Objective: To observe the effect of Ly49A transfected mouse spleen cells on graft versus host disease (GVHD) and graft versus leukemia (GVL) effect after haploidentical allogeneic bone marrow transplantation in mice.
Methods: Ly49A gene was transfected into spleen cells of C57BL/6 mice by retrovirus and the expression rate of Ly49A receptor was evaluated by flow cytometry. The murine model of haploidentical allogeneic acute GVHD was established by using C57BL/6(H - 2b) mouse as donor, and (BALB/c x C57BL/6) F1(H - 2d/b) (CB(6)F(1)) mouse as the recipient which was injected EL9611 cells before transplantation. After irradiation (TBI, (60)Co 10.5 Gy), the recipient received mixed graft of spleen cells and bone marrow cells to establish a GVHD model. The effects of Ly49A transfected spleen cells on GVHD and GVL post haploidentical allogeneic bone marrow transplantation were detected with this model.
Results: The expression rate of Ly49A receptor was (42.20 +/- 4.87)%, (18.67 +/- 2.48)% and (18.73 +/- 3.82)% for pLXSN-Ly49A, pLXSN transfected and untransfected spleen cells respectively. Among haploidentical allo-BMT (C57BL/6(H - 2b)-->CB6F1(H - 2d/b)) groups, the survival time was (7.80 +/- 3.36) days for irradiation group; (21.70 +/- 2.87) days for cyclophosphomide therapy group; (29.40 +/- 6.43) days for mixed bone marrow cells and spleen cells transplantation group; (29.10 +/- 7.39) days for mixed bone marrow cells and pLXSN transfected spleen cells transplantation group and (45.00 +/- 12.38) days for mixed bone marrow cells and Ly49A transfected spleen cells transplantation group, which was much longer than that of any other groups (P = 0.000).
Conclusion: The Ly49A transfected spleen cell transplantation could alleviate GVHD and retain GVL effect in the acute GVHD model post haploidentical allo-BMT.