During systemic infection and inflammation, immune effector cells are in high demand and
are rapidly consumed at sites of need. Although adaptive immune cells have high
proliferative potential, innate immune cells are mostly postmitotic and need to be
replenished from bone marrow (BM) hematopoietic stem and progenitor cells. We here
review how early hematopoiesis has been shaped to deliver efficient responses to
increased need. On the basis of most recent findings, we develop an integrated view of how …

The hemato-lymphoid system is a paradigmatic, somatic stem cell maintained organ with
enormous cellular turnover, ie the continuous de novo generation and subsequent death of
cells. It is estimated that in a 70 kg adult human individual about 3x105 erythrocytes and
3x104 white blood cells are produced per second in steady-state (steady-state
hematopoiesis) and it is documented that during specific demand, eg upon blood loss or
infectious challenges, cellular production can increase several-fold over baseline levels …