(A) Expression of CD30L and CD30 in normal lymphohematopoietic cells. Adherent (Adh+), CD2⁻, CD19⁻, CD14⁺ monocyte-macrophages were purified from PB by a two-step immunomagnetic selection. Normal T and B lymphocytes were purified from PB and tonsil tissues of two different donors (a and b) by positive immunomagnetic selection with anti-CD2 and anti-CD19 MoAbs. Granulocytes were recovered by dextran sedimentation followed by erythrocyte lysis. Activation of CD2⁺ T cells was performed by 24 hours of exposure to TPA (10 ng/mL) and ionomycin A (1.0 μg/mL). In all cases, amplification with CD30L, CD30 (upper panels), and β-actin (lower panel) specific primers was performed using the same cDNA bulks. (B) Two-color immunofluorescence showing the expression of CD30L on PB CD19⁺ B cells, resting CD2⁺ T cells, and CD2⁺ T cells after 24 hours of activation by 10 ng/mL TPA and 1.0 μg/mL ionomycin A. Cells were stained by the anti-CD30L MoAb M80 (Y-axis, PE-red fluorescence) and by anti-CD2 or anti-CD19 MoAbs (X-axis, FITC-green fluorescence).