Alveolar macrophages reduce airway hyperresponsiveness and modulate cytokine levels.

The authors have recently demonstrated that alveolar macrophages (AMs) are important in protecting against early phase reactions and airway hyperresponsiveness following allergen challenge. To further understand the mechanisms involved, the authors investigated the capacity of AMs to modulate airway inflammation and cytokine levels in bronchoalveolar lavage (BAL). AMs from allergy-susceptible Brown Norway (BN) rats or allergy-resistant Sprague-Dawley (SD) rats were transferred into AM-depleted BN rats 24 hours prior to allergen challenge.

Alveolar macrophages in allergic asthma: an expression signature characterized by heat shock protein pathways.

The implication of alveolar macrophages (AM) in asthma, a T(h)2 disease, has not been well characterized. Thus, the goal of this study is to better characterize AM phenotype of allergic asthmatic compared with normal subjects using genomic expression analyses. Microarray analyses were performed with AM isolated from bronchoalveolar lavage.

Alveolar macrophage subpopulations in bronchoalveolar lavage and induced sputum of asthmatic and control subjects.

Background: Alveolar macrophages (AM) are the most numerous immune cells in the airways and are involved in the immunological homeostasis of the lung. Intriguingly, their role in asthma remains unclear probably, in part, because of their heterogeneity.

Objective: To characterize AM population from bronchoalveolar lavage (BAL) and induced sputum (IS) of asthmatic and normal subjects using specific biomarkers.

Coumarinic derivatives show anti-inflammatory effects on alveolar macrophages, but their anti-elastase activity is essential to reduce lung inflammation in vivo.

We have previously demonstrated the potency of coumarinic derivatives to inhibit human leukocyte elastase. Given the anti-inflammatory activities of some coumarins, we investigated the capacity of our coumarinic derivatives to inhibit inflammation and whether their anti-elastase activity was essential for their anti-inflammatory functions. All compounds studied were coumarinic derivatives displaying differential anti-proteinase activity.

Antigen sensitization modulates alveolar macrophage functions in an asthma model.

We have previously demonstrated that adoptive transfer of alveolar macrophages from allergy-resistant rats to alveolar macrophage-depleted allergic rats prevents airway hyperresponsiveness development, suggesting an important role for alveolar macrophages in asthma pathogenesis. Given that ovalbumin sensitization can modulate alveolar macrophage cytokine production, we investigated the role of sensitized and unsensitized alveolar macrophages in an asthma model. Alveolar macrophages from unsensitized or sensitized Brown Norway rats were transferred to alveolar macrophage-depleted sensitized rats 24 h before allergen challenge.