Absence of phosphatidylinositol (PI)-linked proteins in a very early human multipotential haematopoietic marrow cell.

A very early human haematopoietic progenitor cell population which was negative for the major histocompatibility class II antigen (HLA-DR) and positive for the CD34 (MY10) antigen was separated into two subsets according to the expression of decay-accelerating factor (DAF) on the cell surface. Using immunoadherence, cell cycle analysis, and cell culture, we determined that there is a DAF- multipotential cell and a more differentiated DAF+ lineage specific progenitor cell existing in human bone marrow. The DAF- subset was highly enriched for CFU-GEMM, while the DAF+ subset contained only BFU-E and CFU-GM. The DAF- subset was approximately 0.03% and the DAF+ subset approximately 0.008% of the original bone marrow population. MIRL (membrane-inhibitory of reactive lysis), another PI-linked protein, was not expressed on the DAF- population but was expressed on the DAF+ cells. These observations indicate that PI-linked proteins are absent from the multipotential stem cell but are present on an early lineage specific cell. The absence of expression of PI-linked proteins can be used to further isolate and characterize a very early multipotential haematopoietic progenitor cell population.

Duke Scholars

Author Andrew T. Huang Medicine, Hematologic Malignancies and Cellular Therapy