TBI和环磷酰胺选择性去除同种异基因反应供者淋巴细胞的研究

本研究用全身照射(TBI)和环磷酰胺(CY)选择性去除同种异基因反应的供者淋巴细胞,为预防移植物抗宿主病(GVHD)的发生探索新的手段。以(BALB/c×C57BL/6)F1雌性小鼠(H-2d/b)为受鼠,于第0天接受亚致死量的60Co-γ射线全身照射,总剂量为4Gy,第1天接种P388D1白血病细胞,第2天输注由C57BL/6雄性小鼠(H-2b)为供鼠提供的MHC不匹配的供者脾淋巴细胞,在造血干细胞移植前诱导移植物抗白血病效应(GVL)。第6天腹腔注射环磷酰胺(CY)200mg/kg或再次TBI9Gy,选择性去除同种异基因反应供者淋巴细胞,第7天输注(BALB/c×C57BL/6)F1雄性小鼠(H-2d/b)提供的骨髓造血干细胞。结果显示:以CY和TBI选择性去除同种异基因反应供者淋巴细胞组的小鼠无白血病和GVHD的发生,生存期超过了210天,于移植后第21天出现完全供者嵌合,然后嵌合率下降,第90天表现为混合嵌合体(MC)。对照组的小鼠出现了白血病和GVHD,出血、感染明显,生存期短,为20-36天(P<0.01)。结论:同基因骨髓移植前输注不相匹配的供者脾细胞诱导GVL效应,然后再通过TBI和CY选择性去除同种异基因反应的供者淋巴细胞来预防移植物抗宿主病(GVHD)的发生是可能的。

Selective Elimination of Alloreactive Donor Lymphocytes by Using TBI and Cyclophosphamide

This study was aimed to investigate a new method of avoiding graft-vs-host disease (GVHD) through selective elimination of alloreactive donor lymphocytes by using total body irradiation (TBI) and cyclophosphamide (Cy). Female (BALB/c x C57BL/6) F1 mice (H-2(d/b)) as recipients received (60)Co gamma-ray sublethal TBI of 4 Gy on day 0 followed by being inoculated with P388D1 leukemia cell line on day 1, injection of allogeneic splenocytes from C57BL/6 male mice (H-2(b)) was carried out for induction of graft-vs-leukemia (GVL) effect prior to stem cell transplantation (SCT), intraperitoneally injection of cyclophosphamide (Cy) (200 mg/kg) and TBI (9 Gy) was given on day 6. One day later, treated mice were rescued with bone marrow hematopoietic stem cells from (BALB/c x C57BL/6) F1 male mice (H-2(d/b)). The results showed that recipients had no occurrence of leukemia and GVHD through selective elimination of alloreactive donor lymphocytes by Cy and TBI, survived more than 210 days, the complete-donor chimerism occurred on day 21 after transplantation. The ratio of chimerism descended subsequently, but still displayed mixed-chimerism at 90 days. Control mice died of GVHD, leukemia or other death-related-transplantation within 20 to 36 days (P<0.01). It is concluded that to induce GVL effects by MHC mismatched splenocytes given before syngeneic bone marrow transplantation followed by selective elimination of alloreactive donor lymphocytes through TBI and Cy, graft-vs-host disease was thus avoided.