Blood Cells - Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems - page 168

Table 3.40. Mononuclear phagocytic system (Source: [ 304 ]; CSF1: colony-stimulating factor-1,
or mCSF: macrophage colony-stimulating factor; CSF2: colony-stimulating factor-2, or gm-
CSF: granulocyte-monocyte colony-stimulating factor; Ifn: interferon; IL: interleukin; TNF:
tumor-necrosis factor). Colony stimulating factor-1 receptor (CSF1R, mCFSR, or Cluster of
differentiation CD115) is expressed by all cells of the mononuclear phagocytic sys tem.

Cell Differentiation agent

Bone marrow

Pluripotent stem cell
gmCFU
mCFU
Monoblast CSF1

Promonocyte CSF1

Monocyte CSF1

Macrophage CSF1

Blood

Ly6C high monocyte

Ly6C low

monocyte

TIE2 + monocyte

Tissues

Dendritic cell
Tissue-resident dendritic cell IL4, CSF2, CSF1

Tissue-resident macrophage CSF1

Inflammatory macrophage (M1) CSF2, Ifn γ ,TNF

Alternatively activated macrophage (M2) IL4, IL13

TIE2 + macrophage

3.13.2.2 Macrophages before and after Birth

Embryonic macrophages differentiate directly from mesenchymal progenitor cells.
Hematopoietic progenitor cells first populate the primitive liver and a second wave
of progenitor cells from the aorta-gonads-mesonephros region of the embryo
follows. After birth, bones are formed and the main site of hematopoiesis resides
in the bone marrow.
The mononuclear phagocytic system of macrophage classification includes:
(1) bone marrow-derived precursor cells; (2) monocytes circulating in blood; and
(3) mature macrophages in tissues; as well as (4) some dendritic cells that dif-
ferentiate from monocytes and macrophages. Monocyte- and macrophage-derived
dendritic cells often reside in precise regions, such as Langerhans cells in the skin.
In addition, myeloid precursor cells can differentiate into endothelial cells.
Cells of the mononuclear phagocytic system arise in the bone marrow from
pluripotent stem cells and multipotent progenitors that comprise granulocyte-
macrophage colony-forming unit (gmCFU), macrophage CFU (mCFU), monoblast,
and promonocyte [ 304 ](Table 3.40 ).