Myelopoiesis ensures the steady state of the myeloid cell compartment. Technological advances in fate mapping and genetic engineering, as well as the advent of single cell RNA-sequencing, have highlighted the heterogeneity of the hematopoietic system and revealed new concepts in myeloid cell ontogeny. These technologies are also shedding light on mechanisms of myelopoiesis at homeostasis and at different phases of infection and inflammation, illustrating important feedback loops between affected tissues and the bone marrow. We review these findings here and revisit principles in myelopoiesis in light of the evolving understanding of myeloid cell ontogeny and heterogeneity. We argue for the importance of system-wide evaluation of changes in myelopoiesis and discuss how even after the resolution of inflammation, long-lasting alterations in myelopoiesis may play a role in innate immune memory or trained immunity.

骨髓生成可确保骨髓细胞区室的稳定状态。命运作图和基因工程技术的进步，以及单细胞RNA测序技术的出现，突显了造血系统的异质性，并揭示了骨髓细胞个体学中的新概念。这些技术还揭示了稳态过程中以及感染和炎症不同阶段的骨髓生成机制，阐明了受影响组织与骨髓之间的重要反馈回路。我们在这里回顾这些发现，并根据对髓样细胞个体发育和异质性的不断发展的理解，重新探讨骨髓生成的原理。我们主张对骨髓生成的变化进行全系统评估的重要性，并讨论即使炎症消退后，