HIV-1 cofactor activity of LEDGF/p75 ΔPWWP. (a) TL3, and TL3 cells expressing LEDGF/p75 WT or LEDGF/p75 ΔPWWP (eleven different cell lines) were challenged with HIVluc and luciferase activity determined five days later. Expression of LEDGF/p75 proteins in these cell lines was documented by immunoblotting with an anti-LEDGF and anti-FLAG Mabs. Errors bars correspond to four independent infection experiments. (b) LEDGF/p75 mRNA levels in TC3 and cells used in panel (a). The mRNA levels of endogenous LEDGF/p75 were quantified by real time PCR using specific primers. mRNA levels for LEDGF/p75 were normalized to those of GAPDH in the same samples. Errors bars correspond to triplicate real-time PCR measurements.