Fig. 4.

Interplay between Toll‐like receptor (TLR)‐9 and TLR‐7 in induction of microvesicle (MV) release and B cell activation. Peripheral blood mononuclear cells (PBMCs) from six healthy donors (HD) and six systemic lupus erythematosus (SLE) patients [four of whom had active lupus nephritis (LN) at study inclusion] were incubated for 24 h with the TLR‐9 agonist oligodeoxynucleotide (ODN)2395 alone (white events; ODN2395) or in combination with the TLR‐7 agonist gardiquimod (black events; ODN2395+gardiquimod). MVs released into the culture supernatants were subsequently isolated by ultracentrifugation, quantified and characterized with respect to expression of G3BP and dsDNA by flow cytometry. (a) The concentrations of G3BP‐expressing MVs in toto and (b) G3BP and dsDNA double‐positive MVs released from healthy and SLE PBMCs in culture supernatants are shown together with median proportions of MVs bearing these markers (inserted boxes below). (c) Expression of the activation markers CD69 and (d) CD80 by B cells was measured in the corresponding cell fractions by flow cytometry and is shown as median fluorescence intensity (MFI) values. Columns and error bars represent median values and interquartile range.