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Maturation of mast cell progenitors to mucosal mast cells during allergic pulmonary inflammation in mice.

Bankova LG, Dwyer DF, Liu AY, Austen KF, Gurish MF - Mucosal Immunol (2014)

Bottom Line: The resident tracheal CMCs had higher SSC, FcɛRI, and Kit and lower β7-integrin expression than the MMCs.By histology, the MMCs follow similar kinetics to the flow cytometry-identified mature MMCs and are notably persistent for >42 days.Steroid treatment reduced inflammation and MCp influx but had no effect on established MMCs.

View Article: PubMed Central - PubMed

Affiliation: Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital and Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.

ABSTRACT
In contrast to resident constitutive mast cells (CMCs), mucosal MCs (MMCs) appear in the lung and trachea of sensitized mice only following inhalation challenge. We monitored the influx and maturation of MCs by their expression of Kit, FcɛRI, β7-integrin and side scatter (SSC) by flow cytometry. Influx of MC progenitors (MCps) (FcɛRI(lo), Kit(int), β7(hi), and SSC(lo)) peaks 1 day after challenges and subsides to baseline by day 7 after challenge. The mature MMCs appear as a distinct population on day 7 and peak at day 14 with higher SSC and FcɛRI expression, but lower β7 and Kit expression. A distinct transitional population is present between 1 and 7 days after challenge. Maturation occurs more rapidly in the trachea. The resident tracheal CMCs had higher SSC, FcɛRI, and Kit and lower β7-integrin expression than the MMCs. By histology, the MMCs follow similar kinetics to the flow cytometry-identified mature MMCs and are notably persistent for >42 days. Steroid treatment reduced inflammation and MCp influx but had no effect on established MMCs. Thus, changes in SSC, FcɛRI, and Kit together with the expression of αE/α4:β7-integrins characterizes the development of induced MMCs from MCps and distinguishes them from resident CMCs in the trachea and large airways.

No MeSH data available.


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Expression of β7 and β1 integrins and forward and side scatter characteristics of inducible lung MC populations at D7 after challenges. (a) Representative histograms (top panel) and mean (± SEM) net MFI (bottom panel) of β7 integrin expression by the 3 populations of lung MCs: MCp -green, eMMC -red and MMC -blue; black dotted line -isotype control. Net MFI was determined by subtracting the value of the isotype control. (b) Representative histograms (top panel) and mean (± SEM) net MFI (bottom panel) of β1 (CD29) integrin expression by the 3 populations of lung MCs (top panel) colored as in a. (c) Representative histograms show the side scatter profile of the 3 lung MC populations colored as in a. Grey shaded area indicates immature spleen MCp. (d) Representative histograms show the forward scatter profile of the 3 lung MC populations compared to spleen MCp as in c. Histograms in c and d show the mean value from 2-3 mice/group from one of 5 experiments. Bar graphs present means ± SEMs from 3-5 separate experiments with 5-13 mice per group.
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Figure 2: Expression of β7 and β1 integrins and forward and side scatter characteristics of inducible lung MC populations at D7 after challenges. (a) Representative histograms (top panel) and mean (± SEM) net MFI (bottom panel) of β7 integrin expression by the 3 populations of lung MCs: MCp -green, eMMC -red and MMC -blue; black dotted line -isotype control. Net MFI was determined by subtracting the value of the isotype control. (b) Representative histograms (top panel) and mean (± SEM) net MFI (bottom panel) of β1 (CD29) integrin expression by the 3 populations of lung MCs (top panel) colored as in a. (c) Representative histograms show the side scatter profile of the 3 lung MC populations colored as in a. Grey shaded area indicates immature spleen MCp. (d) Representative histograms show the forward scatter profile of the 3 lung MC populations compared to spleen MCp as in c. Histograms in c and d show the mean value from 2-3 mice/group from one of 5 experiments. Bar graphs present means ± SEMs from 3-5 separate experiments with 5-13 mice per group.

Mentions: To further characterize these 3 populations of recruited and induced MCs, we assessed their expression of β7 integrins implicated in the transendothelial recruitment of MCps to mouse lung,20, 21 and also analyzed their size and granularity characteristics by their forward and side scatter profiles (FSC and SSC). The population of MCps at D1 in challenged mice has the highest expression level of β7 integrin as depicted for a representative result (Figure 2a, green histogram) and by the mean net MFI (mean fluorescence intensity) (green bar, bottom panel). The β7 integrin surface expression on these MCps found at D1 does not change as their numbers fall at later time points (data not shown). The eMMCs, have lower β7 integrin expression compared to the MCps on D1 (Figure 2a, red versus green line and bars). The population of MMCs has a similarly lower expression of β7 integrin at D7 (Figure 2a, blue line and bar), indicating a decline of β7 integrin expression with maturation. The level of β1 integrin expression on the cells at the 3 stages of development is similar with a small but statistically significant difference in net MFI between MCp and the more mature MCs (Figure 2b). Comparison for granularity using SSC reveals that on D7, the MCps are the least granular and comparable to splenic MCps (Figure 2c, green line versus grey shaded area). The eMMCs are intermediate for SSC and the MMCs have the highest SSC (Figure 2c, red and blue lines) compatible with further maturation. Comparison of the 3 populations for FSC characteristics shows no differences (Figure 2d).


Maturation of mast cell progenitors to mucosal mast cells during allergic pulmonary inflammation in mice.

Bankova LG, Dwyer DF, Liu AY, Austen KF, Gurish MF - Mucosal Immunol (2014)

Expression of β7 and β1 integrins and forward and side scatter characteristics of inducible lung MC populations at D7 after challenges. (a) Representative histograms (top panel) and mean (± SEM) net MFI (bottom panel) of β7 integrin expression by the 3 populations of lung MCs: MCp -green, eMMC -red and MMC -blue; black dotted line -isotype control. Net MFI was determined by subtracting the value of the isotype control. (b) Representative histograms (top panel) and mean (± SEM) net MFI (bottom panel) of β1 (CD29) integrin expression by the 3 populations of lung MCs (top panel) colored as in a. (c) Representative histograms show the side scatter profile of the 3 lung MC populations colored as in a. Grey shaded area indicates immature spleen MCp. (d) Representative histograms show the forward scatter profile of the 3 lung MC populations compared to spleen MCp as in c. Histograms in c and d show the mean value from 2-3 mice/group from one of 5 experiments. Bar graphs present means ± SEMs from 3-5 separate experiments with 5-13 mice per group.
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Related In: Results  -  Collection

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Figure 2: Expression of β7 and β1 integrins and forward and side scatter characteristics of inducible lung MC populations at D7 after challenges. (a) Representative histograms (top panel) and mean (± SEM) net MFI (bottom panel) of β7 integrin expression by the 3 populations of lung MCs: MCp -green, eMMC -red and MMC -blue; black dotted line -isotype control. Net MFI was determined by subtracting the value of the isotype control. (b) Representative histograms (top panel) and mean (± SEM) net MFI (bottom panel) of β1 (CD29) integrin expression by the 3 populations of lung MCs (top panel) colored as in a. (c) Representative histograms show the side scatter profile of the 3 lung MC populations colored as in a. Grey shaded area indicates immature spleen MCp. (d) Representative histograms show the forward scatter profile of the 3 lung MC populations compared to spleen MCp as in c. Histograms in c and d show the mean value from 2-3 mice/group from one of 5 experiments. Bar graphs present means ± SEMs from 3-5 separate experiments with 5-13 mice per group.
Mentions: To further characterize these 3 populations of recruited and induced MCs, we assessed their expression of β7 integrins implicated in the transendothelial recruitment of MCps to mouse lung,20, 21 and also analyzed their size and granularity characteristics by their forward and side scatter profiles (FSC and SSC). The population of MCps at D1 in challenged mice has the highest expression level of β7 integrin as depicted for a representative result (Figure 2a, green histogram) and by the mean net MFI (mean fluorescence intensity) (green bar, bottom panel). The β7 integrin surface expression on these MCps found at D1 does not change as their numbers fall at later time points (data not shown). The eMMCs, have lower β7 integrin expression compared to the MCps on D1 (Figure 2a, red versus green line and bars). The population of MMCs has a similarly lower expression of β7 integrin at D7 (Figure 2a, blue line and bar), indicating a decline of β7 integrin expression with maturation. The level of β1 integrin expression on the cells at the 3 stages of development is similar with a small but statistically significant difference in net MFI between MCp and the more mature MCs (Figure 2b). Comparison for granularity using SSC reveals that on D7, the MCps are the least granular and comparable to splenic MCps (Figure 2c, green line versus grey shaded area). The eMMCs are intermediate for SSC and the MMCs have the highest SSC (Figure 2c, red and blue lines) compatible with further maturation. Comparison of the 3 populations for FSC characteristics shows no differences (Figure 2d).

Bottom Line: The resident tracheal CMCs had higher SSC, FcɛRI, and Kit and lower β7-integrin expression than the MMCs.By histology, the MMCs follow similar kinetics to the flow cytometry-identified mature MMCs and are notably persistent for >42 days.Steroid treatment reduced inflammation and MCp influx but had no effect on established MMCs.

View Article: PubMed Central - PubMed

Affiliation: Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital and Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.

ABSTRACT
In contrast to resident constitutive mast cells (CMCs), mucosal MCs (MMCs) appear in the lung and trachea of sensitized mice only following inhalation challenge. We monitored the influx and maturation of MCs by their expression of Kit, FcɛRI, β7-integrin and side scatter (SSC) by flow cytometry. Influx of MC progenitors (MCps) (FcɛRI(lo), Kit(int), β7(hi), and SSC(lo)) peaks 1 day after challenges and subsides to baseline by day 7 after challenge. The mature MMCs appear as a distinct population on day 7 and peak at day 14 with higher SSC and FcɛRI expression, but lower β7 and Kit expression. A distinct transitional population is present between 1 and 7 days after challenge. Maturation occurs more rapidly in the trachea. The resident tracheal CMCs had higher SSC, FcɛRI, and Kit and lower β7-integrin expression than the MMCs. By histology, the MMCs follow similar kinetics to the flow cytometry-identified mature MMCs and are notably persistent for >42 days. Steroid treatment reduced inflammation and MCp influx but had no effect on established MMCs. Thus, changes in SSC, FcɛRI, and Kit together with the expression of αE/α4:β7-integrins characterizes the development of induced MMCs from MCps and distinguishes them from resident CMCs in the trachea and large airways.

No MeSH data available.


Related in: MedlinePlus