Figure 7.

The mechanism of neutrophilic inflammation amplification cycle initiated by NETs. (A) Allergen or other stimuli cause the first wave of neutrophil recruitment. (B) NET formation are stimulated by inflammatory factors, bacterial components, or other stimulators. (C) NETs aggregate at the bronchiole and lung-bubble cavities and stimulation of the HBEs and HAEs expressing neutrophilic chemokines. (D) Neutrophils migrate from the peripheral blood to lung interstitial tissue and parenchyma generate more NETs when stimulated.