| First Author | Kobayashi M | Year | 2023 |
| Journal | Cell Rep | Volume | 42 |
| Issue | 3 | Pages | 112239 |
| PubMed ID | 36906851 | Mgi Jnum | J:352455 |
| Mgi Id | MGI:7463838 | Doi | 10.1016/j.celrep.2023.112239 |
| Citation | Kobayashi M, et al. (2023) HSC-independent definitive hematopoiesis persists into adult life. Cell Rep 42(3):112239 |
| abstractText | It is widely believed that hematopoiesis after birth is established by hematopoietic stem cells (HSCs) in the bone marrow and that HSC-independent hematopoiesis is limited only to primitive erythro-myeloid cells and tissue-resident innate immune cells arising in the embryo. Here, surprisingly, we find that significant percentages of lymphocytes are not derived from HSCs, even in 1-year-old mice. Instead, multiple waves of hematopoiesis occur from embryonic day 7.5 (E7.5) to E11.5 endothelial cells, which simultaneously produce HSCs and lymphoid progenitors that constitute many layers of adaptive T and B lymphocytes in adult mice. Additionally, HSC lineage tracing reveals that the contribution of fetal liver HSCs to peritoneal B-1a cells is minimal and that the majority of B-1a cells are HSC independent. Our discovery of extensive HSC-independent lymphocytes in adult mice attests to the complex blood developmental dynamics spanning the embryo-to-adult transition and challenges the paradigm of HSCs exclusively underpinning the postnatal immune system. |
