Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023467 (acute myeloid leukemia)
 35,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An immune response is involved in the control of leukemias as demonstrated by allogeneic bone marrow transplantation, by the eradication of residual leukemic cells by cytotoxic T cells and finally by the identification of tumor antigens which are recognized by effector T cells. Dendritic cells (DC) are professional antigen-presenting cells (APC) able to present antigens in the context of co-stimulatory signals necessary for T cell activation. Although tumor cells may express tumor antigens, they are usually unable to elicit an immune response since they are devoid of co-stimulatory capacities. To overcome this problem, engineering tumors to provide APC function could potentially result in polyvalent immunization to multiple tumor antigens. We have tested the differentiation of AML-5 (monoblastic, promonocytic and monocytic) leukemia cells and demonstrated that eight out of the ten fresh human acute myeloid leukemia populations tested can differentiate in vitro into bona fide APC. Leukemic cells acquire in vitro DC morphology, mature DC markers such as CD83, the up-regulation of MHC and co-stimulatory molecules and the ability to produce IL-12 upon maturation, while retaining their characteristic caryotypic abnormalities. However, we could not obtain an immature DC phenotype. They also acquire the ability to induce the differentiation of allogeneic naive cord blood CD4 and CD8 T cells as well as resting autologous cytotoxic T cells. These results demonstrate that some tumor cells acquire APC phenotype and functions and can thereby induce a potent autologous immune response that will be a valuable tool for detection of new tumor antigens and for in vivo immunization.
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PMID:Human acute myeloblastic leukemia cells differentiate in vitro into mature dendritic cells and induce the differentiation of cytotoxic T cells against autologous leukemias. 1045 72

We investigated early immunological reconstitution and the production of circulating inflammatory mediators and their relationship to aGVHD in children during the first 100 days following unrelated UCBT. Nine patients had an underlying malignant disease (ALL, ANLL), and two, non-malignant diseases (SAA, ALD). The median age was 10 years (range: 1.25-21). Seven of 11 patients were alive by day 100, two died from regimen-related toxicity, and two died from severe aGVHD (grade >/=III). Myeloid engraftment (ANC >/=500/mm3 x 2 days) occurred at a median of 24 days (range: 14-55), while platelet engraftment (platelet count >/=20 000/mm3 untransfused x 7 days) was delayed and occurred at a median of 52 days (range: 33-95). The mean cell dose of CD34+ cells was 3.3 +/- 3.51 x 10(5)/kg, and of CD34+/CD41+ cells was 3.94 +/- 3.99 x 10(4)/kg. Acute GVHD (grade II-IV) developed in seven patients (77%), and severe aGVHD (grade III-IV) developed in five patients (55%). Serum levels of IL-2Ralpha, IL-2, IL-4, IL-7, IL-12, and IFNgamma were not significantly different between patients with grades 0-I aGVHD and patients with grades II-IV aGVHD. Evaluation of immunological reconstitution on day 90 post UCBT demonstrated an early recovery of the absolute numbers of B cells (CD19+) and NK cells (CD3-/CD56+). Immunoglobulin levels for IgG, IgM and IgA remained normal throughout the study period. PMN functional studies demonstrated normal superoxide generation, bacterial killing (BK), and chemotaxis (CTX). However, both helper (CD3+/CD4+) and suppressor (CD3+/CD8+) T cell subsets remained low during the first 100 days post UCBT with mean +/- s.e.m. values of 120 +/- 29/mm3 and 10 +/- 50/mm3, respectively (normal = 900-2860/mm3 (CD3/CD4), normal = 630-1910/mm3 (CD3/CD8)). Mitogen response studies showed low blastogenesis to PHA and PWM, with a mean c.p.m. +/- s.e.m. value of 1.7 +/- 0.67 x 10(4) for PHA (NL >/= 75 x 10(3)) and 8.42 +/- 4.1 x 10(3) for PWM (NL >/=25 x 10(3)). In conclusion, serum levels of inflammatory mediators were not predictive nor did they correlate with the severity of aGVHD. Recovery of NK cells, B cells, and PMN functions occurred within the first 90 days post transplant. However, T cell subsets, CD3+/CD4+ and CD3+/CD8+, and T cell functional activity remained significantly decreased and may account for the high incidence of infectious morbidity seen during this immediate post UCBT period.
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PMID:Immunological reconstitution and correlation of circulating serum inflammatory mediators/cytokines with the incidence of acute graft-versus-host disease during the first 100 days following unrelated umbilical cord blood transplantation. 1048 39

Interleukin-12 (IL-12) is a heterodimeric cytokine mediating a dynamic interplay between T cells and antigen-presenting cells (APCs). Preclinical studies have demonstrated that recombinant murine IL-12 (rmIL-12) promotes specific antitumor immunity mediated by T cells in several types of tumors. However, the in vivo antitumor properties of IL-12 in acute myeloid leukemia (AML) have not been previously reported. We show here in a murine AML model that systemic administration of rmIL-12 significantly delays tumor growth but is incapable of rescuing mice from lethal leukemia. In contrast, AML cells genetically modified to express IL-12 (IL12-AML) using murine stem cell virus (MSCV) p40 + p35 elicit very potent antileukemic activity. Vaccines with lethally irradiated IL12-AML cells protect naive mice against challenge with wild-type AML cells and, more importantly, can cure mice bearing a considerable leukemic burden. Immunized mice show no signs of systemic IL-12 toxicity and their spleen histology is comparable with naive mice spleen. In vivo depletion of IL-12, interferon-gamma (IFN-gamma), or CD8(+) T cells after injections with live IL12-AML cells abrogates completely the antileukemia immune responses. Studies on the in vitro effects of IFN-gamma on AML cells demonstrate enhanced expression of major histocompatibility complex (MHC) and accessory molecules and induction of the costimulatory molecules B7.1 and B7.2, but no significant direct antiproliferative effect. (51)Cr release assays show that rejection of live IL12-AML cells supports the development of long-lasting leukemia-specific cytotoxic T lymphocyte (CTL) activity. In conclusion, our results demonstrate that IL12-AML vaccination is a safe and potent immunotherapeutic approach that has a great potential to eliminate minimal residual disease in patients with AML.
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PMID:Vaccines with interleukin-12-transduced acute myeloid leukemia cells elicit very potent therapeutic and long-lasting protective immunity. 1059 71

The product of the Wilms' tumor gene WT1 is a transcription factor overexpressed not only in leukemic blast cells of almost all patients with acute myeloid leukemia, acute lymphoid leukemia, and chronic myeloid leukemia, but also in various types of solid tumor cells. Thus, it is suggested that the WT1 gene plays an important role in both leukemogenesis and tumorigenesis. Here we tested the potential of WT1 to serve as a target for immunotherapy against leukemia and solid tumors. Four 9-mer WT1 peptides that contain HLA-A2.1-binding anchor motifs were synthesized. Two of them, Db126 and WH187, were determined to bind to HLA-A2.1 molecules in a binding assay using transporter associated with antigen processing-deficient T2 cells. Peripheral blood mononuclear cells from an HLA-A2.1-positive healthy donor were repeatedly sensitized in vitro with T2 cells pulsed with each of these two WT1 peptides, and CD8(+) cytotoxic T lymphocytes (CTLs) that specifically lyse WT1 peptide-pulsed T2 cells in an HLA-A2.1-restricted fashion were induced. The CTLs also exerted specific lysis against WT1-expressing, HLA-A2.1-positive leukemia cells, but not against WT1-expressing, HLA-A2.1-negative leukemia cells, or WT1-nonexpressing, HLA-A2. 1-positive B-lymphoblastoid cells. These data provide the first evidence of human CTL responses specific for the WT1 peptides, and provide a rationale for developing WT1 peptide-based adoptive T-cell therapy and vaccination against leukemia and solid tumors.
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PMID:Human cytotoxic T-lymphocyte responses specific for peptides of the wild-type Wilms' tumor gene (WT1 ) product. 1066 72

The effects of imipenem and cilastatin on human T-lymphocytes were studied in vitro. As responder T-cells were used T-lymphocyte clones derived from acute leukemia patients with chemotherapy-induced cytopenia, and the accessory cells were highly enriched acute myelogenous leukemia (AML) blasts. The effects of imipenem and cilastatin on phytohemagglutinin (PHA), anti-CD3 and anti-CD3+anti-CD28 stimulated activation were assayed, and in addition drug effects on cytokine-dependent proliferation of activated T-lymphocytes were investigated. Imipenem inhibited IL2-dependent proliferation of activated CD4(+) and CD8(+) T-cell clones, and an inhibition was also detected for IL7-, IL12-, IL15-, IL16- and IL17-dependent clonal proliferation. Imipenem caused a weak inhibition of anti-CD3- and PHA-stimulated T-cell proliferation when using 50 Gy irradiated AML blast accessory cells derived from various patients, whereas no effect was observed for anti-CD3+anti-CD28 stimulated and allostimulated activation. Imipenem decreased the release of IL4 and Interferon-gamma by T-cell clones stimulated with anti-CD3 and PHA in the presence of native (nonirradiated) AML blasts. The imipenem effects were observed at concentrations corresponding to levels reached in vivo, whereas even high concentrations of cilastatin did not alter T-cell responses. The T-lymphocyte inhibition is probably caused by a direct effect of imipenem on the T-cells.
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PMID:Effects of imipenem and cilastatin on human T-lymphocytes derived from acute leukemia patients with chemotherapy-induced leucopenia: studies of T-lymphocyte responses in the presence of acute myelogenous leukemia (AML) blast accessory cells. 1068 90

Transplantation using umbilical cord progenitor cells as the source of the stem cells is increasingly recognized as another form of allogeneic transplantation with curative intent. However, the different patterns of hematopoietic and immunological reconstruction have been described in very few patients. A 20-month-old boy presented with acute leukemia. He received standard AML induction and consolidation therapy, after which he underwent allogeneic transplantation using HLA-matched sibling stem cells obtained from the umbilical cord. The preparative regimen consisted of busulfan and cyclophosphamide. White cell recovery, despite concomitant use of G-CSF, was slow, reminiscent of the engraftment pattern without the use of growth factor. Erythroid recovery was best recorded using fetal cell HbF level. Platelet transfusion independence occurred on day +31. Immunologic reconstitution revealed an early NK cell recovery by 6 weeks and progressive T cell recovery until 3 months, with continued increase in counts thereafter. However, the CD4/CD8 ratio remained low even at 14 months post-transplantation. Recovery of B cells was slower until day +120. Proliferative response was within normal range on day +120. This report describes the unique engraftment pattern following umbilical cord blood transplant and emphasizes the pattern of immunological and hematological reconstitution.
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PMID:Immune and hematopoietic reconstitution after transplantation of cord blood progenitor cells: case report and review of the literature. 1080 27

Fifty three patients (pts) received an allogeneic hematopoietic transplant using peripheral blood progenitor cells (PBPC). Diagnosis were acute myeloid leukemia (AML) in 16 pts, acute lymphoblastic leukemia (ALL) in 15, chronic myeloid leukemia (CML) in first chronic phase in 12, aplastic anemia in 4, myelodysplasia in 3 and Hodgkin's disease, major thalasemia and Hunter's syndrome in one each. Mean age was 20 years-old (2-55), 28 males and 25 females. Conditioning regimens were total body irradiation with 1200 cGy and cyclophosphamide 120 mg/kg in 38 pts, busulfan 16 mg/kg and cyclophosphamide 120 mg/kg in 10 pts, total lymphoid irradiation and cyclophosphamide in 3, 2 pts received other chemotherapy based conditionings. PBPC were infused unmanipulated through a central catheter. Graft versus host disease (GVHD) prophylaxis was cyclosporin and short course methotrexate. Donors were 6/6 HLA compatible siblings in 52 cases and 5/6 match in one case. PBPC mobilization was done with G-CSF at a dose of 10 micrograms/kg/day subcutaneously for four days, pheresis started on day 5. Bone marrow harvest was also done in the first thirty cases. Mean cellularities for CD34, CD3, CD4, CD8, CD56, CD19 (cel x 10(6)/kg) were 4.12; 4.59; 2.57; 1.9; 0.55 and 0.68, respectively. Mean recovery of neutrophils > 500/microL was obtained on day +11 and platelets > 20,000/microL on day +13. Patients were hospitalized for a mean period of 26 days (range 18-39) and days with parenteral antibiotics were 12.2 (5-45). Two pts had venoocclusive disease of the liver. Transplant related mortality was 15%. Acute graft versus host disease (GVHD) was observed in 43.4% of pts, only 5 pts had acute GVHD III or IV. Mean time for aGVHD diagnosis was +23 (8-76). Forty three pts were evaluable for chronic GVHD with a mean follow-up of 18 months (4-39). Chronic GVHD was observed in 26.4% by day +240, only 2 pts developed severe cGVHD. The present experience demonstrates an acceptable incidence for cGVHD; however, taking into account recent reports showing an increase of this complication, it seems reasonable not to perform this procedure for non-malignant diseases in which graft versus malignancy effect is not to be expected.
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PMID:[Allogeneic hematopoietic transplantation with stem cells extracted from peripheral blood]. 1096 6

The best strategies for haploidentical stem cell transplants are not known. We used a standard myeloablative pretransplant conditioning regimen (30 mg/kg VP-16, 120 mg/kg cyclophosphamide, and 12 Gy of TBI in six fractions), an increased peripheral stem cell dose of > 10 x 10(6) CD34+ cells/kg, T cell depletion (with CD34+ cell selection and CD4/CD8 depletion steps) to < 1 x 10(5) CD3+ cells/kg and cyclosporine post transplant. Ten patients (7M/3F, median age 11 (3-33) years) with high-risk leukemia (AML in 4, MDS in 2, CML in 1 and T-ALL in 3) received a hemopoietic stem cell transplant (HSCT) from a haploidentical father or sibling. The median number of CD34+ cells was 12.9 (9.5-45.7) x 10(6) cells/kg; median number of CD3+ cells was 0.41 (0.09-1.89) x 10(5) CD3+ cells/kg. All patients initially achieved 0.5 x 10(9)/l neutrophils at a median 12 (10-21) days. Graft failure in two consecutive patients out of four on the original protocol led to a modification adding ATG pretransplant and OKT3 post transplant. Graft failure was observed in one out of six subsequent patients. Acute GVHD > or = grade II was observed in three patients. Three of 10 patients are alive in CR at > 24 and >3 (2) months after transplant. Seven patients died: four of transplant related complications and three of relapse. Increased stem cell dose (> or = 10 x 10(6) CD34+ cells/kg) as obtained using currently available technology may not be sufficient to ensure stable engraftment in patients with high-risk leukemia using standard myeloablative conditioning regimens.
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PMID:Increased stem cell dose, as obtained using currently available technology, may not be sufficient for engraftment of haploidentical stem cell transplants. 1110 99

In this study we compared the lymphocyte reconstitution in 13 multiple myeloma (MM), nine acute myeloid leukemia (AML) and 10 chronic myeloid leukemia (CML) patients after allogeneic G-CSF-mobilized PBSC transplantation from HLA-identical siblings. Conditioning regimens included standard total body irradiation + cyclophosphamide (CY), or busulphan + CY, whereas VP-16 was added in patients with advanced disease. Overall comparable numbers of mononuclear cells, CD34+ cells and CD3+ T cells were infused in each group. A significantly higher CD3+ T cell number was observed in MM and AML than in CML patients 1 month after transplant. However, MM patients showed a faster and better recovery of CD4+ T cells than both AML and CML patients at 3 months (P = 0.01 and P = 0.01, respectively) and 12 months (P = 0.01 vs AML, while P = NS vs CML) after transplant, and had a CD4:CD8 ratio > 1 with a median CD4+ T cell value > 400/microl 1 year after transplant. Development of acute graft-versus-host disease (GVHD) did not affect CD4:CD8 ratios but patients who experienced acute GVHD > grade I had lower CD4+ and CD8+ T cell numbers at all time points. However, after excluding patients with GVHD > grade I, MM patients still showed a significantly higher CD4+ T cell value than patients with myeloproliferative diseases 1 year after transplant. These findings suggest that although allogeneic PBSC transplantation induces rapid immune reconstitution, different kinetics may occur among patients with hematological malignancies. In particular, the rapid reconstitution of CD4+ T cells in MM patients may contribute to the low transplant-related mortality achieved in this disease.
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PMID:Different immune reconstitution in multiple myeloma, chronic myeloid leukemia and acute myeloid leukemia patients after allogeneic transplantation of peripheral blood stem cells. 1122 73

A 17-year-old male with AML FAB M4 relapsed 4 months after myeloablative conditioning and peripheral blood stem cell transplantation (PBSCT) from an HLA-identical unrelated donor. A second PBSC harvest was infused 2 days after completion of cytoreductive therapy with mitoxantrone 7 mg/m(2)/day i.v. for 3 days (total dose 21 mg/m(2)), fludarabine 30 mg/m(2)/day i.v. for 6 days (total dose 180 mg/m(2)) and Ara-C 125 mg/m(2)/day i.v. for 5 days (total dose 625 mg/m(2)). Neutrophil recovery occurred on day +10 and was associated with GVHD grade III of the skin which was treated with cyclosporin A (CsA) and prednisone. Because of fever of unknown origin and progressive fatigue combined with hypotension on day +15 after second PBSCT, echocardiography was performed which revealed a dramatic decrease in systolic function compared to the status pre-transplant. On the same day acute heart failure with consecutive ventricular fibrillation occurred. Although resuscitation was performed immediately the patient died. The autopsy revealed massive infiltration by donor CD8-positive lymphocytes with concomitant extensive damage of the heart tissue. Acute myocarditis of viral origin was excluded by in situ hybridization and nested PCR techniques. In this patient, myocardial involvement by acute GVHD seems to have triggered a fatal arrhythmia and heart failure.
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PMID:Acute heart failure after allogeneic blood stem cell transplantation due to massive myocardial infiltration by cytotoxic T cells of donor origin. 1124 47


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