Effects of wnt3a gene-modified bone marrow mesenchymal stem cells on aute graft-versus-host disease in mice

Objective To explore the effects of injection of wnt3a gene-modified bone marrow mesenchymal stem cells (MSCs) on acute graft-versus-host disease (aGVHD) in a murine allogeneic bone marrow transplantation (allo-BMT) model.Methods C57BL/6 mice were used as the donors and Balb/c mice as the recipients in the murine allo-BMT model.The recipient mice were divided into four groups by random number table method: transplantation control group (group A) (infusion of 5 × 106bone marrow cells via the tail vein of recipient mice); aGVHD group (group B) (infusion of 5 × 106bone marrow cells and 5 × 106 splenocytes via the tail vein of recipient mice); aGVHD + empty vector group (group C) (infusion of 5 × 106 bone marrow cells,5 × 106 splenocytes and 1 × 106 pAd-GFP-transfected MSCs via the tail vein of recipient mice) ; experimental group (group D) (infusion of 5 ×106 bone marrow cells,5 × 106 splenocytes and 1 × 106 wnt3a gene-modified MSCs).The general performance and survival were monitored,the occurrence of aGVHD was observed,the changes of donor T lymphocyte quantity present in the spleen,and interleukin-2 (IL-2) and interferon-γ (IFN γ)levels of the recipient mice were detected in each group after transplantation.Results The survival time of recipient mice in group A was all more than 60 d,and that in groups B,C and D was (19.1 ±6.19),(32.6 ± 19.6) and (47.2 ± 15.6) d,rcspcctivcly.The survival time in group D was significantly longer than in groups B and C (P＜0.05).After the transplant,the aGVHD score points in groups B,CandDwere (8.0±0.41),(6.7±0.29) and (4.0± 1.0),respcctively.The aGVHD score points in group D were significantly less than in groups B and C (P＜0.05),and the pathological grade in group D was significantly reduced.The number and proliferation rate of T lymphocytes were reduced significantly in group D as compared with groups B and C at 3rd and 5th day after transplantation (P ＜ 0.05).The levels of IL-2 and IFN-γ in peripheral blood were decreased significantly in group D as compared with those in groups B and C at 7th,14th,21st and 28th day after transplantation (P＜0.05).The chimeric rate of the murine H-2Kb cells in the bone marrow cells of long-term survival mice was all in the range of 95％ to 100％ 60 d after transplantation.Conclusion The injection of wnt3a gene-modified MSCs can more effectively alleviate aGVHD in murineallo-BMT model,which may be correlated with the Wnt3a overexpression which activating the Wnt/β-catenin signaling pathway of MSCs,thereby inhibiting the early activation and amplification of donor T lymphocytes and the IL-2 and IFN-γ expression. Key words: Mice;  Bone marrow transplantation;  Wnt3a;  Mesenchymal stem cells;  Graft versus host disease