Elucidation of the mechanism of lineage commitment and differentiation in T cell development

点击翻译按钮获取中文摘要

In our previous studies, we have shown that T cell progenitors (p-T) are produced in fetal liver from the hematopoietic stem cell (HSC) through the stage of p-MT that is capable of generating myeloid and T cells. It was unclear, however, whether the p-MT are directly produced from the HSC or through an undetermined intermediate stage. In the present study, we newly developed the MLP<METB> that is assay capable of determining the developmental potential of individual progenitors towards myeloid, erythroid, T and B cell lineages. With this assay, we identified the p-MTB, the common progenitor for p-MT and PMB. P-METB (HSC) and p-ME were also identified. We have previously shown that prethymic p-T as well as the earliest thymic p-T retain NK potential. In the present study, we showed that these p-T/NK also retain DC potential. The developmental potential of p-T/NK/DC were found to be sequentially restricted to T cell lineages in the thymus during the progression of stages from CD44+CD25" to CD44 CD25+. By introducing the Id2 gene into the p-T/NK/DC with a retroviral vector, generation of αβT cells but not γδT cells was completely arrested.