Short term stimulation of monocytes with TLR2 or TLR4 ligand did not significantly modulate cell surface expression of selected immune cell receptors and LPS treatment did not alter the G-protein signaling potential (as measured by intracellular Ca²⁺ flux) to CXCL12 or CCL2 treatment(s).

<p><b>A</b>) Monocytes were treated with LPS (2 ng/ml) or Pam₃CSK₄ (50 ng/ml) for 15 min before staining with fluorescent mAbs against the indicated immune cell receptors. Receptor densities were measured by flow cytometry and the MFVs in stimulated cells are expressed relative (%) to untreated cells as histograms (with error bars, n = 3). <b>B</b>) Agonist dose response of intracellular Ca²⁺ flux to sequential stimulation with CXCL12 and CCL2 in monocytes. <b>C</b>) Ca²⁺ flux profiles of LPS (2 ng/ml, for 15 min after calcium dye loading) treated (interrupted line) and untreated monocytes to sequential stimulation with increasing concentrations of CXCL12 and CCL2. Plots represent results using monocytes from four donors.