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Bidirectional interactions between antigen-bearing respiratory tract dendritic cells (DCs) and T cells precede the late phase reaction in experimental asthma: DC activation occurs in the airway mucosa but not in the lung parenchyma.

Huh JC, Strickland DH, Jahnsen FL, Turner DJ, Thomas JA, Napoli S, Tobagus I, Stumbles PA, Sly PD, Holt PG - J. Exp. Med. (2003)

Bottom Line: Antigen-bearing activated DCs appear in regional lymph nodes at 24 h, suggesting onward migration from the airway.Transient up-regulation of CD86 on AMDC accompanies this process, which can be reproduced by coculture of resting AMDC with T memory cells plus antigen.The APC activity of AMDC can be partially inhibited by anti-CD86, suggesting that CD86 may play an active role in this process and/or is a surrogate for other relevant costimulators.

View Article: PubMed Central - PubMed

Affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, Faculty of Medicine and Dentistry, The University of Western Australia, Perth, Western, Australia 6008.

ABSTRACT
The airway mucosal response to allergen in asthma involves influx of activated T helper type 2 cells and eosinophils, transient airflow obstruction, and airways hyperresponsiveness (AHR). The mechanism(s) underlying transient T cell activation during this inflammatory response is unclear. We present evidence that this response is regulated via bidirectional interactions between airway mucosal dendritic cells (AMDC) and T memory cells. After aerosol challenge, resident AMDC acquire antigen and rapidly mature into potent antigen-presenting cells (APCs) after cognate interactions with T memory cells. This process is restricted to dendritic cells (DCs) in the mucosae of the conducting airways, and is not seen in peripheral lung. Within 24 h, antigen-bearing mature DCs disappear from the airway wall, leaving in their wake activated interleukin 2R+ T cells and AHR. Antigen-bearing activated DCs appear in regional lymph nodes at 24 h, suggesting onward migration from the airway. Transient up-regulation of CD86 on AMDC accompanies this process, which can be reproduced by coculture of resting AMDC with T memory cells plus antigen. The APC activity of AMDC can be partially inhibited by anti-CD86, suggesting that CD86 may play an active role in this process and/or is a surrogate for other relevant costimulators. These findings provide a plausible model for local T cell activation at the lesional site in asthma, and for the transient nature of this inflammatory response.

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In situ analysis of respiratory tract cell populations. (A–C) Tracheal epithelium stained for MHC class II. Sections were taken at (A) 0, (B) 2, and (C) 24 h after OVA aerosol challenge of primed animals. Images are projections along the z axis (“top” view) from stacks of 30 optical sections acquired at 2-μm increments at ×100 magnification. (D) Tracheal sections from primed OVA/ALOH animals after OVA aerosol exposure, stained for eosinophils, T cells, and DCs. Cells were quantitated by light (Epithelial DC, T-cells, Eos) confocal microscopy (Submucosal DC). Data are mean ± SD from three to five observations for each cell type. (E) Lung tissue was isolated at the indicated time points after challenge and single cell suspensions were prepared and immunostained. DCs were enumerated by flow cytometry and results were expressed as numbers recovered per gram wet weight (mean ± SD from three experiments).
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fig1: In situ analysis of respiratory tract cell populations. (A–C) Tracheal epithelium stained for MHC class II. Sections were taken at (A) 0, (B) 2, and (C) 24 h after OVA aerosol challenge of primed animals. Images are projections along the z axis (“top” view) from stacks of 30 optical sections acquired at 2-μm increments at ×100 magnification. (D) Tracheal sections from primed OVA/ALOH animals after OVA aerosol exposure, stained for eosinophils, T cells, and DCs. Cells were quantitated by light (Epithelial DC, T-cells, Eos) confocal microscopy (Submucosal DC). Data are mean ± SD from three to five observations for each cell type. (E) Lung tissue was isolated at the indicated time points after challenge and single cell suspensions were prepared and immunostained. DCs were enumerated by flow cytometry and results were expressed as numbers recovered per gram wet weight (mean ± SD from three experiments).

Mentions: For confocal microscopy studies using whole mounts (see Fig. 1), rat tracheas were stored in 100% ethanol at 4°C overnight, and thereafter washed for 5 h in PBS at room temperature. The samples were incubated with a mixture of mAb Ox6 anti–rat MHC class II or Ox21 isotype control (neat culture supernatant) and rabbit antiserum to rat laminin (1/100; DakoCytomation) for 40 h, washed for 5 h, and then incubated with 0.8 μg/ml Cy3-labeled goat anti–mouse IgG (Jackson ImmunoResearch Laboratories) in combination with Cy5-labeled goat anti–rabbit IgG (1/200; Amersham Biosciences) for 24 h. The specimens were washed for 5 h and mounted in plastic slides. Fluorescent images of the immunostained whole mount preparations were obtained with a confocal laser scanning microscope (MRC-1000; Bio-Rad Laboratories). The preparations were optically sectioned by scanning at increasing focus depths (typically in steps of 1 μm) from the surface epithelial side. Identical series of optical images at increasing depths (image stacks) from one field were obtained for each wavelength. These image stacks were then merged and the three dimensional information (xyz axis) obtained were analyzed with Object-Image 2.08 software (an extended version of NIH image).


Bidirectional interactions between antigen-bearing respiratory tract dendritic cells (DCs) and T cells precede the late phase reaction in experimental asthma: DC activation occurs in the airway mucosa but not in the lung parenchyma.

Huh JC, Strickland DH, Jahnsen FL, Turner DJ, Thomas JA, Napoli S, Tobagus I, Stumbles PA, Sly PD, Holt PG - J. Exp. Med. (2003)

In situ analysis of respiratory tract cell populations. (A–C) Tracheal epithelium stained for MHC class II. Sections were taken at (A) 0, (B) 2, and (C) 24 h after OVA aerosol challenge of primed animals. Images are projections along the z axis (“top” view) from stacks of 30 optical sections acquired at 2-μm increments at ×100 magnification. (D) Tracheal sections from primed OVA/ALOH animals after OVA aerosol exposure, stained for eosinophils, T cells, and DCs. Cells were quantitated by light (Epithelial DC, T-cells, Eos) confocal microscopy (Submucosal DC). Data are mean ± SD from three to five observations for each cell type. (E) Lung tissue was isolated at the indicated time points after challenge and single cell suspensions were prepared and immunostained. DCs were enumerated by flow cytometry and results were expressed as numbers recovered per gram wet weight (mean ± SD from three experiments).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196086&req=5

fig1: In situ analysis of respiratory tract cell populations. (A–C) Tracheal epithelium stained for MHC class II. Sections were taken at (A) 0, (B) 2, and (C) 24 h after OVA aerosol challenge of primed animals. Images are projections along the z axis (“top” view) from stacks of 30 optical sections acquired at 2-μm increments at ×100 magnification. (D) Tracheal sections from primed OVA/ALOH animals after OVA aerosol exposure, stained for eosinophils, T cells, and DCs. Cells were quantitated by light (Epithelial DC, T-cells, Eos) confocal microscopy (Submucosal DC). Data are mean ± SD from three to five observations for each cell type. (E) Lung tissue was isolated at the indicated time points after challenge and single cell suspensions were prepared and immunostained. DCs were enumerated by flow cytometry and results were expressed as numbers recovered per gram wet weight (mean ± SD from three experiments).
Mentions: For confocal microscopy studies using whole mounts (see Fig. 1), rat tracheas were stored in 100% ethanol at 4°C overnight, and thereafter washed for 5 h in PBS at room temperature. The samples were incubated with a mixture of mAb Ox6 anti–rat MHC class II or Ox21 isotype control (neat culture supernatant) and rabbit antiserum to rat laminin (1/100; DakoCytomation) for 40 h, washed for 5 h, and then incubated with 0.8 μg/ml Cy3-labeled goat anti–mouse IgG (Jackson ImmunoResearch Laboratories) in combination with Cy5-labeled goat anti–rabbit IgG (1/200; Amersham Biosciences) for 24 h. The specimens were washed for 5 h and mounted in plastic slides. Fluorescent images of the immunostained whole mount preparations were obtained with a confocal laser scanning microscope (MRC-1000; Bio-Rad Laboratories). The preparations were optically sectioned by scanning at increasing focus depths (typically in steps of 1 μm) from the surface epithelial side. Identical series of optical images at increasing depths (image stacks) from one field were obtained for each wavelength. These image stacks were then merged and the three dimensional information (xyz axis) obtained were analyzed with Object-Image 2.08 software (an extended version of NIH image).

Bottom Line: Antigen-bearing activated DCs appear in regional lymph nodes at 24 h, suggesting onward migration from the airway.Transient up-regulation of CD86 on AMDC accompanies this process, which can be reproduced by coculture of resting AMDC with T memory cells plus antigen.The APC activity of AMDC can be partially inhibited by anti-CD86, suggesting that CD86 may play an active role in this process and/or is a surrogate for other relevant costimulators.

View Article: PubMed Central - PubMed

Affiliation: Telethon Institute for Child Health Research and Centre for Child Health Research, Faculty of Medicine and Dentistry, The University of Western Australia, Perth, Western, Australia 6008.

ABSTRACT
The airway mucosal response to allergen in asthma involves influx of activated T helper type 2 cells and eosinophils, transient airflow obstruction, and airways hyperresponsiveness (AHR). The mechanism(s) underlying transient T cell activation during this inflammatory response is unclear. We present evidence that this response is regulated via bidirectional interactions between airway mucosal dendritic cells (AMDC) and T memory cells. After aerosol challenge, resident AMDC acquire antigen and rapidly mature into potent antigen-presenting cells (APCs) after cognate interactions with T memory cells. This process is restricted to dendritic cells (DCs) in the mucosae of the conducting airways, and is not seen in peripheral lung. Within 24 h, antigen-bearing mature DCs disappear from the airway wall, leaving in their wake activated interleukin 2R+ T cells and AHR. Antigen-bearing activated DCs appear in regional lymph nodes at 24 h, suggesting onward migration from the airway. Transient up-regulation of CD86 on AMDC accompanies this process, which can be reproduced by coculture of resting AMDC with T memory cells plus antigen. The APC activity of AMDC can be partially inhibited by anti-CD86, suggesting that CD86 may play an active role in this process and/or is a surrogate for other relevant costimulators. These findings provide a plausible model for local T cell activation at the lesional site in asthma, and for the transient nature of this inflammatory response.

Show MeSH
Related in: MedlinePlus