i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; Departamento de Biologia Molecular, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal.
Semin Cell Dev Biol. 2021 Apr;112:37-48. doi: 10.1016/j.semcdb.2020.05.014. Epub 2020 Jun 15.
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.
造血是指从骨髓中的造血干细胞（HSC）生成所有血细胞的过程。这是一个高度调控的过程，以便根据身体的需求变化来调整其细胞输出。为了维持 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，必须存在特定的骨髓微环境条件。这些条件被称为“造血龛”，其在细胞类型、位置和可溶性分子成分方面的特征一直是过去几十年中研究的热点。感染是造血系统必须应对的环境挑战之一，它需要为免疫系统提供功能性的细胞成分，并补偿细胞的损失。然而，感染如何影响骨髓造血龛仍然难以捉摸，而且大多数涉及的机制仍然知之甚少。在这里，我们回顾了关于造血龛在稳态下的组成和调控的最新进展，以及龛在应对感染应激时的反应。
