Myeloid cells (monocytes/macrophages and granulocytes) are derived from a common progenitor, the granulocyte-monocyte progenitor (GMP). Combinatorial interactions between hematopoietic transcription factors program the differentiation of the GMP into monocytes and the four granulocytic lineages: neutrophils, eosinophils, basophils, and mast cells. Cytokines and growth factors mainly function to promote proliferation and survival of the myeloid lineages. However, there is evidence demonstrating that cytokines can affect transcription factor expression and influence lineage commitment. Gene targeting experiments in mice have demonstrated that several transcription factors are required to specify distinct myeloid lineages. An essential role for cytokines in steady state hematopoiesis has not been observed; however, several cytokines are required to mobilize proper immune responses to infectious pathogens. A newly recognized class of small RNAs termed micro-RNAs (miRNAs) may be critical in lineage specification. These small RNA molecules regulate the translation of specific mRNAs. Recent research is beginning to support the role of miRNAs in lineage commitment by regulating the protein accumulation of specific hematopoietic transcription factors.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)