title: MDR1 gene expression enhances long-term engraftibility of cultured bone marrow cells.
abstract: Primitive hematopoietic stem cells are responsible for long-term engraftment in irradiated host. Here, we report that multi-drug resistance 1 (mdr1) gene expressing primitive hematopoietic cells were multiplied in ex vivo culture, with the support of extracellular matrix components and cytokines. About 20-fold expansion of total nucleated cells was achieved in a 10-day culture. Lin(-)Sca-1(+) and long-term culture-initiating cells were increased by 54- and 26-fold, respectively. Expanded cells were long-term multi-lineage engraftible in sub-lethally irradiated mice. Donor-derived peripheral blood chimerism was significantly higher (73.2+/-9.1%, p<0.01) in expanded cells than in normal and 5-flurouracil-treated bone marrow cells. Most interestingly, the expression of mdr1 gene was significantly enhanced in cultured cells than in other two sources of donor cells. The mdr1 gene was functional since expanded cells effluxed Hoechst 33342 and Rh123 dyes. These results suggest that primitive engraftible stem cells can be expanded in the presence of suitable microenvironments.
authors.affiliation: National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi-110067, India.
authors.forename: Satyanarayana
authors.initials: S
authors.lastname: Rentala
authors.forename: Murali Mohan
authors.initials: MM
authors.lastname: Sagar Balla
authors.forename: Satish
authors.initials: S
authors.lastname: Khurana
authors.forename: Asok
authors.initials: A
authors.lastname: Mukhopadhyay
mesh_terms: D000818:Animals; D001483:Base Sequence; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism*; D002478:Cells, Cultured; D003470:Culture Media; D017931:DNA Primers; D005434:Flow Cytometry; D019450:Genes, MDR; D051379:Mice; D008810:Mice, Inbred C57BL; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D003470:Culture Media; D017931:DNA Primers