Figure 3.

P2Y₂R and P2X₇R signaling during injury and inflammation. Adenosine triphosphate (ATP) can be released by necrotic cells or apoptotic cells though cytoplasmic channel, pannexin 1. When engaging P2Y₂R, released ATP functions as “find me signal” for macrophages phagocytosis of injured cells and promotes so wound healing. P2Y₂R signaling contributes also to bacterial clearance by stimulating neutrophils chemotaxis. However, excess P2Y₂R signaling in neutrophils or eosinophils contributes, respectively, to chronic lung inflammation and allergic airway disease by promoting the release of pro-allergic mediators. P2X₇R signaling promotes the killing of intracellular bacteria such as Mycobacter Tuberculosis. In dendritic cells, P2X₇R signaling promotes T-cell priming which has been implicated in allergic diseases, graft-versus-host disease (GVH) as well as in psoriasis and inflammatory bowel disease.