Interleukin-17 is required for T helper 1 cell immunity and host resistance to the intracellular pathogen Francisella tularensis - PubMed (original) (raw)

. 2009 Nov 20;31(5):799-810.

doi: 10.1016/j.immuni.2009.08.025. Epub 2009 Oct 22.

Shane Ritchea, Alison Logar, Samantha Slight, Michelle Messmer, Javier Rangel-Moreno, Lokesh Guglani, John F Alcorn, Heather Strawbridge, Sang Mi Park, Reiko Onishi, Nikki Nyugen, Michael J Walter, Derek Pociask, Troy D Randall, Sarah L Gaffen, Yoichiro Iwakura, Jay K Kolls, Shabaana A Khader

Affiliations

Interleukin-17 is required for T helper 1 cell immunity and host resistance to the intracellular pathogen Francisella tularensis

Yinyao Lin et al. Immunity. 2009.

Abstract

The importance of T helper type 1 (Th1) cell immunity in host resistance to the intracellular bacterium Francisella tularensis is well established. However, the relative roles of interleukin (IL)-12-Th1 and IL-23-Th17 cell responses in immunity to F. tularensis have not been studied. The IL-23-Th17 cell pathway is critical for protective immunity against extracellular bacterial infections. In contrast, the IL-23-Th17 cell pathway is dispensable for protection against intracellular pathogens such as Mycobacteria. Here we show that the IL-23-Th17 pathway regulates the IL-12-Th1 cell pathway and was required for protective immunity against F.tularensis live vaccine strain. We show that IL-17A, but not IL-17F or IL-22, induced IL-12 production in dendritic cells and mediated Th1 responses. Furthermore, we show that IL-17A also induced IL-12 and interferon-gamma production in macrophages and mediated bacterial killing. Together, these findings illustrate a biological function for IL-17A in regulating IL-12-Th1 cell immunity and host responses to an intracellular pathogen.

PubMed Disclaimer

Figures

Figure 1

Figure 1. IL-12 dependent IFN-γ is critical for protection following pulmonary tularemia

mRNA induction for IL-23p19, IL-12p35 and IL-12p40 (A) and IFNγ, IL-17 and iNOS (B) in LVS infected B6 lungs vs. uninfected lungs was determined by RT-PCR. B6 mice and IL-12p40−/− (C), B6, IL-12p35−/−IL-23p19−/−, IL-12RB1−/− (D) and B6, IL-12p35−/− and IFNγ−/− (E) were infected with LVS and the lung CFU determined and lung homogenates were assayed for IFNγ (F) or IL-17 (G) levels. Data points represent mean (±SD) from 4-5 mice (A-G). **, p ≤ 0.005, ***, p ≤0.0005. 1 experiment representative of 2 or more.

Figure 2

Figure 2. IL-23 dependent IL-17 is required for protection against pulmonary tularemia

B6 and IL-23p19−/− were infected with LVS and the lung CFU determined (A). Lung IL-17 levels (B) and the number of lung IL-17 producing cells from day 4-infected B6 and IL-23p19−/− mice was determined (C). B6, IL-17−/, IL-17R−/− were infected with LVS and lung CFU determined (D). LVS infected-B6 mice were treated with either control or anti-IL-17 neutralizing antibody and lung CFU determined (E). B6, IL-22−/− and γδ−/− mice (F) were infected with LVS and lung CFU determined. Data points represent mean (±SD) from 4-5 mice (A-F). *, p ≤0.05. **, p ≤0.005, ***, p ≤0.0005. ns-not significant. 1 experiment representative of 2 or more.

Figure 3

Figure 3. IL-17 is required for induction of IFNγ responses during pulmonary tularemia

B6, IL-17−/− and IL-17R−/− mice were infected with LVS and lung G-CSF levels determined (A). Percentage of lung neutrophils in uninfected (UI) or infected B6, IL-17−/− and IL-17R−/− mice was determined (B). Lung homogenates from day 6-infected B6, IL-17−/− and IL-17R−/− mice were assayed for TNF-α (C), IFNγ (D) and IL-17 (E). The induction of specific mRNA was determined by RT-PCR in infected B6 and IL-17−/− lungs (F). *, p ≤0.05. **, p ≤0.005. ***, p ≤0.0005. 1 experiment representative of 2 or more.

Figure 4

Figure 4. IL-17 but not IL-17F or IL-22 can induce IL-12 from BMDCs

B6 BMDCs were left untreated (UN), stimulated with LVS alone or with IL-17 (100 ng/ml) and supernatants assayed for IL-12 (A) or IL-6 (B). B6 BMDCs were treated with LVS alone or with IL-22 or IL-17 (100 ng/ml), or IL-17 (100 ng/ml) alone and IL-12 levels determined (C). B6 BMDCs were left untreated or treated with IL-17 (100 ng/ml), IL-17F (100 ng/ml), or both IL-17 and IL-17F (100 ng/ml each) and cytokine levels determined in supernatants (D). B6 BMDCs were left untreated or treated with IL-17 (100 ng/ml) alone or with soluble IL-17RA or IL-17RC (1000 ng/ml each) and cytokine levels determined in supernatants (E). Lung CD11c+ cells from B6 mice were left untreated or treated with LVS alone or with IL-17(100 ng/ml) or IL-17F (100 ng/ml). IL-17 and IL-17F alone treated cultures were also included and supernatants assayed for IL-12 and IFNγ levels (F). BMDCs were left untreated (white histogram) or treated with IL-17 (grey histogram) and expression of Phospho-NF-κβ p65 determined. Samples were treated in triplicates (A-G). nd-not detectable, *, p ≤0.05. **, p ≤0.005. ***, p ≤0.0005, 1 experiment representative of 2 or more.

Figure 5

Figure 5. IL-17 can induce the polarization of naïve T cells into IFNγ-producing T cells

B6 BMDCs were stimulated with LVS alone or with IL-12 (100 ng/ml), IL-22 (100 ng/ml) or IL-17 (100 ng/ml) and naive OT-II TCR-Tg CD4+ T cells. The frequency of IFNγ (A) and IL-17 producing cells (B) were determined by ELISpot assay. BMDCs generated from B6 mice (C), IL-12p40−/− (D), IL-17R−/−(E) or IFNγ−/− (F) were cultured with naïve OT-II TCR Tg CD4+ T cells alone or with IL-12 (100 ng/ml) or IL-17(100 ng/ml) in triplicates and IL-17 and IFNγ levels determined by flow cytometry; fold induction relative to untreated control group was determined (G). *, p ≤0.05. **, p ≤0.005. ***, p ≤0.0005.

Figure 6

Figure 6. IL-17 induces IFNγ and IL-12 from macrophages and enhances bacterial clearance

BMDMs from B6 mice were either left untreated (UN) or treated with LVS alone, IL-17 (100 ng/ml) alone, IL-17F alone (100 ng/ml) or LVS and IL-17 (100 ng/ml). Some wells received IL-17(100 ng/ml) and soluble IL-17RA or IL-17RC (1000ng/ml each) and protein levels in supernatants determined (A). BMDMs from B6 or IFNγ−/− mice were left untreated or treated with IL-17 (100 ng/ml) and IL-12 levels determined (B). BMDMs from B6 mice (C) or IFNγ−/− (D) were infected with live LVS alone, or with IFN-γ (100 ng/ml) or IL-17 (100 ng/ml) for 24 hours and intracellular CFU determined. Lung alveolar macrophages were treated with LVS alone or with IL-17, IL-17 (100 ng/ml) alone or IL-17F alone (100 ng/ml) and cytokine levels determined (E). Samples were treated in triplicates (A-E). nd-not detectable, *, p ≤0.05. **, p ≤0.005. ***, p ≤0.0005.

Figure 7

Figure 7. Cellular sources of IL-17 in the lung following LVS infection

Uninfected or LVS-infected B6 (A) mice were assayed for cellular sources of IL-17 producing cells in day-6 infected lungs by flow cytometry. The percentage of cells expressing IL-17 within gated populations is shown (A). Log10 fold induction of IL-17 mRNA in sorted lung cell populations from day-6 infected B6 lungs vs. uninfected lungs was determined by RT-PCR (B). mRNA expression of IL-17RA or IL-17RC relative to GAPDH levels was determined by RT-PCR on sorted cell populations (C). The percentage of IFNγ-producing cells within each population in B6 and IL-17−/− infected lungs is shown (D). Log10 fold induction of IL-12p35 mRNA in sorted cells from infected vs. uninfected lungs was determined by RT-PCR (E). LVS-infected IL-23p19−/− or IL-17−/− mice were treated with PBS or rIL-17 and day6-infected lung homogenates assayed for IFNγ and TNF-α (F). The data points represent the mean (±SD) of values from 3-5 mice (A-F). *, p ≤0.05. **, p ≤0.005. ***, p ≤0.0005.

Comment in

Similar articles

Cited by

References

    1. Allen LA, McCaffrey RL. To activate or not to activate: distinct strategies used by Helicobacter pylori and Francisella tularensis to modulate the NADPH oxidase and survive in human neutrophils. Immunol Rev. 2007;219:103–117. - PubMed
    1. Anthony LS, Ghadirian E, Nestel FP, Kongshavn PA. The requirement for gamma interferon in resistance of mice to experimental tularemia. Microb Pathog. 1989;7:421–428. - PubMed
    1. Ashtekar AR, Zhang P, Katz J, Deivanayagam CC, Rallabhandi P, Vogel SN, Michalek SM. TLR4-mediated activation of dendritic cells by the heat shock protein DnaK from Francisella tularensis. J Leukoc Biol. 2008;84:1434–1446. - PMC - PubMed
    1. Aujla SJ, Chan YR, Zheng M, Fei M, Askew DJ, Pociask DA, Reinhart TA, McAllister F, Edeal J, Gaus K, et al. IL-22 mediates mucosal host defense against Gram-negative bacterial pneumonia. Nat Med. 2008;14:275–281. - PMC - PubMed
    1. Bafica A, Scanga C, Feng C, Leifer C, Cheever A, Sher A. TLR9 regulates Th1 responses and cooperates with TLR2 in mediating optimal resistance to Mycobacterium tuberculosis. Journal of Experimental Medicine. 2005;202:1715–1724. - PMC - PubMed

Publication types

MeSH terms

Substances

Grants and funding

LinkOut - more resources