Bone Marrow Transplantation In Rats Research Articles

Systemic monoclonal antibody therapy for eliminating minimal residual leukemia in a rat bone marrow transplant model

In an animal bone marrow transplant (BMT) model that mimics the human clinical condition, we evaluated the effectiveness of monoclonal antibody (MoAb) therapy in eliminating minimal residual disease (MRD) in a leukemic host. Leukemic rats were prepared with marrow ablative but noncurative doses of busulfan (BU) and cyclophosphamide (CY). Two days after syngeneic BMT, rats were treated with MoAb. Although all control rats died of leukemia relapse, 58% of those treated with MoAb were cured without any demonstrable effect on the rate of peripheral blood leukocyte recovery. Furthermore, the level of complement, an important effector in suppressing leukemia proliferation in the normal rat, was not adversely affected by BU/CY, BMT and MoAb. Thus, we demonstrated in an animal model that MoAb therapy may be a useful, nontoxic adjunct to high-dose chemotherapy and BMT in eliminating MRD.

Systemic Monoclonal Antibody Therapy for Eliminating Minimal Residual Leukemia in a Rat Bone Marrow Transplant Model

In an animal bone marrow transplant (BMT) model that mimics the human clinical condition, we evaluated the effectiveness of monoclonal antibody (MoAb) therapy in eliminating minimal residual disease (MRD) in a leukemic host. Leukemic rats were prepared with marrow ablative but noncurative doses of busulfan (BU) and cyclophosphamide (CY). Two days after syngeneic BMT, rats were treated with MoAb. Although all control rats died of leukemia relapse, 58% of those treated with MoAb were cured without any demonstrable effect on the rate of peripheral blood leukocyte recovery. Furthermore, the level of complement, an important effector in suppressing leukemia proliferation in the normal rat, was not adversely affected by BU/CY, BMT and MoAb. Thus, we demonstrated in an animal model that MoAb therapy may be a useful, nontoxic adjunct to high-dose chemotherapy and BMT in eliminating MRD.

Late effects of cyclophosphamide and total body irradiation as a conditioning regimen for bone marrow transplantation in rats (a preliminary report).

The longterm survival and occurrence of neoplastic and nonneoplastic lesions following total body irradiation (TBI), 8.5 Gy, with or without additional cyclophosphamide (Cy; 100 mg kg-1 i.p.) treatment as a conditioning regimen for bone marrow transplantation (BMT) were studied in male BN/BiRij rats. The two groups of rats that were treated with Cy (Cy and Cy + TBI) that survived beyond 100 days after treatment, had a severely decreased median (post treatment) survival time (Cy + TBI: 14.5 months and Cy: 14.1 months). Survival time in the TBI group was moderately decreased (18.5 months) as compared with the untreated controls (27.2 months). All treatment modalities were carcinogenic according to the raw data. After Cy-treatment a high incidence of, frequently multiple, malignant nerve-sheath tumours (Cy: 66 per cent, Cy + TBI: 31 per cent, controls: 2 per cent) was observed. TBI induced an increased occurrence of a great variety of tumours, especially mesenchymal tumours. This effect was more pronounced in animals receiving TBI alone as compared to animals receiving the combined treatment of Cy + TBI; an effect that most likely resulted from the longer median survival after TBI. The multi-target effect of TBI was also reflected in the occurrence of nonneoplastic effects in a variety of tissues, including high incidences of biliary cysts in the liver and severe testicular atrophy. The most important Cy-induced nonneoplastic lesion was incisor dysplasia, which resulted in feeding problems that could only be partly overcome by administering powdered food. Early mortality in the Cy-treated groups was associated with emaciation and generalized organ atrophy. A more definitive estimate of the late effects of supralethal chemoradiotherapy as part of a treatment of malignant disease has to await the results of various conditioning regimens for BMT in rats employing the acute BN myelocytic leukaemia (BNML) as a rat model for human acute myelocytic leukaemia (AML).

Deoxycoformycin (DCF) and desoxyadenosine (dADO) in vitro treatment for graft-versus-host disease (GVHD) prevention

Dividing as well as resting T cells are sensitive to μM concentrations of dADO in the presence of an adenosine-deaminase (ADA) inhibitor such as DCF. Therefore, this drug combination was investigated for its ability to deplete T cells from allogeneic rat bone marrow (BM) and spleen (SP) cells and for its potential to prevent GVHD in fully allogeneic rat bone marrow transplantation(BMT). - It was found that a concentration of 0.5 μM of DCF was sufficient to block ADA-activity in rat BM and SP cells completely. Concentrations as high as 100 μM were not toxic to in vitro colony forming units (CFU-GM). Increasing dADO concentrations in the presence of DCF led to increasing T cell but also increasing CFU toxicity. However, dADO concentrations below 40 μM had no significant influence on CFU growth but clearly exhibited an effect on T cells. T cell functions, as determined by mitogen and alloantigen stimulated thymidine (3HTdR) uptake, were reduced to 10-30% of normal values. Flowcytometric analysis revealed a significant T cell reduction following in vitro treatment. However, some residual T cells were detectable in treated samples. - In accordance with the described in vitro data, rat-recipients of DCF/dADO treated allogeneic BM and SP cell grafts showed a significantly decreased incidence of acute lethal GVHD. - The results indicate that a significant but incomplete depletion of T cells can be achieved through DCF/dADO in vitro treatment using concentrations which are not toxic for stem cells. Such T cell depletion results in modification of acute lethal GVHD intn a chronic form in fully allogeneic rat BMT.

CHRONIC GRAFT-VERSUS-HOST DISEASE IN RATS AFTER SYNGENEIC BONE MARROW TRANSPLANTATION

A disease similar to the chronic graft-versus-host disease (cGVHD) seen following transplantation of human bone marrow was observed after syngeneic and allogeneic bone marrow transplantation in rats. Bone marrow grafts were exchanged between donors and recipients that were syngeneic or genetically different for the RT2 erythrocyte antigen locus by the use of AUG/AUG.2B and PVG/PVG.2A congenic pair donor/recipient strain combinations. After an initial period of well-being (120-180 days posttransplantation), several AUG and AUG.2B recipients of syngeneic or RT2-mismatched bone marrow developed clinical signs compatible with cGVHD. The clinical signs of the disease included: erythema, diffuse alopecia, thickened skin folds, and conjunctivitis. Laboratory findings included peripheral blood eosinophilia and impaired in-vitro proliferative responses to third-party spleen cells in the mixed lymphocyte reaction. Histological examination of the tissues of a limited number of rats with cGVHD showed subepidermal mononuclear inflammation with atrophy of the epidermis and adnexa of the skin, as well as plasmacytic hyperplasia of the lymphoid tissues. None of the PVG or PVG.2A recipients of syngeneic or RT2-mismatched marrow developed cGVHD. The development of cGVHD in AUG.2B recipients of syngeneic marrow and the absence of the disease in reciprocal marrow grafts between the PVG/PVG.2A rat strains suggests that the development of the disease in the AUG and AUG.2B recipients of RT2-mismatched bone marrow is not due to the RT2 disparity, but may be due to an autologous immune reaction. Furthermore, the finding that the cGVHD is only observed when the AUG and AUG.2B strains are used as recipients--not when the PVG or PVG.2A strains are used as recipients--suggests that the development of the disease is associated with the genetic background of the host and is independent of the background of the donor. It is possible that the use of high-dose cyclophosphamide treatment is involved in the pathogenesis of cGVHD, because the disease is observed only when the recipients are conditioned for transplantation with this immunosuppressive agent.

Bone marrow transplantation, Part II, Immunogenetics of rat bone marrow transplantation.

Bone marrow transplantation, Part II, Immunogenetics of rat bone marrow transplantation.

Transplantation of Rat Bone Marrow in Irradiated Mice: Effect of Exposure Rate

Mice were irradiated at several different exposure rates so that they received a total of 900 roentgens over the whole body. Within 2 hours they were injected with rat bone marrow. The success of the transplantation depended upon the rate at which the animals had been irradiated: the higher the rate, the greater the success of the grafts. Failure of grafts in mice subjected to low exposure-rates was associated with antibody formation. The data indicate existence of an immune mechanism which is dependent on the radiation exposure-rate.

Transplantation of bone marrow in rats with sarcoma M-1 after the use of toxic doses of thioTEPA

A study was made of the effect of the bone marrow transplantation in rats of the Wistar line with sarcoma M-1 treated with toxic ThioTEPA doses.

TRANSPLANTATION OF RAT BONE MARROW IN IRRADIATED MICE: EFFECT OF EXPOSURE RATE.

Mice were irradiated at several different exposure rates so that they received a total of 900 roentgens over the whole body. Within 2 hours they were injected with rat bone marrow. The success of the transplantation depended upon the rate at which the animals had been irradiated: the higher the rate, the greater the success of the grafts. Failure of grafts in mice subjected to low exposure-rates was associated with antibody formation. The data indicate existence of an immune mechanism which is dependent on the radiation exposure-rate.

Identification and Follow-up of Homologous and Heterologous Bone-marrow Transplants in Radiation-chimeras

Using differences in the electrophoretic pattern between host and donor haemoglobins, the proliferation of grafted erythropoietic cells has been studied in irradiated mice treated with homologous bone marrow. The results have been compared with observations made after the transplantation of rat bone marrow into irradiated mice. A complete replacement of host erythrocytes by donor-type cells took 60-70 days in mice treated with rat bone marrow. In mice treated with homologous bone marrow, host-type haemoglobin could no longer be identified after about 50 days. In the latter case the complete replacement must have taken somewhat longer, since the method used to identify haemoglobins is not sensitive enough to detect small amounts of one type of haemoglobin in the presence of large amounts of the other. In mice treated with rat bone marrow a considerable number of total and partial reversals occurred after 675-700 r. Only a few partial reversals were found after 800 r. Under similar conditions no reversals were observed after homologous bone-marrow transplantation. It is concluded that the recovery of the host's haematopoietic system depends upon the dose of radiation as well as on the antigenic difference between the host and the donor. © 1959 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.

Antigens responsible for bone marrow transplantation immunity.

The antigens responsible for the bone marrow transplantation immunity were determined by sensitizing the mice 2 or 6 weeks prior to the 950 r and rat bone marrow transplantation (950 r-RBM). Indicative of the sensitizing antigens was the increased mortality 15 and 30 days after 950 r-RBM in comparison to the nonsensitized 950 r-RBM mice. Sensitizing antigens were absent in the serum and red blood cells, but present in nucleated cells. They were localized in the nucleus, mitochondria, and microsomes in a reasonable concentration and in the supernatant fraction in a relatively low concentration. The antigens of the mitochondria and microsomes were resistant to nuclease and protease treatment. The nuclear antigens were resistant to ribonuclease and papain treatment, and slightly susceptible to trypsin. The antigenicity of desoxyribonucleasetreated nuclei was variable. (auth)

Species characteristics of platelets of x-irradiated mice treated with rat bone marrow.

Transplantation of heterologous marrow causes survival of lethally irradiated mice by repopulating the bone marrow of the recipient with donor red and white cells. A study of the extent and duration of the ‘take’ of the transplanted platelet forming tissues was carried out by preparing antisera in rabbits against rat and mouse platelets and using these sera to identify platelets circulating in the mouse at intervals after transplantation of rat bone marrow. Rat platelets were evident in the blood of such mice 2–6 days after transplantation. In some animals, rat platelets were never preponderant; in others, after rat platelets were in the majority, reversion to mouse platelets took place. There was no apparent correlation between platelet species and length of survival. There was evidence of at least a partial ‘take’ of rat platelet precursors in every mouse, but the permanence of the ‘take’ was variable. Submitted on December 19, 1957