Functional expression of CD95/Fas antigen and Bcl-2 on cord blood hematopoietic progenitor cells.
- Author:
Yanping, MA
;
Ping, ZOU
- Publication Type:Journal Article
- MeSH:
Antigens, CD34;
Antigens, CD95/*metabolism;
Apoptosis;
Fetal Blood/*cytology;
Hematopoiesis;
Hematopoietic Stem Cells/*metabolism;
Leukocytes, Mononuclear/metabolism;
Proto-Oncogene Proteins c-bcl-2/*metabolism
- From:
Journal of Huazhong University of Science and Technology (Medical Sciences)
2002;22(1):24-7
- CountryChina
- Language:English
-
Abstract:
The cell-surface expression and functional status of the CD95/Fas antigen on primitive hematopoietic progenitors isolated from human cord blood (CB) were studied. The CD34+ cells freshly isolated from CB displayed low CD95 expression. The combinations of cytokines such as SCF + FL could up-regulate the expression of CD95 in vitro culture and tumor necrosis factor-alpha (TNF-alpha) and interon-gamma (IFN-gamma) further increased the CD95 expression induced by positive cytokines. The functional status of CD95-mediated apoptosis were analyzed by incubation of CD34+ CB cells in the presence of anti-CD95 monoclonal antibodies (McAbs). The effects of anti-CD95 McAbs were measured by viable cell counting, flow cytometry, LTIC and CFU-C assays. A decrease of viable cells, CFU-C and LTIC numbers were observed in the presence of anti-CD95 McAbs and TNF-alpha or IFN-gamma. However, growth factor deprivation or the early-acting cytokine such as SCF and FL cross-linking to CD95 caused low apoptosis of CD34+ cells. The correlation of increased intracytoplasmic levels of bcl-2 and the presence of CD95 on fresh CB CD34+ cells suggested that bcl-2 might be involved in protecting against CD95-mediated apoptosis of CB CD34+ cells.
