Figure 1.

Levels of human CD4⁺ and CD8⁺ T cells are maintained in NSG-BLT mice treated with AAV8-huIL-2. NSG-BLT mice were generated as described in Materials and Methods. Human immune system development was examined in the blood of NSG-BLT mice 12 weeks after implantation of tissues and HSCs (A and B). The gating strategy is shown in (A), with identification of CD3⁺ T cells by gating on human CD45⁺ cells and then gating on CD4⁺ and CD8⁺ T cells. Within the CD4⁺ population, FOXP3⁺CD4⁺ Tregs were identified as CD127^lowCD25⁺FOXP3⁺. Representative human cell engraftment levels are shown in (B). The data shown in (A) and (B) are representative of 40 experiments. (C) NSG-BLT mice were injected intraperitoneally with either AAV8-EGFP or AAV8-huIL-2 (2.5 × 10¹¹ vector particles), and human IL-2 levels were monitored in the serum by ELISA. Human immune system engraftment, including overall engraftment of human CD45⁺ cells, was monitored in the blood of NSG-BLT mice injected with either AAV8-EGFP or AAV8-huIL-2 (D), CD3⁺ T cells (E), CD4⁺ T cells (F), and CD8⁺ T cells (G). These results are representative of four experiments.