Sensitization to inhaled antigen by intratracheal instillation of dendritic cells
Lambrecht, Peleman, Bullock… - Clinical & Experimental …, 2000 - Wiley Online Library
Lambrecht, Peleman, Bullock, Pauwels
Clinical & Experimental Allergy, 2000•Wiley Online LibraryBackground Airway dendritic cells (DCs) capture and present inhaled antigen. It is not
known whether antigen presentation by DCs in the airways is sufficient to induce
sensitization to inhaled antigen in vivo. Methods Rats were immunized by intratracheal
instillation of ovalbumin (OVA)‐pulsed bone marrow‐derived DCs or macrophages and
exposed 10 days later to a 30‐min aerosol of OVA on 3 consecutive days. Total and
differential cell counts and flow cytometry on bronchoalveolar lavage (BAL) fluid, airway …
known whether antigen presentation by DCs in the airways is sufficient to induce
sensitization to inhaled antigen in vivo. Methods Rats were immunized by intratracheal
instillation of ovalbumin (OVA)‐pulsed bone marrow‐derived DCs or macrophages and
exposed 10 days later to a 30‐min aerosol of OVA on 3 consecutive days. Total and
differential cell counts and flow cytometry on bronchoalveolar lavage (BAL) fluid, airway …
Background
Airway dendritic cells (DCs) capture and present inhaled antigen. It is not known whether antigen presentation by DCs in the airways is sufficient to induce sensitization to inhaled antigen in vivo.
Methods
Rats were immunized by intratracheal instillation of ovalbumin (OVA) ‐pulsed bone marrow‐derived DCs or macrophages and exposed 10 days later to a 30‐min aerosol of OVA on 3 consecutive days. Total and differential cell counts and flow cytometry on bronchoalveolar lavage (BAL) fluid, airway histology and serum OVA‐immunoglobulin (Ig) E levels were analysed 24 h after the last exposure.
Results
As few as 2 × 104 OVA‐DC induced sensitization to inhaled OVA. The secondary response to OVA‐aerosol consisted of an antigen‐specific increase in the number of bronchoalveolar mononuclear cells, activated CD4‐positive αβ‐TCR T lymphocytes, neutrophils and few eosinophils. Peribronchial and perivascular mononuclear cell infiltrates were seen on histological analysis. There was no production of systemic OVA‐IgE. Bone marrow‐derived macrophages did not induce sensitization.
Conclusion
Delivering antigen to the respiratory tract via professional antigen‐presenting DCs sensitizes for a secondary response to inhaled antigen leading to airway inflammation. This model will prove very useful for studying the early events of sensitization to inhaled antigen using the respiratory route.
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