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Macrophage activation state determines the response to rhinovirus infection in a mouse model of allergic asthma.

Hong JY, Chung Y, Steenrod J, Chen Q, Lei J, Comstock AT, Goldsmith AM, Bentley JK, Sajjan US, Hershenson MB - Respir. Res. (2014)

Bottom Line: IL-17A was also increased.Bronchoalveolar macrophages showed an M1 polarization pattern and ex vivo RV infection increased macrophage production of TNF-α, IFN-γ and IL-12p40.Finally, lung cells from OVA-treated IL-4R KO mice showed reduced CD206+ CD301+ M2 macrophages, decreased IL-13 and increased TNF-α and IL-17A production by F4/80+, CD11b+ macrophages.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Molecular and Integrative Physiology, University of Michigan Medical School, 48109 Ann Arbor, MI, USA. mhershen@umich.edu.

ABSTRACT

Background: The mechanisms by which viruses cause asthma exacerbations are not precisely known. Previously, we showed that, in ovalbumin (OVA)-sensitized and -challenged mice with allergic airway inflammation, rhinovirus (RV) infection increases type 2 cytokine production from alternatively-activated (M2) airway macrophages, enhancing eosinophilic inflammation and airways hyperresponsiveness. In this paper, we tested the hypothesis that IL-4 signaling determines the state of macrophage activation and pattern of RV-induced exacerbation in mice with allergic airways disease.

Methods: Eight week-old wild type or IL-4 receptor knockout (IL-4R KO) mice were sensitized and challenged with OVA and inoculated with RV1B or sham HeLa cell lysate.

Results: In contrast to OVA-treated wild-type mice with both neutrophilic and eosinophilic airway inflammation, OVA-treated IL-4R KO mice showed increased neutrophilic inflammation with few eosinophils in the airways. Like wild-type mice, IL-4R KO mice showed OVA-induced airway hyperreactivity which was further exacerbated by RV. There was a shift in lung cytokines from a type 2-predominant response to a type 1 response, including production of IL-12p40 and TNF-α. IL-17A was also increased. RV infection of OVA-treated IL-4R KO mice further increased neutrophilic inflammation. Bronchoalveolar macrophages showed an M1 polarization pattern and ex vivo RV infection increased macrophage production of TNF-α, IFN-γ and IL-12p40. Finally, lung cells from OVA-treated IL-4R KO mice showed reduced CD206+ CD301+ M2 macrophages, decreased IL-13 and increased TNF-α and IL-17A production by F4/80+, CD11b+ macrophages.

Conclusions: OVA-treated IL-4R KO mice show neutrophilic airway inflammation constituting a model of allergic, type 1 cytokine-driven neutrophilic asthma. In the absence of IL-4/IL-13 signaling, RV infection of OVA-treated mice increased type 1 cytokine and IL-17A production from conventionally-activated macrophages, augmenting neutrophilic rather than eosinophilic inflammation. In mice with allergic airways inflammation, IL-4R signaling determines macrophage activation state and the response to subsequent RV infection.

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Airway inflammation and airway hyperresponsiveness in OVA-treated wild-type and IL-4R KO mice. Eight-week old wild-type or IL-4R KO mice were treated with PBS or OVA and inoculated with sham or RV. Bronchoalveolar lavage was performed 24 hour post-inoculation. After counting the total number of cells, cytospins were performed and stained with hematoxylin and eosin, and differential counts determined from 200 cells. The identity of neutrophils and eosinophils was confirmed by immunofluorescence staining for neutrophil elastase and major basic protein (not shown). (A) RV infection increases the total number of BAL cells per lung in OVA-sensitized and -challenged wild-type and IL-4R KO mice. (B) RV infection increases the number of airway neutrophils per lung in OVA-treated wild-type and IL-4R KO mice. The neutrophil response was significantly higher in IL-4R KO mice. (C) RV infection increases the number of airway eosinophils per lung in OVA-treated wild-type mice. The eosinophil response was significantly attenuated in IL-4R KO mice. (Mean ± SEM, n = 3, *different from medium, p < 0.05, one-way ANOVA; †different from wild-type, p < 0.05, one-way ANOVA.) (D & E) Airway cholinergic responsiveness was assessed by measuring changes in total respiratory system resistance in response to increasing doses of nebulized methacholine. Data from wild type (D) and IL-4R KO mice (E) are shown. (Mean ± SEM, n = 4-6 in each group, *different from sham, P < 0.05, two-way ANOVA; †different from PBS, P < 0.05, two-way ANOVA).
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Figure 2: Airway inflammation and airway hyperresponsiveness in OVA-treated wild-type and IL-4R KO mice. Eight-week old wild-type or IL-4R KO mice were treated with PBS or OVA and inoculated with sham or RV. Bronchoalveolar lavage was performed 24 hour post-inoculation. After counting the total number of cells, cytospins were performed and stained with hematoxylin and eosin, and differential counts determined from 200 cells. The identity of neutrophils and eosinophils was confirmed by immunofluorescence staining for neutrophil elastase and major basic protein (not shown). (A) RV infection increases the total number of BAL cells per lung in OVA-sensitized and -challenged wild-type and IL-4R KO mice. (B) RV infection increases the number of airway neutrophils per lung in OVA-treated wild-type and IL-4R KO mice. The neutrophil response was significantly higher in IL-4R KO mice. (C) RV infection increases the number of airway eosinophils per lung in OVA-treated wild-type mice. The eosinophil response was significantly attenuated in IL-4R KO mice. (Mean ± SEM, n = 3, *different from medium, p < 0.05, one-way ANOVA; †different from wild-type, p < 0.05, one-way ANOVA.) (D & E) Airway cholinergic responsiveness was assessed by measuring changes in total respiratory system resistance in response to increasing doses of nebulized methacholine. Data from wild type (D) and IL-4R KO mice (E) are shown. (Mean ± SEM, n = 4-6 in each group, *different from sham, P < 0.05, two-way ANOVA; †different from PBS, P < 0.05, two-way ANOVA).

Mentions: Next, we examined the effect of IL-4R KO in mice sensitized and challenged with OVA and infected with RV. As previously [17], RV alone had modest effects on airway neutrophilic inflammation and responsiveness (not shown). As expected, OVA treatment of wild-type mice significantly increased the total number of BAL cells (Figure 2A), augmenting the number of neutrophils and eosinophils (Figure 2B and C). RV infection of wild-type mice further increased lung inflammation, resulting in an additional 2-fold increase in BAL cells. Both neutrophils and eosinophils were increased in the BAL following RV infection. In IL-4R KO mice, OVA sensitization and challenge was also accompanied by a significant increase in BAL inflammatory cells (Figure 2A). The inflammatory cells consisted nearly exclusively of neutrophils, and the number of eosinophils in the airways was significantly reduced compared to wild-type mice (Figure 2B and C). When OVA-treated IL-4R KO mice were infected with RV, neutrophil infiltration further increased (Figure 2B). In contrast to wild-type mice, RV did not induce eosinophilic inflammation. Finally, we found that, similar to wild type mice, IL-4R KO mice showed OVA-induced airway hyperreactivity which was further exacerbated by RV (Figure 2D and E). (There was no difference in airway reactivity between the wild-type and IL-4R KO OVA/RV groups.) Together, these results show that IL-4 receptor signaling is not required for allergen-induced airway inflammation or hyperresponsiveness. Instead, the immune responses to OVA challenge and RV infection were differentially regulated in the absence of IL-4R signaling, accentuating neutrophilic rather than eosinophilic inflammation.


Macrophage activation state determines the response to rhinovirus infection in a mouse model of allergic asthma.

Hong JY, Chung Y, Steenrod J, Chen Q, Lei J, Comstock AT, Goldsmith AM, Bentley JK, Sajjan US, Hershenson MB - Respir. Res. (2014)

Airway inflammation and airway hyperresponsiveness in OVA-treated wild-type and IL-4R KO mice. Eight-week old wild-type or IL-4R KO mice were treated with PBS or OVA and inoculated with sham or RV. Bronchoalveolar lavage was performed 24 hour post-inoculation. After counting the total number of cells, cytospins were performed and stained with hematoxylin and eosin, and differential counts determined from 200 cells. The identity of neutrophils and eosinophils was confirmed by immunofluorescence staining for neutrophil elastase and major basic protein (not shown). (A) RV infection increases the total number of BAL cells per lung in OVA-sensitized and -challenged wild-type and IL-4R KO mice. (B) RV infection increases the number of airway neutrophils per lung in OVA-treated wild-type and IL-4R KO mice. The neutrophil response was significantly higher in IL-4R KO mice. (C) RV infection increases the number of airway eosinophils per lung in OVA-treated wild-type mice. The eosinophil response was significantly attenuated in IL-4R KO mice. (Mean ± SEM, n = 3, *different from medium, p < 0.05, one-way ANOVA; †different from wild-type, p < 0.05, one-way ANOVA.) (D & E) Airway cholinergic responsiveness was assessed by measuring changes in total respiratory system resistance in response to increasing doses of nebulized methacholine. Data from wild type (D) and IL-4R KO mice (E) are shown. (Mean ± SEM, n = 4-6 in each group, *different from sham, P < 0.05, two-way ANOVA; †different from PBS, P < 0.05, two-way ANOVA).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4066837&req=5

Figure 2: Airway inflammation and airway hyperresponsiveness in OVA-treated wild-type and IL-4R KO mice. Eight-week old wild-type or IL-4R KO mice were treated with PBS or OVA and inoculated with sham or RV. Bronchoalveolar lavage was performed 24 hour post-inoculation. After counting the total number of cells, cytospins were performed and stained with hematoxylin and eosin, and differential counts determined from 200 cells. The identity of neutrophils and eosinophils was confirmed by immunofluorescence staining for neutrophil elastase and major basic protein (not shown). (A) RV infection increases the total number of BAL cells per lung in OVA-sensitized and -challenged wild-type and IL-4R KO mice. (B) RV infection increases the number of airway neutrophils per lung in OVA-treated wild-type and IL-4R KO mice. The neutrophil response was significantly higher in IL-4R KO mice. (C) RV infection increases the number of airway eosinophils per lung in OVA-treated wild-type mice. The eosinophil response was significantly attenuated in IL-4R KO mice. (Mean ± SEM, n = 3, *different from medium, p < 0.05, one-way ANOVA; †different from wild-type, p < 0.05, one-way ANOVA.) (D & E) Airway cholinergic responsiveness was assessed by measuring changes in total respiratory system resistance in response to increasing doses of nebulized methacholine. Data from wild type (D) and IL-4R KO mice (E) are shown. (Mean ± SEM, n = 4-6 in each group, *different from sham, P < 0.05, two-way ANOVA; †different from PBS, P < 0.05, two-way ANOVA).
Mentions: Next, we examined the effect of IL-4R KO in mice sensitized and challenged with OVA and infected with RV. As previously [17], RV alone had modest effects on airway neutrophilic inflammation and responsiveness (not shown). As expected, OVA treatment of wild-type mice significantly increased the total number of BAL cells (Figure 2A), augmenting the number of neutrophils and eosinophils (Figure 2B and C). RV infection of wild-type mice further increased lung inflammation, resulting in an additional 2-fold increase in BAL cells. Both neutrophils and eosinophils were increased in the BAL following RV infection. In IL-4R KO mice, OVA sensitization and challenge was also accompanied by a significant increase in BAL inflammatory cells (Figure 2A). The inflammatory cells consisted nearly exclusively of neutrophils, and the number of eosinophils in the airways was significantly reduced compared to wild-type mice (Figure 2B and C). When OVA-treated IL-4R KO mice were infected with RV, neutrophil infiltration further increased (Figure 2B). In contrast to wild-type mice, RV did not induce eosinophilic inflammation. Finally, we found that, similar to wild type mice, IL-4R KO mice showed OVA-induced airway hyperreactivity which was further exacerbated by RV (Figure 2D and E). (There was no difference in airway reactivity between the wild-type and IL-4R KO OVA/RV groups.) Together, these results show that IL-4 receptor signaling is not required for allergen-induced airway inflammation or hyperresponsiveness. Instead, the immune responses to OVA challenge and RV infection were differentially regulated in the absence of IL-4R signaling, accentuating neutrophilic rather than eosinophilic inflammation.

Bottom Line: IL-17A was also increased.Bronchoalveolar macrophages showed an M1 polarization pattern and ex vivo RV infection increased macrophage production of TNF-α, IFN-γ and IL-12p40.Finally, lung cells from OVA-treated IL-4R KO mice showed reduced CD206+ CD301+ M2 macrophages, decreased IL-13 and increased TNF-α and IL-17A production by F4/80+, CD11b+ macrophages.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Molecular and Integrative Physiology, University of Michigan Medical School, 48109 Ann Arbor, MI, USA. mhershen@umich.edu.

ABSTRACT

Background: The mechanisms by which viruses cause asthma exacerbations are not precisely known. Previously, we showed that, in ovalbumin (OVA)-sensitized and -challenged mice with allergic airway inflammation, rhinovirus (RV) infection increases type 2 cytokine production from alternatively-activated (M2) airway macrophages, enhancing eosinophilic inflammation and airways hyperresponsiveness. In this paper, we tested the hypothesis that IL-4 signaling determines the state of macrophage activation and pattern of RV-induced exacerbation in mice with allergic airways disease.

Methods: Eight week-old wild type or IL-4 receptor knockout (IL-4R KO) mice were sensitized and challenged with OVA and inoculated with RV1B or sham HeLa cell lysate.

Results: In contrast to OVA-treated wild-type mice with both neutrophilic and eosinophilic airway inflammation, OVA-treated IL-4R KO mice showed increased neutrophilic inflammation with few eosinophils in the airways. Like wild-type mice, IL-4R KO mice showed OVA-induced airway hyperreactivity which was further exacerbated by RV. There was a shift in lung cytokines from a type 2-predominant response to a type 1 response, including production of IL-12p40 and TNF-α. IL-17A was also increased. RV infection of OVA-treated IL-4R KO mice further increased neutrophilic inflammation. Bronchoalveolar macrophages showed an M1 polarization pattern and ex vivo RV infection increased macrophage production of TNF-α, IFN-γ and IL-12p40. Finally, lung cells from OVA-treated IL-4R KO mice showed reduced CD206+ CD301+ M2 macrophages, decreased IL-13 and increased TNF-α and IL-17A production by F4/80+, CD11b+ macrophages.

Conclusions: OVA-treated IL-4R KO mice show neutrophilic airway inflammation constituting a model of allergic, type 1 cytokine-driven neutrophilic asthma. In the absence of IL-4/IL-13 signaling, RV infection of OVA-treated mice increased type 1 cytokine and IL-17A production from conventionally-activated macrophages, augmenting neutrophilic rather than eosinophilic inflammation. In mice with allergic airways inflammation, IL-4R signaling determines macrophage activation state and the response to subsequent RV infection.

Show MeSH
Related in: MedlinePlus