Objective      To compare the immunomodulatory effects of transplanted neural stem cells (NSCs) and mesenchymal stem cells (MSCs) on inflammation secondary to traumatic brain injury (TBI).       Methods      A total of 264 adult male C57BL/6 mice were randomly assigned into sham operation group (n=54) and TBI group (n=162). Animal models of TBI were established using a free-falling weight drop device

and after 12 h

the mice with neurological severity score scores of 3-7 points were selected for further research. The syngeneic adult NSCs

MSCs and PBS were injected into the brain of TBI mice with aid of a stereotaxic apparatus at 24 h after injury. Then

the mice were randomly sacrificed at 24 and 72 h and 7 d after injection

and the brain sections were stained for morphological analysis and evaluation of infiltrated immune cells. Besides

the expression of cytokines in the brain tissues were detected.       Results      In contrast to the PBS-treated group

the brain damage and tissue exudation were reduced obviously in the NSCs- or MSCs-transplanted group after 7 d. The number of microglias/macrophages in the NSCs- or MSCs-transplanted group was significantly less than that in the PBS-treated group at 72 h and on 7 d(P0.05)

and the number of T cells in the NSCs-transplanted group was significantly less than that in the PBS-treated group on the 7th day (P0.05). The mRNA and protein levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α in the MSCs-transplanted group were significantly lower than those in the PBS-treated group (P0.05). The IL-10 mRNA levels in the NSCs-transplanted group were significantly higher than those in the PBS-treated group at 24 and 72 h (P0.05)

and the IL-10 protein levels were also significantly higher than those in the PBS-treated group and the MSCs-transplanted group at 72 h and on 7 d (P0.05).       Conclusion      Transplanted NSCs and MSCs can affect the infiltration of immune cells and the expression of cytokines so as to regulate the inflammation after TBI.