The Role Of Acute Lung Injury In Neutrophil Migration And Alveolar Macrophages

Objective : This study aimed to investigate the mechanisms of sepsisinduced neutrophil emigration in acute lung injury and the role of AlveolarMacrophages,and the protect role of Antibody –MIP-2 and Antibody-KC。 Methods In vitro, We used AMS, PMNS , septic plasma and pulmonaryendothelial cells to test the hypothesis。 Sham AMS were divided into 5 groups1)The group of control : coincubated with sham mice plasma 2) The groupof sepsis: coincubated with septic plasma 3) The group of Ab -MIP-2 :septic plasma were firstly neutralized with Ab-MIP-2(2ug/ml) and thencoincubated with AMS 4)The group of Ab-KC: septic plasma were firstlyneutralized with Ab-KC(10ug/ml), and then coincubated with AMS 5) Thegroup of Ab-MIP-2 andAb-KC:septic- plasma were firstly neutralized withAb-MIP-2 and Ab-KC and then coincubated with AMS。The percentage ofPMNS emigrate from PECS were measured in five groups。In vivo, 25 micewere randomly attributed to five groups. 1)The group of control: shamoperation, just open abdomen 2) The group of CLP: mice were subjected tocercal ligation and perforation 3)The group of CLP and Ab - MIP-2 : micewere subjected to CLP and injected Ab- MIP-2 in tail(4ug/mouse) 4)Thegroup of CLP and Ab-KC:mice were subjected to CLP and injected Ab-KC intail(20ug/mouse) 5) The group of CLP with Ab-KC and Ab- MIP-2: micewere subjected to CLP and were injected with Ab- MIP-2 and Ab-KC in tail。6 hours after operation, the lung were harvested and were prepared and usedfor optical microscopy and measure the MPO in lung. Results Compared with the group of control, PMN'S transendothelialmigration of the group of sepsis increased greatly。This increase could beprevented if Ab -MIP-2 or Ab – KC or Ab -MIP-2 together with Ab –KC was added into the septic plasma before doing migration。 In vivo, incomparison with the group of control , the group of CLP's opticalmicroscopy showed severe injury of the lung, inflammatory cells infiltration,edema, blood, but the groups of three kinds of antibody were got light injured。In comparison with the group of control , the MPO in lung.in group of CLPincreased greatly, in comparison with the group of CLP , the other three groupsof Antibodys got lower MPO in lung。 Conclusion This findings suggest that the ability of AMS conditioned withseptic plasma to promote PMNS transendothelial migration was largelydependent on the C-X-C chemokine MIP-2 or KC in septic plasma, and theAb- KC and Ab-MIP –2 could neutralize MIP-2 or KC so as to suppress theactivity of AMS and decrease PMN'S transendothelial migration in lung,alleviate this kind of acute lung injury。...