Micro–adhesion rings at the interface between T cells and APCs. (A–D) T cells expressing SLP76-GFP were incubated with 1 µM Ag–loaded activated B cells for 5 min and fixed. The images of SLP76-GFP and anti–LFA-1–Dy549 staining are shown. (A) The xyz dimensions are indicated in the diagram (left). The representative images of 14 cells in the x–y dimension are shown (right). DIC, differential interference contrast. (B) The region in the box in A with a higher magnification is shown. (C) The fluorescence intensity profiles of LFA-1 and SLP76-GFP in between the white arrows in B were plotted (left). The pixel intensities of SLP76-GFP and LFA from 189 pixels were normalized to their median values and plotted (middle). The mean of the correlation coefficients of SLP76-GFP and LFA from 10 T cells conjugated with APC was plotted (right). The correlation coefficients of Pyk2-GFP and Pxn-Halo and TCR and Pxn-GFP were also evaluated from the cells analyzed on the planer bilayer shown in Fig. 1 (B and C). Data are the mean from five cells ± SD. *, P < 0.01. a.u., arbitrary units. (D) The reconstituted x–z images in the box in B are shown. Bars, 3 µm.