Objective: To evaluate whether the chemokine (C-C motif) receptor 7 (CCR7) over-expressing C3H10 T1/2 mesenchymal stem cells are more efficient in immunosuppression effects than the original ones in skin grafts in mice.
Methods: The C3H10 T1/2 cells were amplified and transfered with EGFP-CCR7 gene using lentivirus. The skin grafts were harvested from donators (C57BL/6 mice) and then transplanted to recipients (BALB/c mice). The recipients were divided into 4 groups randomly: CCR7⁺ C3H10 T1/2 group (1 × 10⁶ CCR7⁺ C3H10 T1/2 cells suspended in 1 mL PBS were injected into the recipient mice by caudal vein), C3H10 T1/2 group (1 × 10⁶ C3H10 T1/2 cells were injected into the recipient mice after skin graft), allogenic control group (the mice were injected with 1 mL normal saline), and congenic control group (the BALB/c mice that had received the skin from the congenic ones were injected with 1 mL normal saline). The skin graft survival condition and histopathological changes were observed on the 12th postoperative day. The Th17 cells and regulatory T cells (Tregs) in the lymphocytes of spleen were detected by mouse Th17/Treg phenotyping kit.
Results: On the 12th postoperative day, the skin surface features, histopathologic changes and flow cytometry results indicated that the skin graft survival condition of the allografts treated with CCR7⁺ C3H10 T1/2 or C3H10 T1/2 cells were better than that of the allogenic control group. Compared with C3H10 T1/2 cells, CCR7⁺ C3H10 T1/2 cells had better skin graft survival condition and weaker immune response.
Conclusion: CCR7⁺ C3H10 T1/2 cells induce more intensive immunosuppressive effects than original C3H10 T1/2 cells. CCR7⁺ C3H10 T1/2 cells significantly inhibit inflammatory reaction and improve the living state of skin allograft.