Practice Questions

TLS Online TPP Program

#Question id: 7130

Hematopoietic stem cells can be isolated and grown in culture; if one wished to control their differentiation into either neutrophils or macrophages, what colony stimulating factors could be used?

#Unit 5. Developmental Biology

First, GM-CSF and IL-3 would be added to trigger formation of the granulocyte/macrophage lineage; then, the addition of either G-CSF or M-CSF would select between further differentiation as neutrophils or macrophages, respectively.
Since stem-cell factor (SCF) would maintain the cells as stem cells, the elimination of SCF would trigger differentiation into granulocyte/macrophage precursors; no further manipulation would be necessary.
The stem cells could be simultaneously stimulated with G-CSF, M-CSF, GM-CSF, and IL-3; half would become neutrophils and the other half would become macrophages; no further control is possible.
Since hematopoietic stem cells can become only erythrocytes, neutrophils, or macrophages, and no other cell types, the elimination of erythropoietin (EPO) would be sufficient to trigger formation of neutrophils and macrophages.