Proliferation of monocytes and macrophages in homeostasis, infection, injury, and disease

Monocytes and macrophages are important for tissue function during homeostasis, infection, injury, and disease. It was once thought that these cells don't proliferate, but recent evidence suggests that they do. Macrophages can proliferate in various organs and tissues, including the skin, peritoneum, lung, heart, kidney, liver, pancreas, brain, spinal cord, eye, adipose tissue, and uterus. The pathways that stimulate macrophage proliferation may be context-dependent, with different cytokines and transcription factors implicated in various studies.

• 1
  Macrophages proliferate in various organs and tissues, including skin, peritoneum, lung, heart, aorta, kidney, liver, pancreas, brain, spinal cord, eye, adipose tissue, and uterus, and in different species including mouse, rat, rabbit, and human.
• 2
  Macrophages can proliferate at different stages of differentiation, with infiltrating monocyte-like cells proliferating in certain inflammatory contexts and mature resident macrophages proliferating in other inflammatory contexts and during homeostasis.
• 3
  The pathways involved in stimulating macrophage proliferation also may be context dependent, with different cytokines and transcription factors implicated in different studies.