Eotaxin-rich Proangiogenic Hematopoietic Progenitor Cells and CCR3+ Endothelium in the Atopic Asthmatic Response

摘要

Angiogenesis is closely linked to and precedes eosinophilic infiltration in asthma. Eosinophils are recruited into the airway by chemoattractant eotaxins, which are expressed by endothelial cells, smooth muscles cells, epithelial cells, and hematopoietic cells. We hypothesized that bone marrow-derived proangiogenic progenitor cells that contain eotaxins contribute to the initiation of angiogenesis and inflammation in asthma. Whole lung allergen challenge of atopic asthma patients revealed vascular activation occurs within hours of challenge, and prior to airway inflammation. The eotaxin receptor CCR3 was expressed at high levels on submucosal endothelial cells in patients and murine model of asthma. Exvivo exposure of murine endothelial cells to eotaxins induced migration and angiogenesis. In mechanistic studies, wildtype mice transplanted with eotaxin-1/2 deficient bone marrow had markedly less angiogenesis and inflammation in an atopic asthma model, while adoptive transfer of proangiogenic progenitor cells from wildtype mice in an atopic asthma model into the eotaxin-1/2 deficient mice led to angiogenesis and airway inflammation. The findings indicate that TH2-promoting hematopoietic progenitor cells are rapidly recruited to the lung upon allergen exposure and release eotaxins that coordinately activate endothelial cells, angiogenesis, and airway inflammation.