Lenalidomide increases extended intermediate- and high-affinity LFA-1 expression on CLL-derived T cells and rescues their firm adhesion to CD54. (Ai) The graph shows the percent of positive flow cytometric expression analysis of pan–LFA-1 (mAb 38) and the extended intermediate-affinity LFA-1 (KIM127 mAb) on chemokine CXCL12–treated suspension cells (columns show the mean ± SEM from 6 patients). (Aii) The graph shows MFI ± SD of high-affinity LFA-1 (mAb 24) immunofluorescent staining during T-cell migration on CD54 (3 independent CLL patient experiments) examining untreated or lenalidomide (Lenalid.)–treated peripheral blood CD3 T cells from CLL patients compared with age-matched healthy donor cells. (Aiii) Representative images of mAb 24 staining visualized using confocal microscopy (with Alexa Fluor 488 secondary antibody) are shown for each experimental T-cell population as indicated. The enlarged images (insets) show single-cell mAb 24 staining using a rainbow scale where yellow/red indicates strong expression and blue the weakest). (Bi) The graph shows IRM quantification of the area of close cell contact points during LFA-1–directed motility on CD54 (following chemokine stimulation) for n = 30 T cells (individual dots) per experimental population (dot plots are representative of 3 independent CLL patient experiments). (Bii) Representative cell contact points are shown in the IRM images of T cells from healthy donors (upper panels) compared with CLL patients (lower panels) who were untreated (left panels) and treated with lenalidomide (Lenalid.) (right panels). Phase-contrast images are shown (upper left insets) as are enlarged single-cell IRM images (lower right insets). Original magnification ×63.**P < .01. ns, nonsignificant findings.