Generation of GLuc

<p><b>-expressing patient-derived ALL cells. a</b> Scheme of the lentiviral vector construct; arrow indicates start of transcription; RSV/5′LTR = hybrid of the Rous Sarcoma virus promoter and the U5 long terminal repeat from HIV-1 virus; EF1 P = constitutive elongation factor 1-alpha promoter; GLuc = membrane anchored form of the Gaussia luciferase (GLuc) enzyme fused to the transmembrane domain of CD8; T2A = “self-cleaving” 2A peptide from insect virus <i>Thosea asigna</i>; copGFP = green fluorescent protein cloned from copepod <i>Pontellina plumata</i>; 3′ΔLTR = HIV-1 virus long terminal repeat with a self-inactivating U3 deletion; <b>b, c</b>Transduction efficiency as determined by flow cytometry measurement of GFP expression after one round of amplification of transduced cells in mice; (<b>b</b>) in ALL-50 and ALL-199; (<b>c</b>) in all 9 patient-derived ALL samples studied; <b>d</b> Stability of biological characteristics of patient-derived ALL cells despite of lentiviral transduction; examples from data shown in detail in Supplemental <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052798#pone-0052798-g001" target="_blank">Figure 1</a>; comparison of ALL-199 cells before and after lentiviral transduction and sorting concerning drug-induced cell death after 48 hours in vitro (left panel), expression of cell surface markers (middle panel) and time to engraftment (right panel).