Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Retroviral transfer of T-cell receptors (TCR) to peripheral blood-derived T cells generates large numbers of T cells with the same antigen specificity, potentially useful for adoptive immunotherapy. One drawback of this procedure is the formation of mixed TCR dimers with unknown specificities due to pairing of endogenous and introduced TCR chains. We investigated whether gammadelta T cells can be an alternative effector population for TCR gene transfer because the gammadeltaTCR is not able to form dimers with the alphabetaTCR. Peripheral blood-derived gammadelta T cells were transduced with human leukocyte antigen (HLA) class I- or HLA class II-restricted minor histocompatibility antigen (mHag) or virus-specific TCRs. Because most gammadelta T cells do not express CD4 and CD8, we subsequently transferred these coreceptors. The TCR-transduced gammadelta T cells exerted high levels of antigen-specific cytotoxicity and produced IFN-gamma and IL-4, particularly in the presence of the relevant coreceptor. gammadelta T cells transferred with a TCR specific for the hematopoiesis-specific mHag HA-2 in combination with CD8 displayed high antileukemic reactivity against HA-2-expressing leukemic cells. These data show that transfer of alphabetaTCRs to gammadelta T cells generated potent effector cells for immunotherapy of leukemia, without the expression of potentially hazardous mixed TCR dimers.
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PMID:Alphabeta T-cell receptor engineered gammadelta T cells mediate effective antileukemic reactivity. 1654 Jun 88

Previous studies demonstrated significant differences in a number of HLA allele frequencies in leukemia patients and normal subjects. In this study, we have analyzed HLA class II alleles and haplotypes in 110 leukemia patients (60 acute myelogenous leukemia "AML", 50 chronic myelogenous leukemia"CML") and 180 unrelated normal subjects. Blood samples were collected from all of the patients and control subjects. DNA was extracted by salting out method and HLA typing was performed using PCR-SSP method. Significant positive association with AML was obtained for HLA-DRB1*11allele (35% vs. 24.7%, P=0.033). Two alleles including HLA-DRB4 and -DQB1*0303 were significantly less frequent in AML patients than in controls. HLA-DQB1*0303 allele was never observed in CML patients compared with allele frequency in controls (4.2%). According to haplotype analysis, HLA-DRB1*0101/DQA1*0104/-DQB1*0501 frequencies were significantly higher and -DRB1*16/-DQA1*01021/-DQB1*0501 frequencies were significantly lower in CML patients than in controls. In conclusion it is suggested that HLA-DRB1*16 allele and HLA-DRB1*15/-DQA1*0103/-DQB1*06011 and -DRB1*16/-DQA1*01021/-DQB1*0501 haplotypes predispose individuals to AML and HLA-DRB4 allele predispose to CML. Future studies are needed to confirm these results and establish the role of these associations in AML and CML.
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PMID:HLA class II allele and haplotype frequencies in Iranian patients with leukemia. 1789 34

Patients with hematological malignancies can be successfully treated with HLA-matched T cell-depleted allogeneic stem cell transplantation (alloSCT) and subsequent donor lymphocyte infusions (DLIs). The efficacy of DLI is mediated by donor T cells recognizing minor histocompatibility antigens (mHags) on malignant recipient cells. Because HLA class II molecules are predominantly expressed on hematopoietic cells, mHag-specific CD4(+) T cells may selectively mediate graft versus leukemia (GvL) reactivity without graft versus host disease (GvHD). In this study, we used a recombinant bacteria cDNA library for the identification of the first autosomal HLA class II (HLA-DQB1*0603)-restricted mHag LB-PI4K2B-1S encoded by the broadly expressed phosphatidylinositol 4-kinase type II beta gene. A polyclonal CD4(+) T cell response against LB-PI4K2B-1S was demonstrated in a patient with relapsed chronic myeloid leukemia (CML) who responded to DLI after HLA-matched alloSCT. LB-PI4K2B-1S-specific CD4(+) T cells recognized and lysed the CD34(+) CML cells of the patient and other leukemic cells as well as high HLA-DQ-expressing normal hematopoietic cells. HLA-DQ expression on normal cells of nonhematopoietic origin was moderately up-regulated by IFN-gamma and not sufficient for T cell recognition. We hypothesize that LB-PI4K2B-1S-specific CD4(+) T cells contributed to the antitumor response by both directly eliminating malignant cells as effector cells and stimulating CD8(+) T cell immunity as helper cells.
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PMID:Identification of phosphatidylinositol 4-kinase type II beta as HLA class II-restricted target in graft versus leukemia reactivity. 1831 30

Mismatching for human leukocyte antigen (HLA)-DPB1 in unrelated donor hematopoietic stem cell transplantation (URD-SCT) has been associated with a decreased risk of disease relapse, indicating that HLA-DP may represent a target for graft-versus-leukemia (GVL) reactivity in HLA class II-expressing hematological malignancies. To investigate whether HLA-DP-specific T cells could mediate GVL reactivity following HLA-DPB1-mismatched URD-SCT and donor lymphocyte infusion (DLI), we analyzed the immune response in a patient with leukemic lymphoplasmacytic lymphoma responding to DLI without graft-versus-host disease. The emergence of leukemia-reactive CD4+ T cells during the clinical immune response was demonstrated by interferon-gamma (IFN-gamma) enzyme-linked immunosorbent spot(ELISPOT)analysis. Following clonal isolation of these leukemia-reactive CD4+ T cells, blocking studies, panel studies and retroviral transduction experiments of both mismatched HLA-DPB1 alleles identified HLA-DPB1(*)0201 and HLA-DPB1(*)0301 as the targets of this immune response. The HLA-DPB1-specific CD4+ T-cell clones were capable of recognizing and lysing several HLA-DP-expressing myeloid and lymphoid hematological malignant cells. Since HLA-DP expression is mainly restricted to hematopoietic cells, HLA-DP may be used as a specific target for immunotherapy following T-cell-depleted URD-SCT. Therefore, in patients with HLA class II-expressing hematological malignancies HLA-DP-mismatched SCT may be preferable over fully matched SCT allowing DLI to induce a GVL effect.
Leukemia 2008 Jul
PMID:HLA-DP as specific target for cellular immunotherapy in HLA class II-expressing B-cell leukemia. 1841 6

Chronic lymphocytic leukemia (CLL) is the most frequent type of leukemia in Western countries, but its incidence is low in Asian populations. In the present study we determined the frequency of DRB1 and DQB1 alleles in 87 Iranian CLL patients and 100 healthy controls using a polymerase chain reaction (PCR) technique. An increased frequency of DRB1*07 (p = 0.04), DQB1*06 (p = 0.01) alleles, and DRB1*13/DQB1*03 haplotype (p = 0.01) and decreased frequency of the DQB1*03 (p = 0.01) allele were observed in our patients compared with healthy controls. Comparison between patients with indolent (n = 42) and progressive (n = 38) disease revealed a significant increase in DRB1*04 and DRB5 alleles in progressive patients. Similarly, a higher frequency of DRB5 (p = 0.01) allele was observed in CD38(+) compared with CD38(-) patients. Classification of the patients into immunoglobulin variable region heavy-chain genes mutated and unmutated subtypes did not reveal significant differences for the expression of any of the HLA alleles or haplotypes between these two subtypes. Our findings observed in an Iranian population indicate that CLL could be associated with distinct HLA class II alleles and haplotypes of which the DQB1*06 allele and DRB1*13/DQB1*03 haplotype have not already been reported in CLL patients from other ethnic backgrounds. Some HLA class II alleles may contribute to disease progression in CLL.
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PMID:Human leukocyte antigen class II allele association to disease progression in Iranian patients with chronic lymphocytic leukemia. 1872 91

The extended human major histocompatibility complex (MHC) is a gene-rich region of about 7.6 Mb on chromosome 6, and includes a high proportion of genes involved in the immune response. Among these are the two Human Leukocyte Antigen (HLA) gene clusters, class I and class II, which encode highly polymorphic classical HLA-A, B, C and HLA-DR, DQ and DP genes, respectively. The protein products of the classical HLA genes are heterodimeric cell surface molecules that bind short peptides derived from non-self and self proteins, including infections and auto-antigens. The presentation of these HLA-anchored peptides to T lymphocytes triggers a cascade of responses in immune-associated genes that leads to adaptive immunity. Associations between HLA class II alleles and childhood leukemia have been reported in a number of studies. This could be due to the role of HLA allele-restricted peptide binding and T cell activation, or linkage disequilibrium to an MHC-linked "leukemia gene" in the pathogenesis of childhood leukemia. Efforts are currently in progress to resolve these questions, using large leukemia case-control sample series such as the UK Childhood Cancer Study (UKCCS) and the Northern California Childhood Leukemia Study (NCCLS). Here we review the background to these studies, and present a novel hypothesis based on the paradigm of HLA-associated auto-immune disease that might explain an infection-based etiology of childhood leukemia.
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PMID:The human major histocompatibility complex and childhood leukemia: an etiological hypothesis based on molecular mimicry. 1905

Graft-versus-host disease is still a major complication in stem-cell transplantation. In HLA-identical stem-cell transplantation, mismatches in minor histocompatibility antigens contribute to the development of graft-versus-host disease. As treatment of graft-versus-host disease with immunosuppressive drugs potentially also reduces the graft-versus-leukemia responses, antigen-specific tolerance induction may be used to reduce graft-versus-host disease while leaving the graft-versus-leukemia responses intact. In mouse models, induction of antigen-specific tolerance using IgG-antigen-transduced B cells can prevent and ameliorate autoimmunity. In this study, the principle of the in vivo animal model has been applied to a human in vitro model wherein induction of tolerance against the HLA class II-restricted male-specific minor histocompatibility antigen RPS4Y1 has been analyzed. T cells precultured in the presence of B cells expressing the IgG-coupled HY antigen showed reduced responsiveness selectively against the minor HY antigen RPS4Y1 in different in vitro protocols. These first observations serve as a basis for further studying and understanding the tolerizing potential of IgG constructs with human T cells.
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PMID:Gene therapy with IgG-HY fusion proteins to reduce male-specific T-cell reactivity in vitro. 2064 84

During HLA class II synthesis in antigen-presenting cells, the invariant chain (Ii) not only stabilizes HLA class II complexes in the endoplasmic reticulum, but also mediates their transport to specialized lysosomal antigen-loading compartments termed MIICs. This study explores an alternative HLA class II presentation pathway in leukemic blasts that involves proteasome and transporter associated with antigen processing (TAP)-dependent peptide loading. Although HLA-DR did associate with Ii, Ii silencing in the human class II-associated invariant chain peptide (CLIP)-negative KG-1 myeloid leukemic cell line did not affect total and plasma membrane expression levels of HLA-DR, as determined by western blotting and flow cytometry. Since HLA-DR expression does require peptide binding, we examined the role of endogenous antigen-processing machinery in HLA-DR presentation by CLIP(-) leukemic blasts. The suppression of proteasome and TAP function using various inhibitors resulted in decreased HLA-DR levels in both CLIP(-) KG-1 and ME-1 blasts. Simultaneous inhibition of TAP and Ii completely down-modulated the expression of HLA-DR, demonstrating that together these molecules form the key mediators of HLA class II antigen presentation in leukemic blasts. By the use of a proteasome- and TAP-dependent pathway for HLA class II antigen presentation, CLIP(-) leukemic blasts might be able to present a broad range of endogenous leukemia-associated peptides via HLA class II to activate leukemia-specific CD4(+) T cells.
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PMID:Alternative Ii-independent antigen-processing pathway in leukemic blasts involves TAP-dependent peptide loading of HLA class II complexes. 2082 Jul 76

Alloreactive (allo)-HLA-directed T cell responses after HLA-mismatched allogeneic hematopoietic stem cell transplantation and donor lymphocyte infusion are typically considered detrimental responses mediating graft-versus-host disease (GVHD). Allo-HLA-reactive T cells with beneficial and selective graft-versus-leukemia (GVL) reactivity, however, can also be identified within an HLA-mismatched context. We investigated whether allo-HLA class II-directed T cells with beneficial GVL reactivity induced in NOD/scid mice engrafted with human chronic myelogenous leukemia in lymphoid blast crisis after treatment with donor lymphocyte infusion - mediated detrimental xenogeneic GVHD as a result of broad off-target cross-reactivity. The results demonstrate that beneficial GVL reactivity and xenogeneic GVHD are mediated by separate T cells. GVL reactivity was mediated by human T cells recognizing allo-HLA class II molecules, whereas xenoreactivity was exerted by human T cells recognizing H-2 molecules. Taken together, our data indicate a limited risk for detrimental off-target effects by allo-HLA class II-directed T cells and thereby provide a basis for the development of strategies for selecting allo-HLA-restricted T cells with selective GVL reactivity for adoptive transfer after HLA-mismatched allogeneic hematopoietic stem cell transplantation.
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PMID:Donor T cells administered over HLA class II barriers mediate antitumor immunity without broad off-target toxicity in a NOD/scid mouse model of acute leukemia. 2350 May 32

Wilms tumor gene 1 (WT1) is overexpressed in various malignant neoplasms, and has been demonstrated as an attractive target for cancer immunotherapy. We previously reported the identification of a WT1 protein-derived, 16-mer helper peptide WT1332 that could elicit Th1-type CD4+ T-cell response and bind to multiple HLA class II molecules. In this study, we examined the feasibility of adoptive therapy using CD4+ T cells that were transduced an HLA-DPB1*05:01-restricted, WT1332-specific T-cell receptor (TCR). HLA-DPB1*05:01-restricted, WT1332-specific TCR-transduced CD4+ T cells were successfully generated using lentiviral vector and exhibited strong proliferative response and Th1-type cytokine production in response to WT1332 peptide, WT1 protein, or WT1-expressing tumor cell lysate. Furthermore, the WT1332-specific TCR-transduced CD4+ T cells lysed HLA-DPB1*05:01-positive, WT1-expressing human leukemia cells through granzyme B/perforin pathway. Furthermore, stimulation of peripheral blood mononuclear cells with both HLA-A*24:02-restricted cytotoxic T lymphocytes-epitope peptide (modified 9-mer WT1235 peptide, WT1235m) and WT1332 helper peptide in the presence of WT1332-specific TCR-transduced CD4+ T cells strikingly enhanced the induction of WT1235m-specific cytotoxic T lymphocytes. Thus, these results demonstrated the feasibility of immunotherapy based on adoptive transfer of WT1332-specific TCR-transduced CD4+ T cells for the treatment of leukemia.
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PMID:HLA-DPB1*05: 01-restricted WT1332-specific TCR-transduced CD4+ T lymphocytes display a helper activity for WT1-specific CTL induction and a cytotoxicity against leukemia cells. 2350 63


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