Figure 2.

Innate immune pathways leading to increased myeloid cell production and acceleration of atherosclerosis. A number of pathways and signals increase their input on haematopoietic tissues after a first organ ischaemia. The signals can either be sensed by haematopoietic stem cells or by niche cells which instruct HSC behaviour. Altered niche haematopoietic signals may increase haematopoietic stem cell proliferation (i.e. leucocyte production) and increase their migration out of the bone marrow. As a consequence, splenic leucocyte production increases as well. Altogether, the systemic pool of innate immune cells, including plaque macrophages, expands.