REGULATION OF INTERLEUKIN-8 (IL-8) GENE EXPRESSION BY BACTERIAL EXTRACELLULAR VESICLES ISOLATED FROM ORGANIC DUST IN THE HUMAN HMC3 MICROGLIAL CELL LINE

Exposure to the agricultural environment appears to be a risk factor for Parkinson’s and Alzheimer’s diseases, and dementia. Inhalation of agricultural dust may cause brain inflammation, leading to the development of neurological diseases. We studied the effects of poultry farm dust derived bacterial extracellular vesicles (EVs) (dust EVs) on the regulation of interleukin (IL)-8 expression in the human HMC3 microglial cell line. IL-8 dysregulation has been implicated in several neurological diseases. Microglial cells are brain resident immune cells that play major roles in immune and inflammatory responses. We found that treatment with dust EVs induced IL-8 expression at the transcriptional level via activation of NF-κB and STAT3 transcription factors. Chemical inhibitor and siRNA knockdown studies demonstrated that toll-like receptor (TLR)2 and TLR4 and enhanced intracellular reactive oxygen species (ROS) production by NADPH oxidases (NOX) mediate induction of IL-8 expression.