Figure 3: PGE2-mediated transcriptional attenuation of CCR5 chemokine receptor expression correlates with ICER induction. Human monocytes treated with PGE2 (1 and 2 hrs; lanes 2, 4, 6, and 8) were scored for human chemokine receptor expression (left panel) in parallel with ICER expression (right panel), using RNase protection assay (Ambion). For evaluation of human chemokine receptor expression, a Riboquant hCR8 probe set was used. Levels of chemokine receptor were evaluated after PGE2 treatment (500 ng/ml final for 1h and 2h at 370C in regular media). Levels of CCR5 were inversely related to the levels of ICER mRNA after PGE2 treatment. Templates of the housekeeping genes for the analysis of hL32 and human glyceraldehyde-3-phosphate dehydrogenase (GAPDH) housekeeping genes were included to allow assessment of total RNA levels. In particular, downregulation of CCR5 expression could be critical in heterozygous CCR5wt/Δ32 donor in order to mimick CCR5 null cells from CCR5Δ32/Δ32 homozygous donor [45].