μl FluMist in 40 μl PBS or 55 μl FluZone, and then boosted on day 28 with FluZone or FluMist, as indicated. Mouse blood was collected and the anti-influenza IgG concentration in sera was measured (*p < 0.01 compared with the negative PBS control group). (B) Mice were administered with PBS, PR8, or FluMist intranasally, and lung alveolar fluid was collected on day 14 post-boost. Anti-influenza IgA in lung alveolar fluid was measured (****p < 0.0001 compared with the negative PBS control and PR8 groups). (n = 8 in each group.)
Figure 3
Figure 3
Cytokine levels in lung alveolar fluid of vaccinated mice as determined by ELISA. Mice were primed on day 0, and then boosted on day 28 with PBS, PR8, or FluMist in a 50-μl volume per animal, and then lung alveolar fluid was collected at day 5 post-boost. (A) Interleukin 2 (IL-2) concentration in lung alveolar fluid. (B) Interferon gamma (IFN-γ) level in lung alveolar fluid. (****p < 0.0001 compared with the negative PBS control group; n = 8 in each group.)
Figure 4
Figure 4
Protection conferred by FluMist is dose-dependent. Thirty-two BALB/c mice were divided into four groups randomly. The first group was set as a negative control group and was inoculated intranasally with 50 μl PBS one time at day 0. The second group was vaccinated intranasally with three doses of 10 μl FluMist in 40 μl PBS (total volume of 50 μl per mouse) on day 0, day 15, and day 29. The third group was vaccinated with two doses of FluMist on day 15 and day 29. The fourth group was treated with one dose of FluMist on day 29. All mice were challenged intranasally with 100 × LD50 PR8 influenza virus on day 42. (A) Weight change caused by PR8 influenza virus challenge. (B) Mouse survival rate following the challenge with PR8 influenza virus. (n = 8 in each group.)
Figure 5
Figure 5
Passive protection provided by injection with sera from mice vaccinated with PR8 influenza virus or FluMist. Mice were injected intraperitoneally with 200 μl sera from negative control, PR8 vaccinated, or FluMist (three doses) vaccinated mice, and were then challenged with 100 × LD50 PR8 influenza virus in 50 μl PBS. (A) Weight change after mice were challenged with PR8 influenza virus. (B) Mouse survival rate after mice were challenged with PR8 influenza virus. (n = 8 in each group.)
Figure 6
Figure 6
Contribution of T-cells in protective immunity determined by T-cell depletion experiments in vivo. Cross-strain protective immunity induced by prime– boost vaccination with FluMist was evaluated in mice depleted of T-cells (depletion of CD4+, CD8+, or both CD4+ and CD8+ T-cells). (A) Weight change in mice depleted of T-cells after PR8 influenza virus challenge. (B) Mouse survival rates after PR8 influenza virus challenge. (n = 8 in each group.)
Figure 7
Figure 7
Intranasal vaccination with FluMist induced cross-strain protection. Mice in the negative control group were treated with 50 μl PBS. Mice in the positive control groups were vaccinated with 10 PFU FM/47 (H1N1) or HK/68 (H3N2) influenza viruses in 50 μl PBS on day 0. FluMist groups were vaccinated with three doses of 10 μl FluMist in 40 μl PBS on days 0, 15, and 29. On day 42, mice were challenged with 105 PFU FM/47 or HK/68 influenza virus in 50 μl PBS. (A) Viral titers in lungs of mice challenged with FM/47 at 4 days post-challenge. (B) Viral titers in lungs of mice challenged with HK/68 at 4 days post-challenge. (***p < 0.001 compared with the negative control group; n = 8 in each group.)
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Li J, Arevalo MT, Zeng M. Engineering influenza viral vectors. Bioengineered. 2013;4:9–14. - PMC - PubMed
    1. Horimoto T, Kawaoka Y. Influenza: lessons from past pandemics, warnings from current incidents. Nat Rev Microbiol. 2005;3:591–600. - PubMed
    1. Wise HM, Foeglein A, Sun J, Dalton RM, Patel S, Howard W, et al. A complicated message: identification of a novel PB1-related protein translated from influenza A virus segment 2 mRNA. J Virol. 2009;83:8021–31. - PMC - PubMed
    1. Jagger BW, Wise HM, Kash JC, Walters KA, Wills NM, Xiao YL, et al. An overlapping protein-coding region in influenza A virus segment 3 modulates the host response. Science. 2012;337:199–204. - PMC - PubMed
    1. Tong S, Li Y, Rivailler P, Conrardy C, Castillo DA, Chen LM, et al. A distinct lineage of influenza A virus from bats. Proc Natl Acad Sci U S A. 2012;109:4269–74. - PMC - PubMed

Publication types

MeSH terms