Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.1.1.69 (BMT)
 2,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

After bone marrow transplantation many T-lymphocyte functions, including the production of cytokines (CK), such as interleukin 2, are severely depressed for months. The monocyte-derived cytokines tumor necrosis factor alpha and interleukin 6 are molecules central to immune functions. Moreover, they may be involved in graft-versus-host disease and in graft-versus-leukemia reaction. Hence, we have studied the reappearance of these CKs after BMT by analyzing whole blood cultures stimulated in vitro with lipopolysaccharide for 6 hr, followed by testing for the secretion of TNF in the WEHI 164/actinomycin D cytotoxicity bioassay and for IL-6 in the 7 TD 1 proliferation assay. We performed sequential studies in 6 children who were transplanted for aplastic anemia or leukemia with allogeneic bone marrow. We found that the production of both CKs can be induced as early as 10-14 days post BMT at the very beginning of engraftment, indicating that the regenerating monocyte system is recovering rapidly after BMT. Depletion and neutralization experiments confirmed that monocytes are the cellular source of the LPS-induced CK secretion after BMT. Control levels were reached 3 to 4 weeks post BMT. When analyzing the endotoxin-induced CK production in a larger panel of BMT patients after complete reconstitution, we could not detect any impact of acute or chronic GvHD, or of allogeneic or autologous BMT, nor did treatment with cyclosporine A (CsA) show any suppressive effect. Thus, our data show that the CK production of the monocyte/macrophage lineage is quite resistant to factors that do influence other cell lineages of the immune system during BMT. The coincident appearance of monocyte-derived cytokines and of GvHD suggests a role for these cytokines in GvHD in man.
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PMID:Recovery of monocytes after bone marrow transplantation--rapid reappearance of tumor necrosis factor alpha and interleukin 6 production. 192 48

During the early period following bone marrow transplantation before the immune system has reached full functional maturity, unprimed, nonspecific lytic systems may play a critical role as antiviral or antitumor effectors. The reconstitution of cells with this potential is of particular importance in recipients of bone marrow that has been depleted of mature T lymphocytes to prevent graft v host disease (GVHD). We examined the recovery of natural killer (NK) cells and interleukin 2 (IL 2)-augmented lymphokine-activated killer cells (LAK) in 48 patients at various intervals following transplantation of bone marrow depleted of mature cellular elements by treatment with soybean agglutinin and sheep RBCs (SBA-E- BMT). We found normal levels of both NK and LAK activity as early as 3 weeks following SBA-E- BMT. When compared with cells from controls, NK and LAK precursors from transplant recipients appeared to be activated in vivo in that freshly isolated peripheral blood mononuclear cells (PBMCs) from patients had an elevated cytolytic activity toward NK-insensitive targets and a more rapid response to activation by IL 2. In patients as well as controls, both LAK precursors and LAK effectors lacked antigens present on mature T lymphocytes (CD3, CD4, or CD8) but expressed antigens present on NK cells (CD2, CD16, and NKH1A). The LAK cells did not lyse either donor or host peripheral blood T cell targets. The activity of NK effectors but not LAK precursors survived the in vivo total body irradiation used for pretransplant conditioning in three patients studied. LAK precursors could be demonstrated as early as 18 days following transplant at a time when the bone marrow contained primarily donor-derived cells. Little or no LAK activity could be generated from cells of the SBA-E- BM graft itself, suggesting that LAK precursors differentiate rapidly from more primitive progenitors in the marrow graft. Thus, our data indicate that the NK and LAK lytic systems are among the earliest activities to recover during immune reconstitution following T cell-depleted BMTs.
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PMID:Interleukin 2-activated killer cells in patients following transplants of soybean lectin-separated and E rosette-depleted bone marrow. 311 90

After T-cell depleted marrow transplantation, there is a rapid recovery of cytotoxic effector cells, with activity against targets not susceptible to killing by 'resting' natural killer cells. These targets include Epstein-Barr virus transformed B cells and leukaemic cell lines. Activated killer cell function declines by 3 months after transplantation. We find that when CD3 negative effector cells are obtained from these patients and cultured in vitro with interleukin 2 there is a further enhancement of cytotoxic activity against a range of target cells in the early post-transplant period, and a restoration of high level cytotoxic activity to effector cells obtained 3 months or more after the procedure. These results may have relevance to attempts to reduce the incidence of leukaemic relapse, and EBV + ve lymphoma outgrowth after T-cell depleted BMT.
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PMID:Interleukin 2 enhances cytotoxic cell function in vitro after T-cell depleted marrow transplantation. 331 10

Using OKT3 monoclonal antibody as a mitogen, we have studied interleukin 2 (IL2) production and proliferation in peripheral blood mononuclear cells (PBMC) of 23 patients receiving bone marrow transplants. Twenty patients were recipients of allogeneic bone marrow for treatment of hematologic malignancies, aplastic anemias (AA), or severe combined immunodeficiencies (SCID). Three patients with Hodgkin's disease or neuroblastoma received autologous bone marrow. Endogenous IL2 production was not detectable (less than 0.2 U/mL) in PBMC of 18 patients and was very low in PBMC from five patients (0.5 to 1.5 U/mL), as compared to normal controls (median 3.5 U/mL) or pretransplant patients (median 1.5 U/mL). The low IL2 production was associated with defective OKT3-induced proliferation of PBMC in 19 of 23 patients studied. In the first 6 months after BMT, 14 of 15 patients (93%) showed defective proliferation of PBMC as compared to five of eight patients (63%) tested between 7 and 18 months after BMT (P less than .1). In all but three patients, addition of highly purified human lymphocyte IL2 (hpIL2) restored OKT3-induced proliferation of PBMC to within the normal range. This study demonstrates that PBMC in patients after BMT have a defect of IL2 production but are able to express IL2 receptors in response to OKT3 antibody and to proliferate normally upon addition of hpIL2. PBMC of all patients showed similar functional defects, whether or not they received additional therapy, including various conditioning regimens prior to BMT and immunosuppressive therapy after BMT. These observations suggest that T cell defects after BMT are most likely secondary to quantitative or qualitative defects of transplanted T lymphocytes or their precursors.
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PMID:Defective interleukin 2 production in patients after bone marrow transplantation and in vitro restoration of defective T lymphocyte proliferation by highly purified interleukin 2. 637 75

We have previously demonstrated that syngeneic marrow mixed with H-2 haploidentical marrow transplantation could provide not only protection against graft-versus-host disease (GVHD) but also anti-leukemic (GVL) effects in mice. In the present studies, we report clinical observations using autologous marrow mixed with HLA-haploidentical allogeneic marrow transplantation for treatment of patients with malignant blood diseases. Sixteen cases, including 12 with acute leukemia and four with advanced malignant lymphoma, were treated by autologous marrow, which was purged in vitro by hyperthemia (42.5 degrees C for 70 min) following incubation for 5 days with interleukin 2 (IL-2) in liquid culture and mixed with HLA haploidentical marrow cells from their sibling or parent. Acute GVHD was not observed in any patient after transplantation. Hematological rescue in the clinical setting was demonstrated in all cases but one who died early from hepatic veno-occlusive disease (VOD). Five cases who were transplanted at the time of CR2 or CR3 and in advanced phase of lymphoma, relapsed 4 to 7 months after transplantation. The relapse rate was 31.3%. None of eight patients who received allogeneic BMT within 2 h after ABMT relapsed with median follow-up of 12 months and two of them died from procedure-related complications. Seven cases are still alive and disease-free with a median follow-up of 12 months. Mixed chimerism was found in 3/6 cases, who had different sex donors, by analysis of sex chromosomes. These results show that mixed transplantation is a safe, effective and new approach to treating patients with malignant tumors. In order to detect the effects of GVL, studies are now in progress in our clinic.
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PMID:Autologous bone marrow mixed with HLA-haploidentical allogeneic marrow transplantation for treatment of patients with malignant blood diseases. 911 6

One of the obstacles of BMT that limits its efficacy is failure to eradicate the original tumor. The incidence of tumor relapse is particularly high after autologous BMT. Natural killer (NK) cells comprise various subsets that can express inhibitory receptors for MHC class I determinants. We have recently demonstrated that blockade of NK-cell inhibitory receptors can augment antitumor effects in vitro and in vivo. However, breakdown of tolerance and autoreactivity may occur as a result of the inhibition of NK-cell inactivation to self MHC determinants. We have utilized F(ab')2 fragments of monoclonal antibody, 5E6, against Ly49C/I inhibitory receptors, which are expressed on 35% to 60% of NK cells in H2b strains of mice and are specific for H2Kb, to investigate the effect of inhibitory-receptor blockade on syngeneic bone marrow cell (BMC) and tumor cell growth. We show that treatment of interleukin 2-activated C57BL/6 (B6, H2b) SCID-mouse NK cells with 5E6 F(ab')2 fragments during 48-hour coculture resulted in autoreactivity against syngeneic BMCs as demonstrated by suppression of myeloid reconstitution on day 14 post-BMT. However, this suppressive effect was transient and normalized by day 21 post-BMT. In contrast, blockade of inhibitory receptors during 24-hour coculture had no adverse effects on myeloid reconstitution after BMT. Furthermore, under the same coculture conditions, NK cell-mediated purging of C1498 leukemia cells contaminating syngeneic BMCs was more effective with inhibitory-receptor blockade, leading to a significantly higher proportion of animals with long-term survival compared to the control recipients. These results demonstrate that short-term in vitro blockade of inhibitory receptors can augment antitumor activity without long-term inhibitory effects on BMCs and thus may be of potential use in the purging of contaminating tumor cells prior to autologous BMT.
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PMID:NK inhibitory-receptor blockade for purging of leukemia: effects on hematopoietic reconstitution. 1184 52