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TLR4/MyD88-induced CD11b+Gr-1 int F4/80+ non-migratory myeloid cells suppress Th2 effector function in the lung.

Arora M, Poe SL, Oriss TB, Krishnamoorthy N, Yarlagadda M, Wenzel SE, Billiar TR, Ray A, Ray P - Mucosal Immunol (2010)

Bottom Line: LPS promoted the development of a CD11b(+)Gr1(int)F4/80(+) lung-resident cell resembling myeloid-derived suppressor cells in a Toll-like receptor 4 and myeloid differentiation factor 88 (MyD88)-dependent manner that suppressed lung dendritic cell (DC)-mediated reactivation of primed Th2 cells.Suppression of Th2 effector function was reversed by anti-interleukin-10 (IL-10) or inhibition of arginase 1.These data suggest that CD11b(+)Gr1(int)F4/80(+) cells contribute to the protective effects of LPS in allergic asthma by tempering Th2 effector function in the tissue.

View Article: PubMed Central - PubMed

Affiliation: Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Pittsburgh, Pennsylvania, USA.

ABSTRACT
In humans, environmental exposure to a high dose of lipopolysaccharide (LPS) protects from allergic asthma, the immunological underpinnings of which are not well understood. In mice, exposure to a high LPS dose blunted house dust mite-induced airway eosinophilia and T-helper 2 (Th2) cytokine production. Although adoptively transferred Th2 cells induced allergic airway inflammation in control mice, they were unable to do so in LPS-exposed mice. LPS promoted the development of a CD11b(+)Gr1(int)F4/80(+) lung-resident cell resembling myeloid-derived suppressor cells in a Toll-like receptor 4 and myeloid differentiation factor 88 (MyD88)-dependent manner that suppressed lung dendritic cell (DC)-mediated reactivation of primed Th2 cells. LPS effects switched from suppressive to stimulatory in MyD88(-/-) mice. Suppression of Th2 effector function was reversed by anti-interleukin-10 (IL-10) or inhibition of arginase 1. Lineage(neg) bone marrow progenitor cells could be induced by LPS to develop into CD11b(+)Gr1(int)F4/80(+)cells both in vivo and in vitro that when adoptively transferred suppressed allergen-induced airway inflammation in recipient mice. These data suggest that CD11b(+)Gr1(int)F4/80(+) cells contribute to the protective effects of LPS in allergic asthma by tempering Th2 effector function in the tissue.

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MyD88-dependence of development of CD11b+Gr1int cells. (a) Bone marrow cells were cultured with GM-CSF and LPS for 9 days and phenotypic analysis was performed using flow cytometry. The resulting cells from wild-type Balb/c mice were compared to those from MyD88-deficient (MyD88-/-) mice (left-hand panel), and those from wild-type C57BL/6 mice were compared to TRIF-deficient (TRIF-/-) mice (right-hand panel). (b) Estimation of fold-induction of CD11b+Gr1int cells in response to LPS in the lungs of WT, TLR4-/- and MyD88-/- mice. (c) MyD88 -/- mice received HDM ± LPS i.t. as in Figure 4a. 72 h after the final instillation, BAL fluid and lung tissue samples were obtained. Total and differential counts of cells recovered in the BAL fluid (left-hand panel) and H&E staining of lung sections (right-hand panels) were performed. Values shown are mean ± SD, *, P<0.05, **, P<0.005. The concentration of IL-5 in lung homogenates was measured by multiplex assay and is presented as mean ± SEM ***, P<0.001. The data shown are representative of two independent experiments.
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Figure 5: MyD88-dependence of development of CD11b+Gr1int cells. (a) Bone marrow cells were cultured with GM-CSF and LPS for 9 days and phenotypic analysis was performed using flow cytometry. The resulting cells from wild-type Balb/c mice were compared to those from MyD88-deficient (MyD88-/-) mice (left-hand panel), and those from wild-type C57BL/6 mice were compared to TRIF-deficient (TRIF-/-) mice (right-hand panel). (b) Estimation of fold-induction of CD11b+Gr1int cells in response to LPS in the lungs of WT, TLR4-/- and MyD88-/- mice. (c) MyD88 -/- mice received HDM ± LPS i.t. as in Figure 4a. 72 h after the final instillation, BAL fluid and lung tissue samples were obtained. Total and differential counts of cells recovered in the BAL fluid (left-hand panel) and H&E staining of lung sections (right-hand panels) were performed. Values shown are mean ± SD, *, P<0.05, **, P<0.005. The concentration of IL-5 in lung homogenates was measured by multiplex assay and is presented as mean ± SEM ***, P<0.001. The data shown are representative of two independent experiments.

Mentions: Our next goal was to determine which of the TLR4-induced pathways, MyD88-dependent or -independent (via TRIF), was responsible for the generation of our cell of interest. To match their genetically altered counterparts, WT control mice used for the MyD88-/- mice were on Balb/c background while those for the TRIF-/- animals were on C57BL/6 background. We were able to generate the CD11b+Gr1+ cells in the presence of GM-CSF+LPS but not with either agent alone from lineage- bone marrow progenitor cells (Supplementary Figure 2). GM-CSF alone induced DC development as is standard for generation of bone marrow-derived DCs from mouse cells. No difference in the generation of the CD11b+Gr1int cells has been noted by us whether bone marrow cells are derived from Balb/c or C57BL/6 mice. Cells developed under both conditions expressed the myeloid marker CD11b. In contrast to 80-90% of the cells generated in the presence of GM-CSF being conventional CD11c+ DCs, simultaneous stimulation with LPS reduced CD11c+ cells to less than 5% (Supplementary Figure 2). The lung CD11b+Gr1+ cells were found to express CD11c (Figure 1d), but at a lower level compared to expression by lung cDCs. The GM-CSF+LPS-induced cells also expressed Gr1 and Thy1.2, the latter being only found on the in vitro-generated cells. Interestingly, Thy1.2 expression on a minor subset of splenic CpG ODN-induced CD11c+ DCs was previously described 21. MyD88- but not TRIF-deficiency blocked generation of Gr1+ cells from bone marrow cells in the presence of GM-CSF and LPS (Figure 5a). To further strengthen this observation, we took a complementary approach of culturing bone marrow cells with GM-CSF and poly (I:C), a TLR3 ligand which only signals via TRIF. Unlike LPS, different doses of poly (I:C) when combined with GM-CSF did not induce generation of the CD11b+Gr1int cells (data not shown). To determine the role of MyD88 in vivo, TLR4-/- and MyD88-/- mice were treated with LPS and the frequency of the CD11b+Gr1int cells in their lungs was compared with that in untreated mice. As shown in Figure 5b, the CD11b+Gr1int cells in the lungs of LPS-treated TLR4-/- and MyD88-/- mice increased by only ∼8- and 4-fold respectively as compared to 63-fold in WT mice.


TLR4/MyD88-induced CD11b+Gr-1 int F4/80+ non-migratory myeloid cells suppress Th2 effector function in the lung.

Arora M, Poe SL, Oriss TB, Krishnamoorthy N, Yarlagadda M, Wenzel SE, Billiar TR, Ray A, Ray P - Mucosal Immunol (2010)

MyD88-dependence of development of CD11b+Gr1int cells. (a) Bone marrow cells were cultured with GM-CSF and LPS for 9 days and phenotypic analysis was performed using flow cytometry. The resulting cells from wild-type Balb/c mice were compared to those from MyD88-deficient (MyD88-/-) mice (left-hand panel), and those from wild-type C57BL/6 mice were compared to TRIF-deficient (TRIF-/-) mice (right-hand panel). (b) Estimation of fold-induction of CD11b+Gr1int cells in response to LPS in the lungs of WT, TLR4-/- and MyD88-/- mice. (c) MyD88 -/- mice received HDM ± LPS i.t. as in Figure 4a. 72 h after the final instillation, BAL fluid and lung tissue samples were obtained. Total and differential counts of cells recovered in the BAL fluid (left-hand panel) and H&E staining of lung sections (right-hand panels) were performed. Values shown are mean ± SD, *, P<0.05, **, P<0.005. The concentration of IL-5 in lung homogenates was measured by multiplex assay and is presented as mean ± SEM ***, P<0.001. The data shown are representative of two independent experiments.
© Copyright Policy
Related In: Results  -  Collection

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Figure 5: MyD88-dependence of development of CD11b+Gr1int cells. (a) Bone marrow cells were cultured with GM-CSF and LPS for 9 days and phenotypic analysis was performed using flow cytometry. The resulting cells from wild-type Balb/c mice were compared to those from MyD88-deficient (MyD88-/-) mice (left-hand panel), and those from wild-type C57BL/6 mice were compared to TRIF-deficient (TRIF-/-) mice (right-hand panel). (b) Estimation of fold-induction of CD11b+Gr1int cells in response to LPS in the lungs of WT, TLR4-/- and MyD88-/- mice. (c) MyD88 -/- mice received HDM ± LPS i.t. as in Figure 4a. 72 h after the final instillation, BAL fluid and lung tissue samples were obtained. Total and differential counts of cells recovered in the BAL fluid (left-hand panel) and H&E staining of lung sections (right-hand panels) were performed. Values shown are mean ± SD, *, P<0.05, **, P<0.005. The concentration of IL-5 in lung homogenates was measured by multiplex assay and is presented as mean ± SEM ***, P<0.001. The data shown are representative of two independent experiments.
Mentions: Our next goal was to determine which of the TLR4-induced pathways, MyD88-dependent or -independent (via TRIF), was responsible for the generation of our cell of interest. To match their genetically altered counterparts, WT control mice used for the MyD88-/- mice were on Balb/c background while those for the TRIF-/- animals were on C57BL/6 background. We were able to generate the CD11b+Gr1+ cells in the presence of GM-CSF+LPS but not with either agent alone from lineage- bone marrow progenitor cells (Supplementary Figure 2). GM-CSF alone induced DC development as is standard for generation of bone marrow-derived DCs from mouse cells. No difference in the generation of the CD11b+Gr1int cells has been noted by us whether bone marrow cells are derived from Balb/c or C57BL/6 mice. Cells developed under both conditions expressed the myeloid marker CD11b. In contrast to 80-90% of the cells generated in the presence of GM-CSF being conventional CD11c+ DCs, simultaneous stimulation with LPS reduced CD11c+ cells to less than 5% (Supplementary Figure 2). The lung CD11b+Gr1+ cells were found to express CD11c (Figure 1d), but at a lower level compared to expression by lung cDCs. The GM-CSF+LPS-induced cells also expressed Gr1 and Thy1.2, the latter being only found on the in vitro-generated cells. Interestingly, Thy1.2 expression on a minor subset of splenic CpG ODN-induced CD11c+ DCs was previously described 21. MyD88- but not TRIF-deficiency blocked generation of Gr1+ cells from bone marrow cells in the presence of GM-CSF and LPS (Figure 5a). To further strengthen this observation, we took a complementary approach of culturing bone marrow cells with GM-CSF and poly (I:C), a TLR3 ligand which only signals via TRIF. Unlike LPS, different doses of poly (I:C) when combined with GM-CSF did not induce generation of the CD11b+Gr1int cells (data not shown). To determine the role of MyD88 in vivo, TLR4-/- and MyD88-/- mice were treated with LPS and the frequency of the CD11b+Gr1int cells in their lungs was compared with that in untreated mice. As shown in Figure 5b, the CD11b+Gr1int cells in the lungs of LPS-treated TLR4-/- and MyD88-/- mice increased by only ∼8- and 4-fold respectively as compared to 63-fold in WT mice.

Bottom Line: LPS promoted the development of a CD11b(+)Gr1(int)F4/80(+) lung-resident cell resembling myeloid-derived suppressor cells in a Toll-like receptor 4 and myeloid differentiation factor 88 (MyD88)-dependent manner that suppressed lung dendritic cell (DC)-mediated reactivation of primed Th2 cells.Suppression of Th2 effector function was reversed by anti-interleukin-10 (IL-10) or inhibition of arginase 1.These data suggest that CD11b(+)Gr1(int)F4/80(+) cells contribute to the protective effects of LPS in allergic asthma by tempering Th2 effector function in the tissue.

View Article: PubMed Central - PubMed

Affiliation: Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Pittsburgh, Pennsylvania, USA.

ABSTRACT
In humans, environmental exposure to a high dose of lipopolysaccharide (LPS) protects from allergic asthma, the immunological underpinnings of which are not well understood. In mice, exposure to a high LPS dose blunted house dust mite-induced airway eosinophilia and T-helper 2 (Th2) cytokine production. Although adoptively transferred Th2 cells induced allergic airway inflammation in control mice, they were unable to do so in LPS-exposed mice. LPS promoted the development of a CD11b(+)Gr1(int)F4/80(+) lung-resident cell resembling myeloid-derived suppressor cells in a Toll-like receptor 4 and myeloid differentiation factor 88 (MyD88)-dependent manner that suppressed lung dendritic cell (DC)-mediated reactivation of primed Th2 cells. LPS effects switched from suppressive to stimulatory in MyD88(-/-) mice. Suppression of Th2 effector function was reversed by anti-interleukin-10 (IL-10) or inhibition of arginase 1. Lineage(neg) bone marrow progenitor cells could be induced by LPS to develop into CD11b(+)Gr1(int)F4/80(+)cells both in vivo and in vitro that when adoptively transferred suppressed allergen-induced airway inflammation in recipient mice. These data suggest that CD11b(+)Gr1(int)F4/80(+) cells contribute to the protective effects of LPS in allergic asthma by tempering Th2 effector function in the tissue.

Show MeSH
Related in: MedlinePlus