Hematopoietic supportive function of human bone marrow stromal cell lines established by a recombinant SV40-adenovirus vector.

We have previously reported the establishment of a variety of human bone marrow stromal cell lines using a recombinant SV40-adenovirus vector. Using this vector, we obtained more clonal stromal cells. Here, we have characterized these cells and analyzed their capacity to support the proliferation and differentiation of hematopoietic cells. The stromal cells were cocultured with nonadherent human bone marrow cells used as hematopoietic cells. The total numbers of hematopoietic cells and CFU-GM in culture were counted every week. Two of the six stromal cell lines, AA101 and HAS303, supported the proliferation and differentiation of hematopoietic cells and CFU-GM for more than 9 weeks. Further, granulocytes, macrophages, and megakaryocytes were detected when cocultured with these cells. When hematopoietic cells were cocultured but separated from the two stromal cell lines by a 0.45-microns millipore membrane to prevent their attachment, almost all CFU-GM disappeared within 7 weeks. The supportive stromal cells produced GM-CSF and IL-6. However, other cell lines producing these humoral factors did not support hematopoietic cell proliferation for such a long time. These findings suggest that these established human bone marrow stromal cell lines will be useful, in that analysis of their supportive function in hematopoietic cell proliferation and differentiation through cell-to-cell interaction will shed some light on this area.