Simultaneous measurement of transferrin receptor and DNA content of human IL 2 dependent T cells by flow cytometry

This paper describes a method which enables the simultaneous measurement of both the concentration of cell surface receptors and the DNA content of individual lymphoid cells. Cells fixed with PLP (periodate-lysine-paraformaldehyde) were treated with ribonuclease (RNase). Transferrin receptors were then successively bound with monoclonal antibody against them and FITC-labeled antibody against the monoclonal antibody. Cells thus treated were stained with propidium iodide and two-parameter flow cytometric analysis was carried out. Using this method, the expression of transferrin receptors on lymphoid cells was analyzed in relation to the action of T-cell growth factor (IL 2). It was found that cells in the G1 phase were stimulated by IL 2 which increased transferrin receptor concentration after a lag of a few hours. Subsequently, the cells entered the S phase and the receptor levels remained high throughout the S, G2 and M phases of the cell cycle.