TCR Stimulation Was Shown to Affect ICAM-1 (Integrin Ligand) Binding

Essay

TCR stimulation was shown to affect ICAM-1 (integrin ligand) binding to LFA-1 (integrin) on T cells. To demonstrate this, varying concentrations of purified ICAM-1 were added to unstimulated or TCR-stimulated T cells, and the amount of ICAM-1 binding was measured. The data from such an experiment are displayed on Figure. Assign the red or blue lines correctly to 'unstimulated' or 'TCR-stimulated' T cells, and explain the reasoning for your answer.