Macrophage- but not monocyte-derived extracellular vesicles induce placental pro-inflammatory responses. (September 2018) - Rice, Thomas F.
Abstract: The placenta sheds extracellular vesicles (EVs), including exosomes, into the maternal circulation. We recently demonstrated that this trafficking of EVs is bi‐directional; with uptake of macrophage exosomes by the placenta inducing cytokine release. The specificity of this response is currently unknown. THP-1 cells were cultured as monocytes or differentiated to macrophages, and EVs isolated by ultra-centrifugation. The effect of EVs on human placental explants was measured by cytokine ELISA/luminex. Macrophage, but not monocyte, EVs induce the release of pro-inflammatory cytokines by the placenta. Thus, placental responses to immune cell EVs, including exosomes, reflects the phenotype of the source cell. Highlights: Placenta releases cytokines in response to macrophage extracellular vesicles (EVs). Response is specific to macrophage EVs, with no response to monocyte EVs. The EVs were of the expected size of exosomes, and express exosome markers. Macrophage EVs were larger than monocyte EVs.