关键词：造血干细胞；骨髓；干细胞；造血干细胞
摘 要：Hematopoietic stem cells (HSC) and their progeny reside in specialized niches of the microenvironment (ME) in the bone marrow. The ME niches control HSC self-renewal, differentiation, and maturation. The ME niche cells are derived from non-hematopoietic cells, including fibroblasts, osteoblastic and endothelial cells. Macrophages, which are hematopoietic in origin, are also a critical component of the ME niches, and can influence the function of the ME niche cells. I hypothesize that the macrophages can acquire defects that may compromise ME function and lead to bone marrow failure. To test this hypothesis, I proposed to develop a new in vivo model that allows the inducible depletion of the macrophages in dogs, followed by the documentation of marrow failure, and subsequent therapeutic interventions. At this period, I achieved 4 goals: (1) Optimize culture conditions for generating dog macrophages, (2) Optimize transduction efficiency of a macrophage-specific CD163 promoter construct in dog CD34+ HSC and test its macrophage-specific expression, (3) Establish a luciferase reporter assay to test the macrophage- specific promoter activity, and (4) Generate multiple lentiviral vectors containing the dog/human CD163 promoter, iCasp9, and p140MGMT constructs.