Flt3 ligand accelerates the recovery of the immune system in irradiated mice

Objective: To study the immuno-protective potential of Flt3 ligand (FL) alone or in combination with other cytokines in irradiated mice. Methods: The number of peripheral blood cells was counted by using F-800 apparatus and the phenotype of lymphocytes was analyzed by flow cytometry. the pathological manifestations of spleen, thymus and lymph nodes were also evaluated. Results: FL used alone before irradiation or in combination with other cytokines after irradiation could stimulate the recovery of peripheral white blood cells, especially CD8+ T lymphocytes, and accelerate the recovery of ratio of CD4+/CD8+ T lymphocytes. FL reduced immune tissue damage and stimulated recovery of spleen, thymus and lymph nodes. The administration of FL to mice prior to irradiation and, to a lesser extent, after irradiation, significantly enhanced survival rate of animals. Conclusion: FL can stimulate not only the recovery of hematopoiesis, but also the improvement of immune function in irradiated mice. FL alone or in combination with other cytokines exerts a distinct radio-protection effect