GSE163095
Exposure of CF and WT primary human monocyte derived macrophages to extracellular vesicles secreted by CF or WT primary human airway epithelial cells.
Mutations in CFTR have been shown to alter the immune response of macrophages, for example, by reducing the ability of macrophages to phagocytose and kill bacteria. This contributes to chronic bacterial infection and inflammation in the lungs, which leads to significant morbidity and mortality in cystic fibrosis (CF). Extracellular vesicles (EVs) are secreted by a variety of cell types in the lungs and participate in the host immune response to bacterial infection. However, nothing is known about the effect of EVs secreted by CF airway epithelial cells (AEC) on CF macrophages. Therefore, we examined the effect of EVs secreted by primary CF AEC on CF monocyte derived macrophages (MDM) and compared it with the effect of EVs secreted by wild type (WT) AEC on WT MDM. EVs increased pro-inflammatory cytokine secretion and enhanced the expression of numerous innate immune genes in WT MDM. However, the response of CF MDM to EVs was significantly attenuated compared to WT MDM, a difference that was also observed when EVs were isolated from WT and CF AEC exposed to Pseudomonas aeruginosa. Attenuated responses by CF MDM can be attributed to defects in the CF macrophages themselves rather than differences between CF and WT EVs, because EVs secreted by CF AEC or WT AEC elicited similar cytokine secretion by CF MDM. EVs secreted by P. aeruginosa exposed AEC resulted in the upregulation of immune response genes and increased secretion of pro-inflammatory cytokines, chemoattractants and chemokines involved in tissue repair by WT MDM, whereas the response of CF MDM was attenuated by comparison. To our knowledge, this is the first study examining the effect of EVs secreted by CF AEC on CF MDM, and it demonstrates that the Phe508del mutation in CFTR attenuates the innate immune response of MDM to EVs. Overall design: M-CSF differentiated human monocyte derived macrophages from three CFTR Phe508del homozygous cystic fibrosis donors and three CFTR wild type (WT) donors were exposed to either extracellular vesicles (EV) secreted by Phe508del homozygous CF or WT airway epithelial cells from multiple donors, extracelluar vesicles secreted by CF or WT airway epithelial cells after Pseudomonas aeruginosa exposure (EV-PA), or PBS (Ctrl).