Intrinsic β2 integrin adhesiveness is diminished in both primary T cells and neutrophils derived from distinct LAD-III patients. (A) Spontaneous LFA-1–mediated adhesiveness of control and different LAD-III–derived resting T cells to medium density ICAM-1 (470 CAM sites/μm2). Frequencies of transient and firm attachments measured at a shear stress of 0.5 dyn/cm2 in 2 fields are depicted for the indicated experimental groups. Each LAD-III group was compared with T cells from an age-matched control on an identical ICAM-1-Fc–containing substrate. (B) Spontaneous tethering (transient, rolling, or firm arrest) of control and LAD-III resting T cells (deficient in both Kindlin-3 and CDGI) interacting with high density VCAM-1-Fc (740 CAM sites/μm2) at a shear stress of 0.75 dyn/cm2. The frequency and strength of all tethers were determined in 2 fields of view. All adhesive interactions were eliminated by VLA-4 blocking on T cells (data not shown). (C) Spontaneous β2 integrin-dependent adhesiveness of control and LAD-III–derived neutrophils to medium density ICAM-1 (470 CAM sites/μm2). Each LAD-III group was compared with neutrophils from an age-matched control on an identical ICAM-1–containing substrate. Frequency and strength of all tethers were measured at a shear stress of 0.5 dyn/cm2. All adhesive interactions were eliminated in the presence of the β2 blocking mAb, TS1.18. Results in panels A through C are given as the mean ± range of individual measurements, each a representative of 3 independent experiments.
