title: Extra-thymic physiological T lineage progenitor activity is exclusively confined to cells expressing either CD127, CD90, or high levels of CD117.
abstract: T cell development depends on continuous recruitment of progenitors from bone marrow (BM) to the thymus via peripheral blood. However, both phenotype and functional characteristics of physiological T cell precursors remain ill-defined. Here, we characterized a putative CD135(+)CD27(+) T cell progenitor population, which lacked expression of CD127, CD90, and high levels of CD117 and was therefore termed triple negative precursor (TNP). TNPs were present in both BM and blood and displayed robust T lineage potential, but virtually no myeloid or B lineage potential, in vitro. However, TNPs did not efficiently generate T lineage progeny after intravenous or intrathymic transfer, suggesting that a physiological thymic microenvironment does not optimally support T cell differentiation from TNPs. Thus, we propose that physiological T cell precursors are confined to populations expressing either CD127, CD90, or high levels of CD117 in addition to CD135 and CD27 and that TNPs may have other physiological functions.
authors.affiliation: Institute for Immunology, Hannover Medical School, Hannover, Germany.
authors.forename: Namita
authors.initials: N
authors.lastname: Saran
authors.forename: Jens
authors.initials: J
authors.lastname: Pommerencke
authors.forename: Katrin
authors.initials: K
authors.lastname: Witzlau
authors.forename: Malte
authors.initials: M
authors.lastname: Regelin
authors.forename: Andreas
authors.initials: A
authors.lastname: Krueger
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation; D019070:Cell Lineage; D002478:Cells, Cultured; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D053699:Interleukin-7 Receptor alpha Subunit / Q000378:metabolism*; D017493:Leukocyte Common Antigens / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D018800:Thy-1 Antigens / Q000378:metabolism*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: D053699:Interleukin-7 Receptor alpha Subunit; D018800:Thy-1 Antigens; D019009:Proto-Oncogene Proteins c-kit; D017493:Leukocyte Common Antigens