Dopamine Induces Functional Extracellular Traps in Microglia

Abstract

Extracellular traps (ETs) are used by innate immune cells to trap pathogens. ETs kill pathogens and delay their dissemination giving time to other immune cells to come into action. Poor regulation of these traps may also lead to sterile inflammation and autoimmunity. We have investigated the role of dopamine (DA) in the formation of extracellular traps (ETs) in microglia. Microglia are the primary immune cells of central nervous system. We developed a robust and cost effective protocol for isolating primary adult human microglia. We report that DA can induce ETs in BV2 microglia cell line and primary adult human microglia. We investigated the mechanism of trap formation and found that microglia ETs are formed independent of cell death, reactive oxygen species and actin polymerization. DA induced traps were also functional as they trapped FITC tagged Escherichia coli. We also found the presence of microglia ETs in glioblastoma multiforme (GBM) tissues. We developed an unbiased algorithm for quantification of microglia ETs in GBM. These findings underline an important role of DA in regulation of sterile neuro-inflammation.