DNA-catching BM macrophages set hematopoiesis

Hematopoiesis is well known to be affected by environmental factors, adjusting the balance of lymphoid and myeloid output according to peripheral needs.(1,2) Specifically, the bone marrow (BM), as a site of adult blood cell generation, has been shown to sense the gut microbiome composition and respond to dysbiosis associated with antibiotics treatment and numerous gastrointestinal disorders. In this issue of Blood, Lee et al(3) describe how this remote sensing is achieved and how the microbiota educate the immune system while maintaining critical steady-state myelopoiesis.(4)