Recloned Colonies Positive for T-Cell-Associated Antigens Derived from Mixed Hemopoietic Colonies (CFU-GEMM)

Abstract

Human pluripotent hemopoietic progenitors (CFU-GEMM) can be identified by their ability to form colonies in culture that contain granulocytes, erythroblasts, macrophages and megakaryocytes. Individual mixed colonies (46) from 4 individuals were prepared by cytocentrifugation and examined for cells positive for human T cell markers using the monoclonal antibodies E 2-22 and OKT 3 and fluorescently labeled goat F(ab'')2 anti-mouse IgG antibody. Sixteen primary mixed colonies were positive for the monoclonal antibodies E 2-22 and OKT 3. Primary mixed colonies (79) derived from these 4 individuals were aspirated, dispersed and then recloned. Twenty-three primary mixed colonies formed 97 secondary helmopoietic colonies. All cells in 50 recloned hemopoietic colonies were positive for the antibodies directed against T cells.