[ODP-153] Investigating the influence of EPEC infection on the host biogenesis of exosome
Objective: Enteropathogenic Escherichia coli (EPEC) use various virulence factors to subvert host immune response. Recently, host cells were found to secrete inflammatory exosomes, nano-size membrane bound vesicles, upon microbial/viral challenges. However, whether EPEC proactively influences the biogenesis of exosome remains elusive. In this study, we investigated the degree of exosome secretion upon EPEC infection and evaluated potential signaling pathways contributed to the change.
Method: THP-1 cells were left un-challenged or challenged with indicated strains of E. coli. The released exosome in the cell culture was enriched by either ultra-centrifuge or polyethylene glycol (PEG8000). Western blotting or ELISA were performed to quantify exosome.
Result:
1. Compared to non-pathogenic E. coli, wild type (WT) EPEC caused host cells to release significantly more exosome in a T3SS-dependent manner.
2. Compared to vehicle treated cells, inhibitors of p38 and ERK1/2 of MAPK signaling cascades partially decreased the secreted exosome from WT EPEC-challenged cells.
3. Pretreatment of THP-1 with MCC950, a specific inhibitor of NLRP3 protein, did not reduce secretion of exosome from WT EPEC-challenged cells.
Conclusion: EPEC induces secretion of exosome in a T3SS-dependent manner and activation of p38 and ERK1/2 pathway partially contributed to the increase.
Method: THP-1 cells were left un-challenged or challenged with indicated strains of E. coli. The released exosome in the cell culture was enriched by either ultra-centrifuge or polyethylene glycol (PEG8000). Western blotting or ELISA were performed to quantify exosome.
Result:
1. Compared to non-pathogenic E. coli, wild type (WT) EPEC caused host cells to release significantly more exosome in a T3SS-dependent manner.
2. Compared to vehicle treated cells, inhibitors of p38 and ERK1/2 of MAPK signaling cascades partially decreased the secreted exosome from WT EPEC-challenged cells.
3. Pretreatment of THP-1 with MCC950, a specific inhibitor of NLRP3 protein, did not reduce secretion of exosome from WT EPEC-challenged cells.
Conclusion: EPEC induces secretion of exosome in a T3SS-dependent manner and activation of p38 and ERK1/2 pathway partially contributed to the increase.