[Allogenic BMSCs reverse chimerism inducing the tolerance of xeno-skin graft in mouse model]

To investigate the feasibility of bone marrow mesenchymal stem cells (BMSCs) in inducing immune tolerance and to establish the mouse model of reverse chimerism in xeno-skin transplantation.

The mouse model of bone marrow-chimerism was established with immuncompromised BALB/C-nu/nu female mice by receiving the transplantation of BMSCs from green fluorescent protein (GFP)-C57BL/10 male mice, the optimized chimeric time was identified by RT-PCR testing of SRY gene and immunohistochemistry measurement of GFP expression. In the experiment group, GFP-C57BL/10 male mice received the transplantation of the skin from immuncompromised BALB/C-nu/nu female mice with BMSCs bone marrow-chimerism. In the rejection group, GFP-C57BL/10 male mice received the transplantation of the skin from immuncompromised BALB/C-nu/nu female mice without BMSCs bone marrow-chimerism. In the control group, allo-transplantation of skin was performed in GFP-C57BL/10 male mice. Histological study was performed to investigate the survival rate and angiogenesis of the transplanted skin.

The bone marrow chimeric model was established, the expressions of SRY gene and GFP protein reached the highest level at four weeks (1.22 +/- 0.10; 458.0 +/- 3.4) post-transplanted with BMSCs (10(6)), which was significantly different in comparison with those at one week, two weeks and six weeks posttransplantation(P < 0.05). Four-weeks after transplantation was further confirmed as the optimized chimeric time. The mean survival time of donor skin graft > 14 d in the experimental group, while it only was 5 d in the rejection group.

The bone marrow-chimerism can be formed in the recipient by donor BMSCs transplantation, which can further induce tolerance of mice xeno-skin transplantation by reverse chimerism.