Impact of the delayed LFA-1 inhibition on in vivo T-cell homing. Equal numbers of fluorescently labeled WT and KI T cells were mixed and intravenously injected into C57BL/6J-CD45.1⁺ congenic mice. One hour after cell injection, the mice were injected intravenously with vehicle or 100 μg of anti–LFA-1 mAb M17/4. One hour later, selected organs were harvested and the homing index (KI/WT) was determined. Homing index in LNs was compared with and without delayed M17/4 treatment. Data are expressed as the mean values ± SEM of at least 4 independent experiments. Two-tailed Student t test was used for statistical analyses. Statistical significance was defined as *P < .05, **P < .01, or ***P < .001 vs SP. (#P < .05 or ###P < .001 in groups with and without mAb [M17/4] treatment.) SP indicates spleen; PBL, peripheral blood lymphocytes; BM, bone marrow; PLN, peripheral lymph node; and MLN, mesenteric lymph node.