Correlation between CD11b/CD18 shedding and PMN transmigration. (A) Soluble cleaved CD11b and CD18 fragments detected in PMN migration medium by ELISA (bottom panel) using mAbs LM2/1 and MEM-148, respectively. The isotype matched mouse IgG1 was used as the control. (B) PMN transepithelial migration during the same time frame. (C) Western blot analysis of the CD11b fragment and leukocyte serine proteases (NE and NCG) in the concentrated supernatant of the PMN migration set. Data are presented as mean ± SD (n = 4). *P < .05; **P < .01.