Figure 2.

AM and AEC crosstalk in the lung. AMs release Exos and MVs containing SOCS1 and SOCS3, respectively. Positive regulators of SOCS release include the bioactive lipid PGE₂, the cytokine IL-10, and AEC-derived mediators in response to LPS and infection. Negative regulators include acute, direct AM exposure of LPS, and cigarette smoke. AEC uptake of SOCS-containing EVs might likewise be modulated by constituents of the normal alveolar milieu or by exogenous factors to which the lung is exposed. Additionally, EV uptake by AECs results in inhibition of cytokine-induced STAT activation.