CDK inhibition relieves the block of MIE gene expression in undifferentiated NT2 cells.

<p>(A) Experimental setup. NT2 cells were infected with HCMV-TB40/e (MOI = 5) in the presence of the cyclin-dependent kinase (CDK) inhibitors roscovitine (Rosco), CVT313, SU9515, the histone deacetylase inhibitor trichostatine A (TSA) or solvent (DMSO). CDK inhibitors were used at concentrations from 10 to 50 µM (Rosco, CVT313) and from 2 to 10 µM (SU9516) as indicated. The different compounds were left on the cells for the indicated lengths of time. In addition, NT2 cells were infected after a 7-day exposure to retinoic acid (RA). All cells were harvested at 24 hpi. (B) Cells were stained for IE1/2 and Oct3/4 expression and analyzed by flow cytometry. Shown are dot plots where cells were divided into four subpopulations: MIE⁻Oct⁻ (lower left quadrant), MIE⁺Oct⁻ (upper left quadrant), MIE⁺Oct⁺ (upper right quadrant), MIE⁻Oct⁺ (lower right quadrant). The proportion of each subpopulation is given as percent of total cells. (C) Cells were stained for IE1/2 expression and DNA content and analyzed by flow cytometry. The depicted cells were divided into the following subpopulations: MIE⁻G1 (lower left quadrant), MIE⁺G1 (upper left quadrant), MIE⁺S/G2/M (upper right quadrant) and MIE^-S/G2/M (lower right quadrant) cells. The proportion of each subpopulation is given in percent of total cells.