Hematopoiesis is responsible for the formation of all blood cells from hematopoietic stem cells (HSC) in the bone marrow (BM). It is a highly regulated process, in order to adapt its cellular output to changing body requirements. Specific microenvironmental conditions within the BM must exist in order to maintain HSC pluripotency and self-renewal, as well as to ensure appropriate differentiation of progenitor cells towards each hematopoietic lineage. Those conditions were coined “the hematopoietic niche” and their identity in terms of cell types, location and soluble molecular components has been the subject of intense research in the last decades. Infections are one of the environmental challenges to which hematopoiesis must respond, to feed the immune system with functional cell components and compensate for cellular losses. However, how infections impact the bone marrow hematopoietic niche(s) remains elusive and most of the mechanisms involved are still largely unknown. Here, we review the most recent advances on our knowledge on the hematopoietic niche composition and regulation during homeostasis and also on how the niche responds to infectious stress.

造血功能负责从骨髓 (BM) 中的造血干细胞 (HSC) 形成所有血细胞。这是一个高度受管制的过程，以使其细胞输出适应不断变化的身体需求。BM 内必须存在特定的微环境条件，以维持 HSC 的多能性和自我更新，以及确保祖细胞向每个造血谱系的适当分化。这些条件被称为“造血生态位”，它们在细胞类型、位置和可溶性分子成分方面的特性在过去几十年中一直是深入研究的主题。感染是造血系统必须应对的环境挑战之一，为免疫系统提供功能性细胞成分并补偿细胞损失。然而，感染如何影响骨髓造血生态位仍然难以捉摸，所涉及的大部分机制仍然在很大程度上未知。在这里，我们回顾了我们对稳态过程中造血生态位组成和调节以及生态位如何对传染性压力作出反应的知识的最新进展。