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Lymphotoxin is required for maintaining physiological levels of serum IgE that minimizes Th1-mediated airway inflammation.

Kang HS, Blink SE, Chin RK, Lee Y, Kim O, Weinstock J, Waldschmidt T, Conrad D, Chen B, Solway J, Sperling AI, Fu YX - J. Exp. Med. (2003)

Bottom Line: Although elevated levels of IgE in asthmatic patients are strongly associated with lung infiltration by activated T helper (Th) 2 cells, the physiological role of immunoglobulin E (IgE) in the airway remains largely undefined.Lymphotoxin-deficient alpha (LTalpha-/-) mice exhibit increased airway inflammation, paradoxically accompanied by diminished levels of IgE and reduced airway hyperresponsiveness in response to both environmental and induced antigen challenge.Therefore, this work has revealed that lymphotoxin is essential for IgE production, and a physiological role of IgE in the airway may consist of maintaining the balance of Th1 and Th2 responses to prevent aberrant inflammation.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, The University of Chicago, Chicago, IL 60637, USA.

ABSTRACT
Although elevated levels of IgE in asthmatic patients are strongly associated with lung infiltration by activated T helper (Th) 2 cells, the physiological role of immunoglobulin E (IgE) in the airway remains largely undefined. Lymphotoxin-deficient alpha (LTalpha-/-) mice exhibit increased airway inflammation, paradoxically accompanied by diminished levels of IgE and reduced airway hyperresponsiveness in response to both environmental and induced antigen challenge. The severe lung inflammation in LTalpha-/- mice is Th1 in nature and can be alleviated by IgE reconstitution. Conversely, depletion of IgE in wild-type mice recapitulates the lung pathologies of LTalpha-/- mice. Therefore, this work has revealed that lymphotoxin is essential for IgE production, and a physiological role of IgE in the airway may consist of maintaining the balance of Th1 and Th2 responses to prevent aberrant inflammation.

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Related in: MedlinePlus

Increased inflammation and airway remodeling in LTα−/− and IgE−/− mice. (A) Lung tissues from WT, LTα−/−, and IgE−/− mice (3 mo old) were fixed in 10% buffered formalin and embedded in paraffin. Hematoxylin and eosin staining (top, H&E) and Masson's trichrome staining (bottom) of B6, LTα−/−, and IgE−/− mice are presented. (B) The lung (left) and BAL cells (right) were isolated by collagenase digestion and lavage, respectively, from 3-mo-old B6 (white bars) and LTα−/− (black bars) mice (n = 5 per group). The total number of cells was analyzed with trypan blue staining. The number of leukocytes in the lung of LTα−/− mice is significantly higher than that of the WT (P < 0.001). BAL cells from five mice were pooled for further analysis by FACS®. (C) Lung cells were dually stained with FITC-conjugated anti-CD69 and PE-conjugated anti-CD3. The fluorescence intensity was analyzed from the gated lymphocyte population of B6 (left) and LTα−/− (right) mice. The percentage of CD69+ cells among CD3+ cells is presented. (D) The forward/side scatter dot-plot profiles were analyzed from BAL cells of B6 (left) and LTα−/− (right) mice; (a), (b), and (c) represent the lymphocyte, granulocyte, and macrophage population, respectively. (E) The gated lymphocyte population (a) from the forward/side scatter dot-plot profiles of BAL cells (D) was analyzed for CD4 and B220 expression by FACS® analysis. (F) CCR3 and CD3 expression was analyzed from both the gated lymphocyte (a) and granulocyte (b) populations. (G) The type of BAL cells was determined by calculating the absolute number of each cell type from the FACS® profiles and by the total number of cells (P < 0.0001; WT vs. LTα−/−).(H) B6 and LTα−/− mice were analyzed by three-color staining with FITC–anti-B220, cychrome–anti-CD4, and PE–anti-CD8 or PE–anti-NK1.1. The gated lymphocyte population (a) from the forward/side scatter dot-plot profiles of the lung cells was analyzed for CD4 and B220 (P < 0.01, WT vs. LTα−/− mice). The percentage of CD8+ or NK1.1+ cells gated from B220−CD4− was evaluated. (I) CCR3 and CD3 expression was analyzed from both the gated lymphocyte (a) and granulocyte (b) population. (J) The total number of cells was calculated. The type of lung cells was also determined by calculating the absolute number of each cell type from the FACS® profiles. The results are representative of five independent experiments.
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fig1: Increased inflammation and airway remodeling in LTα−/− and IgE−/− mice. (A) Lung tissues from WT, LTα−/−, and IgE−/− mice (3 mo old) were fixed in 10% buffered formalin and embedded in paraffin. Hematoxylin and eosin staining (top, H&E) and Masson's trichrome staining (bottom) of B6, LTα−/−, and IgE−/− mice are presented. (B) The lung (left) and BAL cells (right) were isolated by collagenase digestion and lavage, respectively, from 3-mo-old B6 (white bars) and LTα−/− (black bars) mice (n = 5 per group). The total number of cells was analyzed with trypan blue staining. The number of leukocytes in the lung of LTα−/− mice is significantly higher than that of the WT (P < 0.001). BAL cells from five mice were pooled for further analysis by FACS®. (C) Lung cells were dually stained with FITC-conjugated anti-CD69 and PE-conjugated anti-CD3. The fluorescence intensity was analyzed from the gated lymphocyte population of B6 (left) and LTα−/− (right) mice. The percentage of CD69+ cells among CD3+ cells is presented. (D) The forward/side scatter dot-plot profiles were analyzed from BAL cells of B6 (left) and LTα−/− (right) mice; (a), (b), and (c) represent the lymphocyte, granulocyte, and macrophage population, respectively. (E) The gated lymphocyte population (a) from the forward/side scatter dot-plot profiles of BAL cells (D) was analyzed for CD4 and B220 expression by FACS® analysis. (F) CCR3 and CD3 expression was analyzed from both the gated lymphocyte (a) and granulocyte (b) populations. (G) The type of BAL cells was determined by calculating the absolute number of each cell type from the FACS® profiles and by the total number of cells (P < 0.0001; WT vs. LTα−/−).(H) B6 and LTα−/− mice were analyzed by three-color staining with FITC–anti-B220, cychrome–anti-CD4, and PE–anti-CD8 or PE–anti-NK1.1. The gated lymphocyte population (a) from the forward/side scatter dot-plot profiles of the lung cells was analyzed for CD4 and B220 (P < 0.01, WT vs. LTα−/− mice). The percentage of CD8+ or NK1.1+ cells gated from B220−CD4− was evaluated. (I) CCR3 and CD3 expression was analyzed from both the gated lymphocyte (a) and granulocyte (b) population. (J) The total number of cells was calculated. The type of lung cells was also determined by calculating the absolute number of each cell type from the FACS® profiles. The results are representative of five independent experiments.

Mentions: To carefully determine the nature of the previously reported accumulation of leukocytes in the lungs of LTα−/− mice (17–19), detailed histopathological analysis was performed. The lungs of LTα−/− mice do not merely harbor leukocytes but gradually develop a chronic airway inflammation that worsens with age (Fig. 1 A). The infiltration consists of mainly mononuclear cells predominantly in the peribronchial and perivascular areas. Histopathological analysis of lung tissues in LTα−/− mice also revealed significant airway remodeling. These changes include bronchial wall thickening, subepithelial fibrosis, increased goblet cell mass, myoblast–myocyte hyperplasia and hypertrophy, epithelial cell hypertrophy, and increased deposition of collagen below the basement membrane; these are all clear indicators of chronic airway inflammation. Furthermore, the thickness of this subepithelial collagen layer was visualized by Masson's trichrome staining, which stains collagen. In naive LTα−/− mice, the collagen layer under the basement membrane was much thicker than that of WT mice (Fig. 1 A). To further determine the type and number of infiltrating cells in the lung tissue, lungs from WT and LTα−/− mice were digested with collagenase. The suspension of cells was analyzed by flow cytometry and a three- to fivefold increase in total cell number was found in LTα−/− mice (Fig. 1 B) with an increased proportion of activated T cells, as measured by CD69 expression, in LTα−/− mice compared with WT mice (Fig. 1 C). Thus, LTα−/− mice, without deliberate challenge, appear to develop a spontaneous, cumulative airway inflammation with active remodeling not seen in WT mice housed in the same specific pathogen-free facility.


Lymphotoxin is required for maintaining physiological levels of serum IgE that minimizes Th1-mediated airway inflammation.

Kang HS, Blink SE, Chin RK, Lee Y, Kim O, Weinstock J, Waldschmidt T, Conrad D, Chen B, Solway J, Sperling AI, Fu YX - J. Exp. Med. (2003)

Increased inflammation and airway remodeling in LTα−/− and IgE−/− mice. (A) Lung tissues from WT, LTα−/−, and IgE−/− mice (3 mo old) were fixed in 10% buffered formalin and embedded in paraffin. Hematoxylin and eosin staining (top, H&E) and Masson's trichrome staining (bottom) of B6, LTα−/−, and IgE−/− mice are presented. (B) The lung (left) and BAL cells (right) were isolated by collagenase digestion and lavage, respectively, from 3-mo-old B6 (white bars) and LTα−/− (black bars) mice (n = 5 per group). The total number of cells was analyzed with trypan blue staining. The number of leukocytes in the lung of LTα−/− mice is significantly higher than that of the WT (P < 0.001). BAL cells from five mice were pooled for further analysis by FACS®. (C) Lung cells were dually stained with FITC-conjugated anti-CD69 and PE-conjugated anti-CD3. The fluorescence intensity was analyzed from the gated lymphocyte population of B6 (left) and LTα−/− (right) mice. The percentage of CD69+ cells among CD3+ cells is presented. (D) The forward/side scatter dot-plot profiles were analyzed from BAL cells of B6 (left) and LTα−/− (right) mice; (a), (b), and (c) represent the lymphocyte, granulocyte, and macrophage population, respectively. (E) The gated lymphocyte population (a) from the forward/side scatter dot-plot profiles of BAL cells (D) was analyzed for CD4 and B220 expression by FACS® analysis. (F) CCR3 and CD3 expression was analyzed from both the gated lymphocyte (a) and granulocyte (b) populations. (G) The type of BAL cells was determined by calculating the absolute number of each cell type from the FACS® profiles and by the total number of cells (P < 0.0001; WT vs. LTα−/−).(H) B6 and LTα−/− mice were analyzed by three-color staining with FITC–anti-B220, cychrome–anti-CD4, and PE–anti-CD8 or PE–anti-NK1.1. The gated lymphocyte population (a) from the forward/side scatter dot-plot profiles of the lung cells was analyzed for CD4 and B220 (P < 0.01, WT vs. LTα−/− mice). The percentage of CD8+ or NK1.1+ cells gated from B220−CD4− was evaluated. (I) CCR3 and CD3 expression was analyzed from both the gated lymphocyte (a) and granulocyte (b) population. (J) The total number of cells was calculated. The type of lung cells was also determined by calculating the absolute number of each cell type from the FACS® profiles. The results are representative of five independent experiments.
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Related In: Results  -  Collection

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fig1: Increased inflammation and airway remodeling in LTα−/− and IgE−/− mice. (A) Lung tissues from WT, LTα−/−, and IgE−/− mice (3 mo old) were fixed in 10% buffered formalin and embedded in paraffin. Hematoxylin and eosin staining (top, H&E) and Masson's trichrome staining (bottom) of B6, LTα−/−, and IgE−/− mice are presented. (B) The lung (left) and BAL cells (right) were isolated by collagenase digestion and lavage, respectively, from 3-mo-old B6 (white bars) and LTα−/− (black bars) mice (n = 5 per group). The total number of cells was analyzed with trypan blue staining. The number of leukocytes in the lung of LTα−/− mice is significantly higher than that of the WT (P < 0.001). BAL cells from five mice were pooled for further analysis by FACS®. (C) Lung cells were dually stained with FITC-conjugated anti-CD69 and PE-conjugated anti-CD3. The fluorescence intensity was analyzed from the gated lymphocyte population of B6 (left) and LTα−/− (right) mice. The percentage of CD69+ cells among CD3+ cells is presented. (D) The forward/side scatter dot-plot profiles were analyzed from BAL cells of B6 (left) and LTα−/− (right) mice; (a), (b), and (c) represent the lymphocyte, granulocyte, and macrophage population, respectively. (E) The gated lymphocyte population (a) from the forward/side scatter dot-plot profiles of BAL cells (D) was analyzed for CD4 and B220 expression by FACS® analysis. (F) CCR3 and CD3 expression was analyzed from both the gated lymphocyte (a) and granulocyte (b) populations. (G) The type of BAL cells was determined by calculating the absolute number of each cell type from the FACS® profiles and by the total number of cells (P < 0.0001; WT vs. LTα−/−).(H) B6 and LTα−/− mice were analyzed by three-color staining with FITC–anti-B220, cychrome–anti-CD4, and PE–anti-CD8 or PE–anti-NK1.1. The gated lymphocyte population (a) from the forward/side scatter dot-plot profiles of the lung cells was analyzed for CD4 and B220 (P < 0.01, WT vs. LTα−/− mice). The percentage of CD8+ or NK1.1+ cells gated from B220−CD4− was evaluated. (I) CCR3 and CD3 expression was analyzed from both the gated lymphocyte (a) and granulocyte (b) population. (J) The total number of cells was calculated. The type of lung cells was also determined by calculating the absolute number of each cell type from the FACS® profiles. The results are representative of five independent experiments.
Mentions: To carefully determine the nature of the previously reported accumulation of leukocytes in the lungs of LTα−/− mice (17–19), detailed histopathological analysis was performed. The lungs of LTα−/− mice do not merely harbor leukocytes but gradually develop a chronic airway inflammation that worsens with age (Fig. 1 A). The infiltration consists of mainly mononuclear cells predominantly in the peribronchial and perivascular areas. Histopathological analysis of lung tissues in LTα−/− mice also revealed significant airway remodeling. These changes include bronchial wall thickening, subepithelial fibrosis, increased goblet cell mass, myoblast–myocyte hyperplasia and hypertrophy, epithelial cell hypertrophy, and increased deposition of collagen below the basement membrane; these are all clear indicators of chronic airway inflammation. Furthermore, the thickness of this subepithelial collagen layer was visualized by Masson's trichrome staining, which stains collagen. In naive LTα−/− mice, the collagen layer under the basement membrane was much thicker than that of WT mice (Fig. 1 A). To further determine the type and number of infiltrating cells in the lung tissue, lungs from WT and LTα−/− mice were digested with collagenase. The suspension of cells was analyzed by flow cytometry and a three- to fivefold increase in total cell number was found in LTα−/− mice (Fig. 1 B) with an increased proportion of activated T cells, as measured by CD69 expression, in LTα−/− mice compared with WT mice (Fig. 1 C). Thus, LTα−/− mice, without deliberate challenge, appear to develop a spontaneous, cumulative airway inflammation with active remodeling not seen in WT mice housed in the same specific pathogen-free facility.

Bottom Line: Although elevated levels of IgE in asthmatic patients are strongly associated with lung infiltration by activated T helper (Th) 2 cells, the physiological role of immunoglobulin E (IgE) in the airway remains largely undefined.Lymphotoxin-deficient alpha (LTalpha-/-) mice exhibit increased airway inflammation, paradoxically accompanied by diminished levels of IgE and reduced airway hyperresponsiveness in response to both environmental and induced antigen challenge.Therefore, this work has revealed that lymphotoxin is essential for IgE production, and a physiological role of IgE in the airway may consist of maintaining the balance of Th1 and Th2 responses to prevent aberrant inflammation.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, The University of Chicago, Chicago, IL 60637, USA.

ABSTRACT
Although elevated levels of IgE in asthmatic patients are strongly associated with lung infiltration by activated T helper (Th) 2 cells, the physiological role of immunoglobulin E (IgE) in the airway remains largely undefined. Lymphotoxin-deficient alpha (LTalpha-/-) mice exhibit increased airway inflammation, paradoxically accompanied by diminished levels of IgE and reduced airway hyperresponsiveness in response to both environmental and induced antigen challenge. The severe lung inflammation in LTalpha-/- mice is Th1 in nature and can be alleviated by IgE reconstitution. Conversely, depletion of IgE in wild-type mice recapitulates the lung pathologies of LTalpha-/- mice. Therefore, this work has revealed that lymphotoxin is essential for IgE production, and a physiological role of IgE in the airway may consist of maintaining the balance of Th1 and Th2 responses to prevent aberrant inflammation.

Show MeSH
Related in: MedlinePlus