Cytokines transduced bone marrow stromal cell lines promote immunohematopoietic reconstitution in mice after allogeneic bone marrow transplantation

Impaired immune reconstitution following allogeneic T-cell depleted bone marrow transplantation (allo-TCD-BMT) is a major obstacle to its clinical application. Stromal cell line QXMSC1, established from bone marrow cells of BALB/c(H-2d), was transfected with murine IL-3 and/ or IL-2 gene, and injected into lethally irradiated C57BL/6(H2b) mice. We evaluated its effects on immunologic and hematopoietic reconstitution after allo-TCD-BMT. The results showed that QXMSC1-IL-3 + IL-2 could significantly increase the numbers of hematopoietic primitive progenitors (CFU-S), committed progenitors (CFU-GM, and BFU-E), and lymphocytes (CD8+ cells, CD4+ cells, and B cells). Similarly, immune functions of recipient mice were significantly enhanced in the QXMSC1-IL-3 + IL-2 group. In addition, QXMSC1-IL-3 or QXMSC1-IL-2 also exerted apparent effects on accelerating immune reconstitution, but these effects were far less than that of QXMSC1-IL-3 + IL-2. Our results demonstrated that stromal cell-mediated IL-3 and IL-2 gene therapy may be a potent approach in promoting immunologic and hematopoietic reconstitution after allo-TCD-BMT.