Freshly isolated monocytes and monocytes matured in vitro with M-CSF secrete CXCL13 after LPS stimulation. Supernatants of cultured cells were analyzed by sandwich ELISA specific for CXCL13. Note different scales of vertical axes. (A) Monocytes were stimulated with LPS (100 ng/mL) and supernatants harvested after 1, 2, and 3 days. Results of independent experiments from 3 different donors are shown. Two additional experiments from other donors were out of scale, one extremely poor and one excessive response, the latter up to 3200 pg/106 cells at day 3 (not shown). (B) Dose response of monocytes 24 hours after LPS stimulation; results of independent experiments from 3 different donors. (C) Dose response of monocytes matured in vitro with M-CSF for 3 days prior to stimulation for 24 hours with LPS; results of independent experiments from 3 different donors. (D) Dose response of monocytes (▪), monocytes matured in vitro with M-CSF for 3 days (□), and monocytes matured in vitro with M-CSF for 6 days (▵) prior to stimulation for 24 hours with LPS; representative results of independent experiments from 3 different donors.
