Objective: To explore the effect of infusing G-CSF mobilized recipient spleen cells at different time after haploidentical stem cell transplantation(HSCT) on graft-versus-host disease (GVHD) in mice and its possible mechanism.
Methods: Forty mice after HSCT were randomly divided into 4 groups (n=10): GVHD positive control group (control group), 1st d recipient cell infusion group after transplantation (+1 d group), 4th d recipient cell infusion group after transplantation(+4 d group), 7th d recipient cell infusion group after transplantation(+7 d group). The mice in control group were injected the normal saline of same equivalent with experimental group which were given the same amount of G-CSF-mobilized recipient spleen cells. The general manifestation and pathological change of GVHD were observed. The expression changes of CD3+CD4+, CD3+CD8+ cell subsets and FasL in peripheral blood were detected by flow cytometry.
Results: The incidence of GVHD was significantly decreased in +4 d group and the median survival time was longer than 60 days, which was significantly higher than that of control group (24 d), +1 d group (21 d), +7 d group (28 d). (P<0.01, P<0.01, P<0.01). The Fasl expression of peripheral blood T lymphocytes in +4 d group were significantly lower than that in the other 3 groups(P<0.05).
Conclusion: The +4 d infusion of G-CSF mobilized recipient spleen cells on 4th day after haploidentical HSC transplantation can inhibit the expression of FasL in donor T lymphocytes, and significantly reduce the incidence of GVHD.