Non-canonical Wnt signaling and lymphostromal interactions: the role of Wnt4/Frizzled6 axis in early immune development

成人免疫系统的所有细胞都来源于少量的骨髓造血干细胞（HSC），这些干细胞存在于专门的口袋或壁龛中，周围被认为调节HSC功能的其他细胞所包围。除了能够发育成不同的血细胞系外，造血干细胞还具有独特的自我更新能力。它们罕见的细胞分裂是不对称的，导致产生一个与母细胞相同的子HSC和一个失去了几个干细胞特征的祖细胞。这种自我更新依赖于造血干细胞与生态位的相互作用，对循环血细胞的持续生成至关重要。该领域最大的技术挑战之一是开发培养中HSC扩展的方法，同时限制其自我更新能力的丧失。

All cells of the adult immune system are derived from a small number of bone marrow hematopoietic stem cells (HSC) that are found in specialized pockets or niches, surrounded by other cells that are believed to regulate HSC function. In addition to being able to develop into the different blood cell lineages, HSC also have the unique ability to self-renew. Their infrequent cell divisions are asymmetrical, resulting in the generation of one daughter HSC, identical to the mother cell, and one progenitor cell that has lost several stem cell characteristics. This self-renewal is dependent on HSC-niche interactions and is essential for the continuous generation of circulating blood cells. One of the greatest technical challenges in the field is to develop methods for HSC expansion in culture while limiting the loss of their self-renewal capacity.