Colony-forming unit granulocyte monocytes

B cell bh4 bp BPI BSA C domain C1-C9 cAMP CAP CD cDNA CFU CFU-GEMM bone-marrow-derived lymphocyte tetrahydrobiopterin base pairs bactericidal/permeability-inducing protein bovine serum albumin constant domain complement components cyclic adenosine monophosphate cationic antimicrobial protein cluster of differentiation complementary deoxynucleic acid colony-forming unit granulocyte-erythroid-monocyte-megakaryocyte CFU... 

Erythropoiesis is a process that starts with a pluripotent stem cell in the bone marrow that eventually differentiates into an erythroid colony-forming unit (CFU-E)4 (Fig. 63-1). The development of these cells depends on stimulation from the appropriate growth factors, primarily erythropoietin. Other cytokines involved include granulocyte-monocyte colony-stimulating factor (GM-CSF) and interleukin 3 (IL-3). Eventually, the CFU-Es differentiate into reticulocytes and cross from the bone marrow into the peripheral blood. Finally, these reticulocytes mature into erythrocytes after 1 to 2 days in the bloodstream. Throughout this process, the cells gradually accumulate more hemoglobin and lose their nuclei.4... 

Figure 2.2. Role of cytokines in blood-cell development. Abbreviations CFU, colony-forming unit CFU-GEMM, granulocyte-erythroid-monocyte-megakaryocyte CFU CFU-GM, granulocyte-macrophage CFU CFU-M, macrophage CFU CFU-G, granulocyte CFU CFU-Eos, eosinophil CFU IL, Interleukin. See text for details.

In comparison to GM-CSF, G-CSF is more lineage specific. A primary effect of G-CSF is to promote the conversion of granulocyte colony-forming units into polymorphonuclear leukocytes. Mice that lack G-CSF have chronic neutropenia and reduced bone marrow myeloid precursors and progenitors. They also have a markedly impaired capacity to increase neutrophil and monocyte counts after infection. 

Derived from the granulocyte-monocyte colony-forming unit, monocytes are peripheral cells in transit from the bone marrow to tissues. Once in the tissues, under the influence of local factors, monocytes become macrophages. Macrophages exist in the liver (Kupffer cells). 

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