Selection of RNAi-based inhibitors for anti-HIV gene therapy

Figure 7 In vivo safety studies in the HIS mouse model. A: Cell suspensions enriched for human hematopoietic progenitor cells (hHPC) are prepared from fetal liver tissue. Live nucleated CD34+ cells are magnetically sorted and further enriched for the hHPC (CD34+CD38- fraction) using fluorescence activated cell sorting. Lentiviral supernatants are produced on 293T cells. hHPC are transduced ex vivo with the shRNA-expressing lentiviral vector and injected intrahepatically into sublethally irradiated newborn BALB/c Rag-2-/-γ_c-/- mice. The transduction efficiency is evaluated based on GFP expression after 3.5 d in culture (GFP in vitro); B: The HIS (BALB-Rag/γ) mice are analyzed in the blood and the organs after at least 8 wk post-transplantation for the presence of human cells (%CD45+ cells) (left graph), which were analyzed for GFP recovery (right graph). The GFP recovery is the ratio between the frequency of human GFP+ cells measured in the animals (GFP in vivo) and the frequency of GFP+ hHPC injected in the newborn mice (GFP in vitro, transduction efficiency). The major subsets of the human immune system in the blood are also analyzed for their frequency and absolute number in the human GFP+ and GFP- population. Adapted from[24,70]. ^aP < 0.05.