In vitro differentiation of murine Sca-1(+)Lin(-) cells into myeloid, B cell and T cell lineages

Hematopoietic progenitor cells were shown to be capable of differentiating into myeloid, B cell and T cell lineages. We used a two-step culture system in which enriched murine hematopoietic progenitors in bone marrow were first plated in viscid culture medium containing methylcellulose, erythropoietin (EPO), stem cell factor (SCF) and interleukin (IL)-7, One thousand enriched murine marrow cells formed 53.5 +/- 12.1 (mean +/- SD) primary colonies. Cells from a single blast colony were separated into two aliquots and replated in secondary methylcellulose cultures containing SCP and IL-7 for B cell lineage and SCP, IL-3, G-CSF, GM-CSF and EPO for myeloid lineage, Nest, cells from five to ten primary blast colonies were cultured again in embryonal thymus (25 GS irradiated). One aliquot of blast colonies in a primary culture contained four colony forming units (CFU) of granulocytes, erythroblasts, macrophages and megakaryocytes, eight CFU-granulocytes and macrophages, and 28 BFU-E in a representative secondary myeloid culture, Another aliquot formed a few B cell colonies (2-10) in a secondary B cell culture, B lymphoid colonies were composed of blast-like cells with B-220 antigen, T cells in a secondary T cell culture consisted of 16% L3T4(+), 16% CD8(+) and 11% CD3(+) of bone marrow origin in the thymus. From these results, ri-e concluded that cells in the primary colonies from Sca-1(+)Lin(-) hematopoietic stem cells could differentiate into B cell, T cell. and myeloid lineages.