[Effect of recipient mouse splenocytes taken orally by donor mouse on GVHD after splenocyte transplantation].

This study was aimed to explore whether the GVHD in mice can be ameliorated and the GVL effect in mice can be reserved by transfusion of lymphocytes of donors fed with recipient splenocytes effect. Male (DBA-2) mice (H-2(d)) as donors were fed with BALB/c splenocytes, DBA-2 splenocytes, bovine serum albumin, or regular chow, every other day. Induction of tolerance was assessed by a mixed lymphocyte reaction (MLR). Female (BALB/c) mice (H-2(d)) as recipients received total body irradiation (TBI) of 6.0 Gy ((60)Cogamma-ray) followed by inoculation of 3 x 10(3) P388 mouse leukemia cells on the same day. Subsequently, tail vein injection of 2 x 10(7) splenocytes supplied by DBA-2 was undertaken. Control groups were fed identically without leukemia cell inoculation. The results showed that GVHD was significantly ameliorated and CD4(+)/CD8(+) ratio increased in recipient-mice transplanted with splenocytes of tolerated donors, compared with control animals. There was no significant difference in survival rate between different groups of recipients inoculated with leukemia cell. It is concluded that the peroral recipient-mouse splenocytes can ameliorate GVHD without hampering effect on GVL.

Synergistic effect of the combination of nanoparticulate Fe3O4 and Au with daunomycin on K562/A02 cells.

In this study, we have explored the possibility of the combination of the high reactivity of nano Fe3O4 or Au nanoparticles and daunomycin, one of the most important antitumor drugs in the treatment of acute leukemia clinically, to inhibit MDR of K562/A02 cells. Initially, to determine whether the magnetic nanoparticle Fe3O4 and Au can facilitate the anticancer drug to reverse the resistance of cancer cells, we have explored the cytotoxic effect of daunomycin (DNR) with and without the magnetic nano-Fe3O4 or nano-Au on K562 and K562/A02 cells by MTT assay. Besides, the intracellular DNR concentration and apoptosis of the K562/A02 cells was further investigated by flow cytometry and confocal fluorescence microscopic studies. The MDR1 gene expression of the K562/A02 cells was also studied by RT-PCR method. Our results indicate that 5.0 x 10(-7) M nano-Fe3O4 or 2.0 x 10(-8) M nano-Au is biocompatible and can apparently raise the intracellular DNR accumulation of the K562/A02 cells and increase the apoptosis of tumor cells. Moreover, our observations illustrate that although these two kinds of nanoparticles themselves could not lower the MDRI gene expression of the K562/A02 cells, yet they could degrade the MDR1 gene level when combining with anticancer drug DNR. This raises the possibility to combine the nano-Fe3O4 or nano-Au with DNR to reverse the drug resistance of K562/A02 cells, which could offer a new strategy for the promising efficient chemotherapy of the leukemia patients.

[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.