The in vitro effects of stem cell factor and PIXY321 on myeloid progenitor formation (CFU-GM) from immunomagnetic separated CD34+ cord blood

Pediatr Res. 1992 Sep;32(3):277-81. doi: 10.1203/00006450-199209000-00005.


Two novel cytokines, stem cell factor (SCF) and PIXY321 (a fusion protein, granulocyte macrophage colony-stimulating factor+IL-3), have recently been demonstrated to enhance in vitro adult myelopoiesis. In this study, we compared the success of separating very early hematopoietic progenitor cells (CD34+) from both cord blood (CB) and adult bone marrow (ABM) and their differential response to SCF, PIXY321, and other later-acting colony-stimulating factors (CSF). Briefly, CD34+ cells were isolated from CB and ABM with an anti-CD34 MAb, HPCA-1, and incubated with various combinations of SCF, PIXY321, and other CSF. The percentage of CD34+ cells was decreased in CB compared to ABM before separation (0.54 versus 1.71%) (p = 0.05). Isolated CD34+ cells from CB and ABM were similar in lineage with respect to CD38, HLA-DR, CD33, and CD5, but decreased in CB with respect to B-lineage expression (CD19, CD10, and CD22) (p = 0.05). SCF increased colony forming unit-granulocyte-macrophage (CFU-GM) formation from CB CD34+ cells compared to unconditioned media and had a significant additive increase with IL-3 (p = 0.006) and granulocyte colony-stimulating factor (p = 0.03). SCF also had an additive increase in CB CFU-GM formation with PIXY321 (p = 0.007). PIXY321 had a similar increase in CFU-GM formation from both CB and ABM CD34+ cells compared to the combination granulocyte macrophage colony-stimulating factor + IL-3. When SCF was added to IL-3, PIXY321, or PIXY321 + IL-6, there was an increase in CFU-GM from CB versus ABM CD34+ cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bone Marrow / drug effects
  • Bone Marrow / metabolism
  • Cytokines / pharmacology*
  • Fetal Blood / metabolism*
  • Granulocyte-Macrophage Colony-Stimulating Factor / drug effects
  • Hematopoietic Cell Growth Factors / pharmacology*
  • Hematopoietic Stem Cells / chemistry*
  • Humans
  • Infant, Newborn
  • Stem Cell Factor


  • Cytokines
  • Hematopoietic Cell Growth Factors
  • Stem Cell Factor
  • Granulocyte-Macrophage Colony-Stimulating Factor