Protective Effect Of Human TREM-1-Ig Fusion Protein On The Mouse Model For Endotoxic Shock

Objective To construct fusion gene of human TREM-1 ectodomain and IgGl Fc and express the fusion protein. Evaluate the protective effect on the mouse model for endotoxic shock of TREM-1-IgGl Fc fusion protein. Methods Primers were designed for TREM-1 extracellular region and IgGl Fc fragment and they were amplified from human peripheral blood lymphocytes and U937 cell line by RT-PCR respectively. Both were connected to a vector pcDNA3.1/myc-his(-)B through multiple clone site. The vector was transfected to NIH/3T3 cell line to obtain cell strain expressing TREM-1-Ig fusion protein stably. Endotoxic shock was modeled by endotoxic injection of 6 to 8-week-old BALB/C mice. Animals were injectedintraperitoneally with D-Gal(20mg) and LPS(1μg) in PBS. The purified hTREM-1-Ig fusion proteinwas injected to models 1h before and in 1h, 2h, 4h and 6h after D-Gal and LPS administration. The blood samples were taken to detect concentration of TNF-α, IL-1β in 1h, 2h, 4h, 6h and 8h after D-Gal and LPS administration. Result TREM-1-Ig fusion protein used in a short time before or after endotoxic shock can degrade the mortality of mice remarkably and lower the concentration of TNF-α, IL-1β in serum significantly (P<0.01) .Conclusions TREM-1-Ig fusion protein can anesis the progress of endotoxic shock. It exert a protective action on endotoxic shock mice.