Comparison of 2A and IRES-mediated eGFP (second gene) expression in bicistronic vectors. To compare the level of second gene product (eGFP) expressed from either eGFP, MGMT-2A-eGFP or MGMT-IRES-eGFP vector, we transduced K562 cells with lentiviral vectors expressing eGFP downstream of either 2A or IRES sequences as shown Figure 1. All other sequences in the vectors were identical. K562 cells (5 × 104) were transduced once with viral particles in the range of 5, 10, 20, 50, 100 and 200 ng of p24. Seven days after the transduction, cells were analyzed by flow cytometry for expression of eGFP. Untransduced K562 cells were used as control. Percentage of positive cells (given as % values on histograms) and the mean fluorescence intensity (given as numbers on histograms) were calculated using Cell Quest software.
Chinnasamy et al. Virology Journal 2006 3:14 doi:10.1186/1743-422X-3-14