Long-term in vivo reconstitution of T-cell development by Pax5-deficient B-cell progenitors

Abstract

The mechanisms controlling the commitment of haematopoietic progenitors to the B-lymphoid lineage are poorly understood. The observations that mice deficient in E2A and EBF lack B-lineage cells have implicated these two transcription factors in the commitment process. Moreover, the expression of genes encoding components of the rearrangement machinery (RAG1, RAG2, TdT) or pre-B-cell receptor (λ5, VpreB, Igα, Igβ) has been considered to indicate B-lineage commitment. All these genes including E2A and EBF are expressed in pro-B ceils lacking the transcription factor Pax5 (refs 5-7). Here we show that cloned Pax5-deficient pro-B cells transferred into RAG2-deficient mice provide longterm recons..