Intra-bone marrow injection of donor bone marrow cells suspended in collagen gel retains injected cells in bone marrow, resulting in rapid hemopoietic recovery in mice.

We have recently developed an innovative bone marrow transplantation (BMT) method, intra-bone marrow (IBM)-BMT, in which donor bone marrow cells (BMCs) are injected directly into the recipient bone marrow (BM), resulting in the rapid recovery of donor hemopoiesis and permitting a reduction in radiation doses as a pretreatment for BMT. However, even with this IBM injection, some of the injected BMCs were found to enter into circulation. Therefore, we attempted to modify the method to allow the efficient retention of injected BMCs in the donor BM. The BMCs of enhanced green fluorescent protein transgenic mice (C57BL/6 background) were suspended in collagen gel (CG) or phosphate-buffered saline (PBS), and these cells were then injected into the BM of irradiated C57BL/6 mice. The numbers of retained donor cells in the injected BM, the day 12 colony-forming units of spleen (CFU-S) counts, and the reconstitution of donor cells after IBM-BMT were compared between the CG and PBS groups. The number of transplanted cells detected in the injected BM in the CG group was significantly higher than that in the PBS group. We next carried out CFU-S assays. The spleens of mice in the CG group showed heavier spleen weight and considerably higher CFU-S counts than in the PBS group. Excellent reconstitution of donor hemopoietic cells in the CG group was observed in the long term (>100 days). These results suggest that the IBM injection of BMCs suspended in CG is superior to the injection of BMCs suspended in PBS.

Administration of granulocyte colony-stimulating factor to recipients followed by intra-bone marrow-bone marrow transplantation accelerates acceptance of allogeneic bone marrow cells in mice.

We have recently established a novel method for bone marrow transplantation: intra-bone marrow-bone marrow transplantation (IBM-BMT), by which the rapid recovery of donor-derived hematopoiesis can be expected even when reduced radiation doses are used. In this paper, we examine, using mice, whether the combination of pretreatment of recipients with granulocyte-colony-stimulating factor (G-CSF) and IBM-BMT can induce a more rapid recovery of donor-derived hematopoiesis than IBM-BMT alone. We first pretreated recipients with recombinant human (rh) G-CSF (250 microg/kg/day) for 5 consecutive days (days -6 to -2). On day -1, the recipients were irradiated, and IBM-BMT was carried out on day 0. On day 12, we performed colony-forming units of spleen (CFU-S) assays. The combination of G-CSF pretreatment and IBM-BMT augmented the CFU-S counts, the weight of spleens, and the numbers of donor-derived hematopoietic cells. We next analyzed the mechanisms underlying these effects of G-CSF and found that (i) G-CSF induces Th2 polarization, which can prevent graft rejection, and (ii) G-CSF augments natural suppressor activity, which suppresses graft rejection. The combination of G-CSF pretreatment and IBM-BMT can produce the rapid recovery of donor-derived hematopoiesis and suppress graft rejection. This method would lighten the burden on patients in allogeneic BMT.

FKBP51 expressed by both normal epithelial cells and adenocarcinoma of colon suppresses proliferation of colorectal adenocarcinoma.

It has been reported, as a result of Western blot analyses, that FKBP51 is expressed in various tissues, but that it is not expressed in the pancreas, lung, colon, stomach, or spleen. In this paper, we show, using Western blot analyses, reverse transcriptase polymerase chain reaction, and immunohistochemical analyses of samples from colon cancer patients, that both normal epithelial cells and adenocarcinoma in the human colon express FKBP51, and that there are no significant differences in the expressions of FKBP51 between them. We also show that FKBP51 suppresses the proliferation of colorectal adenocarcinoma, possibly due to the suppression of functions of the glucocorticoid receptors.

Analyses of expression of cytoglobin by immunohistochemical studies in human tissues.

Cytoglobin (Cygb) is a recently discovered member of the vertebrate globin family, which includes probably most extensively studied proteins, hemoglobin (Hb), myoglobin (Mb) and neuroglobin (Ngb). It has been reported that Cygb is expressed ubiquitously at the mRNA or protein level. However, details of the distribution of Cygb in the various tissues have hitherto been unclear. In this experiment, we clarified the distribution of Cygb in various human tissues by immunohistochemical staining. First, we prepared a rabbit anti human Cygb polyclonal antibody. Using the antibody, we stained a tissue array slide containing 60 normal tissues from 40 human organs. We confirmed the staining patterns of the antibodies in these various tissues using autopsy samples from our university. In general, Cygb is positive in the epithelial cells, hepatocytes, pancreatic acinar cells, cardiomyocytes and skeletal muscle but rarely so in cells in the interstitial tissues. Cytoglobin is usually positive in the cytoplasm, but is also positive in the nucleus in some hepatocytes. In contrast, Cygb is negative in the smooth muscle. The distribution of Cygb could suggest its roles.

Immunotherapy for malignant tumors using combination of allogeneic intra-bone marrow-bone marrow transplantation, donor lymphocyte infusion and dendritic cells.

We have previously shown that the combination of allogeneic intra-bone marrow-bone marrow transplantation (IBM-BMT) and donor lymphocyte infusion (DLI) using CD4+ cell-depleted spleen cells is effective in suppressing tumor growth, but that this does not induce graft-versus-host disease (GVHD) in mice. In this report, we show that formalin-fixed tumor cell-pulsed dendritic cells (FFTCP DCs) have an additive effect with IBM-BMT plus DLI on the suppression of tumor growth, but that the DCs do not augment GVHD. BALB/c mice, which had been subcutaneously inoculated with Meth A (BALB/c-derived fibrosarcoma), were irradiated at a low dose (5 Gy) and were transplanted with bone marrow cells (BMCs) from C57BL/6 (B6) mice into the bone marrow cavity (IBM-BMT). Simultaneously, the mice were intravenously injected with spleen cells from B6 mice, and subcutaneously injected with FFTCP DCs derived from the bone marrow (BM) of B6 mice. At the point of the induction of DCs from BMCs, formalin-fixed Meth A cells were added into the culture. The mice treated with the combination of FFTCP DCs, IBM-BMT and DLI using CD4+ cell-depleted spleen cells showed smaller tumor sizes and longer survival than the mice treated with IBM-BMT plus FFTCP DCs or IBM-BMT plus DLI using CD4+ cell-depleted spleen cells. These results suggest that the combination of FFTCP DCs, IBM-BMT plus DLI using CD4+ cell-depleted spleen cells has potent anti-tumor effects without showing GVHD.

Effects of low-dose irradiation on enhancement of immunity by dendritic cells.

Low-doses of irradiation have been reported to have beneficial effects, particularly anti-tumor effects. In this paper, we show the effects of the low-dose irradiation on T cell activation induced by dendritic cells (DCs). DCs, which had been pre-irradiated at 0.02-1.0 Gy from a (137)Cs source, were cultured with allogeneic T cells, and the proliferation of T cells was then examined. The 0.05Gy-pre-irradiated DCs showed the highest proliferation capacity of T cells. The 0.05Gy-irradiation does not augment the expression of major histocompatibility complexes (MHCs) or costimulatory molecules on DCs, as with non-irradiated DCs or 1Gy-irradiated DCs, but does augment the production of IL-2, IL-12 and IFN-gamma DCs. These results suggest that the low-dose irradiation augments T cell-activation capacity through cytokine production by DCs, which might shift naïve helper T cells to Th1 cells.

Human cord blood cells can differentiate into retinal nerve cells.

Retinal degeneration and dystrophy are the major causes of blindness in the developed world. It has been reported that human cord blood cells (HCBCs) can differentiate into neuron-like cells in vitro. We have recently demonstrated that bone marrow cells (BMCs) of both mice and rats can differentiate into retinal nerve cells (RNCs). In the present study, we show the differentiation capacity of HCBCs into RNCs in vivo. We transplanted lineage-negative HCBCs into the subretinal space of severe combined immunodeficiency (SCID) mice. Two weeks after the transplantation, some of the transplanted cells expressed human nestin, human MAP2, human neuron specific enolase (NSE), beta-III tubulin and also rhodopsin. These results indicate that HCBCs can differentiate into RNCs and suggest that our new strategy could be used for the regeneration of retinal nerve cells in degenerative or dystrophic diseases.

Allogeneic intrabone marrow-bone marrow transplantation plus donor lymphocyte infusion suppresses growth of colon cancer cells implanted in skin and liver of rats.

We have recently found that allogeneic intrabone marrow-bone marrow transplantation (IBM-BMT) + donor lymphocyte infusion (DLI) using CD4(+) cell-depleted spleen cells (CD4(-) cells) can prevent graft-versus-host disease (GvHD) but suppress tumor growth (Meth A: fibrosarcoma) in mice. In the present study, we show that allogeneic IBM-BMT + DLI using CD4(-) cells also has suppressive effects on the growth of colon cancer cells implanted not only in the skin but also in the liver of rats. First, we examined the effects of allogeneic IBM-BMT + DLI on the subcutaneously inoculated ACL-15 (rat colon cancer cell line). Lethally irradiated Fischer rats (F344 rats) were transplanted with T-cell-depleted bone marrow cells (BMCs) from Brown Norway (BN) rats. Simultaneously, DLI was performed using whole spleen cells (whole cells), CD4(+) cell-depleted spleen cells (CD4(-) cells) or CD8(+) cell-depleted spleen cells (CD8(-) cells) of BN rats. Although allogeneic IBM-BMT + DLI suppressed tumor growth, a considerable number of rats treated with allogeneic IBM-BMT + DLI using whole cells or CD8(-) cells died due to GvHD. In contrast, allogeneic IBM-BMT + DLI using CD4(-) cells also suppressed tumor growth, but there was no GvHD. Based on these findings, we next examined the effects of allogeneic IBM-BMT + DLI using CD4(-) cells on the cancer cells implanted in the liver. Allogeneic IBM-BMT + DLI using CD4(-) cells via the portal vein significantly prolonged the survival. These results suggest that allogeneic IBM-BMT + DLI using CD4(-) cells could become a new strategy for the treatment of solid tumors.