Tie Liu
Northwestern Xi'an Jiaotong University Health Science Center, China
Title: The majority of T cells, including Treg cells, NKT and γδ T cells are developed from CD4-CD8- T progenitor cells without the involvement of CD4+CD8+ stage in the thymus
Biography
Biography: Tie Liu
Abstract
We recently have detected higher levels of Foxp3 in DN cells from mice by
development a new method of Flow cytometry 1. In this study, we examined the expression levels of cell markers in thymocytes exhibited an obvious change during different developmental stages of T cells. We found many cells expressed intracellular CD4, intracellular CD8 and intracellular CD4+ CD8+ in CD4-CD8- DN cells. The highest expression level of CD25 was observed in CD4-CD8-DN cells, followed by CD4+CD8- SP, CD4+CD8+DP and CD4-CD8+ SP cells. The expression level of CD44 in DP cells was much lower than that in the DN cells, and also recorded for CD4+CD8- and CD4-CD8+ cells. NKT cells and γδT cells were found in DN and SP cells, but not in DP cells. The highest expression level of Notch1 and CD117 were observed in DN cells, followed by SP and DP cells. Unexpectedly, intracellular CD3 was not only expressed in SP and DP thymocytes, but also in most of DN thymocytes at various stages. Contaminated cells in DN thymocytes could be removed by the intracellular CD3 gated, replaced with specific blocking antibodies. Our results suggested that T cells classification has been completed in the DN thymocytes stage. T cells, including γδ T cells, NKT and Treg cells may develop from DN T progenitor cells, but without the involvement of the CD4+CD8+ stage in the thymus. We present an effective, easy and accurate method that avoids interference of contaminated cells and does not require the use of blocking antibodies to remove contaminated cells.