Spontaneous and LPS-induced TNF-α production by total monocyte population and ILT4⁺ and ILT4⁻ monocyte subsets from patients and controls.

<p>The box plots represent the spontaneous (A) and LPS-induced (B) intracellular production of TNF-α analyzed by FACS as percentage of positive cells. Appropriate controls with isotype matched irrelevant mAbs were carried out and consistently showed <1% of positive cells. The data represent means±SD (error bars). Comparison between means was performed by Student's unpaired t test. (C) LPS-induced TNF-α production by total monocyte population from a representative control subject and a patient with PsA. CD40L-activated monocytes were stimulated with LPS and stained with PE-anti-ILT4 for the determination of surface phenotype. Intracellular TNF-α was detected by staining with FITC-anti-TNF-α. The data are displayed as dot plots.