Analysis of leukocyte antigens detected by immunoenzymatic staining on human bone marrow colonies

Immunoenzymatic (IE) staining for antigen detection on intact human bone marrow (BM) colonies grown in agar layers is described. The reliability of this method allowed a study of antigenic changes during myelomonocytic differentiation. Phenotypic analysis was carried out at different times using the following monoclonal antibodies (MoAbs): S16.144, R1B19, UJ308, TG1 (CD 15), and UCHM1 (CD 14). The results confirmed that the clonogenic assay for human BM cells allows the detection of two granulo-macrophagic colony-forming cells (GM-CFC) appearing at different times during culture. In addition, this study pointed to a temporal sequence in the appearance of the markers analyzed: UJ308 seems the earliest detectable marker followed by R1B19, TG1, UCHM1, and S16.144, respectively. These findings suggest that the granulocytic differentiation occurs earlier than that of monocytes and that UJ308 is probably present on a subpopulation of myeloid cells expanded during hemopoietic regeneration.