Six Emmanuelle M, Bonhomme Delphine, Monteiro Marta, Beldjord Kheira, Jurkowska Monika, Cordier-Garcia Corinne, Garrigue Alexandrine, Dal Cortivo Liliane, Rocha Benedita, Fischer Alain, Cavazzana-Calvo Marina, André-Schmutz Isabelle
Institut National de la Santé et de la Recherche Médicale (INSERM), U768, 75015 Paris, France.
J Exp Med. 2007 Dec 24;204(13):3085-93. doi: 10.1084/jem.20071003. Epub 2007 Dec 10.
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.
鉴定源自人类骨髓（BM）的胸腺播种祖细胞是理解T细胞发育机制的关键里程碑，并为纠正T细胞缺陷提供了新的可能性。我们报告了一种新型淋巴系限制性亚群的特征，它是谱系阴性CD34(+)CD10(+)祖细胞群体的一部分，并且（鉴于缺乏CD24表达）与B细胞定向前体不同。我们证明这些Lin(-)CD34(+)CD10(+)CD24(-)祖细胞具有非常低的髓系分化潜能，但能够产生B细胞、T细胞和自然杀伤淋巴细胞，并共表达重组激活基因1、末端脱氧核苷酸转移酶、PAX5、白细胞介素7受体α和CD3ε。这些祖细胞存在于脐带血和骨髓中，但在一生中的血液中也能找到。此外，它们属于最不成熟的胸腺细胞群体。总的来说，这些发现揭示了一种出生后能够从骨髓迁移到胸腺的淋巴系极化群体的存在。
