Figure 1

SAMHD1 is induced poorly by IFNα in monocyte-derived macrophages. A. 1 to 2 × 10⁶ monocyte-derived macrophages (MDMs) or primary CD4⁺ T cells (T cells), PMA-treated or dividing THP-1 and U937 cells, or U87-MG cells were incubated (or not) with 1000 U/ml IFNα for 24 h prior to total RNA extraction. cDNA was synthesized and the relative levels of SAMHD1 expression (upper panel), as well as two well-known ISGs, ISG15 and APOBEC3A (lower panel), were analyzed by RT-qPCR and the data were normalized to both GAPDH and β-actin expression. The graph shows the data obtained from 3 independent donors for MDMs (#1 #2 #3), and the mean values of relative expression in each cell type, obtained from 3 independent repetitions with cell lines or 3 different donors for CD4⁺ T cells. B. Western blot analysis. MDMs from 2 different donors were treated or not with 1000 U/ml IFNα for 24 h (donor #4), or for 8, 24 and 48 h (donor #5) before cell lysis. Protein levels of SAMHD1 and APOBEC3A (A3A) were determined, and tubulin served as a loading control.