A new paradigm for hematopoietic cell lineages: revision of the classical concept of the myeloid-lymphoid dichotomy.
The concept that blood cells arising from hematopoietic stem cells (HSC) can be subdivided into two major lineages, a myelo-erythroid and a lymphoid lineage, has long persisted. Indeed, it has become almost axiomatic that the first branch point from the HSC produces two progenitors, one for myelo-erythroid cells and the other for lymphoid cells. However, recent studies have provided a battery of findings that cannot be explained by this classical model. We will outline how this classical model arose before describing how we came to propose an alternative 'myeloid-based model', in which myeloid potential is retained in erythroid, T, and B cell branches even after these lineages have segregated from each other.
Laboratory for Lymphocyte Development, RIKEN Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan. kawamoto@rcai.riken.jp
Hiroshi
H
Kawamoto
Yoshimoto
Y
Katsura
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage / Q000502:physiology*; D006410:Hematopoiesis / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000166:cytology; D006801:Humans; D054503:Lymphoid Progenitor Cells / Q000166:cytology; D008954:Models, Biological; D023461:Myeloid Progenitor Cells / Q000166:cytology; D010802:Phylogeny