To gain more insight into initiation and regulation of T cell receptor (TCR) gene rearrangement during human T cell development, we analyzed TCR gene rearrangements by quantitative PCR analysis in nine consecutive T cell developmental stages, including CD34+ lin- cord blood cells as a reference. The same stages were used for gene expression profiling using DNA microarrays. We show that TCR loci rearrange in a highly ordered way (TCRD-TCRG-TCRB-TCRA) and that the initiating Dδ2-Dδ3 rearrangement occurs at the most immature CD34+CD38-CD1a- stage. TCRB rearrangement starts at the CD34+CD38 +CD1a- stage and complete in-frame TCRB rearrangements were first detected in the immature single positive stage. TCRB rearrangement data together with the PTCRA (pTα) expression pattern show that human TCRβ-selection occurs at the CD34+CD38+CD1a + stage. By combining the TCR rearrangement data with gene expression data, we identified candidate factors for the initiation/regulation of TCR recombination. Our data demonstrate that a number of key events occur earlier than assumed previously; therefore, human T cell development is much more similar to murine T cell development than reported before. JEM,
The Journal of Experimental Medicine
Department of Bioinformatics

Dik, W.A, van Dongen, J.J.M, Langerak, A.W, Staal, F.J.T, Pike, K, Weerkamp, F, … Reinders, M.J. (2005). New insights on human T cell development by quantitative T cell receptor gene rearrangement studies and gene expression profiling. The Journal of Experimental Medicine, 201(11), 1715–1723. doi:10.1084/jem.20042524