Diverse effects of anti-CD44 antibodies on the stromal cell-mediated support of normal but not leukaemic (CML) haemopoiesis in vitro.
We have identified three non-cross-reacting anti-human CD44 monoclonal antibodies that have significant positive or negative (or no) effects on normal human haemopoiesis in the long-term culture (LTC) system. These effects manifested as increases or decreases in the number of LTC-initiating cells (LTC-IC), and the number of colony-forming cells (CFC) recovered from cultures in which either unseparated or highly purified CD34+ CD38- normal marrow cells were placed on pre-established normal marrow feeder layers in the presence or absence of each antibody. The effects seen were rapid and sustained, and dependent on the presence of a preformed feeder layer. Interestingly, the same anti-CD44 antibodies had no effect on the maintenance of leukaemic (Ph+) progenitors (from patients with chronic myeloid leukaemia) when these cells were cultured on preformed feeder layers established from normal marrow. CD44 appears to be part of a mechanism by which stromal elements can regulate primitive normal haemopoietic cells but not their leukaemic (Ph+) counterparts.
Ghaffari
S
S
Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada.
Dougherty
G J
GJ
Eaves
A C
AC
Eaves
C J
CJ
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D018952:Antigens, CD34 / Q000276:immunology; D001853:Bone Marrow / Q000276:immunology; D001854:Bone Marrow Cells; D000939:Epitopes; D006410:Hematopoiesis / Q000276:immunology*; D006412:Hematopoietic Stem Cells / Q000276:immunology; D006801:Humans; D018960:Hyaluronan Receptors / Q000276:immunology*; D015466:Leukemia, Myeloid, Chronic-Phase / Q000276:immunology*; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D018952:Antigens, CD34; D000939:Epitopes; D018960:Hyaluronan Receptors