Figure 2.

Hematopoietic reconstitution after transplantation with endothelial cell (EC) expanded CD34⁺ cells. (A): Cell doses used in autologous hematopoietic and progenitor stem cell transplantation in three nonhuman primates (animal identification nos.: A11224, Z13018, A11208). For each naïve animal, CD34⁺ cells were collected from bone marrow (BM), prestimulated with cytokines for 2 days, transduced with P140K‐green fluorescent protein lentivirus vector, cryopreserved, thawed, and then expanded in endothelial cell coculture for 7 days. Each animal received myeloablative conditioning (1,020 cGy) followed by intravenous infusion with a heterogeneous mixture of the transduced CD34⁺ cells and endothelial cell coculture. Cell doses are indicated per kilogram of body weight of BM‐derived transduced CD34⁺ cells before (pre‐expansion) and after (postexpansion infusion product) coculture with endothelial cells. The infusion products contained both the autologous CD34⁺ cells and the xenogeneic human EC dose. (B): Human ECs detected in peripheral blood up to 1 week after cell infusion. Data shown represent mean ± SD for n = 3 monkeys (A11224, Z13018, A11208). Representative flow cytometry analysis of peripheral blood sample 4 days after transplantation of CD34⁺/EC cocultures for detection of the human‐specific cell surface marker CD147 (Tra‐1‐85 antibody) and EC‐specific cell surface markers CD31 and KDR. (C): Hematopoietic recovery (over the first 30 days for each of the three indicated animals) as indicated by complete blood count analysis. Horizontal shaded lines represent minimal threshold of recover for (from top to bottom): platelets, neutrophils, lymphocytes. Abbreviation: EC, endothelial cell.