Protective effect of Flt3L on organ structure during advanced multiorgan dysfunction syndrome in mice.

The present study aimed to examine whether fms-related tyrosine kinase 3 ligand (Flt3L) protects the organs of mice with multiorgan dysfunction syndrome (MODS). Male C57BL/6 mice were randomly assigned to normal control, MODS and Flt3L treatment groups. The mouse models of MODS were established using intraperitoneal zymosan injections, followed by normal saline injections. The treatment group received 5 mu g/kg Flt3L for seven days, beginning on day five following zymosan injection. On day 12, the mortality rates of the Flt3L treatment and the MODS groups were 7 and 18%, respectively. Marked pathological changes were observed in the liver, lungs, kidneys and heart of the mice with MODS, including degeneration and focal necrosis of parenchyma cells. Mild pathological changes were observed in different organs of the Flt3L-treated mice. In the MODS group, the number of CD4(+) T lymphocytes was significantly reduced, whereas the number of CD8(+) T lymphocytes was significantly increased compared with that in the normal control group; thus, the CD4(+)/CD8(+) ratio was reduced. In the Flt3L treatment group, the average number of CD4(+) T lymphocytes was not significantly different to the average number of CD4(+) T lymphocytes in the normal group. In conclusion, Flt3L administration improved the immune status and alleviated the organ damage in mice with late-phase MODS.