[Flt3 ligand in recovering the function of the splenic dendritic cells and the immune system in mice with multiple organ dysfunction syndrome].

OBJECTIVE To study the immunoprotective effect of fms-like tyrosine kinase receptor 3 ligand (FL) in multiple organ dysfunction syndrome(MODS) in mice. METHODS Ninety mice were randomized into three groups: normal, MODS and MODS+FL (each n=30). The MODS model of mice was reproduced. Splenic dendritic cell (DC), I-Ab of peripheral blood mononuclear cells (PBMCs) and T cell subpopulation of peripheral blood of mice were analyzed by flow cytometry. The histomorphology of spleen and DC was studied by light microscope and electron microscope. RESULTS In MODS group, the number of splenic immature DC increased (P<0.05), the number of CD4+ T lymphocytes reduced, while the number of CD8(+)T lymphocytes increased, thus CD4/CD8 ratio was reduced (P<0.05). White pulp of the spleen dispersed, with decrease in splenic bodies. There was apoptosis of DC. The expression of I-Ab of the mononuclear cells decreased remarkably (P<0.01). The mortality of mice before treatment was 18%. In FL treatment groups, the number of splenic mature DC was markedly increased (P<0.05). The number of CD4+ T lymphocytes and CD4/CD8 ratio was also markedly elevated. The expression of I-Ab of the mononuclear cells became normal. The pathological changes in spleen were alleviated. The mortality rate was significantly lowered (7%). CONCLUSION FL can not only stimulate the recovery the DC activity, but also improve the immune function in the late phases of MODS.