Megakaryocytic cells in mixed haemopoietic colonies (CFU‐GEMM) from the peripheral blood of normal individuals

Abstract

The cellular composition of mixed haemopoietic colonies CFU-GEMM from the peripheral blood of normal individuals was investigated using both an improved in vitro culture assay and a monoclonal antibody reactive with the earliest megakaryocytic precursor cells. The frequency of CFU-GEMM was found to be 22 +/- 7/ml blood (mean +/- SE; n = 8) and 4.9 +/- 1.8/10(6) mononuclear cells. Double-labelling of single colonies with monoclonal antibodies against megakaryocytic as well as granulocytic cells revealed that only 18% of mixed colonies from the peripheral blood contained megakaryocytic cells as compared to 87% of mixed colonies from the bone marrow, while no difference existed with regard to granulocytic cells. It is concluded that circulating multilineage progenitor cells either require different culture conditions to express their megakaryocytic component or, alternatively, that the circulating pluripotent stem cell pool mainly consists of bipotent rather than multipotent progenitor cells.

Effect of human recombinant erythropoietin on human hemopoietic progenitor cells in vitro

“…In some experiments, the presence of megakaryocytic cells in individual mixed colonies was analyzed using a monoclonal antibody C17.28 against platelet glycoprotein IIIa [18] and an alkaline phophatase bound goat-anti-mouse immunoglobulin as second antibody [7].…”

Effect of intensified chemotherapy on the pluripotent haematopoietic progenitor cells CFU‐GEMM in adult acute lymphoblastic leukaemia

“…The presence of megakaryocytic and granulocytic cells in individual mixed colonies that were lifted from non-confluent areas of the cultures using a micropipette was assessed simultaneously by an immunoalkaline phosphatase method as described in detail before (Ganser et al, 1985). The presence of megakaryocytic and granulocytic cells in individual mixed colonies that were lifted from non-confluent areas of the cultures using a micropipette was assessed simultaneously by an immunoalkaline phosphatase method as described in detail before (Ganser et al, 1985).…”

“…Double-staining procedures of individual colonies on slides by the imrnunoalkaline phosphatase technique. The presence of megakaryocytic and granulocytic cells in individual mixed colonies that were lifted from non-confluent areas of the cultures using a micropipette was assessed simultaneously by an immunoalkaline phosphatase method as described in detail before (Ganser et al, 1985). The monoclonal antibodies used were C17.28 (kindly provided by Dr P. M. Lansdorp, Amsterdam) directed against platelet glycoprotein IIIa and identifying megakaryocytic cells (Tetteroo et al, 1983), and VIM-D5 (kindly supplied by Dr W. Knapp.…”

“…Besides the determination of the incidence of progenitor cells the capacity of pluripotent progenitor cells to differentiate in vitro along the various cell lineages was investigated by surface analysis of single colonies with monoclonal antibodies against megakaryocytic and granulocytic cells (Ganser et al, 1985). Besides the determination of the incidence of progenitor cells the capacity of pluripotent progenitor cells to differentiate in vitro along the various cell lineages was investigated by surface analysis of single colonies with monoclonal antibodies against megakaryocytic and granulocytic cells (Ganser et al, 1985).…”

“…The aim of the present study therefore was to analyse quantitative and qualitative changes of the pluripotent colony-forming cells CFU-GEMM in the bone marrow of patients with ALL or AUL at various stages of the disease. Besides the determination of the incidence of progenitor cells the capacity of pluripotent progenitor cells to differentiate in vitro along the various cell lineages was investigated by surface analysis of single colonies with monoclonal antibodies against megakaryocytic and granulocytic cells (Ganser et al, 1985). To gain insight into the proliferative activity and involvement of the CFU-GEMM in the haemopoietic regeneration after chemotherapy, the cell cycle status of the pluripotent progenitor cells was studied by determining the proportion of CFU-GEMM sensitive to ara-C as an indication of the fraction in the S-phase of the cell cycle.…”