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Disparity in FcεRI-Induced Degranulation of Primary Human Lung and Skin Mast Cells Exposed to Adenosine

2011; Springer Science+Business Media; Volume: 31; Issue: 3 Linguagem: Inglês

10.1007/s10875-011-9517-7

1573-2592

Gregorio Gomez, Wei Zhao, Lawrence B. Schwartz,

Asthma and respiratory diseases

Inhaled and intravenously administered adenosine induces mast cell-mediated (histamine-dependent) bronchospasm in asthmatics without causing urticaria. A differential response to adenosine by human lung and skin mast cells is shown: low concentrations potentiate FcεRI-induced degranulation of human lung mast cells but not that of skin mast cells. Human lung mast cells were found to express ∼3-fold more A3AR messenger RNA (mRNA) than skin mast cells, suggesting the involvement of the Gi-linked A3AR. Indeed, the adenosine-induced potentiation was sensitive to inhibition by pertussis toxin and, furthermore, could be induced with an A3AR-specific agonist. This study reveals a previously unrecognized disparity in the response to adenosine by primary human mast cells from lung and skin that might explain why adenosine induces a pulmonary but not dermatologic allergy-like response in vivo. In addition, we identify the A3AR as a potentiating receptor of FcεRI-induced degranulation, thereby implicating it in the in vivo bronchoconstrictive response to adenosine in asthmatics.