Anti-CD54Antibody Improves Survival And Immune Function In Mice With Experimental Sepsis

ObjectiveThis study aimed to find whether anti-CD54antibody could improve the survival inmice with sepsis and to explain its potential mechanism.Methods1. The sepsis model used was CLP (cecal ligation and puncture). We randomlydivided12C57BL/6mice into sham group (n=6) and CLP group (n=6). The spleen,thymus and lung were collected to measure the expression of the CD54mRNA byRT-PCR.2. We randomly allocated40C57BL/6mice into sham group (n=10), CLP group(n=10), CLP+anti-CD54antibody intravenously group (n=10), and CLP+isotypeantibody intravenously group (n=10). Anti-CD54antibody or isotype antibody(50μg/200μl/mouse) were injected immediately after surgery, and the survival rate wasdetermined daily for7days after surgery.3. We were randomly24C57BL/6mice divided into sham group (n=6), CLP+saline intravenously group (n=6), CLP+anti-CD54antibody intravenously group (n=6),and CLP+isotype antibody intravenously group (n=6). Anti-CD54antibody or isotypeantibody (50μg/200μl/mouse) were injected immediately after operation.The mice wereexecuted after24hours. The left lungs were taken out and noted the dry weight toanalyze the wet/dry ratios. We assayed the Myekoperoxidase activity of the right upperlungs. The right middle lungs were stored in5%formaldehyde, made into paraffinsection. And then, we observed the pathological changes through the light microscope.The lower right lungs were measured expressiones of the TNF-α, IL-10and IL-6mRNAby RT-PCR. We recorded the blood and peritoneal cavity bacterial burden. Miceperitoneal lavage fluids were gathered to analyze neutrophil count. The spleen andthymuses were used to survey apoptotic level by tunel. And their MPO activities werealso detected. The expression of CD28/CD80(CD86), IL-10and IL-6mRNA of spleen,thymus and lung were measured by RT-PCR.Results1. The CD54mRNA expression of the spleen, thymus and lung were significantlyelevated24h after CLP (p<0.01). 2. Compared with the CLP group and the CLP injected with isotype antibody, theCLP-operated C57BL/6mice treated with anti-CD54antibody had a remarkableimprovement in the survival rate (p<0.05).3. The lungs from CLP injected with anti-CD54antibody groups showed lowerwet-to-dry ratio compared with CLP group and CLP+isotype antibody group (p<0.01).CLP+anti-CD54antibody group showed lower lung, spleen and thymus MPO activities(p<0.01); Compared with the CLP group and anti-CD54antibody isotype, the degree ofdamage occurred in anti-CD54antibody group was the slightest; The RT-PCR resultsshowed that the quantities of TNF-α and IL-10mRNA expression were obviouslydecreased in anti-CD54antibody group (p<0.01), but the expression of IL-6mRNA wasinsignificant (p>0.05); CLP+anti-CD54antibody group showed higher peripheral bloodand peritoneal lavage fluids bacterial clearance rate than the others. Peritoneal lavagefluids neutrophil cell count were elevated after administration of anti-CD54antibody inCLP mice (p<0.001); The expression of CD28/CD80(CD86) mRNA of spleen, thymusand lung were elevated, but the expression of IL-10and IL-6mRNA were decreasedafter treated with anti-CD54antibody (p<0.05); The percentage of the TUNEL-positivecells was used to determine the apoptosis rates were decreased (p<0.01).ConclusionAnti-CD54antibody could cure the septic mice. The mechnism maybe realted toanti-CD54antibody can ameliorate the lung injury, increase blood and peritoneal lavagefluids bacterial clearance, decrease the spleen and thymus’apoptosis.