Report

Patrolling monocytes control tumor metastasis to the lung

See allHide authors and affiliations

Science  20 Nov 2015:
Vol. 350, Issue 6263, pp. 985-990
DOI: 10.1126/science.aac9407
  • Fig. 1 Nr4a1-GFPhigh monocytes patrol the vasculature and interact with tumor cells in the lung.

    (A) Quantification of Nr4a1-GFPhigh PMo per microliter of blood volume in lung for control tissue (Untreated) or 4 or 24 hours after IV LLC-RFP transfer (n = 5 mice per group). (B) Quantification of Nr4a1-GFPhigh monocyte movement in the lung before (Untreated), 4 hours after, or 24 hours after LLC-RFP tumor injection. (Left) Monocyte tracks transposed to a common origin from a representative 20-min movie (scale bar, 100 μm). (Right) Quantification of median speed of monocytes (combined speed data from analysis of three separate mice; *P < 0.001 lower than untreated; **P < 0.001 lower than 4-hour tumor). (C) Representative gating of Nr4a1-GFPhighCD11b+ cells from all live CD45+CD11clow cells 24 hours after IV LLC-RFP transfer. (D) Representative confocal image of Nr4a1-GFPhigh monocytes (green) interacting with LLC-RFP cells (red) in the lung 7 days after IV LLC-RFP transfer. Immune cells in the vasculature were labeled with IV-injected antibody to CD45 (blue). (E) Quantification of free (>100 μm from tumor site) and tumor-associated (<50 μm from tumor site) Nr4a1-GFPhigh monocytes in the lung at various time points after tumor injection (combined analysis of five mice per group; P < 0.01 for each tumor-associated area compared with tumor-free areas for each time point). Error bars indicate SEM.

  • Fig. 2 Increased lung metastasis of tumors in Nr4a1−/− mice.

    (A) (Left) In vivo luciferase detection in WT control and Nr4a1−/− mice 24 hours after IV injection of 5 × 105 B16F10 melanoma cells expressing luciferase. (Right) Luciferase quantification (*P < 0.03, representative experiment with five mice per group). (B) In vivo luciferase detection (left) and quantification (right) in WT and Nr4a1−/− mice 7 days after IV injection with 3 × 105 B16F10-luciferase cells (*P < 0.001, n = 18 mice per group combined from three separate experiments). (C) Number of spontaneous tumor metastases per 5000 μm2 of lung surface 28 days after subcutaneous injection of 1 × 105 B16F10-YFP cells (*P < 0.01, n = 7 mice per group). (D and E) Lung tumor metastasis in MMTV-PyMT mice reconstituted with WT (WT:PyMT) or Nr4a1−/− (Nr4a1−/−:PyMT) bone marrow. (D) (Left) Representative MMTV-PyMT mouse lung histology, stained with hematoxylin and eosin. (Right) Quantification of the number of spontaneous lung metastases per 5000 μm2 of lung surface (*P < 0.05, n = 12 for WT and 15 for Nr4a1−/−). (E) Quantification of primary breast tumor growth in MMTV-PyMT mice (n = 12 for WT and 15 for Nr4a1−/−). Error bars indicate SEM.

  • Fig. 3 Nr4a1-expressing PMo reduce tumor metastasis and engulf tumor material in the lung.

    (A) In vivo imaging (left) and quantification (right) of lung tumors in CSF1R-CreNr4a1fl/fl (CSF1R-Cre) or CSF1R-Cre+Nr4a1fl/fl (CSF1R-Cre+) mice 7 days after IV injection of 3 × 105 B16F10-luciferase tumor cells (n = 6 mice per group, *P < 0.01; experiment replicated twice). (B) Quantification of the number of tumor metastases per lung of CSF1R-CreNr4a1fl/fl (CSF1R-Cre) and CSF1R-Cre+Nr4a1fl/fl (CSF1R-Cre+) mice 7 days after IV injection of 3 × 105 B16F10-YFP tumor cells (n = 8 mice per group, *P < 0.01). (C and D) Nr4a1−/− mice were injected intravenously with 5 × 105 WT Ly6C PMo, Ly6C+ inflammatory monocytes, or PBS at day 0. On day 1, 3 × 105 B16F10-luciferase tumor cells were injected intravenously, and tumor metastasis and growth were measured by in vivo imaging on day 8. Shown are representative in vivo images (C) and quantification (D) of B16F10-luciferase metastasis 8 days after monocyte transfer and 7 days after tumor transfer in WT or Nr4a1−/− mice (combined data from five separate experiments with n = 2 mice per group; *P < 0.01 statistically different from WT; **P < 0.05 statistically different from Nr4a1−/−). (E) Imaging of tumor material uptake in lung by Nr4a1-GFPhigh monocytes 24 hours after IV injection of LLC-RFP tumor cells. Representative higher-magnification images are shown at right. Note that Nr4a1-GFP expression is primarily nuclear, so monocyte cell membranes are not visible in these images. (F) Uptake of LLC-RFP tumor material by CX3CR1-GFPhighLy6C PMo after 24 hours of coculture. (G) Representative flow plot (left) and quantification (right) of tumor material uptake by all monocytes in the lung 24 hours after IV tumor injection of 3 × 105 LLC-RFP cells (n = 4 mice per group; *P < 0.01; experiment replicated three times). Error bars indicate SEM.

  • Fig. 4 Patrolling monocytes detect tumor material in a CX3CR1-dependent manner and recruit NK cells to the lung tumor environment.

    (A) Ratio of fluorescent intensity of tumor material engulfed by PMo (black) to fluorescent intensity of whole tumor (black and gray) 3 hours after IV LLC tumor injection. LLC tumors were labeled with either CellTrace Violet control dye (Control) or a pH-sensitive pHrodo Red dye (pHrodo) and then intravenously injected in a 1:1 ratio into a WT mouse (n = 3 mice per group, experiment replicated three times). Representative tracking (B) and median speed (C) of Cx3cr1−/− or Cx3cr1−/+ monocyte movement 24 hours after IV tumor injection in the lung. Monocyte tracks transposed to a common origin from representative 20-min movies (scale bar, 100 μm; representative tracks are shown from one mouse, median speed was calculated from tumor areas analyzed in three separate mice per group, *P < 0.001). (D) (Left) Percentage of Ly6C PMo containing LLC-RFP tumor material in the lung 3 hours after IV injection of tumor into representative WT, Cx3cr1−/−, or Tlr7−/− mice. (Right) Quantification of tumor material uptake (n = 3 per group, *P < 0.001 versus WT). (E) Percentage of CD31+ CX3CL1+ lung ECs isolated from untreated (UN) mice or from CX3CL1-mCherry mice, 24 hours or 7 days after IV injection of B16F10-YFP tumor cells. (F) Representative imaging of CX3CL1-mCherry (red) expression in lung 24 hours after IV injection of B16F10-YFP tumor cells (green) in CX3CL1-mCherry mice. CD45+ immune cells are labeled in blue. (G) Relative chemokine mRNA expression in Ly6C+ or Ly6C monocytes isolated from lungs by fluorescence-activated cell sorting 24 hours after IV B16F10 tumor injection (monocyte populations isolated from three separate mice; *P < 0.01; experiment repeated three times). (H) Percentage of NK cells in the lungs of CSF1R-CreNr4a1fl/fl (CSF1R-Cre) or CSF1R-Cre+Nr4a1fl/fl (CSF1R-Cre+) mice 7 days after IV injection of 3 × 105 B16F10-luciferase tumor cells (n = 6 mice per group, *P < 0.01). Error bars indicate SEM.

Supplementary Materials

  • Patrolling monocytes control tumor metastasis to the lung

    Richard N. Hanna, Caglar Cekic, Duygu Sag, Robert Tacke, Graham D. Thomas, Heba Nowyhed, Erica Herrley, Nicole Rasquinha, Sara McArdle, Runpei Wu, Esther Peluso, Daniel Metzger, Hiroshi Ichinose, Iftach Shaked, Grzegorz Chodaczek, Subhra K. Biswas, Catherine C. Hedrick

    Materials/Methods, Supplementary Text, Tables, Figures, and/or References

    Download Supplement
    • Materials and Methods
    • Figs. S1 to S18
    • Captions for Movies S1 to S6
    • Full Reference List

    Images, Video, and Other Other Media

    Movie S1
    Live imaging of Nr4a1-GFPhigh monocytes (Green) patrolling the lung vasculature followed by a repeat of the movie with analysis of monocyte tracks (time=21 min). Vasculature labeled with dextran dye (Red).
    Movie S2
    Live imaging of Nr4a1-GFPhigh monocytes (Green) recruited to LLC-RFP tumor (Red) in the lung 30 min after IV tumor injection. Neutrophils and vasculature labeled Ly6G antibody (Blue).
    Movie S3
    Live imaging of Nr4a1-GFPhigh monocytes (Green) recruited to LLC-RFP tumor (Red) in the lung 4 hrs after IV tumor injection. Immune cells and vasculature labeled with CD45 antibody (Blue).
    Movie S4
    Live imaging of Nr4a1-GFPhigh monocytes (Green) recruited to LLC-RFP tumor (Red) in the lung 24 hrs after IV tumor injection. Ly6G+ neutrophils, Ly6C+ classical monocytes and vasculature labeled with Ly6G/C (GR-1) antibody (Blue).
    Movie S5
    Live imaging of Nr4a1-GFPhigh monocytes (Green) recruited to LLC-RFP tumor (Red) in the lung 7 days after IV tumor injection. Neutrophils and vasculature labeled with Ly6G antibody (Blue).
    Movie S6
    Live imaging of Cx3cr1−/− monocytes (Green) recruited to LLC-RFP tumor (Red) in the lung 24 hours after IV tumor injection. Vasculature labeled with dextran dye (Blue). Note: CX3CR1-GFPhigh monocytes were tracked manually and carefully isolated from CX3CR1-GFPhigh dendritic cells observed on the surface of the lung.
    Correction (18 November 2015): In the right bar graph of fig. S13A, the control population was incorrectly identified. It is now correctly labeled as "GFP Control." Similarly, in the right bar graph of fig. S15B, the grey bar was not properly identified. It is now correctly labeled as "Nr4a1−/−:PyMT."
    The original version is accessible here.

Navigate This Article