Fig. 7

Transgene expression level and stability upon transduction with titrated RIP and non-RIP retrovectors. Two α- (RCANBP(A) CMV or RIP 3HAH2BYFP) and two γ- (pSERS SF or RIP GFP-IRES-ZeoR) retroviral supernatants, harboring either an ubiquitous (CMV or SFFV U3) or a β-specific (RIP) promoter were titrated in mouse MIN6-TVA insulinoma cells. Two human cells lines, either 293 T-TVA (left) or EndoC-βΗ2-TVA (right) cells were next transduced with the indicated retroviral supernatant, at a similar MOI (see internal legend) according to this titration. The percentage of fluorescent cells (a) and the MFI fold increase (b) were determined by flow cytometry 6 days after transduction (short term). The histogram shows the means and SD of the measures in three independent populations. The estimated mean viral copy number per cell (VCN) is indicated below each corresponding column. For clarity, VCN values have been mentioned only below the upper histogram. The same three populations of EndoC-βΗ2-TVA cells transduced with RCANBP(A) RIP 3HAH2BYFP or pSERS RIP GFP-IRES-ZeoR were cultured without selection and re-analyzed by flow cytometry for MFI fold increase and percentage of transduced cells 48 or 38 days after transduction, respectively, (long term). The MFI fold increase and percentage of fluorescent cells correspond to the mean and SD of the values measured in the three independent populations. ND: not done