This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ralph, S. J. Articles by Berridge, M. V. Search for Related Content PubMed PubMed Citation Articles by Ralph, S. J. Articles by Berridge, M. V.

Binding of Monoclonal Antibodies That Inhibit Spleen Colony Formation to Leukemic Cell Lines¹

Wellington Cancer and Medical Research Institute, Wellington Clinical School of Medicine, Wellington Hospital, Wellington 2, New Zealand

Clonogenic tumor cells and normal stem cells share the property of extensive proliferative potential. Normal stem cells are under stringent growth restraint and respond to appropriate differentiation signals, whereas tumor stem cells have lost the ability to respond normally to these controls. In an attempt to define cell surface molecules involved in the control of hemopoietic cell proliferation and differentiation, we have produced 5 monoclonal antibodies against antigens held in common between hemopoietic stem cells and the Abelson virus-induced pre-B-lymphoma cells from which they were derived. Four of these monoclonal antibodies produced greater than 90% reduction of spleen colony-forming cells, whereas the other bound to a subpopulation (60 to 70%) of spleen colony-forming cells at plateau values. The expression of antigens recognized by these and two other anti-stem cell monoclonal antibodies has been shown to correlate with the differentiation status of a panel of tumor cell lines, with greater expression being observed on cells more closely resembling the pluripotent stem cell than mature hemopoietic cells. Immunoperoxidase staining of bone marrow showed that these antigens are mainly expressed by monocytes and blast cells. Treatment of bone marrow cells with those antibodies which extensively inhibited spleen colony formation and with rabbit complement abolished the ability of progenitor cells to form colonies in soft agar. Quantitative absorption studies distinguished the antigens recognized by two of the anti-stem cell monoclonal antibodies from those detected by anti-H-2^k 11-4.1 monoclonal antibody. These observations suggest that the antigens involved may play a role in the regulation of growth and differentiation of stem cells and undifferentiated leukemic cells.

¹ This work was supported by the Malaghan Trust, the Cancer Society of New Zealand, and the Wellington Branch of the Cancer Society of New Zealand.

² To whom requests for reprints should be addressed.

Received 5/ 2/83. Accepted 6/ 7/84.