Effect of Human Recombinant Interleukin-3 in Long-term Bone Marrow Culture

Abstract

Proliferation and differentiation of human stem cells depend on an appropriate microenvironment in the bone marrow where hemopoietic growth factors function as humoral messengers within a heterogeneous network of accessory cells. Various culture systems have been established for the evaluation of hemopoietic stem cells and accessory cells [1]. By the development of an adherent stromal cell layer, the human long-term bone marrow culture (LTBMC) for hemopoietic progenitor cells [2] supports self-renewal of the myeloid progenitor population. The stromal monolayer is formed by adipocytes, endothelial cells, macrophages, bone marrow fibroblasts, and blanket cells [3]. The extracellular matrix, which is essentially composed of fibronectin, laminin, collagen, and glycosaminoglycans, is able to absorb and compartmentalize the soluble hemopoietic growth factors within the stromal microenvironment [4]. Interleukin-3 (IL-3) is a growth factor involved in the regulation of hemopoiesis, not only stimulating myeloid, erythroid, mega-karyocyte, and lymphoid but also multipotential hemopoietic stem cells [5, 6]. The purpose of our study was to investigate the effect of recombinant human IL-3 (rhuIL-3) in human LTBMC with respect to its proliferative and differentiative capacity.