[Effects of CD11/CD18 on adhesion between endothelial cell and PMN and its expression in early stage postburn]

This study was to investigate the expressions of CD11a/CD18 and CD11b/CD18 on burn patient's polymorphonuclear neutrophil (PMN) in early postburn stage and effects of CD11/CD18 mAb on PMN-EC adhesion and endothelial cell (EC) damage induced by PMN. Adhesive rate between PMN and EC, the filtration coefficient (kf) and monolayer volume flux (Jv) were determined after incubating burn patient's PMN with human umbilical vein endothelial cell (HUVEC) for 24 hours. CD11a/CD18 monoclonal antibodies (mAb) and CD11b/CD18 mAb were used to pretreat burn patient's PMNs in order to demonstrate the role of CD11/CD18 in PMN-EC adhesion and EC damage. Expressions of CD11a/CD18 and CD11b/CD18 were determined by flow cytometry 1, 3, 5, 7 d postburn. The results indicated that expressions of CD11a/CD18 and CD11b/CD18 on burn patient's PMNs increased quickly, reaching the peak on day 1 postburn and remained in high level till 7 days postburn. The values of Kf and Jv were increased markedly after burn patient's PMNs was incubated with HUVECs, which were cultured on micropore filter membrane. When burn patient's PMNs were pretreated with CD11a/CD18 mAb and CD11b/CD18 mAb, PMN-HUVEC adhesive rate was inhibited by 70%-80% and the values of Jv and kf were decreased significantly. It suggested that there were increased expressions of CD11a/CD18 and CD11b/CD18 on PMNs after burn injury. Burn patient's PMNs could damage EC and increased EC monolayer permeability (kf, Jv). CD11/CD18 mAb inhibited PMN-EC adhesion and attenuated EC damage induced by PMNs.