Representative microphotographs of TLR4 silenced and non-silenced MSCs primed with LPS and co-cultured with neutrophils. Immunostaining was performed with an antibody detecting NETs (DNA-histone, red). Of note, TLR4 silenced MSCs upon LPS priming cannot mount any adaptive response and fail to enhance NET formation (lower row, outer right panel) as compared to non-silenced, LPS primed MSCs co-cultured with PMA activated neutrophils (lower row, outer left panel). Neutrophils and DMSO served as a negative control (upper row, outer left panel), while neutrophils activated by the protein C kinase activator PMA served as a positive control depicting enhanced NET formation (upper row, middle panel). Co-culture with MSCs suppressed enhanced NET formation (upper row, outer left panel) induced by PMA. Scale bars: 50μm. 