title: Early T cell development and the pitfalls of potential.
abstract: The long-standing model for hematopoiesis, which features a dichotomy into separate lymphoid and myeloid branches, predicts that progenitor T cells arise from a lymphocyte-restricted pathway. However, experiments that have detected myeloid potential in progenitor T cells have been reported as evidence to question this model. Mapping physiological differentiation pathways has now led to opposite conclusions, by showing that T cells and thymic myeloid cells have distinct origins and that, in vivo, T cell progenitors lack significant potential for myeloid lineages including dendritic cells. Here, we review the underlying experiments that have led to such fundamentally different conclusions. The current controversy might reflect a need to distinguish between cell fates that are possible experimentally from physiological fate choices, to build a map of immunological differentiation pathways.
authors.affiliation: Department for Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Schlenner
authors.forename: Hans-Reimer
authors.initials: HR
authors.lastname: Rodewald
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000276:immunology; D019070:Cell Lineage; D006410:Hematopoiesis; D006801:Humans; D051880:Receptors, Notch / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology
chemical_list: D051880:Receptors, Notch