Fig. 2

T cell egress is blocked by hydrocortisone. The representative images taken from control or hydrocortisone (HC)-treated mice are shown in (a). LYVE-1⁺ cortical sinuses are shown in blue pseudocolor in order to distinguish them with CMTMR labeled T cells (red) and the representative sinus area is delineated by a dotted white line. The dotted yellow line outlines the area within 30 μm of distance from the outer boundaries of cortical sinuses. Note: few T cells within cortical sinus in the presence of HC. Scale bar, 50 μm. Frequencies at which T cells entered (b), moved away (c), crawled on (d), or stuck to (e) (kept adhering to one point on the sinus wall and never displaced during the imaging period after they engaged the sinus) the cortical sinuses in control and HC-treated mice were calculated by manually tracking individual cells in each time-lapse image, with a total of 200 cells randomly selected in 10~15 imaging stacks. Each dot represents data from a single time-lapse image, and bars represent the means. Significance was measured using non-parametric Mann-Whitney t test. *P < 0.05, ***P < 0.001 in the presence or absence of hydrocortisone. Data are combined from two independent experiments each with two lymph nodes imaged in each treatment. The experiment was repeated two times with similar results