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Interleukin-12 and interleukin-27 regulate macrophage control of Mycobacterium tuberculosis - PubMed

  • ️Tue Jan 01 2008

Interleukin-12 and interleukin-27 regulate macrophage control of Mycobacterium tuberculosis

Cory M Robinson et al. J Infect Dis. 2008.

Abstract

Mycobacterium tuberculosis is an intracellular pathogen that persists within macrophages and remains a considerable global threat to human health. The purpose of this study was to investigate how interleukin (IL)-12 and IL-27 regulate human macrophage interactions with M. tuberculosis. Quantitative measurement of transcripts showed that IL-12 or M. tuberculosis induced IL-27 gene expression in human macrophages. Furthermore, IL-27 receptor subunits were shown by reverse transcription-polymerase chain reaction and flow cytometry to be expressed and present at the cell surface. Neutralization of IL-27 in the presence of IL-12 reduced viable M. tuberculosis recovered from macrophages. Antimycobacterial activity was accompanied by a heightened inflammatory response that included tumor necrosis factor, IL-6, interferon-gamma, and a subset of chemokines. These results implicate IL-12 and IL-27 in regulating human macrophages, and IL-27 derived from macrophages during infection impedes control of M. tuberculosis growth.

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Conflict of interest statement

The authors listed in this manuscript have no potential conflicts of interest.

Figures

Figure 1
Figure 1

IL-27 expression by human macrophages. Macrophages were stimulated with IL-12, infected with MTB, or their combination for indicated time points. Quantitative analysis of EBI3 (top panel) or p28 (bottom panel) transcripts is presented as the mean log2 change in gene expression of triplicate samples ± standard errors. Values were normalized to the mean expression of GAPDH within a triplicate sample group and expressed relative to that of medium alone at 2 h.

Figure 2
Figure 2

Expression of the IL-27 receptor by human macrophages. (A) WSX-1, gp130, and the β-actin internal reference amplification products from cDNA or no reverse transcriptase controls. RNA was obtained from macrophages at resting state or stimulated for 24 h as indicated. (B) Unstimulated macrophages were harvested and immunolabeled for surface receptors. Histograms that represent results repeated several times for each cell surface receptor (dashed line) compared with isotype control (solid line) are presented. WSX-1 and gp130 data are derived from CD14 positive cell populations. RFU designates relative fluorescence units.

Figure 3
Figure 3

Macrophage restriction of M. tuberculosis growth. Human macrophages were stimulated with IL-12, sIL-27R, their combination, or medium alone for 4 h prior to infection by MTB as indicated. Data is represented as the mean CFUs recovered from infected macrophages ± standard error for (A) two combined experiments over time, (B) five independent experiments at 72 h, or (C) an individual experiment evaluating the function of IFN-γ with IFN-γ neutralizing or isotype (Iso) control antibodies. (B) A two-way ANOVA or (C) student’s t-test was used to establish statistical significance in the 95% confidence interval between individual sample groups as indicated.

Figure 4
Figure 4

The effects of IL-12 and IL-27 neutralization on induction of infected macrophage inflammatory response. Quantitative analysis of transcripts from human macrophage cultures stimulated as indicated are represented as the mean log2 change in gene expression of triplicate samples ± standard errors. Values were normalized to the mean expression of GAPDH within a triplicate sample group and expressed relative to medium alone at each time point. Typical results from an individual experiment repeated three times are presented.

Figure 5
Figure 5

The effects of IL-12 and IL-27 neutralization on cytokine and chemokine production in infected macrophages. (A, C) Cytokine concentrations in supernatants collected at labeled time points from macrophage cultures treated as indicated were determined by ELISA. Time points were selected based on kinetics of gene expression and where differences in protein amounts were observed. Data from an individual experiment representative of three are presented as mean ± standard error. Samples that did not contain detectable quantities of protein are indicated (ND). Sample groups that contain the same symbols (# for early time series; * for later time series) are not statistically different. (B) A histogram representative of typical results for IFN-γ intracellular staining of human macrophages stimulated with IL-12, sIL-27R, and heat-killed MTB (dashed line) or left untreated (solid line). Only cells positive for CD14 were selected for analysis. RFU designates relative fluorescence units.

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References

    1. World Health Organization. Detailed estimates of TB burden for 2005. [Accessed 17 September 2007]. Available at http://www.who.int/tb/country/tb_burden/en/index.html.
    1. Gonzalez-Juarrero M, Turner OC, Turner J, Marietta P, Brooks JV, Orme IM. Temporal and spatial arrangement of lymphocytes within lung granulomas induced by aerosol infection with Mycobacterium tuberculosis. Infect Immun. 2001;69:1722–1728. - PMC - PubMed
    1. Algood HM, Chan J, Flynn JL. Chemokines and tuberculosis. Cytokine Gowth Factor Rev. 2003;14:467–477. - PubMed
    1. Flynn JL, Goldstein MM, Chan J, et al. Tumor necrosis factor-α is required in the protective immune response against M. tuberculosis in mice. Immunity. 1995;2:561–572. - PubMed
    1. Bean AGD, Roach DR, Briscoe H, France MP, Korner H, Sedgwick JD, Britton WJ. Structural deficiencies in granuloma formation in TNF gene-targeted mice underlie the heightened susceptibility to aerosol Mycobacterium tuberculosis infection, which is not compensated for by lymphotoxin. J Immunol. 1999;162:3504–3511. - PubMed

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