title: A human postnatal lymphoid progenitor capable of circulating and seeding the thymus.
abstract: Identification of a thymus-seeding progenitor originating from human bone marrow (BM) constitutes a key milestone in understanding the mechanisms of T cell development and provides new potential for correcting T cell deficiencies. We report the characterization of a novel lymphoid-restricted subset, which is part of the lineage-negative CD34(+)CD10(+) progenitor population and which is distinct from B cell-committed precursors (in view of the absence of CD24 expression). We demonstrate that these Lin(-)CD34(+)CD10(+)CD24(-) progenitors have a very low myeloid potential but can generate B, T, and natural killer lymphocytes and coexpress recombination activating gene 1, terminal deoxynucleotide transferase, PAX5, interleukin 7 receptor alpha, and CD3epsilon. These progenitors are present in the cord blood and in the BM but can also be found in the blood throughout life. Moreover, they belong to the most immature thymocyte population. Collectively, these findings unravel the existence of a postnatal lymphoid-polarized population that is capable of migrating from the BM to the thymus.
authors: Institut National de la Santé et de la Recherche Médicale (INSERM), U768, 75015 Paris, France.
authors: Emmanuelle M
authors: EM
authors: Six
authors: Delphine
authors: D
authors: Bonhomme
authors: Marta
authors: M
authors: Monteiro
authors: Kheira
authors: K
authors: Beldjord
authors: Monika
authors: M
authors: Jurkowska
authors: Corinne
authors: C
authors: Cordier-Garcia
authors: Alexandrine
authors: A
authors: Garrigue
authors: Liliane
authors: L
authors: Dal Cortivo
authors: Benedita
authors: B
authors: Rocha
authors: Alain
authors: A
authors: Fischer
authors: Marina
authors: M
authors: Cavazzana-Calvo
authors: Isabelle
authors: I
authors: André-Schmutz
mesh_terms: D018952:Antigens, CD34 / Q000096:biosynthesis; D001854:Bone Marrow Cells / Q000378:metabolism; D051927:CD24 Antigen / Q000096:biosynthesis; D017252:CD3 Complex / Q000096:biosynthesis; D002478:Cells, Cultured; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D015260:Neprilysin / Q000096:biosynthesis; D010641:Phenotype; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D013949:Thymus Extracts / Q000378:metabolism*; D013950:Thymus Gland / Q000378:metabolism*
chemical_list: D018952:Antigens, CD34; D051927:CD24 Antigen; D017252:CD3 Complex; D013949:Thymus Extracts; D015260:Neprilysin