Single-cell analysis of Ets-1 transcription factor expression during lymphocyte activation and apoptosis

The Ets-1 proto-oncogene is a prototype member of Ets family of transcription factors. It is preferentially expressed in lymphoid cells, where it is essential for the maintenance of the normal pool of resting T and B cells. We have investigated the protein expression of the Ets-1 transcription factor during the activation and apoptosis of T and B cells by flow cytometry and confocal microscopy. Cells of the thymus, spleen and bursa expressed high levels of Ets-1 protein, while resting peripheral blood mononuclear cells had lower Ets-1 expression. Activation and proliferation of T cells induced the upregulation of Ets-1. alphabeta-T cells were found to upregulate Ets-1 expression more than gammadelta-T cells. Increased Ets-1 protein expression was located predominantly in the perinuclear area. In contrast, during apoptosis, Ets-1 expression was downregulated. Collectively, our results indicate that Ets-1 expression can be accurately determined by flow cytometry and confocal microscopy. Ets-1 expression level and distribution are differentially controlled in resting, activated and apoptotic lymphocytes.