[Immunomodulatory effect of UC-MSC on function of immunocytes of rats with collagen type II induced arthritis].

This study was purposed to observe the influence of umbilical cord mesenchymal stem cells (UC-MSC) on the peripheral blood CD4(+)CD25(+)regulatory T cells (Treg), Th17 cells and neutrophils in rats with collagen type II-induced arthritis(CIA), and to explore the regulating effect of UC-MSC transplantation on immunocyte subgroup. The rats wee divided into 3 groups: CIA group (model group), UC-MSC treated group and blank control group. The CIA rats were injected with UC-MSC via tail vein. The percentage of CD4(+)CD25(+) cells in peripheral blood and the expression of NCD11b on neutrophil surface in CIA rates was detected by flow cytometry (FCM), and the serum interleukin-17 (IL-17) was observed by enzyme-linked immunosorbent assay (ELISA). The results showed that the mean fluorescence intensity(MFI) of NCD11b and the level of IL-17 in the model group were significantly higher than those in the blank control group, and the ratio of CD4(+)CD25(+) cells were significantly lower (P < 0.05). The MIF of NCD11b and the level of IL-17 in the UC-MSC treated group were significantly lower than that in the model group (P < 0.05), while the proportion of CD4(+)CD25(+) Treg increased (P < 0.05). Since the fifth week, the above indicators in the UC-MSC group have almostly approached the control group. It is concluded that the UC-MSC can increase peripheral blood Treg proportion in CIA rat, inhibit the secretion of Th17 and the activity of neutrophils, reduce the immune inflammation reaction, decrease the release of proinflammatory factor, and induce immune reconstruction.