Immunofluorescent identification of human megakaryocyte colonies using an
antiplatelet glycoprotein antiserum
EM Mazur, R Hoffman, J Chasis, S Marchesi and E Bruno
The development of a satisfactory in vitro assay system for human
megakaryocyte colony forming progenitor cells has been delayed by the lack
of a suitable marker for cells of human megakaryocyte lineage. For this
purpose we raised an antiserum directed against a purified human platelet
glycoprotein preparation. In conjunction with indirect immunofluorescent
staining of human bone marrow, this antiserum labeled only platelets,
megakaryocytes, and an infrequent population of small mononuclear cells.
These small mononuclear cells, not otherwise identifiable as members of the
megakaryocyte series, constituted 22.9% of the total fluorescein positive
nucleated bone marrow cells. This antiserum was also used to label colonies
cultured from human peripheral blood mononuclear cells using a modified
plasma clot technique. A mean of 123 fluorescein-labeled colonies were
cloned per 10(6) mononuclear cells cultured. Granulocyte-macrophage and
erythroid burst colonies did not label using this method. No augmentation
of colony numbers was found with varying concentrations of erythropoietin,
human embryonic kidney cell conditioned media (a source of thrombopoietin),
or media conditioned by a human T lymphoblast cell line (a source of both
colony stimulating and burst promoting activities). Immunofluorescent
labeling for platelet glycoproteins is a convenient phenotypic marker for
cells of human megakaryocyte lineage useful in the study of in vitro human
megakaryocytopoiesis.
Volume 57,
Issue 2,
pp. 277-286,
02/01/1981
Copyright © 1981 by The American Society of Hematology
