Effect of NAC on the mRNA and soluble versus membrane form expression of TNFα and TNF-RII. (a) Kinetics expression of membrane and soluble TNFα by T cells stimulated with PMA plus ionomycin in the presence of 20 mmol/L NAC. Membrane TNFα (□) is expressed in percent of increase of MFI values and TNFα production (▪) in percent of increase or decrease of TNFα release (mean ± SD, n = 6). (b) Soluble TNF-RII was determined on T cells stimulated for 48 hours with PMA plus ionomycin in the presence (solid line) or the absence (dashed line) of 20 mmol/L NAC. Results are expressed in pg/mL (mean ± SD, n = 6). (c) Kinetics analysis of TNFα and TNF-RII mRNA expression by stimulated T cells in the presence of 20 mmol/L NAC. T cells were stimulated for the indicated time and TNFα, TNF-RII, and β-actin mRNA expression was determined by PCR.