Extracellular ATP triggers and maintains airway inflammation in human and murine models of asthma by activating dendritic cells

Extracellular nucleotides have a key signaling role in cell-to-cell communication. In particular, extracellular ATP can act at plasma membrane P2 receptors (P2R) and thus serve as a danger signal to alert the immune system of tissue damage during the early phases of inflammation. Here we show that allergen challenge causes acute accumulation of ATP not only in the airways of asthmatic subjects but also in ovalbumin (OVA)-sensitized mice. In this mouse model, antigen challenge with OVA leads to airway eosinophilia, lymphocytosis, globet cell hyperplasia and Th2 cytokine secretion which were completely abrogated b…