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Sample records for cell leukemia virus

  1. The receptors for gibbon ape leukemia virus and amphotropic murine leukemia virus are not downregulated in productively infected cells

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    Eiden Maribeth V

    2011-07-01

    Full Text Available Abstract Background Over the last several decades it has been noted, using a variety of different methods, that cells infected by a specific gammaretrovirus are resistant to infection by other retroviruses that employ the same receptor; a phenomenon termed receptor interference. Receptor masking is thought to provide an earlier means of blocking superinfection, whereas receptor down regulation is generally considered to occur in chronically infected cells. Results We used replication-competent GFP-expressing viruses containing either an amphotropic murine leukemia virus (A-MLV or the gibbon ape leukemia virus (GALV envelope. We also constructed similar viruses containing fluorescence-labeled Gag proteins for the detection of viral particles. Using this repertoire of reagents together with a wide range of antibodies, we were able to determine the presence and availability of viral receptors, and detect viral envelope proteins and particles presence on the cell surface of chronically infected cells. Conclusions A-MLV or GALV receptors remain on the surface of chronically infected cells and are detectable by respective antibodies, indicating that these receptors are not downregulated in these infected cells as previously proposed. We were also able to detect viral envelope proteins on the infected cell surface and infected cells are unable to bind soluble A-MLV or GALV envelopes indicating that receptor binding sites are masked by endogenously expressed A-MLV or GALV viral envelope. However, receptor masking does not completely prevent A-MLV or GALV superinfection.

  2. Mechanisms of pathogenesis induced by bovine leukemia virus (BLV as a model for human T-cell leukemia virus (HTLV

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    Yoko eAida

    2013-11-01

    Full Text Available Bovine leukemia virus (BLV and human T-cell leukemia virus type 1 (HTLV-1 make up a unique retrovirus family. Both viruses induce chronic lymphoproliferative diseases with BLV affecting the B-cell lineage and HTLV-1 affecting the T-cell lineage. The pathologies of BLV- and HTLV-induced infections are notably similar, with an absence of chronic viraemia and a long latency period. These viruses encode at least two regulatory proteins, namely, Tax and Rex, in the pX region located between the env gene and the 3’ long terminal repeat. The Tax protein is a key contributor to the oncogenic potential of the virus, and is also the key protein involved in viral replication. However, BLV infection is not sufficient for leukemogenesis, and additional events such as gene mutations must take place. In this review, we first summarize the similarities between the two viruses in terms of genomic organization, virology and pathology. We then describe the current knowledge of the BLV model, which may also be relevant for the understanding of leukemogenesis caused by HTLV-1. In addition, we address our improved understanding of Tax functions through the newly identified BLV Tax mutants, which have a substitution between amino acids 240 and 265.

  3. Cell surface antigens of radiation leukemia virus-induced BALB/c leukemias defined by syngeneic cytotoxic T lymphocytes

    International Nuclear Information System (INIS)

    Kaneko, Yukio; Oettgen, H.F.; Obata, Yuichi; Nakayama, Eiichi.

    1989-01-01

    Two cell surface antigens of mouse leukemias were defined by BALB/c cytotoxic T lymphocytes (CTL) generated against syngeneic radiation leukemia virus (RadLV)-induced leukemia, BALBRV1 or BALBRVD. Hyperimmunization of BALB/c mice with irradiated leukemias followed by in vitro sensitization of primed spleen cells resulted in the generation of CTL with high killing activity. The specificity of CTL was examined by direct cytotoxicity assays and competitive inhibition assays. A shared cell surface antigen, designated as BALBRV1 antigen, was detected by BALB/c anti-BALBRV1 CTL. BALBRV1 antigen was expressed not only on RadLV-induced BALB/c leukemias except for BALBRVD, but also on spontaneous or X-ray-induced BALB/c leukemias, chemically-induced leukemias with the H-2 d haplotype and some chemically-induced BALB/c sarcomas. In contrast, a unique cell surface antigen, designated as BALBRVD antigen, was detected by BALB/c anti-BALBRVD CTL. BALBRVD antigen was expressed only on BALBRVD, but not on thirty-nine normal lymphoid or tumor cells. These two antigens could be distinguished from those previously defined on Friend, Moloney, Rauscher or Gross murine leukemia virus (MuLV) leukemias, or MuLV-related antigens. Both cytotoxic responses were blocked by antisera against H-2K d , but not H-2D d . The relationship of BALBRV1 antigen and BALBRVD antigen to endogenous MuLV is discussed with regard to the antigenic distribution on tumor cell lines. (author)

  4. Assembly of the murine leukemia virus is directed towards sites of cell-cell contact.

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    Jing Jin

    2009-07-01

    Full Text Available We have investigated the underlying mechanism by which direct cell-cell contact enhances the efficiency of cell-to-cell transmission of retroviruses. Applying 4D imaging to a model retrovirus, the murine leukemia virus, we directly monitor and quantify sequential assembly, release, and transmission events for individual viral particles as they happen in living cells. We demonstrate that de novo assembly is highly polarized towards zones of cell-cell contact. Viruses assembled approximately 10-fold more frequently at zones of cell contact with no change in assembly kinetics. Gag proteins were drawn to adhesive zones formed by viral Env glycoprotein and its cognate receptor to promote virus assembly at cell-cell contact. This process was dependent on the cytoplasmic tail of viral Env. Env lacking the cytoplasmic tail while still allowing for contact formation, failed to direct virus assembly towards contact sites. Our data describe a novel role for the viral Env glycoprotein in establishing cell-cell adhesion and polarization of assembly prior to becoming a fusion protein to allow virus entry into cells.

  5. Decay of Moloney leukemia virus production after enucleation of chronically infected mouse cells

    International Nuclear Information System (INIS)

    Ber, R.; Fenyo, E.M.; Nexo, B.A.; Skoog, L.

    1981-01-01

    The effect of enucleation on synthesis of Moloney leukemia virus was studied in chronically infected YACIR-A9 mouse hybrid cells. The synthesis of infectious virus decreased gradually until, 12 h after enucleation, virtually no infectious virus was produced. As determined by particle-bound p30 and reverse transcriptase, cytoplasts produced a low level of noninfectious viral particles. Thus, the assembly of virus particles does not appear to be wholly dependent on the presence of the cell nucleus. In contrast, production of infectious particles shows an absolute requirement for the cell nucleus. (author)

  6. Animals Models of Human T Cell Leukemia Virus Type I Leukemogenesis.

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    Niewiesk, Stefan

    2016-01-01

    Infection with human T cell leukemia virus type I (HTLV-I) causes adult T cell leukemia (ATL) in a minority of infected individuals after long periods of viral persistence. The various stages of HTLV-I infection and leukemia development are studied by using several different animal models: (1) the rabbit (and mouse) model of persistent HTLV-I infection, (2) transgenic mice to model tumorigenesis by HTLV-I specific protein expression, (3) ATL cell transfers into immune-deficient mice, and (4) infection of humanized mice with HTLV-I. After infection, virus replicates without clinical disease in rabbits and to a lesser extent in mice. Transgenic expression of both the transactivator protein (Tax) and the HTLV-I bZIP factor (HBZ) protein have provided insight into factors important in leukemia/lymphoma development. To investigate factors relating to tumor spread and tissue invasion, a number of immune-deficient mice based on the severe combined immunodeficiency (SCID) or non-obese diabetic/SCID background have been used. Inoculation of adult T cell leukemia cell (lines) leads to lymphoma with osteolytic bone lesions and to a lesser degree to leukemia development. These mice have been used extensively for the testing of anticancer drugs and virotherapy. A recent development is the use of so-called humanized mice, which, upon transfer of CD34(+)human umbilical cord stem cells, generate human lymphocytes. Infection with HTLV-I leads to leukemia/lymphoma development, thus providing an opportunity to investigate disease development with the aid of molecularly cloned viruses. However, further improvements of this mouse model, particularly in respect to the development of adaptive immune responses, are necessary. © The Author 2016. Published by Oxford University Press on behalf of the Institute for Laboratory Animal Research. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Quantitation, in vitro propagation, and characterization of preleukemic cells induced by radiation leukemia virus

    International Nuclear Information System (INIS)

    Yefenof, E.; Epszteyn, S.; Kotler, M.

    1991-01-01

    Intrathymic (i.t.) inoculation of radiation leukemia virus into C57BL/6 mice induces a population of preleukemic (PL) cells that can progress into mature thymic lymphomas upon transfer into syngeneic recipients. A minimum of 10(3) PL thymic cells are required to induce lymphomas in the recipient. Most of the individual lymphomas developed in mice which were inoculated with cells of a single PL thymus, derived from different T-cell precursors. PL thymic cells could be grown in vitro on a feeder layer consisting of splenic stromal cells. Growth medium was supplemented with supernatant harvested from an established radiation leukemia virus-induced lymphoma cell line (SR4). The in vitro-grown PL cells were characterized as Thy-1+, CD4+, CD8- T-cells, most of which expressed radiation leukemia virus antigens. Cultured PL cells were found to be nontumorigenic, based on their inability to form s.c. tumors. However, these cells could develop into thymic lymphomas if inoculated i.t. into syngeneic recipients. A culture of PL cells, maintained for 2 mo, showed clonal T-cell receptor arrangement. Lymphomas which developed in several recipient mice upon injection with these PL cells were found to possess the same T-cell receptor arrangement. These results indicate that PL cells can be adapted for in vitro growth while maintaining their preleukemic character

  8. Androgen-independent proliferation of LNCaP prostate cancer cells infected by xenotropic murine leukemia virus-related virus

    International Nuclear Information System (INIS)

    Kakoki, Katsura; Kamiyama, Haruka; Izumida, Mai; Yashima, Yuka; Hayashi, Hideki; Yamamoto, Naoki; Matsuyama, Toshifumi; Igawa, Tsukasa; Sakai, Hideki; Kubo, Yoshinao

    2014-01-01

    Highlights: • XMRV infection induces androgen-independent growth in LNCaP cells. • XMRV infection reduces expression of androgen receptor. • XMRV promotes appearance of androgen blocker-resistant prostate cancer cells. - Abstract: Xenotropic murine leukemia virus-related virus (XMRV) is a novel gammaretrovirus that was originally isolated from human prostate cancer. It is now believed that XMRV is not the etiologic agent of prostate cancer. An analysis of murine leukemia virus (MLV) infection in various human cell lines revealed that prostate cancer cell lines are preferentially infected by XMRV, and this suggested that XMRV infection may confer some sort of growth advantage to prostate cancer cell lines. To examine this hypothesis, androgen-dependent LNCaP cells were infected with XMRV and tested for changes in certain cell growth properties. We found that XMRV-infected LNCaP cells can proliferate in the absence of the androgen dihydrotestosterone. Moreover, androgen receptor expression is significantly reduced in XMRV-infected LNCaP cells. Such alterations were not observed in uninfected and amphotropic MLV-infected LNCaP cells. This finding explains why prostate cancer cell lines are preferentially infected with XMRV

  9. Human T-cell leukemia virus type 1 p8 protein increases cellular conduits and virus transmission.

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    Van Prooyen, Nancy; Gold, Heather; Andresen, Vibeke; Schwartz, Owen; Jones, Kathryn; Ruscetti, Frank; Lockett, Stephen; Gudla, Prabhakar; Venzon, David; Franchini, Genoveffa

    2010-11-30

    The human T-cell leukemia virus type 1 (HTLV-1) is the cause of adult T-cell leukemia/lymphoma as well as tropical spastic paraparesis/HTLV-1-associated myelopathy. HTLV-1 is transmitted to T cells through the virological synapse and by extracellular viral assemblies. Here, we uncovered an additional mechanism of virus transmission that is regulated by the HTLV-1-encoded p8 protein. We found that the p8 protein, known to anergize T cells, is also able to increase T-cell contact through lymphocyte function-associated antigen-1 clustering. In addition, p8 augments the number and length of cellular conduits among T cells and is transferred to neighboring T cells through these conduits. p8, by establishing a T-cell network, enhances the envelope-dependent transmission of HTLV-1. Thus, the ability of p8 to simultaneously anergize and cluster T cells, together with its induction of cellular conduits, secures virus propagation while avoiding the host's immune surveillance. This work identifies p8 as a viral target for the development of therapeutic strategies that may limit the expansion of infected cells in HTLV-1 carriers and decrease HTLV-1-associated morbidity.

  10. Human T-cell leukemia virus types I and II exhibit different DNase I protection patterns

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    Altman, R.; Harrich, D.; Garcia, J.A.; Gaynor, R.B.

    1988-01-01

    Human T-cell leukemia virus types I (HTLV-I) and II (HTLV-II) are human retroviruses which normally infect T-lymphoid cells. HTLV-I infection is associated with adult T-cell leukemia-lymphoma, and HTLV-II is associated with an indolent form of hairy-cell leukemia. To identify potential transcriptional regulatory elements of these two related human retroviruses, the authors performed DNase I footprinting of both the HTLV-I and HTLV-II long terminal repeats (LTRs) by using extracts prepared from uninfected T cells, HTLV-I and HTLV-II transformed T cells, and HeLa cells. Five regions of the HTLV-I LTR and three regions of the HTLV-II LTR showed protection by DNase I footprinting. All three of the 21-base-pair repeats previously shown to be important in HTLV transcriptional regulation were protected in the HTLV-I LTR, whereas only one of these repeats was protected in the HTLV-II LTR. Several regions exhibited altered protection in extracts prepared from lymphoid cells as compared with HeLa cells, but there were minimal differences in the protection patterns between HTLV-infected and uninfected lymphoid extracts. A number of HTLV-I and HTLV-II LTR fragments which contained regions showing protection in DNase I footprinting were able to function as inducible enhancer elements in transient CAT gene expression assays in the presence of the HTLV-II tat protein. The alterations in the pattern of the cellular proteins which bind to the HTLV-I and HTLV-II LTRs may in part be responsible for differences in the transcriptional regulation of these two related viruses

  11. Barriers to Infection of Human Cells by Feline Leukemia Virus: Insights into Resistance to Zoonosis.

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    Terry, Anne; Kilbey, Anna; Naseer, Asif; Levy, Laura S; Ahmad, Shamim; Watts, Ciorsdaidh; Mackay, Nancy; Cameron, Ewan; Wilson, Sam; Neil, James C

    2017-03-01

    The human genome displays a rich fossil record of past gammaretrovirus infections, yet no current epidemic is evident, despite environmental exposure to viruses that infect human cells in vitro Feline leukemia viruses (FeLVs) rank high on this list, but neither domestic nor workplace exposure has been associated with detectable serological responses. Nonspecific inactivation of gammaretroviruses by serum factors appears insufficient to explain these observations. To investigate further, we explored the susceptibilities of primary and established human cell lines to FeLV-B, the most likely zoonotic variant. Fully permissive infection was common in cancer-derived cell lines but was also a feature of nontransformed keratinocytes and lung fibroblasts. Cells of hematopoietic origin were generally less permissive and formed discrete groups on the basis of high or low intracellular protein expression and virion release. Potent repression was observed in primary human blood mononuclear cells and a subset of leukemia cell lines. However, the early steps of reverse transcription and integration appear to be unimpaired in nonpermissive cells. FeLV-B was subject to G→A hypermutation with a predominant APOBEC3G signature in partially permissive cells but was not mutated in permissive cells or in nonpermissive cells that block secondary viral spread. Distinct cellular barriers that protect primary human blood cells are likely to be important in protection against zoonotic infection with FeLV. IMPORTANCE Domestic exposure to gammaretroviruses such as feline leukemia viruses (FeLVs) occurs worldwide, but the basis of human resistance to infection remains incompletely understood. The potential threat is evident from the human genome sequence, which reveals many past epidemics of gammaretrovirus infection, and from recent cross-species jumps of gammaretroviruses from rodents to primates and marsupials. This study examined resistance to infection at the cellular level with the most

  12. Adenosine Selectively Depletes Alloreactive T Cells to Prevent GVHD While Conserving Immunity to Viruses and Leukemia.

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    Whitehill, Greg D; Amarnath, Shoba; Muranski, Pawel; Keyvanfar, Keyvan; Battiwalla, Minoo; Barrett, Austin J; Chinnassamy, Dhanalakshmi

    2016-09-01

    Selective depletion (SD) of alloreactive T cells from allogeneic hematopoeitic stem cell transplants to prevent graft-versus-host disease (GVHD) without compromising immune reconstitution and antitumor responses remains a challenge. Here, we demonstrate a novel SD strategy whereby alloreacting T cells are efficiently deleted ex vivo with adenosine. SD was achieved in human leukocyte antigen (HLA) mismatched cocultures by multiple exposures to 2 mmol/l adenosine over 7 days. Adenosine depleted greater than to 90% of alloproliferating T cells in mismatched, haploidentical, and matched sibling pairs while conserving response to third-party antigens. Alloreactive CD4 and CD8 T cells were targeted for depletion while NK and B cells were preserved. Our novel approach also preserved nonalloreactive naive, central, and effector memory T-cell subsets, Tregs, and notably preserved T-cell responses against DNA viruses that contribute to transplant related mortality after allogeneic hematopoeitic stem cell transplants. Additionally, T cells recognizing leukemia-associated antigens were efficiently generated in vitro from the cell product post-SD. This study is the first to demonstrate that adenosine depletion of alloactivated T cells maintains a complete immune cell profile and recall viral responses. Expansion of tumor antigen-specific subsets postdepletion opens the possibility of generating T-cell products capable of graft-versus-tumor responses without causing GVHD.

  13. Silencing of human T-cell leukemia virus type I gene transcription by epigenetic mechanisms

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    Mueller Nancy

    2005-10-01

    Full Text Available Abstract Background Human T-cell leukemia virus type I (HTLV-I causes adult T-cell leukemia (ATL after a long latent period. Among accessory genes encoded by HTLV-I, the tax gene is thought to play a central role in oncogenesis. However, Tax expression is disrupted by several mechanims including genetic changes of the tax gene, deletion/hypermethylation of 5'-LTR. To clarify the role of epigenetic changes, we analyzed DNA methylation and histone modification in the whole HTLV-I provirus genome. Results The gag, pol and env genes of HTLV-I provirus were more methylated than pX region, whereas methylation of 5'-LTR was variable and 3'-LTR was not methylated at all. In ATL cell lines, complete DNA methylation of 5'-LTR was associated with transcriptional silencing of viral genes. HTLV-I provirus was more methylated in primary ATL cells than in carrier state, indicating the association with disease progression. In seroconvertors, DNA methylation was already observed in internal sequences of provirus just after seroconversion. Taken together, it is speculated that DNA methylation first occurs in the gag, pol and env regions and then extends in the 5' and 3' directions in vivo, and when 5'-LTR becomes methylated, viral transcription is silenced. Analysis of histone modification in the HTLV-I provirus showed that the methylated provirus was associated with hypoacetylation. However, the tax gene transcript could not be detected in fresh ATL cells regardless of hyperacetylated histone H3 in 5'-LTR. The transcription rapidly recovered after in vitro culture in such ATL cells. Conclusion These results showed that epigenetic changes of provirus facilitated ATL cells to evade host immune system by suppressing viral gene transcription. In addition, this study shows the presence of another reversible mechanism that suppresses the tax gene transcription without DNA methylation and hypoacetylated histone.

  14. Up-regulation of hepatitis C virus replication by human T cell leukemia virus type I-encoded Tax protein.

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    Zhang, Jing; Yamada, Osamu; Kawagishi, Kenji; Yoshida, Hiroshi; Araki, Hiromasa; Yamaoka, Shoji; Hattori, Toshio; Shimotohno, Kunitada

    2007-12-05

    Co-infection of hepatitis C virus (HCV) with other blood-borne pathogens such as human T cell leukemia virus (HTLV) is common in highly endemic areas. Clinical evidence showing a correlation between HTLV-I co-infection and rapid progression of HCV-associated liver disease promoted us to investigate the effect of HTLV-I-encoded Tax protein on HCV replication. Reporter assay showed that HCV replicon-encoded luciferase expression was significantly augmented by co-transfection of the Tax-expressing plasmid. Further, HCV RNA replication in replicon cells was increased either by co-culture with cells stably expressing Tax protein (Huhtax) or by culture in the presence of Huhtax-conditioned medium, indicating that Tax could also modulate HCV replication of adjacent cells in a paracrine manner. Additionally, HCV replication in Huhtax exhibited a reduced responsiveness to interferon-alpha-induced antiviral activity. This study demonstrates the facilitation of HCV replication by Tax protein, which may partially account for severer clinical consequences of HCV-related disease in HCV/HTLV co-infected individuals.

  15. Phosphorylation regulates human T-cell leukemia virus type 1 Rex function

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    Ward Michael

    2009-11-01

    Full Text Available Abstract Background Human T-cell leukemia virus type 1 (HTLV-1 is a pathogenic complex deltaretrovirus, which is the causative agent of adult T-cell leukemia/lymphoma (ATL and HTLV-1-associated myelopathy/tropical spastic paraparesis. In addition to the structural and enzymatic viral gene products, HTLV-1 encodes the positive regulatory proteins Tax and Rex along with viral accessory proteins. Tax and Rex proteins orchestrate the timely expression of viral genes important in viral replication and cellular transformation. Rex is a nucleolar-localizing shuttling protein that acts post-transcriptionally by binding and facilitating the export of the unspliced and incompletely spliced viral mRNAs from the nucleus to the cytoplasm. HTLV-1 Rex (Rex-1 is a phosphoprotein and general protein kinase inhibition correlates with reduced function. Therefore, it has been proposed that Rex-1 function may be regulated through site-specific phosphorylation. Results We conducted a phosphoryl mapping of Rex-1 over-expressed in transfected 293 T cells using a combination of affinity purification and liquid chromatography tandem mass spectrometry. We achieved 100% physical coverage of the Rex-1 polypeptide and identified five novel phosphorylation sites at Thr-22, Ser-36, Thr-37, Ser-97, and Ser-106. We also confirmed evidence of two previously identified residues, Ser-70 and Thr-174, but found no evidence of phosphorylation at Ser-177. The functional significance of these phosphorylation events was evaluated using a Rex reporter assay and site-directed mutational analysis. Our results indicate that phosphorylation at Ser-97 and Thr-174 is critical for Rex-1 function. Conclusion We have mapped completely the site-specific phosphorylation of Rex-1 identifying a total of seven residues; Thr-22, Ser-36, Thr-37, Ser-70, Ser-97, Ser-106, and Thr-174. Overall, this work is the first to completely map the phosphorylation sites in Rex-1 and provides important insight into

  16. Role of Tax protein in human T-cell leukemia virus type-I leukemogenicity

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    Aboud Mordechai

    2004-08-01

    Full Text Available Abstract HTLV-1 is the etiological agent of adult T-cell leukemia (ATL, the neurological syndrome TSP/HAM and certain other clinical disorders. The viral Tax protein is considered to play a central role in the process leading to ATL. Tax modulates the expression of many viral and cellular genes through the CREB/ATF-, SRF- and NF-κB-associated pathways. In addition, Tax employs the CBP/p300 and p/CAF co-activators for implementing the full transcriptional activation competence of each of these pathways. Tax also affects the function of various other regulatory proteins by direct protein-protein interaction. Through these activities Tax sets the infected T-cells into continuous uncontrolled replication and destabilizes their genome by interfering with the function of telomerase and topoisomerase-I and by inhibiting DNA repair. Furthermore, Tax prevents cell cycle arrest and apoptosis that would otherwise be induced by the unrepaired DNA damage and enables, thereby, accumulation of mutations that can contribute to the leukemogenic process. Together, these capacities render Tax highly oncogenic as reflected by its ability to transform rodent fibroblasts and primary human T-cells and to induce tumors in transgenic mice. In this article we discuss these effects of Tax and their apparent contribution to the HTLV-1 associated leukemogenic process. Notably, however, shortly after infection the virus enters into a latent state, in which viral gene expression is low in most of the HTLV-1 carriers' infected T-cells and so is the level of Tax protein, although rare infected cells may still display high viral RNA. This low Tax level is evidently insufficient for exerting its multiple oncogenic effects. Therefore, we propose that the latent virus must be activated, at least temporarily, in order to elevate Tax to its effective level and that during this transient activation state the infected cells may acquire some oncogenic mutations which can enable them to

  17. Expression of mink cell focus-forming murine leukemia virus-related transcripts in AKR mice

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    Khan, A.S.; Laigret, F.; Rodi, C.P.

    1987-01-01

    The authors used a synthetic 16-base-pair mink cell focus-forming (MCF) env-specific oligomer as radiolabeled probe to study MCF murine leukemia virus (MuLV)-related transcripts in brain, kidney, liver, spleen, and thymus tissues of AKR mice ranging from 5 weeks to 6 months (mo) of age. Tissue-specific expression of poly(A) + RNAs was seen. In addition, all the tissues tested contained 3.0-kb messages. The transcription of these MCF-related mRNAs was independent of the presence of ecotropic and xenotropic MuLVs. In general, expression of the MCF env-related transcripts appeared to peak at 2 mo of age; these messages were barely detectable in brain, kidney, liver, and spleen tissues after 2 mo and in thymus tissue after 4 mo of age. All of the subgenomic MCF env-related mRNAs appeared to contain the 190-base-pair cellular DNA insert, characteristic of the long terminal repeats associated with endogenous MCF env-related proviruses. No genomic-size (8.4-kb) transcripts corresponding to endogenous MCF-related proviruses were detected. An 8.4-kb MCF env-related mRNA was first seen at 3 mo of age, exclusively in thymus tissue. This species most likely represents the first appearance of a recombinant MCF-related MuLV genome. The transcripts which were detected in thymus tissue might be involved in the generation of leukemogenic MCF viruses

  18. Kinetic analysis of human T-cell leukemia virus type 1 gene expression in cell culture and infected animals.

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    Li, Min; Kesic, Matthew; Yin, Han; Yu, Lianbo; Green, Patrick L

    2009-04-01

    Human T-cell leukemia virus type 1 (HTLV-1) infection causes adult T-cell leukemia and is associated with a variety of lymphocyte-mediated disorders. It has been hypothesized that a highly regulated pattern of HTLV-1 gene expression is critical for virus survival and disease pathogenesis. In this study, real-time reverse transcriptase PCR was used to determine the kinetics of viral gene expression in cells transiently transfected with an HTLV-1 proviral plasmid, in newly infected human peripheral blood mononuclear cells (PBMCs), and in PBMCs from newly infected rabbits. The HTLV-1 gene expression profiles in transiently transfected and infected cells were similar; over time, all transcripts increased and then maintained stable levels. gag/pol, tax/rex, and env mRNA were detected first and at the highest levels, whereas the expression levels of the accessory genes, including the antisense Hbz, were significantly lower than the tax/rex levels (ranging from 1 to 4 logs depending on the specific mRNA). In infected rabbits, tax/rex and gag/pol mRNA levels peaked early after inoculation and progressively decreased, which correlated inversely with the proviral load and host antibody response against viral proteins. Interestingly, Hbz mRNA was detectable at 1 week postinfection and increased and stabilized. The expression levels of all other HTLV-1 genes in infected rabbit PBMCs were at or below our limit of detection. This analysis provides insight into viral gene expression under various in vitro and in vivo experimental conditions. Our in vivo data indicate that in infected rabbits, Hbz mRNA expression over time directly correlates with the proviral load, which provides the first evidence linking Hbz expression to proviral load and the survival of the virus-infected cell in the host.

  19. Human T-cell leukemia virus type-I Tax induces the expression of CD83 on T cells.

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    Tanaka, Yuetsu; Mizuguchi, Mariko; Takahashi, Yoshiaki; Fujii, Hideki; Tanaka, Reiko; Fukushima, Takuya; Tomoyose, Takeaki; Ansari, Aftab A; Nakamura, Masataka

    2015-07-01

    CD83, a cell surface glycoprotein that is stably expressed on mature dendritic cells, can be transiently induced on other hematopoietic cell lineages upon cell activation. In contrast to the membrane form of CD83, soluble CD83 appears to be immunosuppressive. In an analysis of the phenotype of leukemic CD4(+) T cells from patients with adult T-cell leukemia (ATL), we found that a number of primary CD4(+) T cells became positive for cell surface CD83 after short-term culture, and that most of these CD83(+) CD4(+) T cells were positive for human T-cell leukemia virus type-I (HTLV-I) Tax (Tax1). We hypothesized that Tax1 is involved in the induction of CD83. We found that CD83 was expressed selectively on Tax1-expressing human CD4(+) T cells in short-term cultured peripheral blood mononuclear cells (PBMCs) isolated from HTLV-I(+) donors, including ATL patients and HTLV-I carriers. HTLV-I-infected T cell lines expressing Tax1 also expressed cell surface CD83 and released soluble CD83. CD83 can be expressed in the JPX-9 cell line by cadmium-mediated Tax1 induction and in Jurkat cells or PBMCs by Tax1 introduction via infection with a recombinant adenovirus carrying the Tax1 gene. The CD83 promoter was activated by Tax1 in an NF-κB-dependent manner. Based on a previous report showing soluble CD83-mediated prostaglandin E2 (PGE2) production from human monocytes in vitro, we tested if PGE2 affected HTLV-I propagation, and found that PGE2 strongly stimulated expression of Tax1 and viral structural molecules. Our results suggest that HTLV-I induces CD83 expression on T cells via Tax1 -mediated NF-κB activation, which may promote HTLV-I infection in vivo.

  20. Identification of a novel gene, Vin-1, in murine leukemia virus-induced T-cell leukemias by provirus insertional mutagenesis.

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    Tremblay, P J; Kozak, C A; Jolicoeur, P

    1992-01-01

    The BL/VL3 radiation leukemia virus is a nondefective retrovirus which induces clonal or oligoclonal T-cell leukemia in mice. To study the role of provirus insertional mutagenesis in the development of these neoplasias, we searched for common provirus integration sites in BL/VL3 radiation leukemia virus-induced tumors. Using cellular sequences flanking a provirus cloned from one of these thymomas, we found that the viral genome was integrated into a common region, designated Vin-1, in a low percentage (5%) of these tumors. The proviruses found in this locus were integrated in the same orientation, close to a CpG-rich island, at proximity of a transcriptional unit encoding a 6-kb RNA. Vin-1 RNA was detected in several organs of the adult mouse. Vin-1 RNA levels were high in tumors having a provirus inserted within the Vin-1 region but were also high in some other tumors whose Vin-1 region was not found to be rearranged. Vin-1 was found to be well conserved among mammalian species and was mapped to mouse chromosome 6, between raf and K-ras-2. Vin-1 appears to be a novel gene which may be involved in tumor development. Images PMID:1738193

  1. Inhibition of apoptosis in T cells expressing human T cell leukemia virus type I Tax.

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    Copeland, K F; Haaksma, A G; Goudsmit, J; Krammer, P H; Heeney, J L

    1994-10-01

    This study set out to determine whether T cell dysfunction associated with HTLV-I led to increased sensitivity of infected cells to apoptosis or, owing to their potential to develop ATL, if infected cells would become resistant to this process. To test this hypothesis we utilized the monoclonal antibody anti-APO-1, which has been demonstrated to induce apoptosis in human T cells. Human T cell lines expressing HTLV-I showed reduced susceptibility to anti-APO-1-induced apoptosis despite expression of high levels of cell surface APO-1. Cell-free supernatant of the Tax-expressing cell line C8166 and heat-inactivated supernatant of the HTLV-I-producing cell line MT2 transferred increased resistance to anti-APO-1 to susceptible Jurkat T cells. Susceptible T cells transfected with an HTLV-I Tax-expressing vector or treated with soluble Tax protein became less susceptible to anti-APO-1-induced cell death. Furthermore, primary human lymphocytes treated with soluble Tax were less susceptible to apoptosis induced by anti-APO-1. The protective effect of Tax in T cell lines and primary human lymphocytes was reversed by the addition of anti-Tax antibodies. Anti-APO-1-induced apoptosis was also found to be inhibited in Jurkat cells by the induction of protein kinase C (PKC) with 12-O-tetradecanoylphorbol-13-acetate (TPA). Resistance to apoptosis conferred by HTLV-I Tax and an active PKC pathway may be factors contributing to the survival of dysregulated HTLV-I-infected T cells prone to the development of adult T cell leukemia.

  2. Alloreactivity of virus-specific T cells: possible implication of graft-versus-host disease and graft-versus-leukemia effects.

    Science.gov (United States)

    Fuji, Shigeo; Kapp, Markus; Einsele, Hermann

    2013-10-14

    Immune reconstitution of functional virus-specific T cells after allogeneic hematopoietic stem cell transplantation (HSCT) has been intensively investigated. However, the possible role of crossreactivity of these virus-specific T cells against allogeneic targets is still unclear. Theoretically, as in the field of organ transplantation, virus-specific T cells possess crossreactivity potential after allogeneic HSCT. Such crossreactivity is assumed to play a role in graft-versus-host disease and graft-versus-leukemia effects. In this article, we aim to give a comprehensive overview of current understanding about crossreactivity of virus-specific T cells.

  3. Regulation of expression driven by human immunodeficiency virus type 1 and human T-cell leukemia virus type I long terminal repeats in pluripotential human embryonic cells

    International Nuclear Information System (INIS)

    Maio, J.; Brown, F.L.

    1988-01-01

    Human pluripotential embryonic teratocarcinoma cells differentially expressed gene activity controlled by the human immunodeficiency virus type 1 (HIV-1) and human T-cell leukemia virus type I (HTLV-I) long terminal repeats (LTRs) when differentiation was induced by the morphogen all-trans retinoic acid. The alterations occurred after commitment and before the appearance of the multiple cell types characteristic of these pluripotential cells. After commitment, gene activity controlled by the HIV-1 LTR markedly increased, whereas that controlled by the HTLV-I LTR decreased. Steady-state mRNA levels and nuclear run-on transcription indicated that the increased HIV-1-directed activity during differentiation occurred posttranscriptionally, whereas the decreased HTLV-I activity was at the transcriptional level. Phorbol esters did not cause commitment but strongly enhanced expression by both viral LTRs at the transcriptional level. Differentiating cells gradually lost the ability to respond to phorbol ester stimulation. Experiments with a deletion mutant of the HIV-1 LTR suggested that this was due to imposition of negative regulation during differentiation that was not reversed by phorbol ester induction. Cycloheximide, with or without phorbol ester, slightly stimulated HIV-1-directed activity at the transcriptional level and massively increased the amounts of steady-state mRNA by posttranscriptional superinduction. It appeared, however, that new nuclear protein synthesis was required for maximal transcriptional stimulation by phorbol esters. Thus, changing cellular regulatory mechanisms influenced human retrovirus expression during human embryonic cell differentiation

  4. PDZ domain-binding motif of human T-cell leukemia virus type 1 Tax oncoprotein augments the transforming activity in a rat fibroblast cell line

    International Nuclear Information System (INIS)

    Hirata, Akira; Higuchi, Masaya; Niinuma, Akiko; Ohashi, Minako; Fukushi, Masaya; Oie, Masayasu; Akiyama, Tetsu; Tanaka, Yuetsu; Gejyo, Fumitake; Fujii, Masahiro

    2004-01-01

    While human T-cell leukemia virus type 1 (HTLV-1) is associated with the development of adult T-cell leukemia (ATL), HTLV-2 has not been reported to be associated with such malignant leukemias. HTLV-1 Tax1 oncoprotein transforms a rat fibroblast cell line (Rat-1) to form multiple large colonies in soft agar, and this activity is much greater than that of HTLV-2 Tax2. We have demonstrated here that the increased number of transformed colonies induced by Tax1 relative to Tax2 was mediated by a PDZ domain-binding motif (PBM) in Tax1, which is absent in Tax2. Tax1 PBM mediated the interaction of Tax1 with the discs large (Dlg) tumor suppressor containing PDZ domains, and the interaction correlated well with the transforming activities of Tax1 and the mutants. Through this interaction, Tax1 altered the subcellular localization of Dlg from the detergent-soluble to the detergent-insoluble fraction in a fibroblast cell line as well as in HTLV-1-infected T-cell lines. These results suggest that the interaction of Tax1 with PDZ domain protein(s) is critically involved in the transforming activity of Tax1, the activity of which may be a crucial factor in malignant transformation of HTLV-1-infected cells in vivo

  5. Human T cell leukemia virus type I prevents cell surface expression of the T cell receptor through down-regulation of the CD3-gamma, -delta, -epsilon, and -zeta genes

    NARCIS (Netherlands)

    de Waal Malefyt, R.; Yssel, H.; Spits, H.; de Vries, J. E.; Sancho, J.; Terhorst, C.; Alarcon, B.

    1990-01-01

    Infection and transformation by human T cell leukemia virus type I (HTLV-I) up-regulates expression of several inducible genes including those coding for cytokines involved in the proliferation of normal and leukemic T cells. We demonstrate that HTLV-I can also shut off expression of the CD3-gamma,

  6. Inhibition of apoptosis in T cells expressing human T cell leukemia virus type I Tax

    NARCIS (Netherlands)

    Copeland, K. F.; Haaksma, A. G.; Goudsmit, J.; Krammer, P. H.; Heeney, J. L.

    1994-01-01

    This study set out to determine whether T cell dysfunction associated with HTLV-I led to increased sensitivity of infected cells to apoptosis or, owing to their potential to develop ATL, if infected cells would become resistant to this process. To test this hypothesis we utilized the monoclonal

  7. Endogenous CD317/Tetherin limits replication of HIV-1 and murine leukemia virus in rodent cells and is resistant to antagonists from primate viruses.

    Science.gov (United States)

    Goffinet, Christine; Schmidt, Sarah; Kern, Christian; Oberbremer, Lena; Keppler, Oliver T

    2010-11-01

    Human CD317 (BST-2/tetherin) is an intrinsic immunity factor that blocks the release of retroviruses, filoviruses, herpesviruses, and arenaviruses. It is unclear whether CD317 expressed endogenously in rodent cells has the capacity to interfere with the replication of the retroviral rodent pathogen murine leukemia virus (MLV) or, in the context of small-animal model development, contributes to the well-established late-phase restriction of human immunodeficiency virus type 1 (HIV-1). Here, we show that small interfering RNA (siRNA)-mediated knockdown of CD317 relieved a virion release restriction and markedly enhanced the egress of HIV-1, HIV-2, and simian immunodeficiency virus (SIV) in rat cells, including primary macrophages. Moreover, rodent CD317 potently inhibited MLV release, and siRNA-mediated depletion of CD317 in a mouse T-cell line resulted in the accelerated spread of MLV. Several virus-encoded antagonists have recently been reported to overcome the restriction imposed by human or monkey CD317, including HIV-1 Vpu, envelope glycoproteins of HIV-2 and Ebola virus, Kaposi's sarcoma-associated herpesvirus K5, and SIV Nef. In contrast, both rat and mouse CD317 showed a high degree of resistance to these viral antagonists. These data suggest that CD317 is a broadly acting and conserved mediator of innate control of retroviral infection and pathogenesis that restricts the release of retroviruses and lentiviruses in rodents. The high degree of resistance of the rodent CD317 restriction factors to antagonists from primate viruses has implications for HIV-1 small-animal model development and may guide the design of novel antiviral interventions.

  8. Cell Infectivity in relation to bovine leukemia virus gp51 and p24 in bovine milk exosomes.

    Directory of Open Access Journals (Sweden)

    Tetsuya Yamada

    Full Text Available Exosomes are small membranous microvesicles (40-100 nm in diameter and are extracellularly released from a wide variety of cells. Exosomes contain microRNA, mRNA, and cellular proteins, which are delivered into recipient cells via these exosomes, and play a role in intercellular communication. In bovine leukemia virus (BLV infection of cattle, although it is thought to be a minor route of infection, BLV can be transmitted to calves via milk. Here, we investigated the association between exosomes and BLV in bovine milk. BLV structural proteins, gp51 (Env and p24 (Gag, were detected in bovine milk exosomes from BLV-infected cattle by Western blot analysis. In cells inoculated with these milk exosomes, BLV DNA was not detected during three serial passages by nested PCR. Purification of exosomes from persistently BLV-infected cells was achieved by immuno-magnetic separation using an antibody against exosomes coupled to magnetic beads. Consistently, BLV gp51 and p24 proteins were detected in purified exosomes. Moreover, reverse transcriptase activity was observed in purified exosomes, meaning that exosomes also contain viral enzyme. However, BLV DNA was not detected in serially passaged cells after inoculation of purified exosomes, indicating that exosomes carrying BLV proteins appeared to be not infectious. These results suggest that BLV proteins are released with milk exosomes and could be transferred into recipient cells of calves via milk exosomes as an alternative route not requiring virus infection. Moreover it is also possible that bovine milk exosomes play a role in clearance of BLV proteins from infected cells.

  9. Increased expression of the regulatory T cell-associated marker CTLA-4 in bovine leukemia virus infection.

    Science.gov (United States)

    Suzuki, Saori; Konnai, Satoru; Okagawa, Tomohiro; Ikebuchi, Ryoyo; Nishimori, Asami; Kohara, Junko; Mingala, Claro N; Murata, Shiro; Ohashi, Kazuhiko

    2015-02-15

    Regulatory T cells (Tregs) play a critical role in the maintenance of the host's immune system. Tregs, particularly CD4(+)CD25(+)Foxp3(+) T cells, have been reported to be involved in the immune evasion mechanism of tumors and several pathogens that cause chronic infections. Recent studies showed that a Treg-associated marker, cytotoxic T-lymphocyte antigen 4 (CTLA-4), is closely associated with the progression of several diseases. We recently reported that the proportion of Foxp3(+)CD4(+) cells was positively correlated with the number of lymphocytes, virus titer, and virus load but inversely correlated with IFN-γ expression in cattle infected with bovine leukemia virus (BLV), which causes chronic infection and lymphoma in its host. Here the kinetics of CTLA-4(+) cells were analyzed in BLV-infected cattle. CTLA-4 mRNA was predominantly expressed in CD4(+) T cells in BLV-infected cattle, and the expression was positively correlated with Foxp3 mRNA expression. To test for differences in the protein expression level of CTLA-4, we measured the proportion of CTLA-4-expressing cells by flow cytometry. In cattle with persistent lymphocytosis (PL), mean fluorescence intensities (MFIs) of CTLA-4 on CD4(+) and CD25(+) T cells were significantly increased compared with that in control and aleukemic (AL) cattle. The percentage of CTLA-4(+) cells in the CD4(+) T cell subpopulation was positively correlated with TGF-β mRNA expression, suggesting that CD4(+)CTLA-4(+) T cells have a potentially immunosuppressive function in BLV infection. In the limited number of cattle that were tested, the anti-CTLA-4 antibody enhanced the expression of CD69, IL-2, and IFN-γ mRNA in anti-programmed death ligand 1 (PD-L1) antibody-treated peripheral blood mononuclear cells from BLV-infected cattle. Together with previous findings, the present results indicate that Tregs may be involved in the inhibition of T cell function during BLV infection. Copyright © 2014 Elsevier B.V. All rights

  10. Induction of IL-10- and IFN-gamma-producing T-cell responses by autoreactive T-cells expressing human T-cell leukemia virus type I Tax.

    Science.gov (United States)

    Takatsuka, Natsuko; Hasegawa, Atsuhiko; Takamori, Ayako; Shimizu, Yukiko; Kato, Hirotomo; Ohashi, Takashi; Amagasa, Teruo; Masuda, Takao; Kannagi, Mari

    2009-09-01

    Human T-cell leukemia virus type I (HTLV-I) is associated with adult T-cell leukemia, HTLV-I-associated myelopathy/tropical spastic paraparesis and various autoimmune-like disorders. T-cell immune suppression is also associated with HTLV-I infection. Mechanisms of diverse immune dysregulation in HTLV-I infection are obscure. Here, we investigated a potential link between autoimmunity and immune suppression in HTLV-I infection. G14, an IL-2-dependent HTLV-I-negative CD4(+)CD8(+) T-cell line previously established from an HTLV-I-infected rat, constantly proliferated and produced IFN-gamma. IFN-gamma production by G14 cells was dependent on interactions between CD4 and MHC-II, suggesting that G14 cells recognized self-antigens presented by MHC-II on themselves. To examine immune response to G14 cells, we inoculated G14 cells into syngeneic naive rats. Interestingly, T-cells isolated from these rats vigorously proliferated when stimulated with G14-Tax cells that stably expressed HTLV-I Tax, but not with G14 cells. G14-Tax-mediated T-cell proliferation was abrogated by antibodies to CD80 and CD86 that were up-regulated in G14-Tax cells. T-cells propagated by repetitive G14-Tax cell stimulations in culture with IL-2 expressed CD4, CD25 and cytolytic T lymphocyte-associated antigen 4 (CTLA-4), produced abundant amounts of IL-10 and IFN-gamma in response to G14 cells and suppressed growth of G14 cells mainly through supernatant-mediated mechanisms. Similar IL-10- and IFN-gamma-producing CD4(+)CD25(+)CTLA-4(+) T-cells were predominantly induced in culture of splenocytes from HTLV-I-infected rats following stimulation with G14-Tax cells. These results implied that expression of Tax in the otherwise low immunogenic autoreactive T-cells induced IL-10- and IFN-gamma-producing T-cell responses with regulatory effects against the autoreactive cells. Our findings provide new insights into the complex immune conditions underlying HTLV-I-associated diseases.

  11. Chimeras of receptors for gibbon ape leukemia virus/feline leukemia virus B and amphotropic murine leukemia virus reveal different modes of receptor recognition by retrovirus

    DEFF Research Database (Denmark)

    Pedersen, Lene; Johann, Stephen V; van Zeijl, Marja

    1995-01-01

    Glvr1 encodes the human receptor for gibbon ape leukemia virus (GALV) and feline leukemia virus subgroup B (FeLV-B), while the related gene Glvr2 encodes the human receptor for amphotropic murine leukemia viruses (A-MLVs). The two proteins are 62% identical in their amino acid sequences...

  12. Bovine leukemia virus G4 enhances virus production.

    Science.gov (United States)

    Murakami, Hironobu; Asano, Shotaro; Uchiyama, Jumpei; Sato, Reiichiro; Sakaguchi, Masahiro; Tsukamoto, Kenji

    2017-06-15

    The nonstructural G4 gene of bovine leukemia virus (BLV) has been thought to function in virus replication. However, the discovery of the AS1 gene on the antisense strand of the G4 gene has affected this interpretation. In this study, we investigated the function of G4 in virus production independent of the AS1 gene using a reverse genetic approach, and briefly examined the association of the G4 protein with Tax, which is also a nonstructural protein that promotes virus replication. First, we constructed a mutant molecular clone of BLV with a nonsense mutation in G4 that had a minimal effect on the AS1 gene. Comparison of the wild-type and mutant molecular clones indicated that the nonsense mutation resulted in a reduction of virus in the culture supernatant and accumulation of viral RNA (vRNA) in cells. Moreover, G4 and Tax expression in cells was shown to synergistically enhance virus production. Therefore, we suggest that G4 enhances virus production through abrogation of vRNA accumulation. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. C-terminal Domain Modulates the Nucleic Acid Chaperone Activity of Human T-cell Leukemia Virus Type 1 Nucleocapsid Protein via an Electrostatic Mechanism*

    OpenAIRE

    Qualley, Dominic F.; Stewart-Maynard, Kristen M.; Wang, Fei; Mitra, Mithun; Gorelick, Robert J.; Rouzina, Ioulia; Williams, Mark C.; Musier-Forsyth, Karin

    2009-01-01

    Retroviral nucleocapsid (NC) proteins are molecular chaperones that facilitate nucleic acid (NA) remodeling events critical in viral replication processes such as reverse transcription. Surprisingly, the NC protein from human T-cell leukemia virus type 1 (HTLV-1) is an extremely poor NA chaperone. Using bulk and single molecule methods, we find that removal of the anionic C-terminal domain (CTD) of HTLV-1 NC results in a protein with chaperone properties comparable with that of other retrovir...

  14. Downregulation of proapoptotic Bim augments IL-2-independent T-cell transformation by human T-cell leukemia virus type-1 Tax

    International Nuclear Information System (INIS)

    Higuchi, Masaya; Takahashi, Masahiko; Tanaka, Yuetsu; Fujii, Masahiro

    2014-01-01

    Human T-cell leukemia virus type 1 (HTLV-1), an etiological agent of adult T-cell leukemia, immortalizes and transforms primary human T cells in vitro in both an interleukin (IL)-2-dependent and IL-2-independent manner. Expression of the HTLV-1 oncoprotein Tax transforms the growth of the mouse T-cell line CTLL-2 from being IL-2-dependent to IL-2-independent. Withdrawal of IL-2 from normal activated T cells induces apoptosis, which is mediated through the inducible expression of several proapoptotic proteins, including Bim. In this study, we found that Tax protects IL-2-depleted T cells against Bim-induced apoptosis. Withdrawal of IL-2 from CTLL-2 cells induced a prominent increase in the level of Bim protein in CTLL-2 cells, but not in Tax-transformed CTLL-2 cells. This inhibition of Bim in Tax-transformed CTLL-2 cells was mediated by two mechanisms: downregulation of Bim mRNA and posttranscriptional reduction of Bim protein. Transient expression of Tax in CTLL-2 cells also inhibited IL-2 depletion–induced expression of Bim, however, this decrease in Bim protein expression was not due to downregulation of Bim mRNA, thus indicating that Bim mRNA downregulation in Tax-transformed CTLL-2 occurs only after long-term expression of Tax. Transient expression of Tax in CTLL-2 cells also induced Erk activation, however, this was not involved in the reduction of Bim protein. Knockdown of Bim expression in CTLL-2 cells augmented Tax-induced IL-2-independent transformation. HTLV-1 infection of human T cells also reduced their levels of Bim protein, and restoring Bim expression in HTLV-1-infected cells reduced their proliferation by inducing apoptosis. Taken together, these results indicate that Tax-induced downregulation of Bim in HTLV-1-infected T cells promotes their IL-2-independent growth, thereby supporting the persistence of HTLV-1 infection in vivo

  15. Host virus and pneumococcus-specific immune responses in high-count monoclonal B-cell lymphocytosis and chronic lymphocytic leukemia: implications for disease progression.

    Science.gov (United States)

    Criado, Ignacio; Muñoz-Criado, Santiago; Rodríguez-Caballero, Arancha; Nieto, Wendy G; Romero, Alfonso; Fernández-Navarro, Paulino; Alcoceba, Miguel; Contreras, Teresa; González, Marcos; Orfao, Alberto; Almeida, Julia

    2017-07-01

    Patients diagnosed with chronic lymphocytic leukemia (CLL) display a high incidence of infections due to an associated immunodeficiency that includes hypogammaglobulinemia. A higher risk of infections has also been recently reported for high-count monoclonal B-cell lymphocytosis, while no information is available in low-count monoclonal B-cell lymphocytosis. Here, we evaluated the status of the humoral immune system in patients with chronic lymphocytic leukemia (n=58), as well as in low- (n=71) and high- (n=29) count monoclonal B-cell lymphocytosis versus healthy donors (n=91). Total free plasma immunoglobulin titers and specific levels of antibodies against cytomegalovirus, Epstein-Barr virus, influenza and S.pneumoniae were measured by nephelometry and ELISA-based techniques, respectively. Overall, our results show that both CLL and high-count monoclonal B-cell lymphocytosis patients, but not low-count monoclonal B-cell lymphocytosis subjects, present with relatively high levels of antibodies specific for the latent viruses investigated, associated with progressively lower levels of S.pneumoniae -specific immunoglobulins. These findings probably reflect asymptomatic chronic reactivation of humoral immune responses against host viruses associated with expanded virus-specific antibody levels and progressively decreased protection against other micro-organisms, denoting a severe humoral immunodeficiency state not reflected by the overall plasma immunoglobulin levels. Alternatively, these results could reflect a potential role of ubiquitous viruses in the pathogenesis of the disease. Further analyses are necessary to establish the relevance of such asymptomatic humoral immune responses against host viruses in the expansion of the tumor B-cell clone and progression from monoclonal B-cell lymphocytosis to CLL. Copyright© 2017 Ferrata Storti Foundation.

  16. In Vitro Activation of the IκB Kinase Complex by Human T-cell Leukemia Virus Type-1 Tax*

    Science.gov (United States)

    Mukherjee, Sohini; Negi, Veera S.; Keitany, Gladys; Tanaka, Yuetsu; Orth, Kim

    2008-01-01

    Human T-cell leukemia virus type-I expresses Tax, a 40-kDa oncoprotein that activates IκB kinase (IKK), resulting in constitutive activation of NFκB. Herein, we have developed an in vitro signaling assay to analyze IKK complex activation by recombinant Tax. Using this assay in combination with reporter assays, we demonstrate that Tax-mediated activation of IKK is independent of phosphatases. We show that sustained activation of the Tax-mediated activation of the NFκB pathway is dependent on an intact Hsp90-IKK complex. By acetylating and thereby preventing activation of the IKK complex by the Yersinia effector YopJ, we demonstrate that Tax-mediated activation of the IKK complex requires a phosphorylation step. Our characterization of an in vitro signaling assay system for the mechanism of Tax-mediated activation of the IKK complex with a variety of mutants and inhibitors results in a working model for the biochemical mechanism of Tax-induced activation. PMID:18223255

  17. Short communication. Microculture syncytia assay for bovine leukemia virus

    Energy Technology Data Exchange (ETDEWEB)

    Paul, P.S.; Castro, A.E.; Pomeroy, K.A.; Johnson, D.W.; Muscoplat, C.C.

    1978-01-01

    A microculture syncytia assay for the detection of bovine leukemia virus (BLV) has been described and compared with the conventional macroculture assay. The microculture assay required fewer indicator cells, was as sensitive as the macroculture assay and provided a reproducible test for the detection and titration of BLV.

  18. Human T-cell leukemia virus type-I (HTLV-I) tax is not the only one factor to enhance human immunodeficiency virus type-I (HIV-1) infection in culture-supernatants.

    Science.gov (United States)

    Tempaku, A; Maeda, Y; Song, W; Harada, S

    2001-01-01

    It is hypothesized that supernatants from cell cultures contain several factors to modify the human immunodeficiency virus type-1 (HIV-1) infection. Single round infection with pseudotyped viruses with envelope from HIV-1, amphotropic murine leukemia virus (A-MLV) and vesicular stomatitis virus G-protein (VSV-G) carrying luciferase reporter gene detected that not only human T-cell leukemia/lymphoma virus type-I (HTLV-1) transformed cells but also HTLV-I-unrelated T-cells and BJA-B cells released factors enhancing the infection with all pseudotyped viruses in their culture-supernatants. No supernatants upregulated the level of transcription from transfected DNA probe. suggesting that the action of supernatants is different from that of tumor necrosis factor (TNF) and Tax of HTLV-I. These results indicated that factors not always related to HTLV-I were ubiquitously produced and promoted viral infections, probably due to non-specific enhancement of early phase of the infection.

  19. Gene profiling of Graffi murine leukemia virus-induced lymphoid leukemias: identification of leukemia markers and Fmn2 as a potential oncogene.

    Science.gov (United States)

    Charfi, Cyndia; Voisin, Véronique; Levros, Louis-Charles; Edouard, Elsy; Rassart, Eric

    2011-02-10

    The Graffi murine leukemia virus induces a large spectrum of leukemias in mice and thus provides a good model to compare the transcriptome of all types of leukemias. We analyzed the gene expression profiles of both T and B leukemias induced by the virus with DNA microarrays. Given that we considered that a 4-fold change in expression level was significant, 388 probe sets were associated to B, to T, or common to both leukemias. Several of them were not yet associated with lymphoid leukemia. We confirmed specific deregulation of Fmn2, Arntl2, Bfsp2, Gfra2, Gpm6a, and Gpm6b in B leukemia, of Nln, Fbln1, and Bmp7 in T leukemias, and of Etv5 in both leukemias. More importantly, we show that the mouse Fmn2 induced an anchorage-independent growth, a drastic modification in cell shape with a concomitant disruption of the actin cytoskeleton. Interestingly, we found that human FMN2 is overexpressed in approximately 95% of pre-B acute lymphoblastic leukemia with the highest expression levels in patients with a TEL/AML1 rearrangement. These results, surely related to the role of FMN2 in meiotic spindle maintenance, suggest its important role in leukemogenesis. Finally, we propose a new panel of genes potentially involved in T and/or B leukemias.

  20. Human T Cell Leukemia Virus Type I Tax-Induced IκB-ζ Modulates Tax-Dependent and Tax-Independent Gene Expression in T Cells1

    Science.gov (United States)

    Kimura, Ryuichiro; Senba, Masachika; Cutler, Samuel J; Ralph, Stephen J; Xiao, Gutian; Mori, Naoki

    2013-01-01

    Human T cell leukemia virus type I (HTLV-I) is the etiologic agent of adult T cell leukemia (ATL) and various inflammatory disorders including HTLV-I-associated myelopathy/tropical spastic paraparesis. HTLV-I oncoprotein Tax is known to cause permanent activation of many cellular transcription factors including nuclear factor-κB (NF-κB), cyclic adenosine 3′,5′-monophosphate response element-binding protein, and activator protein 1 (AP-1). Here, we show that NF-κB-binding cofactor inhibitor of NF-κB-ζ (IκB-ζ) is constitutively expressed in HTLV-I-infected T cell lines and ATL cells, and Tax transactivates the IκB-ζ gene, mainly through NF-κB. Microarray analysis of IκB-ζ-expressing uninfected T cells demonstrated that IκB-ζ induced the expression of NF-κB. and interferon-regulatory genes such as B cell CLL/lymphoma 3 (Bcl3), guanylate-binding protein 1, and signal transducer and activator of transcription 1. The transcriptional activation domain, nuclear localization signal, and NF-κB-binding domain of IκB-ζ were required for Bcl3 induction, and IκB-ζ synergistically enhanced Tax-induced Bcl3 transactivation in an NF-κB-dependent manner. Interestingly, IκB-ζ inhibited Tax-induced NF-κB, AP-1 activation, and HTLV-I transcription. Furthermore, IκB-ζ interacted with Tax in vitro and this interaction was also observed in an HTLV-I-transformed T cell line. These results suggest that IκB-ζ modulates Tax-dependent and Tax-independent gene transcription in T cells. The function of IκB-ζ may be of significance in ATL genesis and pathogenesis of HTLV-I-associated diseases. PMID:24027435

  1. Human T Cell Leukemia Virus Type I Tax-Induced IκB-ζ Modulates Tax-Dependent and Tax-Independent Gene Expression in T Cells

    Directory of Open Access Journals (Sweden)

    Ryuichiro Kimura

    2013-09-01

    Full Text Available Human T cell leukemia virus type I (HTLV-I is the etiologic agent of adult T cell leukemia (ATL and various inflammatory disorders including HTLV-I-associated myelopathy/tropical spastic paraparesis. HTLV-I oncoprotein Tax is known to cause permanent activation of many cellular transcription factors including nuclear factor-κB (NF-κB, cyclic adenosine 3′,5′-monophosphate response element-binding protein, and activator protein 1 (AP-1. Here, we show that NF-κB-binding cofactor inhibitor of NF-κB-ζ (IκB-ζ is constitutively expressed in HTLV-I-infected T cell lines and ATL cells, and Tax transactivates the IκB-ζ gene, mainly through NF-κB. Microarray analysis of IκB-ζ-expressing uninfected T cells demonstrated that IκB-ζ induced the expression of NF-κB. and interferon-regulatory genes such as B cell CLL/lymphoma 3 (Bcl3, guanylate-binding protein 1, and signal transducer and activator of transcription 1. The transcriptional activation domain, nuclear localization signal, and NF-κB-binding domain of IκB-ζ were required for Bcl3 induction, and IκB-ζ synergistically enhanced Tax-induced Bcl3 transactivation in an NF-κB-dependent manner. Interestingly, IκB-ζ inhibited Tax-induced NF-κB, AP-1 activation, and HTLV-I transcription. Furthermore, IκB-ζ interacted with Tax in vitro and this interaction was also observed in an HTLV-I-transformed T cell line. These results suggest that IκB-ζ modulates Tax-dependent and Tax-independent gene transcription in T cells. The function of IκB-ζ may be of significance in ATL genesis and pathogenesis of HTLV-I-associated diseases.

  2. Low CD4/CD8 T-Cell Ratio Associated with Inflammatory Arthropathy in Human T-Cell Leukemia Virus Type I Tax Transgenic Mice

    Science.gov (United States)

    Ohsugi, Takeo; Kumasaka, Toshio

    2011-01-01

    Background Human T-cell leukemia virus type I (HTLV-1) can cause an aggressive malignancy known as adult T-cell leukemia/lymphoma (ATL) as well as inflammatory diseases such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). A transgenic mouse that expresses HTLV-1 Tax also develops T-cell leukemia/lymphoma and an inflammatory arthropathy that resembles rheumatoid arthritis. The aim of this study was to identify the primary T-cell subsets involved in the development of arthropathy in Tax transgenic mice. Principal Findings By 24 months of age, Tax transgenic mice developed severe arthropathy with a cumulative incidence of 22.8%. The pathological findings of arthropathy in Tax transgenic mice were similar to those seen in human rheumatoid arthritis or mouse models of rheumatoid arthritis, with synovial proliferation and a positive rheumatoid factor. Before the onset of spontaneous arthropathy, young and old Tax transgenic mice were not sensitive to collagen and did not develop arthritis after immunization with type II collagen. The arthropathic Tax transgenic mice showed a significantly decreased proportion of splenic CD4+ T cells, whereas the proportion of splenic CD8+ T cells was increased. Regulatory T cells (CD4+CD25+Foxp3+) were significantly decreased and CD8+ T cells that expressed the chemokine receptor CCR4 (CD8+CCR4+) were significantly increased in arthropathic Tax transgenic mice. The expression of tax mRNA was strong in the spleen and joints of arthropathic mice, with a 40-fold increase compared with healthy transgenic mice. Conclusions Our findings reveal that Tax transgenic mice develop rheumatoid-like arthritis with proliferating synovial cells in the joints; however, the proportion of different splenic T-cell subsets in these mice was completely different from other commonly used animal models of rheumatoid arthritis. The crucial T-cell subsets in arthropathic Tax transgenic mice appear to resemble those in HAM/TSP patients

  3. Low CD4/CD8 T-cell ratio associated with inflammatory arthropathy in human T-cell leukemia virus type I Tax transgenic mice.

    Directory of Open Access Journals (Sweden)

    Takeo Ohsugi

    Full Text Available BACKGROUND: Human T-cell leukemia virus type I (HTLV-1 can cause an aggressive malignancy known as adult T-cell leukemia/lymphoma (ATL as well as inflammatory diseases such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP. A transgenic mouse that expresses HTLV-1 Tax also develops T-cell leukemia/lymphoma and an inflammatory arthropathy that resembles rheumatoid arthritis. The aim of this study was to identify the primary T-cell subsets involved in the development of arthropathy in Tax transgenic mice. PRINCIPAL FINDINGS: By 24 months of age, Tax transgenic mice developed severe arthropathy with a cumulative incidence of 22.8%. The pathological findings of arthropathy in Tax transgenic mice were similar to those seen in human rheumatoid arthritis or mouse models of rheumatoid arthritis, with synovial proliferation and a positive rheumatoid factor. Before the onset of spontaneous arthropathy, young and old Tax transgenic mice were not sensitive to collagen and did not develop arthritis after immunization with type II collagen. The arthropathic Tax transgenic mice showed a significantly decreased proportion of splenic CD4(+ T cells, whereas the proportion of splenic CD8(+ T cells was increased. Regulatory T cells (CD4(+CD25(+Foxp3(+ were significantly decreased and CD8(+ T cells that expressed the chemokine receptor CCR4 (CD8(+CCR4(+ were significantly increased in arthropathic Tax transgenic mice. The expression of tax mRNA was strong in the spleen and joints of arthropathic mice, with a 40-fold increase compared with healthy transgenic mice. CONCLUSIONS: Our findings reveal that Tax transgenic mice develop rheumatoid-like arthritis with proliferating synovial cells in the joints; however, the proportion of different splenic T-cell subsets in these mice was completely different from other commonly used animal models of rheumatoid arthritis. The crucial T-cell subsets in arthropathic Tax transgenic mice appear to resemble

  4. Plasma cell leukemia

    DEFF Research Database (Denmark)

    Fernández de Larrea, C; Kyle, R A; Durie, B G M

    2013-01-01

    Plasma cell leukemia (PCL) is a rare and aggressive variant of myeloma characterized by the presence of circulating plasma cells. It is classified as either primary PCL occurring at diagnosis or as secondary PCL in patients with relapsed/refractory myeloma. Primary PCL is a distinct clinic......-pathological entity with different cytogenetic and molecular findings. The clinical course is aggressive with short remissions and survival duration. The diagnosis is based upon the percentage (≥ 20%) and absolute number (≥ 2 × 10(9)/l) of plasma cells in the peripheral blood. It is proposed that the thresholds...... regimens and bortezomib-based regimens are recommended followed by high-dose therapy with autologous stem cell transplantation if feasible. Allogeneic transplantation can be considered in younger patients. Prospective multicenter studies are required to provide revised definitions and better understanding...

  5. The Icsbp locus is a common proviral insertion site in mature B-cell lymphomas/plasmacytomas induced by exogenous murine leukemia virus

    International Nuclear Information System (INIS)

    Ma Shiliang; Sorensen, Annette Balle; Kunder, Sandra; Sorensen, Karina Dalsgaard; Quintanilla-Martinez, Leticia; Morris, David W.; Schmidt, Joerg; Pedersen, Finn Skou

    2006-01-01

    ICSBP (interferon consensus sequence binding protein)/IRF8 (interferon regulatory factor 8) is an interferon gamma-inducible transcription factor expressed predominantly in hematopoietic cells, and down-regulation of this factor has been observed in chronic myelogenous leukemia and acute myeloid leukemia in man. By screening about 1200 murine leukemia virus (MLV)-induced lymphomas, we found proviral insertions at the Icsbp locus in 14 tumors, 13 of which were mature B-cell lymphomas or plasmacytomas. Only one was a T-cell lymphoma, although such tumors constituted about half of the samples screened. This indicates that the Icsbp locus can play a specific role in the development of mature B-lineage malignancies. Two proviral insertions in the last Icsbp exon were found to act by a poly(A)-insertion mechanism. The remaining insertions were found within or outside Icsbp. Since our results showed expression of Icsbp RNA and protein in all end-stage tumor samples, a simple tumor suppressor function of ICSBP is not likely. Interestingly, proviral insertions at Icsbp have not been reported from previous extensive screenings of mature B-cell lymphomas induced by endogenous MLVs. We propose that ICSBP might be involved in an early modulation of an immune response to exogenous MLVs that might also play a role in proliferation of the mature B-cell lymphomas

  6. Comparative analysis of radiation- and virus-induced leukemias in BALB/c mice

    International Nuclear Information System (INIS)

    Newcomb, E.W.; Binari, R.; Fleissner, E.

    1985-01-01

    Endogenous murine leukemia virus (MuLV) proviral copies were analyzed in thymomas induced in normal BALB/c (Fv-1b) and in Fv-1n congenic mice by X-irradiation. Both strains of mice developed leukemia with similar kinetics, indicating that N-tropism of endogenous MuLV was not a rate-limiting factor in development of disease. Southern blot analysis, using a probe specific for ecotropic virus and for ecotropic-specific sequences retained in pathogenic, env-recombinant viruses, showed that the majority of radiation leukemias lacked newly acquired, clonally integrated, proviruses. This was in contrast to virus-induced leukemias, which routinely exhibited several new proviral integration sites. When an internal proviral DNA restriction fragment was monitored, some radiation leukemias showed evidence of nonclonal infection, accounting for more frequent isolation of infectious virus from such leukemias. Differences in expression of T-cell surface antigens were found in X-ray-induced and virus-induced leukemias. All radiation leukemias were TL positive, whereas virus-induced leukemias were primarily negative for TL. Some differences were also found in Lyt-1 and Lyt-2 expression. The data as a whole suggest that, in the majority of cases, radiation leukemogenesis is not initiated by a viral route--that is, the sort of viral mechanism for which exogenous infection by known pathogenic MuLV is the paradigm

  7. Comparative analysis of radiation- and virus-induced leukemias in BALB/c mice

    Energy Technology Data Exchange (ETDEWEB)

    Newcomb, E.W.; Binari, R.; Fleissner, E.

    1985-01-15

    Endogenous murine leukemia virus (MuLV) proviral copies were analyzed in thymomas induced in normal BALB/c (Fv-1b) and in Fv-1n congenic mice by X-irradiation. Both strains of mice developed leukemia with similar kinetics, indicating that N-tropism of endogenous MuLV was not a rate-limiting factor in development of disease. Southern blot analysis, using a probe specific for ecotropic virus and for ecotropic-specific sequences retained in pathogenic, env-recombinant viruses, showed that the majority of radiation leukemias lacked newly acquired, clonally integrated, proviruses. This was in contrast to virus-induced leukemias, which routinely exhibited several new proviral integration sites. When an internal proviral DNA restriction fragment was monitored, some radiation leukemias showed evidence of nonclonal infection, accounting for more frequent isolation of infectious virus from such leukemias. Differences in expression of T-cell surface antigens were found in X-ray-induced and virus-induced leukemias. All radiation leukemias were TL positive, whereas virus-induced leukemias were primarily negative for TL. Some differences were also found in Lyt-1 and Lyt-2 expression. The data as a whole suggest that, in the majority of cases, radiation leukemogenesis is not initiated by a viral route--that is, the sort of viral mechanism for which exogenous infection by known pathogenic MuLV is the paradigm.

  8. Downregulation of proapoptotic Bim augments IL-2-independent T-cell transformation by human T-cell leukemia virus type-1 Tax.

    Science.gov (United States)

    Higuchi, Masaya; Takahashi, Masahiko; Tanaka, Yuetsu; Fujii, Masahiro

    2014-12-01

    Human T-cell leukemia virus type 1 (HTLV-1), an etiological agent of adult T-cell leukemia, immortalizes and transforms primary human T cells in vitro in both an interleukin (IL)-2-dependent and IL-2-independent manner. Expression of the HTLV-1 oncoprotein Tax transforms the growth of the mouse T-cell line CTLL-2 from being IL-2-dependent to IL-2-independent. Withdrawal of IL-2 from normal activated T cells induces apoptosis, which is mediated through the inducible expression of several proapoptotic proteins, including Bim. In this study, we found that Tax protects IL-2-depleted T cells against Bim-induced apoptosis. Withdrawal of IL-2 from CTLL-2 cells induced a prominent increase in the level of Bim protein in CTLL-2 cells, but not in Tax-transformed CTLL-2 cells. This inhibition of Bim in Tax-transformed CTLL-2 cells was mediated by two mechanisms: downregulation of Bim mRNA and posttranscriptional reduction of Bim protein. Transient expression of Tax in CTLL-2 cells also inhibited IL-2 depletion-induced expression of Bim, however, this decrease in Bim protein expression was not due to downregulation of Bim mRNA, thus indicating that Bim mRNA downregulation in Tax-transformed CTLL-2 occurs only after long-term expression of Tax. Transient expression of Tax in CTLL-2 cells also induced Erk activation, however, this was not involved in the reduction of Bim protein. Knockdown of Bim expression in CTLL-2 cells augmented Tax-induced IL-2-independent transformation. HTLV-1 infection of human T cells also reduced their levels of Bim protein, and restoring Bim expression in HTLV-1-infected cells reduced their proliferation by inducing apoptosis. Taken together, these results indicate that Tax-induced downregulation of Bim in HTLV-1-infected T cells promotes their IL-2-independent growth, thereby supporting the persistence of HTLV-1 infection in vivo. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  9. Multicentric T-cell lymphoma associated with feline leukemia virus infection in a captive namibian cheetah (Acinonyx jubatus).

    Science.gov (United States)

    Marker, Laurie; Munson, Linda; Basson, Peter A; Quackenbush, Sandra

    2003-07-01

    This case report describes a multicentric lymphoma in a 4 yr old female wildborn captive cheetah (Acinonyx jubatus) in Namibia after being housed in an enclosure adjacent to a feline leukemia virus (FeLV) infected cheetah that had previously been in contact with domestic cats. The year prior to the onset of clinical signs, the wild-born cheetah was FeLV antigen negative. The cheetah subsequently developed lymphoma, was found to be infected with FeLV, and then rapidly deteriorated and died. At necropsy, the liver, spleen, lymph nodes, and multiple other organs were extensively infiltrated with neoplastic T-lymphocytes. Feline leukemia virus DNA was identified in neoplastic lymphocytes from multiple organs by polymerase chain reaction and Southern blot analysis. Although the outcome of infection in this cheetah resembles that of FeLV infections in domestic cats, the transmission across an enclosure fence was unusual and may indicate a heightened susceptibility to infection in cheetahs. Caution should be exercised in holding and translocating cheetahs where contact could be made with FeLV-infected domestic, feral, or wild felids.

  10. Enhanced MDR1 gene expression in human T-cell leukemia virus-I-infected patients offers new prospects for therapy.

    Science.gov (United States)

    Lau, A; Nightingale, S; Taylor, G P; Gant, T W; Cann, A J

    1998-04-01

    Overexpression of P-glycoprotein (P-gp), the protein product of the multidrug resistance gene (MDR1), confers a drug resistant phenotype on cells. This phenotype is reminiscent of human T-cell leukemia virus (HTLV)-transformed leukemic cells, for which no consistently effective chemotherapeutic regime has been found. The presence of an active multiple drug resistance (MDR) phenotype in freshly isolated peripheral blood mononuclear cells (PBMC) from HTLV-I-infected subjects was investigated. Significant P-gp-mediated efflux activity and enhanced MDR1 mRNA expression was observed in nine of 10 HTLV-infected subjects. The development of MDR phenotypes was found to be independent of disease type or status with significant MDR activities being observed in adult T-cell leukemia (ATL), HTLV-associated myelopathy (HAM)/tropical spastic paraparesis (TSP), and asymptomatic HTLV-infected individuals. P-gp-mediated drug efflux was also found to be restricted to CD3+ T-cell populations. Furthermore, we show the novel finding that the MDR1 gene promoter is transcriptionally activated by the HTLV-I tax protein, suggesting a molecular basis for the development of drug resistance in HTLV-I infections. These observations open up the possibility of new chemotherapeutic approaches to HTLV-associated diseases through the use of P-gp inhibitors.

  11. Bovine leukemia virus infection in cattle of China: Association with reduced milk production and increased somatic cell score.

    Science.gov (United States)

    Yang, Y; Fan, W; Mao, Y; Yang, Z; Lu, G; Zhang, R; Zhang, H; Szeto, C; Wang, C

    2016-05-01

    The main objective of this study was to investigate the individual cow effect of bovine leukemia virus (BLV) infection on milk production and somatic cell score (SCS). The fluorescence resonance energy transfer (FRET) quantitative PCR established in this study and a commercial ELISA kit revealed that 49.1% of dairy cattle (964/1,963) from 6 provinces of China and 1.6% of beef cattle (22/1,390) from 15 provinces were BLV positive. In a detailed study of 105 cows, BLV was found most commonly in buffy coat samples that also had highest copy numbers (10(4.75±1.56) per mL); all cows negative for BLV in buffy coat samples were also negative in vaginal swab, milk, and fecal samples. Copy numbers of BLV were 10(2.90±0.42)/gram of feces, 10(0.83±0.62)/mL of milk, and 10(2.18±0.81) per vaginal swab. The BLV-positive cows had significantly lower milk production in the early (26.8 vs. 30.9kg) and middle stages of lactation (22.2 vs. 26.1kg) in animals with ≥4 parities than the BLV-negative cows; they also had significantly higher SCS in early and middle lactation stages (early=5.2 vs. 4.3; middle=4.9 vs. 3.9) in animals with ≥4 parities. Milk production and SCS did not significantly differ between the BLV-infected and -uninfected cows when they were in the late lactation stage or in animals with ≤3 parities. Taken together, our results indicate that BLV infections are widespread in the dairy farms of China. Vaginal secretions and feces may be involved in BLV transmission. A BLV infection may result in reduced milk yield and increased SCS in a parity and lactation stage-restricted manner. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Human T-cell leukemia virus type 2 post-transcriptional control protein p28 is required for viral infectivity and persistence in vivo.

    Science.gov (United States)

    Yamamoto, Brenda; Li, Min; Kesic, Matthew; Younis, Ihab; Lairmore, Michael D; Green, Patrick L

    2008-05-12

    Human T-cell leukemia virus (HTLV) type 1 and type 2 are related but distinct pathogenic complex retroviruses. HTLV-1 is associated with adult T-cell leukemia and a variety of immune-mediated disorders including the chronic neurological disease termed HTLV-1-associated myelopathy/tropical spastic paraparesis. In contrast, HTLV-2 displays distinct biological differences and is much less pathogenic, with only a few reported cases of leukemia and neurological disease associated with infection. In addition to the structural and enzymatic proteins, HTLV encodes regulatory (Tax and Rex) and accessory proteins. Tax and Rex positively regulate virus production and are critical for efficient viral replication and pathogenesis. Using an over-expression system approach, we recently reported that the accessory gene product of the HTLV-1 and HTLV-2 open reading frame (ORF) II (p30 and p28, respectively) acts as a negative regulator of both Tax and Rex by binding to and retaining their mRNA in the nucleus, leading to reduced protein expression and virion production. Further characterization revealed that p28 was distinct from p30 in that it was devoid of major transcriptional modulating activity, suggesting potentially divergent functions that may be responsible for the distinct pathobiologies of HTLV-1 and HTLV-2. In this study, we investigated the functional significance of p28 in HTLV-2 infection, proliferation, and immortaliztion of primary T-cells in culture, and viral survival in an infectious rabbit animal model. An HTLV-2 p28 knockout virus (HTLV-2Deltap28) was generated and evaluated. Infectivity and immortalization capacity of HTLV-2Deltap28 in vitro was indistinguishable from wild type HTLV-2. In contrast, we showed that viral replication was severely attenuated in rabbits inoculated with HTLV-2Deltap28 and the mutant virus failed to establish persistent infection. We provide direct evidence that p28 is dispensable for viral replication and cellular immortalization of

  13. Human T-cell leukemia virus type 2 post-transcriptional control protein p28 is required for viral infectivity and persistence in vivo

    Directory of Open Access Journals (Sweden)

    Kesic Matthew

    2008-05-01

    Full Text Available Abstract Background Human T-cell leukemia virus (HTLV type 1 and type 2 are related but distinct pathogenic complex retroviruses. HTLV-1 is associated with adult T-cell leukemia and a variety of immune-mediated disorders including the chronic neurological disease termed HTLV-1-associated myelopathy/tropical spastic paraparesis. In contrast, HTLV-2 displays distinct biological differences and is much less pathogenic, with only a few reported cases of leukemia and neurological disease associated with infection. In addition to the structural and enzymatic proteins, HTLV encodes regulatory (Tax and Rex and accessory proteins. Tax and Rex positively regulate virus production and are critical for efficient viral replication and pathogenesis. Using an over-expression system approach, we recently reported that the accessory gene product of the HTLV-1 and HTLV-2 open reading frame (ORF II (p30 and p28, respectively acts as a negative regulator of both Tax and Rex by binding to and retaining their mRNA in the nucleus, leading to reduced protein expression and virion production. Further characterization revealed that p28 was distinct from p30 in that it was devoid of major transcriptional modulating activity, suggesting potentially divergent functions that may be responsible for the distinct pathobiologies of HTLV-1 and HTLV-2. Results In this study, we investigated the functional significance of p28 in HTLV-2 infection, proliferation, and immortaliztion of primary T-cells in culture, and viral survival in an infectious rabbit animal model. An HTLV-2 p28 knockout virus (HTLV-2Δp28 was generated and evaluated. Infectivity and immortalization capacity of HTLV-2Δp28 in vitro was indistinguishable from wild type HTLV-2. In contrast, we showed that viral replication was severely attenuated in rabbits inoculated with HTLV-2Δp28 and the mutant virus failed to establish persistent infection. Conclusion We provide direct evidence that p28 is dispensable for

  14. Identification of human T cell leukemia virus type 1 tax amino acid signals and cellular factors involved in secretion of the viral oncoprotein.

    Science.gov (United States)

    Jain, Pooja; Mostoller, Kate; Flaig, Katherine E; Ahuja, Jaya; Lepoutre, Veronique; Alefantis, Timothy; Khan, Zafar K; Wigdahl, Brian

    2007-11-23

    Human T cell leukemia virus type 1 (HTLV-1) is the etiologic agent of a number of pathologic abnormalities, including adult T cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The viral oncoprotein Tax has been implicated in the pathogenesis of these diseases. Recently, cell-free Tax was detected in the cerebrospinal fluid of HAM/TSP patients, implying that extracellular Tax may be relevant to neurologic disease. Additionally, the presence of a nuclear export signal within Tax and its active secretion has been demonstrated in vitro. However, the mechanism of Tax secretion remains to be established. Studies reported herein elucidate the process of Tax secretion and identify domains of Tax critical to its subcellular localization and secretion. Tax was shown to interact with a number of cellular secretory pathway proteins in both the model cell line BHK (baby hamster kidney)-21 and an HTLV-1-infected T cell line, C8166, physiologically relevant to HTLV-1-induced disease. Silencing of selected components of the secretory pathway affected Tax secretion, further confirming regulated secretion of Tax. Additionally, mutations in two putative secretory signals within Tax DHE and YTNI resulted in aberrant subcellular localization of Tax and significantly altered protein secretion. Together, these studies demonstrate that Tax secretion is a regulated event facilitated by its interactions with proteins of the cellular secretory pathway and the presence of secretory signals within the carboxyl-terminal domain of the protein.

  15. Leukemia

    Science.gov (United States)

    Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, the bone marrow produces abnormal white blood cells. ...

  16. Permissive Sense and Antisense Transcription from the 5′ and 3′ Long Terminal Repeats of Human T-Cell Leukemia Virus Type 1

    Science.gov (United States)

    Polakowski, Nicholas; Hoang, Kimson

    2016-01-01

    ABSTRACT Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus, and, as such, its genome becomes chromosomally integrated following infection. The resulting provirus contains identical 5′ and 3′ peripheral long terminal repeats (LTRs) containing bidirectional promoters. Antisense transcription from the 3′ LTR regulates expression of a single gene, hbz, while sense transcription from the 5′ LTR controls expression of all other viral genes, including tax. Both the HBZ and Tax proteins are implicated in the development of adult T-cell leukemia (ATL), a T-cell malignancy caused by HTLV-1 infection. However, these proteins appear to harbor opposing molecular functions, indicating that they may act independently and at different time points prior to leukemogenesis. Here, we used bidirectional reporter constructs to test whether transcriptional interference serves as a mechanism that inhibits simultaneous expression of Tax and HBZ. We found that sense transcription did not interfere with antisense transcription from the 3′ LTR and vice versa, even with strong transcription emanating from the opposing direction. Therefore, bidirectional transcription across the provirus might not restrict hbz or tax expression. Single-cell analyses revealed that antisense transcription predominates in the absence of Tax, which transactivates viral sense transcription. Interestingly, a population of Tax-expressing cells exhibited antisense but not activated sense transcription. Consistent with the ability of Tax to induce cell cycle arrest, this population was arrested in G0/G1 phase. These results imply that cell cycle arrest inhibits Tax-mediated activation of sense transcription without affecting antisense transcription, which may be important for long-term viral latency. IMPORTANCE The chromosomally integrated form of the retrovirus human T-cell leukemia virus type 1 (HTLV-1) contains identical DNA sequences, known as long terminal repeats (LTRs), at its 5′ and 3

  17. Permissive Sense and Antisense Transcription from the 5' and 3' Long Terminal Repeats of Human T-Cell Leukemia Virus Type 1.

    Science.gov (United States)

    Laverdure, Sylvain; Polakowski, Nicholas; Hoang, Kimson; Lemasson, Isabelle

    2016-01-20

    Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus, and, as such, its genome becomes chromosomally integrated following infection. The resulting provirus contains identical 5' and 3' peripheral long terminal repeats (LTRs) containing bidirectional promoters. Antisense transcription from the 3' LTR regulates expression of a single gene, hbz, while sense transcription from the 5' LTR controls expression of all other viral genes, including tax. Both the HBZ and Tax proteins are implicated in the development of adult T-cell leukemia (ATL), a T-cell malignancy caused by HTLV-1 infection. However, these proteins appear to harbor opposing molecular functions, indicating that they may act independently and at different time points prior to leukemogenesis. Here, we used bidirectional reporter constructs to test whether transcriptional interference serves as a mechanism that inhibits simultaneous expression of Tax and HBZ. We found that sense transcription did not interfere with antisense transcription from the 3' LTR and vice versa, even with strong transcription emanating from the opposing direction. Therefore, bidirectional transcription across the provirus might not restrict hbz or tax expression. Single-cell analyses revealed that antisense transcription predominates in the absence of Tax, which transactivates viral sense transcription. Interestingly, a population of Tax-expressing cells exhibited antisense but not activated sense transcription. Consistent with the ability of Tax to induce cell cycle arrest, this population was arrested in G(0)/G(1) phase. These results imply that cell cycle arrest inhibits Tax-mediated activation of sense transcription without affecting antisense transcription, which may be important for long-term viral latency. The chromosomally integrated form of the retrovirus human T-cell leukemia virus type 1 (HTLV-1) contains identical DNA sequences, known as long terminal repeats (LTRs), at its 5' and 3' ends. The LTRs modulate

  18. Immortalization of CD4(+) and CD8(+) T lymphocytes by human T-cell leukemia virus type 1 Tax mutants expressed in a functional molecular clone.

    Science.gov (United States)

    Robek, M D; Ratner, L

    1999-06-01

    The human T-cell leukemia virus type 1 (HTLV-1) transcriptional trans-activator Tax has been demonstrated to have transforming activity in multiple cell culture and transgenic-mouse models. In addition to activating transcription from the viral long terminal repeat (LTR) through the cyclic AMP response element binding protein/activating transcription factor (CREB/ATF) family of transcription factors, Tax activates the expression of multiple cellular promoters through the NF-kappaB pathway of transcriptional activation. The Tax mutants M22 and M47 have previously been demonstrated to selectively abrogate the ability of Tax to activate transcription through the NF-kappaB or CREB/ATF pathway, respectively. These mutations were introduced in the tax gene of the ACH functional molecular clone of HTLV-1, and virus produced from the mutant ACH clones was examined for the ability to replicate and immortalize primary human lymphocytes. While virus derived from the clone containing the M47 mutation retained the ability to immortalize T lymphocytes, the M22 mutant lost the ability to immortalize infected cells. These results indicate that activation of the CREB/ATF pathway by Tax is dispensable for the immortalization of T cells by HTLV-1, whereas activation of the NF-kappaB pathway may be critical.

  19. Monoclonal antibodies reactive with hairy cell leukemia

    NARCIS (Netherlands)

    Visser, L; Shaw, A; Slupsky, J; Vos, H; Poppema, S

    Monoclonal antibodies reactive with hairy cell leukemia were developed to aid in the diagnosis of this subtype of B cell chronic lymphocytic leukemia and to gain better insight into the origin of hairy cells. Three antibodies were found to be of value in the diagnosis of hairy cell leukemia.

  20. Hairy Cell Leukemia Treatment Option Overview

    Science.gov (United States)

    ... Childhood ALL Treatment Childhood AML Treatment Research Hairy Cell Leukemia Treatment (PDQ®)–Patient Version General Information About Hairy Cell Leukemia Go to Health Professional Version Key Points ...

  1. General Information About Hairy Cell Leukemia

    Science.gov (United States)

    ... ALL Treatment Childhood AML Treatment Research Hairy Cell Leukemia Treatment (PDQ®)–Patient Version General Information About Hairy Cell Leukemia Go to Health Professional Version Key Points Hairy ...

  2. B-cell leukemia/lymphoma panel

    Science.gov (United States)

    ... ency/article/003518.htm B-cell leukemia/lymphoma panel To use the sharing features on this page, please enable JavaScript. B-cell leukemia/lymphoma panel is a blood test that looks for certain ...

  3. Differential patterns of human cytomegalovirus gene expression in various T-cell lines carrying human T-cell leukemia-lymphoma virus type I: role of Tax-activated cellular transcription factors.

    Science.gov (United States)

    Beck, Zoltán; Bácsi, Attila; Liu, Xiangdong; Ebbesen, Peter; Andirkó, István; Csoma, Eszter; Kónya, József; Nagy, Etelka; Tóth, Ferenc D

    2003-09-01

    Replication of human cytomegalovirus (HCMV) was investigated in various T-cell lines expressing the tax gene product of human T-cell leukemia-lymphoma virus type I (HTLV-I). Differential patterns of HCMV replication were found in HTLV-I-carrying cell lines. HCMV gene expression was restricted to the immediate-early genes in MT-2 and MT-4 cells, whereas full replication cycle of the virus was observed in C8166-45 cells. Productive HCMV infection induced a cytopathic effect resulting in the lysis of infected cells. The results of electrophoretic mobility shift assay (EMSA) showed high levels of NF-kappaB-, CREB/ATF-1-, and SRF-specific DNA binding activity in all Tax-positive cell lines. In contrast, SP1 activity could be detected only in C8166-45 cells. Using an inducible system (Jurkat cell line JPX-9), a dramatic increase in NF-kappaB, CREB/ATF-1, SRF, and SP1 binding activity, as well as productive HCMV infection, were observed upon Tax expression. Overexpression of SP1 in MT-2 and MT-4 cells converted HCMV infection from an abortive to a productive one. These data suggest that the stimulatory effect of Tax protein on HCMV in T cells is accomplished through at least five host-related transcription factor pathways. The results of this study provide possible mechanisms whereby HCMV infections might imply suppression of adult T-cell leukemia. Copyright 2003 Wiley-Liss, Inc.

  4. Induction of apoptosis in murine clonal osteoblasts expressed by human T-cell leukemia virus type I tax by NF-kappa B and TNF-alpha.

    Science.gov (United States)

    Kitajima, I; Nakajima, T; Imamura, T; Takasaki, I; Kawahara, K; Okano, T; Tokioka, T; Soejima, Y; Abeyama, K; Maruyama, I

    1996-02-01

    We investigated the effects of various cytokines in the presence of human T-cell leukemia virus type I (HTLV-I) tax protein in murine clonal osteoblasts, MC3T3-E1 cells. Skeletal remodeling by osteoclasts and osteoblasts is coordinated by cytokines, which are activated by HTLV-I tax protein via nuclear factor-kappa B (NF-kappa B). MC3T3-E1 cells were cocultured with an irradiated HTLV-I-producing lymphocyte cell line, MT-2. After coculture, the tumor necrosis factor-alpha (TNF-alpha) level in the medium was markedly elevated during the 7 days of culture, and MC3T3-E1 cells underwent apoptotic cell death. Marked apoptosis was also observed in MC3T3-E1 cells treated with MT-2 culture medium and in HTLV-I tax-expressing MC3T3-E1 clones, which both expressed high levels of TNF-alpha. This apoptosis was prevented by treatment with neutralizing anti-TNF-alpha antibody (alpha TNF). HTLV-I tax protein and TNF-alpha induced activation of NF-kappa B in apoptotic MC3T3-E1 cells. Decreased NF-kappa B activation was observed in HTLV-I tax-expressing MC3T3-E1 cells treated with alpha TNF. Our results suggest that HTLV-I tax activated NF-kappa B and subsequently TNF-alpha, leading to apoptosis of osteoblasts.

  5. Human T-cell leukemia virus type I tax transformation is associated with increased uptake of oligodeoxynucleotides in vitro and in vivo.

    Science.gov (United States)

    Kitajima, I; Shinohara, T; Minor, T; Bibbs, L; Bilakovics, J; Nerenberg, M

    1992-12-25

    We have utilized antisense oligodeoxynucleotides (ODNs) to modulate transcriptional activation by the human T-cell leukemia virus type I (HTLV-I) tax gene, the major transcriptional regulator of this virus. 3'-Terminal phosphorothioate-modified antisense ODNs were shown to efficiently inhibit Tax protein expression both in vitro and in vivo. Terminal substitution did not affect the affinity of ODNs for their target sequence but conferred a 9-fold increase in tax inhibition in vitro. When delivered into mice by intraperitoneal injection, ODNs inhibited tax expression in established tumors by 90%. Unmanipulated tax-transformed mouse fibroblasts, or HTLV-I-transformed human lymphocytes, showed at least 5-fold higher ODN binding and uptake over control cells. Balb/3T3 cell binding was induced to similar levels by cellular activators. This suggests that constitutive activation by tax transformation may increase susceptibility of HTLV-I-transformed cells to antisense therapy, providing a rationale for the use of antisense ODN therapeutics in HTLV-I-associated diseases.

  6. Two cis-acting elements responsible for posttranscriptional trans-regulation of gene expression of human T-cell leukemia virus type I

    International Nuclear Information System (INIS)

    Seiki, Motoharu; Inoue, Junichiro; Hidaka, Makoto; Yoshida, Mitsuaki

    1988-01-01

    The pX sequence of human T-cell leukemia virus type I codes for two nuclear proteins, p40 tax and p27 rex and a cytoplasmic protein, p21 X-III . p40 tax activates transcription from the long terminal repeat (LTR), whereas p27 rex modulates posttranscriptional processing to accumulate gag and env mRNAs that retain intron sequences. In this paper, the authors identify two cis-acting sequence elements needed for regulation by p27 rex : a 5' splice signal and a specific sequence in the 3' LTR. These two sequence elements are sufficient for regulation by p27 rex ; expression of a cellular gene (metallothionein I) became sensitive to rex regulation when the LTR was inserted at the 3' end of this gene. The requirement for these two elements suggests and unusual regulatory mechanism of RNA processing in the nucleus

  7. TORC1 and TORC2 Coactivators Are Required for Tax Activation of the Human T-Cell Leukemia Virus Type 1 Long Terminal Repeats

    Science.gov (United States)

    Siu, Yeung-Tung; Chin, King-Tung; Siu, Kam-Leung; Yee Wai Choy, Elizabeth; Jeang, Kuan-Teh; Jin, Dong-Yan

    2006-01-01

    Human T-cell leukemia virus type 1 (HTLV-1) Tax protein activates viral transcription from the long terminal repeats (LTR). Mechanisms through which Tax activates LTR have been established, but coactivators of this process remain to be identified and characterized. Here we show that all three members of the TORC family of transcriptional regulators are coactivators of Tax for LTR-driven expression. TORC coactivation requires CREB, but not ATF4 or other bZIP factors. Tax physically interacts with TORC1, TORC2, and TORC3 (TORC1/2/3), and the depletion of TORC1/2/3 inhibited Tax activity. TORC coactivation can be further enhanced by transcriptional coactivator p300. In addition, coactivators in the p300 family are required for full activity of Tax independently of TORC1/2/3. Thus, both TORC and p300 families of coactivators are essential for optimal activation of HTLV-1 transcription by Tax. PMID:16809310

  8. The Tax-Inducible Actin-Bundling Protein Fascin Is Crucial for Release and Cell-to-Cell Transmission of Human T-Cell Leukemia Virus Type 1 (HTLV-1.

    Directory of Open Access Journals (Sweden)

    Christine Gross

    2016-10-01

    Full Text Available The delta-retrovirus Human T-cell leukemia virus type 1 (HTLV-1 preferentially infects CD4+ T-cells via cell-to-cell transmission. Viruses are transmitted by polarized budding and by transfer of viral biofilms at the virological synapse (VS. Formation of the VS requires the viral Tax protein and polarization of the host cytoskeleton, however, molecular mechanisms of HTLV-1 cell-to-cell transmission remain incompletely understood. Recently, we could show Tax-dependent upregulation of the actin-bundling protein Fascin (FSCN-1 in HTLV-1-infected T-cells. Here, we report that Fascin contributes to HTLV-1 transmission. Using single-cycle replication-dependent HTLV-1 reporter vectors, we found that repression of endogenous Fascin by short hairpin RNAs and by Fascin-specific nanobodies impaired gag p19 release and cell-to-cell transmission in 293T cells. In Jurkat T-cells, Tax-induced Fascin expression enhanced virus release and Fascin-dependently augmented cell-to-cell transmission to Raji/CD4+ B-cells. Repression of Fascin in HTLV-1-infected T-cells diminished virus release and gag p19 transfer to co-cultured T-cells. Spotting the mechanism, flow cytometry and automatic image analysis showed that Tax-induced T-cell conjugate formation occurred Fascin-independently. However, adhesion of HTLV-1-infected MT-2 cells in co-culture with Jurkat T-cells was reduced upon knockdown of Fascin, suggesting that Fascin contributes to dissemination of infected T-cells. Imaging of chronically infected MS-9 T-cells in co-culture with Jurkat T-cells revealed that Fascin's localization at tight cell-cell contacts is accompanied by gag polarization suggesting that Fascin directly affects the distribution of gag to budding sites, and therefore, indirectly viral transmission. In detail, we found gag clusters that are interspersed with Fascin clusters, suggesting that Fascin makes room for gag in viral biofilms. Moreover, we observed short, Fascin-containing membrane

  9. The Tax-Inducible Actin-Bundling Protein Fascin Is Crucial for Release and Cell-to-Cell Transmission of Human T-Cell Leukemia Virus Type 1 (HTLV-1).

    Science.gov (United States)

    Gross, Christine; Wiesmann, Veit; Millen, Sebastian; Kalmer, Martina; Wittenberg, Thomas; Gettemans, Jan; Thoma-Kress, Andrea K

    2016-10-01

    The delta-retrovirus Human T-cell leukemia virus type 1 (HTLV-1) preferentially infects CD4+ T-cells via cell-to-cell transmission. Viruses are transmitted by polarized budding and by transfer of viral biofilms at the virological synapse (VS). Formation of the VS requires the viral Tax protein and polarization of the host cytoskeleton, however, molecular mechanisms of HTLV-1 cell-to-cell transmission remain incompletely understood. Recently, we could show Tax-dependent upregulation of the actin-bundling protein Fascin (FSCN-1) in HTLV-1-infected T-cells. Here, we report that Fascin contributes to HTLV-1 transmission. Using single-cycle replication-dependent HTLV-1 reporter vectors, we found that repression of endogenous Fascin by short hairpin RNAs and by Fascin-specific nanobodies impaired gag p19 release and cell-to-cell transmission in 293T cells. In Jurkat T-cells, Tax-induced Fascin expression enhanced virus release and Fascin-dependently augmented cell-to-cell transmission to Raji/CD4+ B-cells. Repression of Fascin in HTLV-1-infected T-cells diminished virus release and gag p19 transfer to co-cultured T-cells. Spotting the mechanism, flow cytometry and automatic image analysis showed that Tax-induced T-cell conjugate formation occurred Fascin-independently. However, adhesion of HTLV-1-infected MT-2 cells in co-culture with Jurkat T-cells was reduced upon knockdown of Fascin, suggesting that Fascin contributes to dissemination of infected T-cells. Imaging of chronically infected MS-9 T-cells in co-culture with Jurkat T-cells revealed that Fascin's localization at tight cell-cell contacts is accompanied by gag polarization suggesting that Fascin directly affects the distribution of gag to budding sites, and therefore, indirectly viral transmission. In detail, we found gag clusters that are interspersed with Fascin clusters, suggesting that Fascin makes room for gag in viral biofilms. Moreover, we observed short, Fascin-containing membrane extensions surrounding

  10. Chronic lymphocytic leukemia/small lymphocytic lymphoma with Reed-Sternberg-like cells and possible transformation to Hodgkin's disease. Mediation by Epstein-Barr virus.

    Science.gov (United States)

    Momose, H; Jaffe, E S; Shin, S S; Chen, Y Y; Weiss, L M

    1992-09-01

    The pathogenesis of Reed-Sternberg cells and variants (RS-H cells) found in rare cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is unknown. We studied 13 such cases by immunohistochemistry and in situ hybridization for identification of Epstein-Barr virus (EBV) RNA. The RS-H cells in five cases expressed the B-lineage marker CD20 and were negative for CD15. In two cases, the RS-H cells showed expression of both CD20 and CD15, whereas in another six cases, the cells were positive for CD15 but negative for CD20. Three of the cases expressing CD15 showed subsequent evidence of disseminated Hodgkin's disease. Regardless of the phenotype or clinical behavior, the RS-H cells in 12 of 13 cases were found to contain EBV RNA by in situ hybridization, but the surrounding neoplastic lymphocytes were invariably negative for EBV RNA. It is suggested that EBV has an important role in the pathogenesis of the RS-H cells in these rare cases.

  11. Evidence for the replication of bovine leukemia virus in the B lymphocytes

    International Nuclear Information System (INIS)

    Paul, P.S.; Pomeroy, K.A.; Johnson, D.W.; Muscoplat, C.C.; Handwerger, B.S.; Soper, F.F.; Sorensen, D.K.

    1977-01-01

    Bovine peripheral blood lymphocytes from a cow with persistent lymphocytosis were separated on nylon wool columns into nylon-adherent and nonadherent populations. Nylon-adherent cells were highly enriched for surface immunoglobulin (SIg) bearing B lymphocytes (95.5%) and nonadherent cells for SIg negative non-B cells, presumably T lymphocytes (96.3%). The B lymphocytes were found to be the major producers for bovine leukemia virus. A total of 39% of the B-enriched cells, surviving after 72 hours in culture, produced bovine leukemia virus as compared with 0.5% of the non-B cells

  12. Identification of bovine leukemia virus tax function associated with host cell transcription, signaling, stress response and immune response pathway by microarray-based gene expression analysis

    Directory of Open Access Journals (Sweden)

    Arainga Mariluz

    2012-03-01

    Full Text Available Abstract Background Bovine leukemia virus (BLV is associated with enzootic bovine leukosis and is closely related to human T-cell leukemia virus type I. The Tax protein of BLV is a transcriptional activator of viral replication and a key contributor to oncogenic potential. We previously identified interesting mutant forms of Tax with elevated (TaxD247G or reduced (TaxS240P transactivation effects on BLV replication and propagation. However, the effects of these mutations on functions other than transcriptional activation are unknown. In this study, to identify genes that play a role in the cascade of signal events regulated by wild-type and mutant Tax proteins, we used a large-scale host cell gene-profiling approach. Results Using a microarray containing approximately 18,400 human mRNA transcripts, we found several alterations after the expression of Tax proteins in genes involved in many cellular functions such as transcription, signal transduction, cell growth, apoptosis, stress response, and immune response, indicating that Tax protein has multiple biological effects on various cellular environments. We also found that TaxD247G strongly regulated more genes involved in transcription, signal transduction, and cell growth functions, contrary to TaxS240P, which regulated fewer genes. In addition, the expression of genes related to stress response significantly increased in the presence of TaxS240P as compared to wild-type Tax and TaxD247G. By contrast, the largest group of downregulated genes was related to immune response, and the majority of these genes belonged to the interferon family. However, no significant difference in the expression level of downregulated genes was observed among the Tax proteins. Finally, the expression of important cellular factors obtained from the human microarray results were validated at the RNA and protein levels by real-time quantitative reverse transcription-polymerase chain reaction and western blotting

  13. Mechanisms in endogenous leukemia virus induction by radiation and chemicals

    International Nuclear Information System (INIS)

    Tennant, R.W.; Rascati, R.J.; Lavelle, G.C.

    1976-01-01

    A model of endogenous leukemia virus induction in AKR strain mouse cells based on two distinct types of alterations in cellular or proviral DNA is presented. The first type are non-repairable alterations, such as those caused by the incorporation of halogenated pyrimidines; the second type are repairable lesions, such as those caused by irradiation or certain other chemicals. The production of non-repairable lesions leads to the formation of a stable, proviral state which is dependent upon cell division for complete virus expression. A stable provirus intermediate state is not demonstrable in cells induced by treatments which cause repairable lesions, since replication of damaged or altered DNA must occur before the lesions are removed by repair synthesis. Experimental support for this model is presented

  14. Bovine leukemia virus reduces anti-viral cytokine activities and NK cytotoxicity by inducing TGF-β secretion from regulatory T cells.

    Science.gov (United States)

    Ohira, Kosuke; Nakahara, Ayako; Konnai, Satoru; Okagawa, Tomohiro; Nishimori, Asami; Maekawa, Naoya; Ikebuchi, Ryoyo; Kohara, Junko; Murata, Shiro; Ohashi, Kazuhiko

    2016-03-01

    CD4(+)CD25(high)Foxp3(+) T cells suppress excess immune responses that lead to autoimmune and/or inflammatory diseases, and maintain host immune homeostasis. However, CD4(+)CD25(high)Foxp3(+) T cells reportedly contribute to disease progression by over suppressing immune responses in some chronic infections. In this study, kinetic and functional analyses of CD4(+)CD25(high)Foxp3(+) T cells were performed in cattle with bovine leukemia virus (BLV) infections, which have reported immunosuppressive characteristics. In initial experiments, production of the Th1 cytokines IFN-γ and TNF-α was reduced in BLV-infected cattle compared with uninfected cattle, and numbers of IFN-γ or TNF-α producing CD4(+) T cells decreased with disease progression. In contrast, IFN-γ production by NK cells was inversely correlated with BLV proviral loads in infected cattle. Additionally, during persistent lymphocytosis disease stages, NK cytotoxicity was depressed as indicated by low expression of the cytolytic protein perforin. Concomitantly, total CD4(+)CD25(high)Foxp3(+) T cell numbers and percentages of TGF-β(+) cells were increased, suggesting that TGF-β plays a role in the functional declines of CD4(+) T cells and NK cells. In further experiments, recombinant bovine TGF-β suppressed IFN-γ and TNF-α production by CD4(+) T cells and NK cytotoxicity in cultured cells. These data suggest that TGF-β from CD4(+)CD25(high)Foxp3(+) T cells is immunosuppressive and contributes to disease progression and the development of opportunistic infections during BLV infection.

  15. Dairy Cows Naturally Infected with Bovine Leukemia Virus Exhibit Abnormal B- and T-Cell Phenotypes after Primary and Secondary Exposures to Keyhole Limpet Hemocyanin

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    Meredith C. Frie

    2017-07-01

    Full Text Available Bovine leukemia virus (BLV is a retrovirus that is highly prevalent in US dairy herds: over 83% are BLV infected and the within-herd infection rate can be almost 50% on average. While BLV is known to cause lymphosarcomas, only 5% or fewer infected cattle will develop lymphoma; this low prevalence of cancer has historically not been a concern to dairy producers. However, more recent research has found that BLV+ cows without lymphoma produce less milk and have shorter lifespans than uninfected herdmates. It has been hypothesized that BLV infection interferes with normal immune function in infected cattle, and this could lead to reduced dairy production. To assess how naturally infected BLV+ cows responded to a primary and secondary immune challenge, 10 BLV+ and 10 BLV− cows were injected subcutaneously with keyhole limpet hemocyanin (KLH and dimethyldioctadecylammonium bromide. B- and T-cell responses were characterized over the following 28 days. A total of 56 days after primary KLH exposure, cows were re-injected with KLH and B- and T-cell responses were characterized again over the following 28 days. BLV+ cows produced less KLH-specific IgM after primary immune stimulation; demonstrated fewer CD45R0+ B cells, altered proportions of CD5+ B cells, altered expression of CD5 on CD5+ B cells, and reduced MHCII surface expression on B cells ex vivo; exhibited reduced B-cell activation in vitro; and displayed an increase in BLV proviral load after KLH exposure. In addition, BLV+ cows had a reduced CD45R0+γδ+ T-cell population in the periphery and demonstrated a greater prevalence of IL4-producing T cells in vitro. All together, our results demonstrate that both B- and T-cell immunities are disrupted in BLV+ cows and that antigen-specific deficiencies can be detected in BLV+ cows even after a primary immune exposure.

  16. Murine leukemia virus-derived retroviral vector has differential integration patterns in human cell lines used to produce recombinant factor VIII

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    Marcela Cristina Correa de Freitas

    2014-06-01

    Full Text Available OBJECTIVE: Nowadays recombinant factor VIII is produced in murine cells including in Chinese hamster ovary (CHO and baby hamster kidney cells (BHK. Previous studies, using the murine leukemia virus-derived retroviral vector pMFG-FVIII-P140K, modified two recombinant human cell lines, HepG2 and Hek293 to produce recombinant factor VIII. In order to characterize these cells, the present study aimed to analyze the integration pattern of retroviral vector pMFG-FVIII-P140K.METHODS: This study used ligation-mediated polymerase chain reaction to locate the site of viral vector integration by sequencing polymerase chain reaction products. The sequences were compared to genomic databases to characterize respective clones.RESULTS: The retroviral vector presented different and non-random profiles of integration between cells lines. A preference of integration for chromosomes 19, 17 and 11 was observed for HepG2FVIIIdB/P140K and chromosome 9 for Hek293FVIIIdB/P140K. In genomic regions such as CpG islands and transcription factor binding sites, there was no difference in the integration profiles for both cell lines. Integration in intronic regions of encoding protein genes (RefSeq genes was also observed in both cell lines. Twenty percent of integrations occurred at fragile sites in the genome of the HepG2 cell line and 17% in Hek293.CONCLUSION: The results suggest that the cell type can affect the profile of chromosomal integration of the retroviral vector used; these differences may interfere in the level of expression of recombinant proteins.

  17. Integration of human immunodeficiency virus types 1 and 2 DNA in vitro by cytoplasmic extracts of Moloney murine leukemia virus-infected mouse NIH 3T3 cells

    NARCIS (Netherlands)

    C. Vink (Cornelis); D.C. van Gent (Dik); R.H. Plassterk

    1990-01-01

    textabstractAn essential step in the life cycle of the human immunodeficiency virus (HIV) is integration of a DNA copy of the viral RNA into the genome of the infected cell. We show here that this step can be faithfully accomplished in vitro by the enzymatic machinery of another

  18. MicroRNAs Encoded by Bovine Leukemia Virus (BLV Are Associated with Reduced Expression of B Cell Transcriptional Regulators in Dairy Cattle Naturally Infected with BLV

    Directory of Open Access Journals (Sweden)

    Meredith C. Frie

    2018-01-01

    Full Text Available Bovine leukemia virus (BLV is estimated to infect over 83% of dairy herds and over 40% of all dairy cows in the United States. While, BLV only causes leukemia in a small proportion of animals, research indicates that BLV+ cattle exhibit reduced milk production and longevity that is distinct from lymphoma development. It is hypothesized that BLV negatively affects production by interfering with cattle immunity and increasing the risk of secondary infections. In particular, BLV+ cows demonstrate reduced circulating levels of both antigen-specific and total IgM. This study investigated possible mechanisms by which BLV could interfere with the production of IgM in naturally infected cattle. Specifically, total plasma IgM and the expression of genes IGJ, BLIMP1, BCL6, and PAX5 in circulating IgM+ B cells were measured in 15 naturally infected BLV+ and 15 BLV− cows. In addition, BLV proviral load (PVL (a relative measurement of BLV provirus integrated into host DNA and the relative expression of BLV TAX and 5 BLV microRNAs (miRNAs were characterized and correlated to the expression of selected endogenous genes. BLV+ cows exhibited lower total plasma IgM and lower expression of IGJ, BLIMP1, and BCL6. While, BLV TAX and BLV miRNAs failed to correlate with IGJ expression, both BLV TAX and BLV miRNAs exhibited negative associations with BLIMP1 and BCL6 gene expression. The results suggest a possible transcriptional pathway by which BLV interferes with IgM production in naturally infected cattle.

  19. Human T-Cell Leukemia Virus Type 1 Tax-Deregulated Autophagy Pathway and c-FLIP Expression Contribute to Resistance against Death Receptor-Mediated Apoptosis

    Science.gov (United States)

    Wang, Weimin; Zhou, Jiansuo; Shi, Juan; Zhang, Yaxi; Liu, Shilian

    2014-01-01

    ABSTRACT The human T-cell leukemia virus type 1 (HTLV-1) Tax protein is considered to play a central role in the process that leads to adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-1 Tax-expressing cells show resistance to apoptosis induced by Fas ligand (FasL) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). The regulation of Tax on the autophagy pathway in HeLa cells and peripheral T cells was recently reported, but the function and underlying molecular mechanism of the Tax-regulated autophagy are not yet well defined. Here, we report that HTLV-1 Tax deregulates the autophagy pathway, which plays a protective role during the death receptor (DR)-mediated apoptosis of human U251 astroglioma cells. The cellular FLICE-inhibitory protein (c-FLIP), which is upregulated by Tax, also contributes to the resistance against DR-mediated apoptosis. Both Tax-induced autophagy and Tax-induced c-FLIP expression require Tax-induced activation of IκB kinases (IKK). Furthermore, Tax-induced c-FLIP expression is regulated through the Tax-IKK-NF-κB signaling pathway, whereas Tax-triggered autophagy depends on the activation of IKK but not the activation of NF-κB. In addition, DR-mediated apoptosis is correlated with the degradation of Tax, which can be facilitated by the inhibitors of autophagy. IMPORTANCE Our study reveals that Tax-deregulated autophagy is a protective mechanism for DR-mediated apoptosis. The molecular mechanism of Tax-induced autophagy is also illuminated, which is different from Tax-increased c-FLIP. Tax can be degraded via manipulation of autophagy and TRAIL-induced apoptosis. These results outline a complex regulatory network between and among apoptosis, autophagy, and Tax and also present evidence that autophagy represents a new possible target for therapeutic intervention for the HTVL-1 related diseases. PMID:24352466

  20. Recombinant feline leukemia virus (FeLV) variants establish a limited infection with altered cell tropism in specific-pathogen-free cats in the absence of FeLV subgroup A helper virus.

    Science.gov (United States)

    Bechtel, M K; Hayes, K A; Mathes, L E; Pandey, R; Stromberg, P C; Roy-Burman, P

    1999-03-01

    Feline leukemia virus subgroup B (FeLV-B) is commonly associated with feline lymphosarcoma and arises through recombination between endogenous retroviral elements inherited in the cat genome and corresponding regions of the envelope (env) gene from FeLV subgroup A (FeLV-A). In vivo infectivity for FeLV-B is thought to be inefficient in the absence of FeLV-A. Proposed FeLV-A helper functions include enhanced replication efficiency, immune evasion, and replication rescue for defective FeLV-B virions. In vitro analysis of the recombinant FeLV-B-like viruses (rFeLVs) employed in this study confirmed these viruses were replication competent prior to their use in an in vivo study without FeLV-A helper virus. Eight specific-pathogen-free kittens were inoculated with the rFeLVs alone. Subsequent hematology and histology results were within normal limits, however, in the absence of detectable viremia, virus expression, or significant seroconversion, rFeLV proviral DNA was detected in bone marrow tissue of 4/4 (100%) cats at 45 weeks postinoculation (pi), indicating these rFeLVs established a limited but persistent infection in the absence of FeLV-A. Altered cell tropism was also noted. Focal infection was seen in T-cell areas of the splenic follicles in 3/4 (75%) rFeLV-infected cats analyzed, while an FeLV-A-infected cat showed focal infection in B-cell areas of the splenic follicles. Nucleotide sequence analysis of the surface glycoprotein portion of the rFeLV env gene amplified from bone marrow tissue collected at 45 weeks pi showed no sequence alterations from the original rFeLV inocula.

  1. Adult T-cell leukemia/lymphoma in a Peruvian hospital in human T-lymphotropic virus type 1 (HTLV-1) positive patients.

    Science.gov (United States)

    Rodríguez-Zúñiga, Milton José Max; Cortez-Franco, Florencio; Qujiano-Gomero, Eberth

    2017-05-01

    Adult T-cell leukemia/lymphoma (ATLL) is an aggressive neoplasm of T-lymphocytes associated with human T-lymphotropic virus type I (HTLV-1) infection. As HTLV-1 is endemic in native ethnics in South America, and its infection leads to several chronic diseases as ATLL with poor prognosis, we aimed to present three ATLL cases and to review current literature. Two cases were from the mountains of Peru, while one was from an endemic harbor of the country. An acute ATLL patient presented with multipapular infiltration of the skin and died 2 weeks after admission because of septic shock. The two chronic ATLL patients presented with erythematous plaques and erythroderma. They had swollen lymph nodes, lymphocytosis, and atypical lymphocytes on blood smear, with normal biochemical results. They both passed away a few months after diagnosis. ATLL is developed after years of HTLV-1 carrier status; therefore, physicians should know the principal clinical and laboratory findings in order to make prompt diagnosis. Prognosis is still poor in aggressive and indolent variants, with survival rates from months to a few years. Treatment based on chemotherapy, antiretroviral, and allogeneic stem cell transplantation are improving survival rates but with limited results. © 2017 The International Society of Dermatology.

  2. Treatment of Aggressive NK-Cell Leukemia

    DEFF Research Database (Denmark)

    Boysen, Anders Kindberg; Jensen, Paw; Johansen, Preben

    2011-01-01

    Aggressive NK-cell leukemia is a rare malignancy with neoplastic proliferation of natural killer cells. It often presents with constitutional symptoms, a rapid declining clinical course, and a poor prognosis with a median survival of a few months. The disease is usually resistant to cytotoxic...... literature concerning treatment of aggressive NK-cell leukemia....

  3. Hairy cell leukemia: current concepts.

    Science.gov (United States)

    Cannon, Timothy; Mobarek, Dalia; Wegge, Julia; Tabbara, Imad A

    2008-10-01

    Hairy cell Leukemia (HCL) is a chronic lymphoproliferative disorder that was characterized in the late 1950s. HCL is defined, according to the WHO classification, as a mature (peripheral) B-cell neoplasm (1). HCL accounts for between 2-3% of all leukemia cases, with about 600 new cases diagnosed in the U.S. each year (1). HCL occurs more commonly in males, with an overall male to female ratio of approximately 4:1. The median age of onset is 52 years. This disease is seen more commonly in Caucasians and appears to be especially frequent in Ashkenazi Jewish males, with rare occurrence in persons of Asian and African descents (1). Hairy cells are distinct, clonal B cells arrested at a late stage of maturation. They are small B lymphoid cells that possess oval nuclei and abundant cytoplasm with characteristic micro-filamentous ("hairy") projections. They strongly express CD103, CD22, and CD11c (2). These cells typically infiltrate the bone marrow, the spleen, and to a lesser extent the liver, lymph nodes, and skin. Many patients present with splenomegaly and pancytopenia. Other clinical manifestations include recurrent opportunistic infections and vasculitis. Historically, HCL was considered uniformly fatal (2). However, recent treatment advances, using purine analogues such as Cladribine and Pentostatin, led to a significant improvement in prognosis with achievement of high response rates and durable remissions (2).

  4. Paradoxical expression of IL-28B mRNA in peripheral blood in human T-cell leukemia virus Type-1 mono-infection and co-infection with hepatitis C Virus

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    Kamihira Shimeru

    2012-02-01

    Full Text Available Abstract Background Human T-cell leukemia virus type-1 (HTLV-1 carriers co-infected with and hepatitis C virus (HCV have been known to be at higher risk of their related diseases than mono-infected individuals. The recent studies clarified that IL-28B polymorphism rs8099917 is associated with not only the HCV therapeutic response by IFN, but also innate immunity and antiviral activity. The aim of our research was to clarify study whether IL-28B gene polymorphism (rs8099917 is associated with HTLV-1/HCV co-infection. Results The genotyping and viral-serological analysis for 340 individuals showed that IL-28B genotype distribution of rs8099917 SNP did not differ significantly by respective viral infection status. However, the IL-28B mRNA expression level was 3.8 fold higher in HTLV-1 mono-infection than HTLV-1/HCV co-infection. The high expression level was associated with TT (OR, 6.25, whiles the low expression was associated with co-infection of the two viruses (OR, 9.5. However, there was no association between down-regulation and ATL development (OR, 0.8. Conclusion HTLV-1 mono-infection up-regulates the expression of IL-28B transcripts in genotype-dependent manner, whiles HTLV-1/HCV co-infection down-regulates regardless of ATL development.

  5. Murine leukemia virus (MLV replication monitored with fluorescent proteins

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    Bittner Alexandra

    2004-12-01

    Full Text Available Abstract Background Cancer gene therapy will benefit from vectors that are able to replicate in tumor tissue and cause a bystander effect. Replication-competent murine leukemia virus (MLV has been described to have potential as cancer therapeutics, however, MLV infection does not cause a cytopathic effect in the infected cell and viral replication can only be studied by immunostaining or measurement of reverse transcriptase activity. Results We inserted the coding sequences for green fluorescent protein (GFP into the proline-rich region (PRR of the ecotropic envelope protein (Env and were able to fluorescently label MLV. This allowed us to directly monitor viral replication and attachment to target cells by flow cytometry. We used this method to study viral replication of recombinant MLVs and split viral genomes, which were generated by replacement of the MLV env gene with the red fluorescent protein (RFP and separately cloning GFP-Env into a retroviral vector. Co-transfection of both plasmids into target cells resulted in the generation of semi-replicative vectors, and the two color labeling allowed to determine the distribution of the individual genomes in the target cells and was indicative for the occurrence of recombination events. Conclusions Fluorescently labeled MLVs are excellent tools for the study of factors that influence viral replication and can be used to optimize MLV-based replication-competent viruses or vectors for gene therapy.

  6. Seroprevalence and correlates of human T-cell lymphoma/leukemia virus type 1 antibodies among pregnant women at the University of Nigeria Teaching Hospital, Enugu, Nigeria

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    Okoye AE

    2014-09-01

    Full Text Available Augustine Ejike Okoye,1 Obike Godswill Ibegbulam,2 Robinson Chukwudi Onoh,3 Paul Olisaemeka Ezeonu,3 Ngozi I Ugwu,1 Lucky Osaheni Lawani,3 Chukwudi Simon Anigbo,2 Charles E Nonyelu21Department of Haematology and Immunology, Federal Teaching Hospital, Abakaliki, 2Department of Haematology and Immunology, University of Nigeria Teaching Hospital (UNTH, Ituku-Ozalla, 3Department of Obstetrics and Gynaecology, Federal Teaching Hospital, Abakaliki, NigeriaBackground: Human T-cell lymphoma/leukemia virus (HTLV-1 is a retrovirus transmitted vertically from mother to child parenterally and sexually by infected lymphocytes.Objective: The objective of this study was to determine the seroprevalence of HTLV-1 antibodies and associated risk factors for HTLV-1 infection among pregnant women in University of Nigeria Teaching Hospital, Enugu, southeast Nigeria.Materials and methods: A cross-sectional study was carried out from July to October 2010. Two hundred pregnant women were recruited consecutively from the antenatal clinic. Five milliliters of blood was collected from each of the participants into a plain sterile bottle and allowed to clot. The serum obtained was stored at -20°C until required for analysis. The serum samples were then analyzed for antibodies to HTLV-1 using a one-step incubation double-antigen sandwich enzyme-linked immunosorbent assay kit. Participants' demographic characteristics and degree of exposure to the risk factors associated with HTLV-1 infection were captured using a questionnaire. Statistical analysis of results was done using SPSS version 17.Results: The average age of the pregnant women was 28.94 years (standard deviation 4.17. The age-group with the highest representation was those between the ages of 26 and 30 years. Thirty-six percent of the population was above 30 years old. The result of the tests showed that only one respondent, a 31-year-old pregnant woman tested positive for HTLV-1 antibodies. Therefore, the

  7. Reevaluation of confirmatory tests for human T-cell leukemia virus Type 1 using a luciferase immunoprecipitation system in blood donors.

    Science.gov (United States)

    Furuta, Rika A; Ma, Guangyong; Matsuoka, Masao; Otani, Satoshi; Matsukura, Harumichi; Hirayama, Fumiya

    2015-04-01

    Recently, Japanese Red Cross blood centers have changed the confirmatory test method from an indirect immunofluorescence (IF) technique to Western blotting (WB) for antibodies against human T-cell leukemia virus Type 1 (HTLV-1). In this study, these HTLV-1 tests were assessed using another sensitive method, that is, a luciferase immunoprecipitation system (LIPS), to identify a better confirmatory test for HTLV-1 infection. Plasma samples from 54 qualified donors and 114 HTLV-1 screening-positive donors were tested by LIPS for antibodies against HTLV-1 Gag, Tax, Env, and HBZ recombinant proteins. The donors were categorized into six groups, namely, (Group I) qualified donors, screening positive; (Group II) IF positive; (Group III) IF negative; (Group IV) WB positive; (Group V) WB negative; and (Group VI) screening positive in the previous blood donation, but WB-indeterminate during this study period. In Groups II and IV, all plasma samples tested positive by LIPS for antibodies against Gag and Env proteins. In Group V, all samples tested negative by LIPS, whereas some Group III samples reacted with single or double antigens in LIPS. In Group VI, the LIPS test identified a donor with suspected HTLV-1 infection. The first case of a blood donor with plasma that reacted with HBZ was identified by LIPS. Reevaluation of the current HTLV-1 screening method using the LIPS test showed that both confirmatory tests had similar sensitivity and specificity only when WB indeterminate results were eliminated. LIPS is a promising method for detecting and characterizing HTLV-1 antibodies. © 2014 AABB.

  8. C-terminal domain modulates the nucleic acid chaperone activity of human T-cell leukemia virus type 1 nucleocapsid protein via an electrostatic mechanism.

    Science.gov (United States)

    Qualley, Dominic F; Stewart-Maynard, Kristen M; Wang, Fei; Mitra, Mithun; Gorelick, Robert J; Rouzina, Ioulia; Williams, Mark C; Musier-Forsyth, Karin

    2010-01-01

    Retroviral nucleocapsid (NC) proteins are molecular chaperones that facilitate nucleic acid (NA) remodeling events critical in viral replication processes such as reverse transcription. Surprisingly, the NC protein from human T-cell leukemia virus type 1 (HTLV-1) is an extremely poor NA chaperone. Using bulk and single molecule methods, we find that removal of the anionic C-terminal domain (CTD) of HTLV-1 NC results in a protein with chaperone properties comparable with that of other retroviral NCs. Increasing the ionic strength of the solution also improves the chaperone activity of full-length HTLV-1 NC. To determine how the CTD negatively modulates the chaperone activity of HTLV-1 NC, we quantified the thermodynamics and kinetics of wild-type and mutant HTLV-1 NC/NA interactions. The wild-type protein exhibits very slow dissociation kinetics, and removal of the CTD or mutations that eliminate acidic residues dramatically increase the protein/DNA interaction kinetics. Taken together, these results suggest that the anionic CTD interacts with the cationic N-terminal domain intramolecularly when HTLV-1 NC is not bound to nucleic acids, and similar interactions occur between neighboring molecules when NC is NA-bound. The intramolecular N-terminal domain-CTD attraction slows down the association of the HTLV-1 NC with NA, whereas the intermolecular interaction leads to multimerization of HTLV-1 NC on the NA. The latter inhibits both NA/NC aggregation and rapid protein dissociation from single-stranded DNA. These features make HTLV-1 NC a poor NA chaperone, despite its robust duplex destabilizing capability.

  9. Therapy-induced selective loss of leukemia-initiating activity in murine adult T cell leukemia.

    Science.gov (United States)

    El Hajj, Hiba; El-Sabban, Marwan; Hasegawa, Hideki; Zaatari, Ghazi; Ablain, Julien; Saab, Shahrazad T; Janin, Anne; Mahfouz, Rami; Nasr, Rihab; Kfoury, Youmna; Nicot, Christophe; Hermine, Olivier; Hall, William; de Thé, Hugues; Bazarbachi, Ali

    2010-12-20

    Chronic HTLV-I (human T cell lymphotropic virus type I) infection may cause adult T cell leukemia/lymphoma (ATL), a disease with dismal long-term prognosis. The HTLV-I transactivator, Tax, initiates ATL in transgenic mice. In this study, we demonstrate that an As(2)O(3) and IFN-α combination, known to trigger Tax proteolysis, cures Tax-driven ATL in mice. Unexpectedly, this combination therapy abrogated initial leukemia engraftment into secondary recipients, whereas the primary tumor bulk still grew in the primary hosts, only to ultimately abate later on. This loss of initial transplantability required proteasome function. A similar regimen recently yielded unprecedented disease control in human ATL. Our demonstration that this drug combination targeting Tax stability abrogates tumor cell immortality but not short-term growth may foretell a favorable long-term efficiency of this regimen in patients.

  10. Human T-cell leukemia virus type I Tax genotype analysis in Okinawa, the southernmost and remotest islands of Japan: Different distributions compared with mainland Japan and the potential value for the prognosis of aggressive adult T-cell leukemia/lymphoma.

    Science.gov (United States)

    Sakihama, Shugo; Saito, Mineki; Kuba-Miyara, Megumi; Tomoyose, Takeaki; Taira, Naoya; Miyagi, Takashi; Hayashi, Masaki; Kinjo, Shigeko; Nakachi, Sawako; Tedokon, Iori; Nishi, Yukiko; Tamaki, Keita; Morichika, Kazuho; Uchihara, Jun-Nosuke; Morishima, Satoko; Karube, Ken-Nosuke; Tanaka, Yuetsu; Masuzaki, Hiroaki; Fukushima, Takuya

    2017-10-01

    Okinawa, comprising remote islands off the mainland of Japan, is an endemic area of human T-cell leukemia virus type I (HTLV-1), the causative virus of adult T-cell leukemia-lymphoma (ATL) and HTLV-1-associated myelopathy (HAM). We investigated the tax genotype of HTLV-1 among 29 HTLV-1 carriers, 74 ATL patients, and 33 HAM patients in Okinawa. The genotype distribution-60 (44%) taxA cases and 76 (56%) taxB cases-differed from that of a previous report from Kagoshima Prefecture in mainland Japan (taxA, 10%; taxB, 90%). A comparison of the clinical outcomes of 45 patients (taxA, 14; taxB, 31) with aggressive ATL revealed that the overall response and 1-year overall survival rates for taxA (50% and 35%, respectively) were lower than those for taxB (71% and 49%, respectively). In a multivariate analysis of two prognostic indices for aggressive ATL, Japan Clinical Oncology Group-Prognostic Index and Prognostic Index for acute and lymphoma ATL, with respect to age, performance status, corrected calcium, soluble interleukin-2 receptor, and tax genotype, the estimated hazard ratio of taxA compared with taxB was 2.68 (95% confidence interval, 0.87-8.25; P=0.086). Our results suggest that the tax genotype has clinical value as a prognostic factor for aggressive ATL. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Leukemia-Initiating Cells in T-Cell Acute Lymphoblastic Leukemia

    OpenAIRE

    Tan, Shi Hao; Bertulfo, Fatima Carla; Sanda, Takaomi

    2017-01-01

    T-cell acute lymphoblastic leukemia (T-ALL) is a hematological malignancy characterized by the clonal proliferation of immature T-cell precursors. T-ALL has many similar pathophysiological features to acute myeloid leukemia, which has been extensively studied in the establishment of the cancer stem cell (CSC) theory, but the CSC concept in T-ALL is still debatable. Although leukemia-initiating cells (LICs), which can generate leukemia in a xenograft setting, have been found in both human T-AL...

  12. Eliminating Hairy Cell Leukemia Minimal Residual Disease

    Science.gov (United States)

    In this trial, patients with hairy cell leukemia who have disease-related symptoms that require treatment will be randomly assigned to receive cladribine with either concurrent rituximab or rituximab at least 6 months after completing cladribine therapy.

  13. Presentation of human T cell leukemia virus type 1 (HTLV-1) Tax protein by dendritic cells: the underlying mechanism of HTLV-1-associated neuroinflammatory disease.

    Science.gov (United States)

    Manuel, Sharrón L; Schell, Todd D; Acheampong, Edward; Rahman, Saifur; Khan, Zafar K; Jain, Pooja

    2009-11-01

    HTLV-1 is the etiologic agent of a debilitating neurologic disorder, HAM/TSP. This disease features a robust immune response including the oligoclonal expansion of CD8+ CTLs specific for the viral oncoprotein Tax. The key pathogenic process resulting in the proliferation of CTLs and the presentation of Tax peptide remains uncharacterized. We have investigated the role of APCs, particularly DCs, in priming of the anti-Tax CTL response under in vitro and in vivo conditions. We investigated two routes (direct vs. indirect) of Tax presentation using live virus, infected primary CD4+/CD25+ T cells, and the CD4+ T cell line (C8166, a HTLV-1-mutated line that only expresses Tax). Our results indicated that DCs are capable of priming a pronounced Tax-specific CTL response in cell cultures consisting of naïve PBLs as well as in HLA-A*0201 transgenic mice (line HHD II). DCs were able to direct the presentation of Tax successfully through infected T cells, live virus, and cell-free Tax. These observations were comparable with those made with a known stimulant of DC maturation, a combination of CD40L and IFN-gamma. Our studies clearly establish a role for this important immune cell component in HTLV-1 immuno/neuropathogenesis and suggest that modulation of DC functions could be an important tool for therapeutic interventions.

  14. Regulation of the tumor marker Fascin by the viral oncoprotein Tax of human T-cell leukemia virus type 1 (HTLV-1) depends on promoter activation and on a promoter-independent mechanism.

    Science.gov (United States)

    Mohr, Caroline F; Gross, Christine; Bros, Matthias; Reske-Kunz, Angelika B; Biesinger, Brigitte; Thoma-Kress, Andrea K

    2015-11-01

    Adult T-cell leukemia/lymphoma is a highly infiltrative neoplasia of CD4(+) T-lymphocytes that occurs in about 5% of carriers infected with the deltaretrovirus human T-cell leukemia virus type 1 (HTLV-1). The viral oncoprotein Tax perturbs cellular signaling pathways leading to upregulation of host cell factors, amongst them the actin-bundling protein Fascin, an invasion marker of several types of cancer. However, transcriptional regulation of Fascin by Tax is poorly understood. In this study, we identified a triple mode of transcriptional induction of Fascin by Tax, which requires (1) NF-κB-dependent promoter activation, (2) a Tax-responsive region in the Fascin promoter, and (3) a promoter-independent mechanism sensitive to the Src family kinase inhibitor PP2. Thus, Tax regulates Fascin by a multitude of signals. Beyond, using Tax-expressing and virus-transformed lymphocytes as a model system, our study is the first to identify the invasion marker Fascin as a novel target of PP2, an inhibitor of metastasis. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Macropinocytosis is the entry mechanism of amphotropic murine leukemia virus.

    Science.gov (United States)

    Rasmussen, Izabela; Vilhardt, Frederik

    2015-02-01

    The entry mechanism of murine amphotropic retrovirus (A-MLV) has not been unambiguously determined. We show here that A-MLV is internalized not by caveolae or other pinocytic mechanisms but by macropinocytosis. Thus, A-MLV infection of mouse embryonic fibroblasts deficient for caveolin or dynamin, and NIH 3T3 cells knocked down for caveolin expression, was unaffected. Conversely, A-MLV infection of NIH 3T3 and HeLa cells was sensitive to amiloride analogues and actin-depolymerizing drugs that interfere with macropinocytosis. Further manipulation of the actin cytoskeleton through conditional expression of dominant positive or negative mutants of Rac1, PAK1, and RhoG, to increase or decrease macropinocytosis, similarly correlated with an augmented or inhibited infection with A-MLV, respectively. The same experimental perturbations affected the infection of viruses that use clathrin-coated-pit endocytosis or other pathways for entry only mildly or not at all. These data agree with immunofluorescence studies and cryo-immunogold labeling for electron microscopy, which demonstrate the presence of A-MLV in protrusion-rich areas of the cell surface and in cortical fluid phase (dextran)-filled macropinosomes, which also account for up to a half of the cellular uptake of the cell surface-binding lectin concanavalin A. We conclude that A-MLV use macropinocytosis as the predominant entry portal into cells. Binding and entry of virus particles into mammalian cells are the first steps of infection. Understanding how pathogens and toxins exploit or divert endocytosis pathways has advanced our understanding of membrane trafficking pathways, which benefits development of new therapeutic schemes and methods of drug delivery. We show here that amphotropic murine leukemia virus (A-MLV) pseudotyped with the amphotropic envelope protein (which expands the host range to many mammalian cells) gains entry into host cells by macropinocytosis. Macropinosomes form as large, fluid

  16. Immunological aspects of adult T-cell leukemia/lymphoma (ATLL), a possible neoplasm of regulatory T-cells

    OpenAIRE

    Yamada, Yasuaki; Kamihira, Shimeru

    2008-01-01

    Adult T-cell leukemia/lymphoma (ATLL) is a distinct disease caused by the first discovered human oncogenic retrovirus, human T-cell leukemia virus type-1 (HTLV-1). The peculiarity of this disease is not only in its causative agent HTLV-1 but also in the character of leukemia cells. ATLL cells express the mature helper/inducer T-cell antigens, CD2, CD3, CD4 and CD5 but usually lacking CD8. Despite CD4 expression, it has long been known that ATLL cells exhibit strong immunosuppressive activity ...

  17. Enhancers Are Major Targets for Murine Leukemia Virus Vector Integration

    Science.gov (United States)

    De Ravin, Suk See; Su, Ling; Theobald, Narda; Choi, Uimook; Macpherson, Janet L.; Poidinger, Michael; Symonds, Geoff; Pond, Susan M.; Ferris, Andrea L.; Hughes, Stephen H.

    2014-01-01

    ABSTRACT Retroviral vectors have been used in successful gene therapies. However, in some patients, insertional mutagenesis led to leukemia or myelodysplasia. Both the strong promoter/enhancer elements in the long terminal repeats (LTRs) of murine leukemia virus (MLV)-based vectors and the vector-specific integration site preferences played an important role in these adverse clinical events. MLV integration is known to prefer regions in or near transcription start sites (TSS). Recently, BET family proteins were shown to be the major cellular proteins responsible for targeting MLV integration. Although MLV integration sites are significantly enriched at TSS, only a small fraction of the MLV integration sites (integration map of more than one million integration sites from CD34+ hematopoietic stem cells transduced with a clinically relevant MLV-based vector. The integration sites form ∼60,000 tight clusters. These clusters comprise ∼1.9% of the genome. The vast majority (87%) of the integration sites are located within histone H3K4me1 islands, a hallmark of enhancers. The majority of these clusters also have H3K27ac histone modifications, which mark active enhancers. The enhancers of some oncogenes, including LMO2, are highly preferred targets for integration without in vivo selection. IMPORTANCE We show that active enhancer regions are the major targets for MLV integration; this means that MLV preferentially integrates in regions that are favorable for viral gene expression in a variety of cell types. The results provide insights for MLV integration target site selection and also explain the high risk of insertional mutagenesis that is associated with gene therapy trials using MLV vectors. PMID:24501411

  18. Murine leukemia virus vector integration favors promoter regions and regional hot spots in a human T-cell line

    International Nuclear Information System (INIS)

    Tsukahara, Tomonori; Agawa, Hideyuki; Matsumoto, Sayori; Matsuda, Mizuho; Ueno, Shuichi; Yamashita, Yuki; Yamada, Koichiro; Tanaka, Nobuyuki; Kojima, Katsuhiko; Takeshita, Toshikazu

    2006-01-01

    Genomic analysis of integration will be important in evaluating the safety of human gene therapy with retroviral vectors. Here, we investigated MLV vector integration sites in human T-cells, since they are amenable to gene transfer studies, and have been used therapeutically in clinical trials. We mapped 340 MLV vector integration sites in the infected human T-cell clones we established. The data showed that MLV preferred integration near the transcription start sites (±5 kb), near CpG islands (±1 kb), and within the first intron of RefSeq genes. We also identified MLV integration hot spots that contained three or more integrations within a 100 kb region. RT-PCR revealed that mRNA-levels of T-cell clones that contained MLV integrations near transcription start sites or introns were dysregulated compared to the uninfected cells. These studies help define the profile of MLV integration in T-cells and the risks associated with MLV-based gene therapy

  19. Oncogenic Viruses and Breast Cancer: Mouse Mammary Tumor Virus (MMTV), Bovine Leukemia Virus (BLV), Human Papilloma Virus (HPV), and Epstein–Barr Virus (EBV)

    OpenAIRE

    James S. Lawson; Brian Salmons; Wendy K. Glenn

    2018-01-01

    BackgroundAlthough the risk factors for breast cancer are well established, namely female gender, early menarche and late menopause plus the protective influence of early pregnancy, the underlying causes of breast cancer remain unknown. The development of substantial recent evidence indicates that a handful of viruses may have a role in breast cancer. These viruses are mouse mammary tumor virus (MMTV), bovine leukemia virus (BLV), human papilloma viruses (HPVs), and Epstein–Barr virus (EBV-al...

  20. Human T-Cell Leukemia Virus Type I-Mediated Repression of PDZ-LIM Domain-Containing Protein 2 Involves DNA Methylation But Independent of the Viral Oncoprotein Tax

    Directory of Open Access Journals (Sweden)

    Pengrong Yan

    2009-10-01

    Full Text Available Human T-cell leukemia virus type I (HTLV-I is the etiological agent of adult T-cell leukemia (ATL. Our recent studies have shown that one important mechanism of HTLV-I-Mediated tumorigenesis is through PDZ-LIM domain-containing protein 2 (PDLIM2 repression, although the involved mechanism remains unknown. Here, we further report that HTLV-I-Mediated PDLIM2 repression was a pathophysiological event and the PDLIM2 repression involved DNA methylation. Whereas DNA methyltransferases 1 and 3b but not 3a were upregulated in HTLV-I-transformed T cells, the hypomethylating agent 5-aza-2′-deoxycytidine (5-aza-dC restored PDLIM2 expression and induced death of these malignant cells. Notably, the PDLIM2 repression was independent of the viral regulatory protein Tax because neither short-term induction nor long-term stable expression of Tax could downregulate PDLIM2 expression. These studies provide important insights into PDLIM2 regulation, HTLV-I leukemogenicity, long latency, and cancer health disparities. Given the efficient antitumor activity with no obvious toxicity of 5-aza-dC, these studies also suggest potential therapeutic strategies for ATL.

  1. Inhibition of Cell-Free Human T-Cell Leukemia Virus Type 1 Infection at a Postbinding Step by the Synthetic Peptide Derived from an Ectodomain of the gp21 Transmembrane Glycoprotein

    Science.gov (United States)

    Jinno, A.; Haraguchi, Y.; Shiraki, H.; Hoshino, H.

    1999-01-01

    To investigate the roles of human T-cell leukemia virus type 1 (HTLV-1) envelope (Env) proteins gp46 and gp21 in the early steps of infection, the effects of the 23 synthetic peptides covering the entire Env proteins on transmission of cell-free HTLV-1 were examined by PCR and by the plaque assay using a pseudotype of vesicular stomatis virus (VSV) bearing the Env of HTLV-1 [VSV(HTLV-1)]. The synthetic peptide corresponding to amino acids 400 to 429 of the gp21 Env protein (gp21 peptide 400-429, Cys-Arg-Phe-Pro-Asn-Ile-Thr-Asn-Ser-His-Val-Pro-Ile-Leu-Gln-Glu-Arg-Pro-Pro-Leu-Glu-Asn-Arg-Val-Leu-Thr-Gly-Trp-Gly-Leu) strongly inhibited infection of cell-free HTLV-1. By using the mutant peptide, Asn407, Ser408, and Leu413, -419, -424, and -429 were confirmed to be important amino acids for neutralizing activity of the gp21 peptide 400-429. Addition of this peptide before or during adsorption of HTLV-1 at 4°C did not affect its entry. However, HTLV-1 infection was inhibited about 60% when the gp21 peptide 400-429 was added even 30 min after adsorption of HTLV-1 to cells, indicating that the amino acid sequence 400 to 429 on the gp21 Env protein plays an important role at the postbinding step of HTLV-1 infection. In contrast, a monoclonal antibody reported to recognize the gp46 191-196 peptide inhibited the infection of HTLV-1 at the binding step. PMID:10516085

  2. Leukemia

    International Nuclear Information System (INIS)

    Kamada, Nanao

    1992-01-01

    This chapter deals with clinical features associated with chromosomal aberration in A-bomb survivors with leukemia. Clinical features are presented by dividing them into three categories: (1) those from preleukemic stage up to the development of overt leukemia, (2) those specific to A-bomb survivors, and (3) changes in chromosomes. Many of the A-bomb survivors had normocytic anemia and leukopenia for a long time preceding the development of overt leukemia. A woman exposed to 483 rad (estimated by the T65D) 800 m from the hypocenter who finally developed erythroleukemia is presented; and in 6 other A-bomb survivors, abnormal hematological findings up to the development of overt acute leukemia are mentioned. Hematological findings in chronic myeloid leukemia (CML) are discussed by presenting two cases: one was exposed at 800 m from the hypocenter and developed CML 35 years later and the other was exposed at 1800 m and developed it 22 years later. In A-bomb survivors, acute leukemia tended to be associated with smaller number of leukemic cells in both peripheral blood and bone marrow, and non-leukemic leukemia was observed. Chromosomal analysis has been made in 75 A-bomb survivors with acute leukemia and 55 CML A-bomb survivors. In acute leukemic patients exposed to one Gy or more, bone marrow stem cells with chromosomal aberrations occurring at the time of exposure were considered to be proliferated by various factors. A-bomb survivors with CML are found to be characterized by having Philadelphia chromosome, t(9;22)(q34;q11). (N.K.)

  3. Morphological changes in cultured bovine lymphoid cell lines associated with bovine viral diarrhea virus (BVDV) single and dual infections with bovine leukemia virus (BLV)

    Science.gov (United States)

    Currently, American Type Culture Collection (ATCC) makes available two cell lines derived from the same lymphoblast-like suspension cell that have been confirmed by next-generation sequencing and RT-PCR to have either a single contaminate of BVDV2a (CRL-8037) or dual contaminates of both BVDV and BL...

  4. Leukemia-Initiating Cells in T-Cell Acute Lymphoblastic Leukemia.

    Science.gov (United States)

    Tan, Shi Hao; Bertulfo, Fatima Carla; Sanda, Takaomi

    2017-01-01

    T-cell acute lymphoblastic leukemia (T-ALL) is a hematological malignancy characterized by the clonal proliferation of immature T-cell precursors. T-ALL has many similar pathophysiological features to acute myeloid leukemia, which has been extensively studied in the establishment of the cancer stem cell (CSC) theory, but the CSC concept in T-ALL is still debatable. Although leukemia-initiating cells (LICs), which can generate leukemia in a xenograft setting, have been found in both human T-ALL patients and animal models, the nature and origin of LICs are largely unknown. In this review, we discuss recent studies on LICs in T-ALL and the potential mechanisms of LIC emergence in this disease. We focus on the oncogenic transcription factors TAL1, LMO2 , and NOTCH1 and highlight the significance of the transcriptional regulatory programs in normal hematopoietic stem cells and T-ALL.

  5. Leukemia-Initiating Cells in T-Cell Acute Lymphoblastic Leukemia

    Directory of Open Access Journals (Sweden)

    Shi Hao Tan

    2017-09-01

    Full Text Available T-cell acute lymphoblastic leukemia (T-ALL is a hematological malignancy characterized by the clonal proliferation of immature T-cell precursors. T-ALL has many similar pathophysiological features to acute myeloid leukemia, which has been extensively studied in the establishment of the cancer stem cell (CSC theory, but the CSC concept in T-ALL is still debatable. Although leukemia-initiating cells (LICs, which can generate leukemia in a xenograft setting, have been found in both human T-ALL patients and animal models, the nature and origin of LICs are largely unknown. In this review, we discuss recent studies on LICs in T-ALL and the potential mechanisms of LIC emergence in this disease. We focus on the oncogenic transcription factors TAL1, LMO2, and NOTCH1 and highlight the significance of the transcriptional regulatory programs in normal hematopoietic stem cells and T-ALL.

  6. Simian T-cell leukemia virus (STLV) infection in wild primate populations in Cameroon: evidence for dual STLV type 1 and type 3 infection in agile mangabeys (Cercocebus agilis).

    Science.gov (United States)

    Courgnaud, Valerie; Van Dooren, Sonia; Liegeois, Florian; Pourrut, Xavier; Abela, Bernadette; Loul, Severin; Mpoudi-Ngole, Eitel; Vandamme, Annemieke; Delaporte, Eric; Peeters, Martine

    2004-05-01

    Three types of human T-cell leukemia virus (HTLV)-simian T-cell leukemia virus (STLV) (collectively called primate T-cell leukemia viruses [PTLVs]) have been characterized, with evidence for zoonotic origin from primates for HTLV type 1 (HTLV-1) and HTLV-2 in Africa. To assess human exposure to STLVs in western Central Africa, we screened for STLV infection in primates hunted in the rain forests of Cameroon. Blood was obtained from 524 animals representing 18 different species. All the animals were wild caught between 1999 and 2002; 328 animals were sampled as bush meat and 196 were pets. Overall, 59 (11.2%) of the primates had antibodies cross-reacting with HTLV-1 and/or HTLV-2 antigens; HTLV-1 infection was confirmed in 37 animals, HTLV-2 infection was confirmed in 9, dual HTLV-1 and HTLV-2 infection was confirmed in 10, and results for 3 animals were indeterminate. Prevalences of infection were significantly lower in pets than in bush meat, 1.5 versus 17.0%, respectively. Discriminatory PCRs identified STLV-1, STLV-3, and STLV-1 and STLV-3 in HTLV-1-, HTLV-2-, and HTLV-1- and HTLV-2-cross-reactive samples, respectively. We identified for the first time STLV-1 sequences in mustached monkeys (Cercopithecus cephus), talapoins (Miopithecus ogouensis), and gorillas (Gorilla gorilla) and confirmed STLV-1 infection in mandrills, African green monkeys, agile mangabeys, and crested mona and greater spot-nosed monkeys. STLV-1 long terminal repeat (LTR) and env sequences revealed that the strains belonged to different PTLV-1 subtypes. A high prevalence of PTLV infection was observed among agile mangabeys (Cercocebus agilis); 89% of bush meat was infected with STLV. Cocirculation of STLV-1 and STLV-3 and STLV-1-STLV-3 coinfections were identified among the agile mangabeys. Phylogenetic analyses of partial LTR sequences indicated that the agile mangabey STLV-3 strains were more related to the STLV-3 CTO604 strain isolated from a red-capped mangabey (Cercocebus torquatus

  7. Increase of cells expressing PD-L1 in bovine leukemia virus infection and enhancement of anti-viral immune responses in vitro via PD-L1 blockade

    Directory of Open Access Journals (Sweden)

    Ikebuchi Ryoyo

    2011-09-01

    Full Text Available Abstract The inhibitory receptor programmed death-1 (PD-1 and its ligand, programmed death-ligand 1 (PD-L1 are involved in immune evasion mechanisms for several pathogens causing chronic infections. Blockade of the PD-1/PD-L1 pathway restores anti-virus immune responses, with concomitant reduction in viral load. In a previous report, we showed that, in bovine leukemia virus (BLV infection, the expression of bovine PD-1 is closely associated with disease progression. However, the functions of bovine PD-L1 are still unknown. To investigate the role of PD-L1 in BLV infection, we identified the bovine PD-L1 gene, and examined PD-L1 expression in BLV-infected cattle in comparison with uninfected cattle. The deduced amino acid sequence of bovine PD-L1 shows high homology to the human and mouse PD-L1. The proportion of PD-L1 positive cells, especially among B cells, was upregulated in cattle with the late stage of the disease compared to cattle at the aleukemic infection stage or uninfected cattle. The proportion of PD-L1 positive cells correlated positively with prediction markers for the progression of the disease such as leukocyte number, virus load and virus titer whilst on the contrary, it inversely correlated with the degree of interferon-gamma expression. Blockade of the PD-1/PD-L1 pathway in vitro by PD-L1-specific antibody upregulated the production of interleukin-2 and interferon-gamma, and correspondingly, downregulated the BLV provirus load and the proportion of BLV-gp51 expressing cells. These data suggest that PD-L1 induces immunoinhibition in disease progressed cattle during chronic BLV infection. Therefore, PD-L1 would be a potential target for developing immunotherapies against BLV infection.

  8. In vitro radiosensitivity of human leukemia cell lines

    International Nuclear Information System (INIS)

    Weichselbaum, R.R.; Greenberger, J.S.; Schmidt, A.; Karpas, A.; Moloney, W.C.; Little, J.B.

    1981-01-01

    The in vitro radiobiologic survival values (anti n, D 0 ) of four tumor lines derived from human hematopoietic tumors were studied. These cell lines were HL60 promyelocytic leukemia; K562 erythroleukemia; 45 acute lymphocytic leukemia; and 176 acute monomyelogenous leukemia. More cell lines must be examined before the exact relationship between in vitro radiosensitivity and clinical radiocurability is firmly established

  9. No Evidence of Murine Leukemia Virus-Related Viruses in Live Attenuated Human Vaccines

    Science.gov (United States)

    Switzer, William M.; Zheng, HaoQiang; Simmons, Graham; Zhou, Yanchen; Tang, Shaohua; Shankar, Anupama; Kapusinszky, Beatrix; Delwart, Eric L.; Heneine, Walid

    2011-01-01

    Background The association of xenotropic murine leukemia virus (MLV)-related virus (XMRV) in prostate cancer and chronic fatigue syndrome reported in previous studies remains controversial as these results have been questioned by recent data. Nonetheless, concerns have been raised regarding contamination of human vaccines as a possible source of introduction of XMRV and MLV into human populations. To address this possibility, we tested eight live attenuated human vaccines using generic PCR for XMRV and MLV sequences. Viral metagenomics using deep sequencing was also done to identify the possibility of other adventitious agents. Results All eight live attenuated vaccines, including Japanese encephalitis virus (JEV) (SA-14-14-2), varicella (Varivax), measles, mumps, and rubella (MMR-II), measles (Attenuvax), rubella (Meruvax-II), rotavirus (Rotateq and Rotarix), and yellow fever virus were negative for XMRV and highly related MLV sequences. However, residual hamster DNA, but not RNA, containing novel endogenous gammaretrovirus sequences was detected in the JEV vaccine using PCR. Metagenomics analysis did not detect any adventitious viral sequences of public health concern. Intracisternal A particle sequences closest to those present in Syrian hamsters and not mice were also detected in the JEV SA-14-14-2 vaccine. Combined, these results are consistent with the production of the JEV vaccine in Syrian hamster cells. Conclusions We found no evidence of XMRV and MLV in eight live attenuated human vaccines further supporting the safety of these vaccines. Our findings suggest that vaccines are an unlikely source of XMRV and MLV exposure in humans and are consistent with the mounting evidence on the absence of these viruses in humans. PMID:22216219

  10. No evidence of murine leukemia virus-related viruses in live attenuated human vaccines.

    Directory of Open Access Journals (Sweden)

    William M Switzer

    Full Text Available The association of xenotropic murine leukemia virus (MLV-related virus (XMRV in prostate cancer and chronic fatigue syndrome reported in previous studies remains controversial as these results have been questioned by recent data. Nonetheless, concerns have been raised regarding contamination of human vaccines as a possible source of introduction of XMRV and MLV into human populations. To address this possibility, we tested eight live attenuated human vaccines using generic PCR for XMRV and MLV sequences. Viral metagenomics using deep sequencing was also done to identify the possibility of other adventitious agents.All eight live attenuated vaccines, including Japanese encephalitis virus (JEV (SA-14-14-2, varicella (Varivax, measles, mumps, and rubella (MMR-II, measles (Attenuvax, rubella (Meruvax-II, rotavirus (Rotateq and Rotarix, and yellow fever virus were negative for XMRV and highly related MLV sequences. However, residual hamster DNA, but not RNA, containing novel endogenous gammaretrovirus sequences was detected in the JEV vaccine using PCR. Metagenomics analysis did not detect any adventitious viral sequences of public health concern. Intracisternal A particle sequences closest to those present in Syrian hamsters and not mice were also detected in the JEV SA-14-14-2 vaccine. Combined, these results are consistent with the production of the JEV vaccine in Syrian hamster cells.We found no evidence of XMRV and MLV in eight live attenuated human vaccines further supporting the safety of these vaccines. Our findings suggest that vaccines are an unlikely source of XMRV and MLV exposure in humans and are consistent with the mounting evidence on the absence of these viruses in humans.

  11. Seroprevalence of human T-cell lymphotropic virus type 1 infection ...

    African Journals Online (AJOL)

    Human T-cell lymphotropic virus type-1 (HTLV1) is a lymphotropic virus which can contribute to carcinogenesis in adult T-cell leukemia, myleopathy and other disorders. 20 million people are affected by this virus in the world. The aim of this study was to determine the incidence of human T-cell lymph tropic virus type 1 ...

  12. Overexpression of Rac1 in leukemia patients and its role in leukemia cell migration and growth

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiying [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 288 Nanjing Road, Tianjin 300020 (China); Rao, Qing, E-mail: raoqing@gmail.com [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 288 Nanjing Road, Tianjin 300020 (China); Wang, Min; Wei, Hui; Xing, Haiyan; Liu, Hang; Wang, Yanzhong; Tang, Kejing; Peng, Leiwen; Tian, Zheng; Wang, Jianxiang [State Key Laboratory of Experimental Hematology, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 288 Nanjing Road, Tianjin 300020 (China)

    2009-09-04

    Rac1 belongs to the Rho family that act as critical mediators of signaling pathways controlling cell migration and proliferation and contributes to the interactions of hematopoietic stem cells with their microenvironment. Alteration of Rac1 might result in unbalanced interactions and ultimately lead to leukemogenesis. In this study, we analyze the expression of Rac1 protein in leukemia patients and determine its role in the abnormal behaviours of leukemic cells. Rac1 protein is overexpressed in primary acute myeloid leukemia cells as compared to normal bone marrow mononuclear cells. siRNA-mediated silencing of Rac1 in leukemia cell lines induced inhibition of cell migration, proliferation, and colony formation. Additionally, blocking Rac1 activity by an inhibitor of Rac1-GTPase, NSC23766, suppressed cell migration and growth. We conclude that overexpression of Rac1 contributes to the accelerated migration and high proliferation potential of leukemia cells, which could be implicated in leukemia development and progression.

  13. Overexpression of Rac1 in leukemia patients and its role in leukemia cell migration and growth

    International Nuclear Information System (INIS)

    Wang, Jiying; Rao, Qing; Wang, Min; Wei, Hui; Xing, Haiyan; Liu, Hang; Wang, Yanzhong; Tang, Kejing; Peng, Leiwen; Tian, Zheng; Wang, Jianxiang

    2009-01-01

    Rac1 belongs to the Rho family that act as critical mediators of signaling pathways controlling cell migration and proliferation and contributes to the interactions of hematopoietic stem cells with their microenvironment. Alteration of Rac1 might result in unbalanced interactions and ultimately lead to leukemogenesis. In this study, we analyze the expression of Rac1 protein in leukemia patients and determine its role in the abnormal behaviours of leukemic cells. Rac1 protein is overexpressed in primary acute myeloid leukemia cells as compared to normal bone marrow mononuclear cells. siRNA-mediated silencing of Rac1 in leukemia cell lines induced inhibition of cell migration, proliferation, and colony formation. Additionally, blocking Rac1 activity by an inhibitor of Rac1-GTPase, NSC23766, suppressed cell migration and growth. We conclude that overexpression of Rac1 contributes to the accelerated migration and high proliferation potential of leukemia cells, which could be implicated in leukemia development and progression.

  14. Genetically Modified T-cell Immunotherapy in Treating Patients With Relapsed/Refractory Acute Myeloid Leukemia and Persistent/Recurrent Blastic Plasmacytoid Dendritic Cell Neoplasm

    Science.gov (United States)

    2018-03-02

    Adult Acute Myeloid Leukemia in Remission; Acute Biphenotypic Leukemia; Early Relapse of Acute Myeloid Leukemia; Late Relapse of Acute Myeloid Leukemia; Recurrent Adult Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Blastic Plasmacytoid Dendritic Cell Neoplasm; Acute Myeloid Leukemia; Adult Acute Lymphoblastic Leukemia; Interleukin-3 Receptor Subunit Alpha Positive; Minimal Residual Disease; Refractory Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

  15. Recombinant human T-cell leukemia virus types 1 and 2 Tax proteins induce high levels of CC-chemokines and downregulate CCR5 in human peripheral blood mononuclear cells.

    Science.gov (United States)

    Barrios, Christy S; Abuerreish, Muna; Lairmore, Michael D; Castillo, Laura; Giam, Chou-Zen; Beilke, Mark A

    2011-12-01

    Human T-cell leukemia viruses types 1 (HTLV-1) and 2 (HTLV-2) produce key transcriptional regulatory gene products, known as Tax1 and Tax2, respectively. Tax1 and Tax2 transactivate multiple host genes involved in cellular immune responses within the cellular microenvironment, including induction of genes encoding expression of CC-chemokines. It is speculated that HTLV Tax proteins may act as immune modulators. In this study, recombinant Tax1 and Tax2 proteins were tested for their effects on the viability of cultured peripheral blood mononuclear cells (PBMCs), and their ability to induce expression of CC-chemokines and to downregulate the level of CCR5 expression in PBMCs. PBMCs obtained from uninfected donors were cultured in a range of Tax1 and Tax2 concentrations (10-100 pM), and supernatant fluids were harvested at multiple time points for quantitative determinations of MIP-1α/CCL3, MIP-1β/CCL4, and RANTES/CCL5. Treatment of PBMCs with Tax1 and Tax2 proteins (100 pM) resulted in a significant increase in viability over a 7-d period compared to controls (pTax1 and Tax2 induced high levels of all three CC-chemokines over the dosing range compared to mock-treated controls (pTax2, as well as lymphocytes from HTLV-2-infected donors, showed a significantly lower percentage of CCR5-positive cells compared to those of uninfected donors and from mock-treated lymphocytes, respectively (pTax1 and Tax2 could promote innate immunity in the extracellular environment during HTLV-1 and HTLV-2 infections via CC-chemokine ligands and receptors.

  16. Biological Therapy in Treating Patients With Advanced Myelodysplastic Syndrome, Acute or Chronic Myeloid Leukemia, or Acute Lymphoblastic Leukemia Who Are Undergoing Stem Cell Transplantation

    Science.gov (United States)

    2017-03-27

    Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); B-cell Adult Acute Lymphoblastic Leukemia; B-cell Childhood Acute Lymphoblastic Leukemia; Childhood Chronic Myelogenous Leukemia; Childhood Myelodysplastic Syndromes; Chronic Myelomonocytic Leukemia; Essential Thrombocythemia; Polycythemia Vera; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Excess Blasts in Transformation; Relapsing Chronic Myelogenous Leukemia; Secondary Acute Myeloid Leukemia; T-cell Adult Acute Lymphoblastic Leukemia; T-cell Childhood Acute Lymphoblastic Leukemia

  17. Human T-cell leukemia virus type 1 (HTLV-1 tax requires CADM1/TSLC1 for inactivation of the NF-κB inhibitor A20 and constitutive NF-κB signaling.

    Directory of Open Access Journals (Sweden)

    Rajeshree Pujari

    2015-03-01

    Full Text Available Persistent activation of NF-κB by the Human T-cell leukemia virus type 1 (HTLV-1 oncoprotein, Tax, is vital for the development and pathogenesis of adult T-cell leukemia (ATL and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP. K63-linked polyubiquitinated Tax activates the IKK complex in the plasma membrane-associated lipid raft microdomain. Tax also interacts with TAX1BP1 to inactivate the NF-κB negative regulatory ubiquitin-editing A20 enzyme complex. However, the molecular mechanisms of Tax-mediated IKK activation and A20 protein complex inactivation are poorly understood. Here, we demonstrated that membrane associated CADM1 (Cell adhesion molecule1 recruits Ubc13 to Tax, causing K63-linked polyubiquitination of Tax, and IKK complex activation in the membrane lipid raft. The c-terminal cytoplasmic tail containing PDZ binding motif of CADM1 is critical for Tax to maintain persistent NF-κB activation. Finally, Tax failed to inactivate the NF-κB negative regulator ubiquitin-editing enzyme A20 complex, and activate the IKK complex in the lipid raft in absence of CADM1. Our results thus indicate that CADM1 functions as a critical scaffold molecule for Tax and Ubc13 to form a cellular complex with NEMO, TAX1BP1 and NRP, to activate the IKK complex in the plasma membrane-associated lipid rafts, to inactivate NF-κB negative regulators, and maintain persistent NF-κB activation in HTLV-1 infected cells.

  18. Expression of IMP1 Enhances Production of Murine Leukemia Virus Vector by Facilitating Viral Genomic RNA Packaging

    OpenAIRE

    Mai, Yun; Gao, Guangxia

    2010-01-01

    Murine leukemia virus (MLV)-based retroviral vector is widely used for gene transfer. Efficient packaging of the genomic RNA is critical for production of high-titer virus. Here, we report that expression of the insulin-like growth factor II mRNA binding protein 1 (IMP1) enhanced the production of infectious MLV vector. Overexpression of IMP1 increased the stability of viral genomic RNA in virus producer cells and packaging of the RNA into progeny virus in a dose-dependent manner. Downregulat...

  19. Antibody responses against xenotropic murine leukemia virus-related virus envelope in a murine model.

    Directory of Open Access Journals (Sweden)

    Natalia Makarova

    2011-04-01

    Full Text Available Xenotropic murine leukemia virus-related virus (XMRV was recently discovered to be the first human gammaretrovirus that is associated with chronic fatigue syndrome and prostate cancer (PC. Although a mechanism for XMRV carcinogenesis is yet to be established, this virus belongs to the family of gammaretroviruses well known for their ability to induce cancer in the infected hosts. Since its original identification XMRV has been detected in several independent investigations; however, at this time significant controversy remains regarding reports of XMRV detection/prevalence in other cohorts and cell type/tissue distribution. The potential risk of human infection, coupled with the lack of knowledge about the basic biology of XMRV, warrants further research, including investigation of adaptive immune responses. To study immunogenicity in vivo, we vaccinated mice with a combination of recombinant vectors expressing codon-optimized sequences of XMRV gag and env genes and virus-like particles (VLP that had the size and morphology of live infectious XMRV.Immunization elicited Env-specific binding and neutralizing antibodies (NAb against XMRV in mice. The peak titers for ELISA-binding antibodies and NAb were 1:1024 and 1:464, respectively; however, high ELISA-binding and NAb titers were not sustained and persisted for less than three weeks after immunizations.Vaccine-induced XMRV Env antibody titers were transiently high, but their duration was short. The relatively rapid diminution in antibody levels may in part explain the differing prevalences reported for XMRV in various prostate cancer and chronic fatigue syndrome cohorts. The low level of immunogenicity observed in the present study may be characteristic of a natural XMRV infection in humans.

  20. Donor Umbilical Cord Blood Transplant With or Without Ex-vivo Expanded Cord Blood Progenitor Cells in Treating Patients With Acute Myeloid Leukemia, Acute Lymphoblastic Leukemia, Chronic Myelogenous Leukemia, or Myelodysplastic Syndromes

    Science.gov (United States)

    2018-03-05

    Acute Biphenotypic Leukemia; Acute Erythroid Leukemia; Acute Lymphoblastic Leukemia in Remission; Acute Megakaryoblastic Leukemia; Acute Myeloid Leukemia Arising From Previous Myelodysplastic Syndrome; Acute Myeloid Leukemia in Remission; Blasts Under 10 Percent of Bone Marrow Nucleated Cells; Blasts Under 5 Percent of Bone Marrow Nucleated Cells; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Mixed Phenotype Acute Leukemia; Myelodysplastic Syndrome; Myelodysplastic Syndrome With Excess Blasts; Pancytopenia; Refractory Anemia; Secondary Acute Myeloid Leukemia

  1. Seroprevalence of Toxoplasma gondii and concurrent Bartonella spp., feline immunodeficiency virus, feline leukemia virus, and Dirofilaria immitis infections in Egyptian cats

    Science.gov (United States)

    Toxoplasma gondii and Bartonella spp. are zoonotic pathogens of cats. Feline Immunodeficiency Virus (FIV), and Feline Leukemia Virus (FeLv) are related to Human Immunodeficiency Virus, and Human Leukemia Virus, respectively, and these viruses are immunosuppressive. In the present study, the prevalen...

  2. Seroprevalence of bovine immunodeficiency virus and bovine leukemia virus in draught animals in Cambodia.

    Science.gov (United States)

    Meas, S; Ohashi, K; Tum, S; Chhin, M; Te, K; Miura, K; Sugimoto, C; Onuma, M

    2000-07-01

    Since bovine immunodeficiency virus (BIV), known as bovine lentivirus, has been detected in dairy and beef cattle in various countries around the world, a prevalence study of antibodies to BIV and bovine leukemia virus (BLV) was conducted in draught animals in five provinces in Cambodia, where protozoan parasite infections were suspected in some animals. To clarify the status of draught animals including Haryana, Brahman, mixed-breed, local breed cattle and muscle water buffaloes, a total of 544 cattle and 42 buffaloes were tested, and 26.3 and 16.7%, respectively, were found positive for anti-BIV p26 antibodies determined by Western blotting. There were 5.3% positive for anti-BLV antibodies detected by immunodiffusion test among the cattle, but no reactors among buffaloes and no dual infection for both BIV and BLV was determined in this study. Peripheral blood mononuclear cells from BIV-seropositive cattle were found to have BIV-provirus DNA, as detected by polymerase chain reaction and subsequent Southern blot hybridization. This is the first evidence for the presence of BIV and BLV infections in draught animals in tropical countries such as Cambodia. This wide distribution of BIV suggests its association with problems in animal health as reported worldwide, and that a primary BIV infection can predispose death of affected animals by other aggressive pathogens or stresses.

  3. Immunotherapy of murine leukemia. Efficacy of passive serum therapy of Friend leukemia virus-induced disease in immunocompromised mice

    International Nuclear Information System (INIS)

    Genovesi, E.V.; Livnat, D.; Collins, J.J.

    1983-01-01

    Previous studies have demonstrated that the passive therapy of Friend murine leukemia virus (F-MuLV)-induced disease with chimpanzee anti-F-MuLV serum is accompanied by the development of host antiviral humoral and cellular immunity, the latter measurable in adoptive transfer protocols and by the ability of serum-protected mice to resist virus rechallenge. The present study was designed to further examine the contribution of various compartments of the host immune system to serum therapy itself, as well as to the acquired antiviral immunity that develops in serum-protected mice, through the use of naturally immunocompromised animals [e.g., nude athymic mice and natural killer (NK)-deficient beige mutant mice] or mice treated with immunoabrogating agents such as sublethal irradiation, cyclophosphamide [Cytoxan (Cy)], cortisone, and 89 Sr. The studies in nude mice indicate that while mature T-cells are not needed for effective serum therapy, they do appear to be necessary for the long-term resistance of serum-protected mice to virus rechallenge and for the generation of the cell population(s) responsible for adoptive transfer of antiviral immunity. Furthermore, this acquired resistance is not due to virus neutralization by serum antibodies since antibody-negative, Cy-treated, serum-protected mice still reject the secondary virus infection. Lastly, while the immunocompromise systems examined did effect various host antiviral immune responses, none of them, including the NK-deficient beige mutation, significantly diminished the efficacy of the passive serum therapy of F-MuLV-induced disease

  4. Mitochondrial disfunction and apoptosis in leukemia cells

    Directory of Open Access Journals (Sweden)

    Annamaria PALLAG

    2008-05-01

    Full Text Available Apoptosis or programmed cell death is a process which involves the intentional degradation of the cell from the inside, the participation of the mitochondria to propagate the apoptotic signal, the alteration of the phospholipid cell membrane composition, the perturbation and alteration of the cell metabolism.The antineoplastic drugs is inducing the apoptotic process in the sensitive cells.It have been studied acute lymphoblastic leukemia cells. Using Annexin V-PE Apoptosis Detection Kit and flow cytometer, the amount of cells undergoing apoptosis, in various stages of the antineoplasic treatment, was detected. At the same time, were monitored, the serum level of malondialdehyde. The results obtained confirm the alteration of the mitochondrial metabolism. We can observed the mitochondrial dysfunction role in cell apoptosis.

  5. Autonomous growth potential of leukemia blast cells is associated with poor prognosis in human acute leukemias.

    Science.gov (United States)

    Yan, Ying; Wieman, Eric A; Guan, Xiuqin; Jakubowski, Ann A; Steinherz, Peter G; O'Reilly, Richard J

    2009-12-29

    We have described a severe combined immunodeficiency (SCID) mouse model that permits the subcutaneous growth of primary human acute leukemia blast cells into a measurable subcutaneous nodule which may be followed by the development of disseminated disease. Utilizing the SCID mouse model, we examined the growth potential of leukemic blasts from 133 patients with acute leukemia, (67 acute lymphoblastic leukemia (ALL) and 66 acute myeloid leukemia (AML)) in the animals after subcutaneous inoculation without conditioning treatment. The blasts displayed three distinct growth patterns: "aggressive", "indolent", or "no tumor growth". Out of 133 leukemias, 45 (33.8%) displayed an aggressive growth pattern, 14 (10.5%) displayed an indolent growth pattern and 74 (55.6%) did not grow in SCID mice. The growth probability of leukemias from relapsed and/or refractory disease was nearly 3 fold higher than that from patients with newly diagnosed disease. Serial observations found that leukemic blasts from the same individual, which did not initiate tumor growth at initial presentation and/or at early relapse, may engraft and grow in the later stages of disease, suggesting that the ability of leukemia cells for engraftment and proliferation was gradually acquired following the process of leukemia progression. Nine autonomous growing leukemia cell lines were established in vitro. These displayed an aggressive proliferation pattern, suggesting a possible correlation between the capacity of human leukemia cells for autonomous proliferation in vitro and an aggressive growth potential in SCID mice. In addition, we demonstrated that patients whose leukemic blasts displayed an aggressive growth and dissemination pattern in SClD mice had a poor clinical outcome in patients with ALL as well as AML. Patients whose leukemic blasts grew indolently or whose leukemia cells failed to induce growth had a significantly longer DFS and more favorable clinical course.

  6. Autonomous growth potential of leukemia blast cells is associated with poor prognosis in human acute leukemias

    Directory of Open Access Journals (Sweden)

    Jakubowski Ann A

    2009-12-01

    Full Text Available Abstract We have described a severe combined immunodeficiency (SCID mouse model that permits the subcutaneous growth of primary human acute leukemia blast cells into a measurable subcutaneous nodule which may be followed by the development of disseminated disease. Utilizing the SCID mouse model, we examined the growth potential of leukemic blasts from 133 patients with acute leukemia, (67 acute lymphoblastic leukemia (ALL and 66 acute myeloid leukemia (AML in the animals after subcutaneous inoculation without conditioning treatment. The blasts displayed three distinct growth patterns: "aggressive", "indolent", or "no tumor growth". Out of 133 leukemias, 45 (33.8% displayed an aggressive growth pattern, 14 (10.5% displayed an indolent growth pattern and 74 (55.6% did not grow in SCID mice. The growth probability of leukemias from relapsed and/or refractory disease was nearly 3 fold higher than that from patients with newly diagnosed disease. Serial observations found that leukemic blasts from the same individual, which did not initiate tumor growth at initial presentation and/or at early relapse, may engraft and grow in the later stages of disease, suggesting that the ability of leukemia cells for engraftment and proliferation was gradually acquired following the process of leukemia progression. Nine autonomous growing leukemia cell lines were established in vitro. These displayed an aggressive proliferation pattern, suggesting a possible correlation between the capacity of human leukemia cells for autonomous proliferation in vitro and an aggressive growth potential in SCID mice. In addition, we demonstrated that patients whose leukemic blasts displayed an aggressive growth and dissemination pattern in SClD mice had a poor clinical outcome in patients with ALL as well as AML. Patients whose leukemic blasts grew indolently or whose leukemia cells failed to induce growth had a significantly longer DFS and more favorable clinical course.

  7. HA-1 T TCR T Cell Immunotherapy for the Treating of Patients With Relapsed or Refractory Acute Leukemia After Donor Stem Cell Transplant

    Science.gov (United States)

    2018-03-26

    HLA-A*0201 HA-1 Positive Cells Present; Minimal Residual Disease; Recurrent Acute Biphenotypic Leukemia; Recurrent Acute Undifferentiated Leukemia; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Refractory Acute Myeloid Leukemia; Refractory Adult Acute Lymphoblastic Leukemia; Refractory Childhood Acute Lymphoblastic Leukemia

  8. Leukemia Mediated Endothelial Cell Activation Modulates Leukemia Cell Susceptibility to Chemotherapy through a Positive Feedback Loop Mechanism.

    Directory of Open Access Journals (Sweden)

    Bahareh Pezeshkian

    Full Text Available In acute myeloid leukemia (AML, the chances of achieving disease-free survival are low. Studies have demonstrated a supportive role of endothelial cells (ECs in normal hematopoiesis. Here we show that similar intercellular relationships exist in leukemia. We demonstrate that leukemia cells themselves initiate these interactions by directly modulating the behavior of resting ECs through the induction of EC activation. In this inflammatory state, activated ECs induce the adhesion of a sub-set of leukemia cells through the cell adhesion molecule E-selectin. These adherent leukemia cells are sequestered in a quiescent state and are unaffected by chemotherapy. The ability of adherent cells to later detach and again become proliferative following exposure to chemotherapy suggests a role of this process in relapse. Interestingly, differing leukemia subtypes modulate this process to varying degrees, which may explain the varied response of AML patients to chemotherapy and relapse rates. Finally, because leukemia cells themselves induce EC activation, we postulate a positive-feedback loop in leukemia that exists to support the growth and relapse of the disease. Together, the data defines a new mechanism describing how ECs and leukemia cells interact during leukemogenesis, which could be used to develop novel treatments for those with AML.

  9. Molecular cloning of a feline leukemia virus that induces fatal immunodeficiency disease in cats.

    Science.gov (United States)

    Overbaugh, J; Donahue, P R; Quackenbush, S L; Hoover, E A; Mullins, J I

    1988-02-19

    A replication-defective variant of feline leukemia virus was molecularly cloned directly from infected tissue and found to induce a rapid and fatal immunodeficiency syndrome in cats. Studies with cloned viruses also showed that subtle mutational changes would convert a minimally pathogenic virus into one that would induce an acute form of immunodeficiency. The data suggest that acutely pathogenic viruses may be selected against by current methods for isolation of the human and simian immunodeficiency viruses.

  10. Functional impairment of Tax-specific but not cytomegalovirus-specific CD8+ T lymphocytes in a minor population of asymptomatic human T-cell leukemia virus type 1-carriers

    Directory of Open Access Journals (Sweden)

    Takamori Ayako

    2011-12-01

    Full Text Available Abstract Background Human T-cell leukemia virus type 1 (HTLV-1 causes adult T-cell leukemia (ATL and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP in a small percentage of infected individuals. ATL is often associated with general immune suppression and an impaired HTLV-1-specific T-cell response, an important host defense system. We previously found that a small fraction of asymptomatic HTLV-1-carriers (AC already showed impaired T-cell responses against the major target antigen, Tax. However, it is unclear whether the impaired HTLV-1 Tax-specific T-cell response in these individuals is an HTLV-1-specific phenomenon, or merely reflects general immune suppression. In this study, in order to characterize the impaired HTLV-1-specific T-cell response, we investigated the function of Tax-specific CD8+ T-cells in various clinical status of HTLV-1 infection. Results By using tetramers consisting of HLA-A*0201, -A*2402, or -A*1101, and corresponding Tax epitope peptides, we detected Tax-specific CD8+ T-cells in the peripheral blood from 87.0% of ACs (n = 20/23 and 100% of HAM/TSP patients (n = 18/18 tested. We also detected Tax-specific CD8+ T-cells in 38.1% of chronic type ATL (cATL patients (n = 8/21, although its frequencies in peripheral blood CD8+ T cells were significantly lower than those of ACs or HAM/TSP patients. Tax-specific CD8+ T-cells detected in HAM/TSP patients proliferated well in culture and produced IFN-γ when stimulated with Tax peptides. However, such functions were severely impaired in the Tax-specific CD8+ T-cells detected in cATL patients. In ACs, the responses of Tax-specific CD8+ T-cells were retained in most cases. However, we found one AC sample whose Tax-specific CD8+ T-cells hardly produced IFN-γ, and failed to proliferate and express activation (CD69 and degranulation (CD107a markers in response to Tax peptide. Importantly, the same AC sample contained cytomegalovirus (CMV pp65-specific CD8+ T-cells

  11. Functional impairment of Tax-specific but not cytomegalovirus-specific CD8+ T lymphocytes in a minor population of asymptomatic human T-cell leukemia virus type 1-carriers.

    Science.gov (United States)

    Takamori, Ayako; Hasegawa, Atsuhiko; Utsunomiya, Atae; Maeda, Yasuhiro; Yamano, Yoshihisa; Masuda, Masato; Shimizu, Yukiko; Tamai, Yotaro; Sasada, Amane; Zeng, Na; Choi, Ilseung; Uike, Naokuni; Okamura, Jun; Watanabe, Toshiki; Masuda, Takao; Kannagi, Mari

    2011-12-07

    Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in a small percentage of infected individuals. ATL is often associated with general immune suppression and an impaired HTLV-1-specific T-cell response, an important host defense system. We previously found that a small fraction of asymptomatic HTLV-1-carriers (AC) already showed impaired T-cell responses against the major target antigen, Tax. However, it is unclear whether the impaired HTLV-1 Tax-specific T-cell response in these individuals is an HTLV-1-specific phenomenon, or merely reflects general immune suppression. In this study, in order to characterize the impaired HTLV-1-specific T-cell response, we investigated the function of Tax-specific CD8+ T-cells in various clinical status of HTLV-1 infection. By using tetramers consisting of HLA-A*0201, -A*2402, or -A*1101, and corresponding Tax epitope peptides, we detected Tax-specific CD8+ T-cells in the peripheral blood from 87.0% of ACs (n = 20/23) and 100% of HAM/TSP patients (n = 18/18) tested. We also detected Tax-specific CD8+ T-cells in 38.1% of chronic type ATL (cATL) patients (n = 8/21), although its frequencies in peripheral blood CD8+ T cells were significantly lower than those of ACs or HAM/TSP patients. Tax-specific CD8+ T-cells detected in HAM/TSP patients proliferated well in culture and produced IFN-γ when stimulated with Tax peptides. However, such functions were severely impaired in the Tax-specific CD8+ T-cells detected in cATL patients. In ACs, the responses of Tax-specific CD8+ T-cells were retained in most cases. However, we found one AC sample whose Tax-specific CD8+ T-cells hardly produced IFN-γ, and failed to proliferate and express activation (CD69) and degranulation (CD107a) markers in response to Tax peptide. Importantly, the same AC sample contained cytomegalovirus (CMV) pp65-specific CD8+ T-cells that possessed functions upon CMV pp

  12. Nonreciprocal Pseudotyping: Murine Leukemia Virus Proteins Cannot Efficiently Package Spleen Necrosis Virus-Based Vector RNA

    OpenAIRE

    Certo, Jeanine L.; Shook, Betsy F.; Yin, Philip D.; Snider, John T.; Hu, Wei-Shau

    1998-01-01

    It has been documented that spleen necrosis virus (SNV) can package murine leukemia virus (MLV) RNA efficiently and propagate MLV vectors to the same titers as it propagates SNV-based vectors. Although the SNV packaging signal (E) and MLV packaging signal (Ψ) have little sequence homology, similar double-hairpin RNA structures were predicted and supported by experimental evidence. To test whether SNV RNA can be packaged by MLV proteins, we modified an SNV vector to be expressed in an MLV-base...

  13. Xenotropic murine leukemia virus-related virus does not pose a risk to blood recipient safety.

    Science.gov (United States)

    Dodd, Roger Y; Hackett, John; Linnen, Jeffrey M; Dorsey, Kerri; Wu, Yanyun; Zou, Shimian; Qiu, Xiaoxing; Swanson, Priscilla; Schochetman, Gerald; Gao, Kui; Carrick, James M; Krysztof, David E; Stramer, Susan L

    2012-02-01

    When xenotropic murine leukemia virus-related virus (XMRV) was first reported in association with chronic fatigue syndrome, it was suggested that it might offer a risk to blood safety. Thus, the prevalence of the virus among blood donors and, if present, its transmissibility by transfusion need to be defined. Two populations of routine blood donor samples (1435 and 13,399) were obtained for prevalence evaluations; samples from a linked donor-recipient repository were also evaluated. Samples were tested for the presence of antibodies to XMRV-related recombinant antigens and/or for XMRV RNA, using validated, high-throughput systems. The presence of antibodies to XMRV could not be confirmed among a total of 17,249 blood donors or recipients (0%; 95% confidence interval [CI], 0%-0.017%); 1763 tested samples were nonreactive for XMRV RNA (0%; 95% CI, 0%-0.17%). Evidence of infection was absent from 109 recipients and 830 evaluable blood samples tested after transfusion of a total of 3741 blood components. XMRV and related murine leukemia virus (MLV) markers are not present among a large population of blood donors and evidence of transfusion transmission could not be detected. Thus, these viruses do not currently pose a threat to blood recipient safety and further actions relating to XMRV and MLV are not justified. © 2012 American Association of Blood Banks.

  14. Visualizing spatiotemporal dynamics of apoptosis after G1 arrest by human T cell leukemia virus type 1 Tax and insights into gene expression changes using microarray-based gene expression analysis

    Directory of Open Access Journals (Sweden)

    Arainga Mariluz

    2012-06-01

    Full Text Available Abstract Background Human T cell leukemia virus type 1 (HTLV-1 Tax is a potent activator of viral and cellular gene expression that interacts with a number of cellular proteins. Many reports show that Tax is capable of regulating cell cycle progression and apoptosis both positively and negatively. However, it still remains to understand why the Tax oncoprotein induces cell cycle arrest and apoptosis, or whether Tax-induced apoptosis is dependent upon its ability to induce G1 arrest. The present study used time-lapse imaging to explore the spatiotemporal patterns of cell cycle dynamics in Tax-expressing HeLa cells containing the fluorescent ubiquitination-based cell cycle indicator, Fucci2. A large-scale host cell gene profiling approach was also used to identify the genes involved in Tax-mediated cell signaling events related to cellular proliferation and apoptosis. Results Tax-expressing apoptotic cells showed a rounded morphology and detached from the culture dish after cell cycle arrest at the G1 phase. Thus, it appears that Tax induces apoptosis through pathways identical to those involved in G1 arrest. To elucidate the mechanism(s by which Tax induces cell cycle arrest and apoptosis, regulation of host cellular genes by Tax was analyzed using a microarray containing approximately 18,400 human mRNA transcripts. Seventeen genes related to cell cycle regulation were identified as being up or downregulated > 2.0-fold in Tax-expressing cells. Several genes, including SMAD3, JUN, GADD45B, DUSP1 and IL8, were involved in cellular proliferation, responses to cellular stress and DNA damage, or inflammation and immune responses. Additionally, 23 pro- and anti-apoptotic genes were deregulated by Tax, including TNFAIP3, TNFRS9, BIRC3 and IL6. Furthermore, the kinetics of IL8, SMAD3, CDKN1A, GADD45A, GADD45B and IL6 expression were altered following the induction of Tax, and correlated closely with the morphological changes observed by time

  15. Visualizing spatiotemporal dynamics of apoptosis after G1 arrest by human T cell leukemia virus type 1 Tax and insights into gene expression changes using microarray-based gene expression analysis.

    Science.gov (United States)

    Arainga, Mariluz; Murakami, Hironobu; Aida, Yoko

    2012-06-22

    Human T cell leukemia virus type 1 (HTLV-1) Tax is a potent activator of viral and cellular gene expression that interacts with a number of cellular proteins. Many reports show that Tax is capable of regulating cell cycle progression and apoptosis both positively and negatively. However, it still remains to understand why the Tax oncoprotein induces cell cycle arrest and apoptosis, or whether Tax-induced apoptosis is dependent upon its ability to induce G1 arrest. The present study used time-lapse imaging to explore the spatiotemporal patterns of cell cycle dynamics in Tax-expressing HeLa cells containing the fluorescent ubiquitination-based cell cycle indicator, Fucci2. A large-scale host cell gene profiling approach was also used to identify the genes involved in Tax-mediated cell signaling events related to cellular proliferation and apoptosis. Tax-expressing apoptotic cells showed a rounded morphology and detached from the culture dish after cell cycle arrest at the G1 phase. Thus, it appears that Tax induces apoptosis through pathways identical to those involved in G1 arrest. To elucidate the mechanism(s) by which Tax induces cell cycle arrest and apoptosis, regulation of host cellular genes by Tax was analyzed using a microarray containing approximately 18,400 human mRNA transcripts. Seventeen genes related to cell cycle regulation were identified as being up or downregulated > 2.0-fold in Tax-expressing cells. Several genes, including SMAD3, JUN, GADD45B, DUSP1 and IL8, were involved in cellular proliferation, responses to cellular stress and DNA damage, or inflammation and immune responses. Additionally, 23 pro- and anti-apoptotic genes were deregulated by Tax, including TNFAIP3, TNFRS9, BIRC3 and IL6. Furthermore, the kinetics of IL8, SMAD3, CDKN1A, GADD45A, GADD45B and IL6 expression were altered following the induction of Tax, and correlated closely with the morphological changes observed by time-lapse imaging. Taken together, the results of this

  16. Expression of antigens coded in murine leukemia viruses on thymocytes of allogeneic donor origin in AKR mice following syngeneic or allogeneic bone marrow transplantation

    International Nuclear Information System (INIS)

    Wustrow, T.P.; Good, R.A.

    1985-01-01

    Removal of T-lymphocytes from marrow inoculum with monoclonal antibody plus complement permitted establishment of long-lived allogeneic chimeras between C57BL/6 and AKR/J mice. Development of leukemia was prevented for 15 mo. Protection from leukemia occurred with both young (4 wk) and older (4 mo) recipients. AKR mice reconstituted with syngeneic marrow or control AKR mice all developed leukemia-lymphoma before 1 yr of age. During spontaneous lymphomagenesis in AKR mice, amplified expression of gag or env gene-coded virus antigens on the surface of thymocytes preceded leukemia development and evidence for amplification of other virus genes. These changes generally appeared before 6 mo. Similar viral gene expression and viral gene amplification occurred in the thymus and spleen cells of leukemia-resistant chimeric mice. Using monoclonal antibodies to Mr 70,000 glycoprotein epitopes characteristic of ecotropic, xenotropic, or dualtropic viruses, antigens marking each virus form were found on thymocytes of allogeneic 4-wk and 4-mo chimeras as well as on the cells of AKR mice and of AKR mice reconstituted with syngeneic marrow. Flow cytometric analysis showed amplification of the virus genes in mice protected from leukemia-lymphoma by allogeneic bone marrow transplantation from leukemia-resistant mice. Allogeneic chimeras and syngeneically transplanted mice both showed evidence of accelerated viremia and of recombinant virus formation. The findings suggest that an event essential to leukemogenesis which occurs within the AKR lymphoid cells or their environment is lacking in the allogeneic chimeras. The nature of this influence of a resistance gene or genes introduced into AKR mice by allogeneic bone marrow transplantation deserves further study

  17. Hairy cell leukemia – immunotargets and therapies

    Directory of Open Access Journals (Sweden)

    Basheer F

    2014-06-01

    Full Text Available Faisal Basheer, David M Bloxham, Mike A Scott, George A FollowsDepartment of Haematology, Addenbrookes Hospital, University of Cambridge, Cambridge, UKAbstract: Hairy cell leukemia (HCL is an indolent low-grade B-cell lymphoproliferative disorder that is reasonably sensitive to standard first-line purine analog therapy. However, in many cases, repeat relapses occur, requiring multiple courses of purine analog therapy, promoting eventual drug resistance. This, coupled with the concerning side effects of repeated purine analog exposure, has prompted the search for alternative targets and therapies that may provide deeper remissions. Novel strategies employing immune-mediated targeting via monoclonal antibody therapies and recombinant immunotoxins appear promising in HCL and are currently under investigation. More recently, the concept of targeted kinase inhibition using small-molecule inhibitors in HCL has emerged as another potentially viable option. As a deeper understanding of the aberrant molecular pathways contributing to the pathogenesis of HCL develops, the landscape of management for HCL, particularly in the relapse setting, may change significantly in the future as a result of these promising immunotargets and therapies.Keywords: hairy cell leukemia, immunotargets, therapies

  18. Transplantability of human lymphoid cell line, lymphoma, and leukemia in splenectomized and/or irradiated nude mice

    International Nuclear Information System (INIS)

    Watanabe, S.; Shimosato, Y.; Kuroki, M.; Sato, Y.; Nakajima, T.

    1980-01-01

    The effects of splenectomy and/or whole-body irradiation of nude mice before xenotransplantation of lymphoid cell lines, lymphoma, and leukemia were studied. Transplantation after whole-body irradiation resulted in the increased ''take'' rate of three cultured cell lines (two of T-cell-derived acute lymphocytic leukemia and one of B-cell derived acute lymphocytic leukemia) and in the tumorous growth of Burkitt-derived Raji and spontaneously transformed lymphoblastoid cell lines. With splenectomy plus irradiation as a pretreatment, tumorous growth occurred in four other cell lines which were not transplantable after irradiation only (two cell lines of Epstein-Barr virus-transformed cord blood cells and one each of null acute lymphocytic leukemia and nodular lymphoma-derived cell lines). Direct transplantation of leukemia and lymphoma cells into the pretreated mice was successful in 7 of 24 cases (29%). B-cell-derived diffuse large lymphoid lymphoma was transplantable in three of seven cases (43%). However, lymphoma and leukemia of peripheral T-cell origin was difficult to transplant even with pretreatment, and only one pleomorphic T-cell lymphoma grew to a significant size (2 cm). One tumor each of B-cell-derived diffuse large lymphoid and T-cell diffuse lymphoblastic lymphoma became transplantable

  19. Leukemia

    International Nuclear Information System (INIS)

    Mabuchi, Kiyohiko; Kusumi, Shizuyo

    1992-01-01

    Leukemia is the first malignant disease found among A-bomb survivors. Leukemia registration has greatly contributed to epidemiological and hematological studies on A-bomb radiation-related leukemia and other hematopoietic diseases, consisting of community population and the RERF Life Span Study (LSS) sample (approximately 120,000 persons containing A-bomb survivors). Using the fixed LSS cohort, the prevalence rate of leukemia reached the peak during the years 1950-1954, and thereafter, it has been gradually decreased. However, risk patterns for leukemia are still unsolved: has leukemia risk increased in recent years?; are serial changes in leukemia risk influenced by age at the time of exposure (ATE)?; is there variation between Hiroshima and Nagasaki?; and others. To solve these questions, leukemia data are now under analysis using the revised DS86. Relative risk for leukemia, especially chronic myelogenous leukemia and acute lymphocytic leukemia (ALL), is found to be linearly increased with increasing bone marrow doses. Serial patterns of both excess risk and excess relative risk have revealed that leukemia risk is high at 5-10 years after A-bombing in younger A-bomb survivors ATE. The influence of age ATE on serial changes is noticeable in ALL. Another factor involved in the prevalence of leukemia is background (spontaneously developed leukemia), which is the recent interest because young A-bomb survivors ATE reach the cancer-prone age. (N.K.)

  20. Molecular cloning of osteoma-inducing replication-competent murine leukemia viruses from the RFB osteoma virus stock

    DEFF Research Database (Denmark)

    Pedersen, Lene; Behnisch, Werner; Schmidt, Jörg

    1992-01-01

    We report the molecular cloning of two replication-competent osteoma-inducing murine leukemia viruses from the RFB osteoma virus stock (M. P. Finkel, C. A. Reilly, Jr., B. O. Biskis, and I. L. Greco, p. 353-366, in C. H. G. Price and F. G. M. Ross, ed., Bone--Certain Aspects of Neoplasia, 1973...

  1. Molecular Pathology of Adult T-Cell Leukemia/Lymphoma.

    Science.gov (United States)

    Ohshima, Koichi

    2015-01-01

    Adult T-cell leukemia/lymphoma (ATLL) is a peripheral T-cell neoplasm of highly pleomorphic lymphoid cells. ATLL is usually widely disseminated, and it is caused by human T-cell leukemia virus type 1 (HTLV-1). It is a disease with a long latency, and affected individuals are usually exposed to the virus very early in life. The cumulative incidence of ATLL is estimated to be 2.5% among HTLV-1 carriers. ATLL cells express CD2, CD3, CD5, CD4, and CD25, as well as CCR4 and FoxP3 of the regulatory T-cell marker. HTLV-1 is causally linked to ATLL, but infection alone is not sufficient to result in neoplastic transformation. A significant finding in this connection is that the Tax viral protein leads to transcriptional activation of many genes, while the HTLV-1 basic leucine zipper factor is thought to be important for T-cell proliferation and oncogenesis. Half of ATLL cases retain the ability to express HTLV-1 Tax, which is a target of HTLV-1-specific cytotoxic T lymphocytes (CTL). An increase in HTLV-1-specific CTL responses is observed in some asymptomatic HTLV-1 carriers. Although HTLV-1-specific CTL are also present in the peripheral blood of ATLL patients, they do not expand sufficiently. We investigated the clinicopathological features and analyzed the staining of Tax-specific CTL and FoxP3. Tax-specific CTL correlated inversely with FoxP3, an increase in the ratio of CD163+ tumor-associated macrophages was associated with worse clinical prognosis, and ATLL cell lines proliferated significantly following direct co-culture with M2 macrophages. Several clinical variants of ATLL have been identified: acute, lymphomatous, chronic, and smoldering. Oligo-array comparative genomic hybridization revealed that genomic loss of 9p21.3 was a significant characteristic of acute-type, but not of chronic-type ATLL. Furthermore, we found that genomic alteration of CD58, which is implicated in immune escape, is more frequently observed in acute than in chronic ATLL. Interestingly

  2. Graft-versus-Leukemia Effect Following Hematopoietic Stem Cell Transplantation for Leukemia

    Directory of Open Access Journals (Sweden)

    Anne M. Dickinson

    2017-06-01

    Full Text Available The success of hematopoietic stem cell transplantation (HSCT lies with the ability of the engrafting immune system to remove residual leukemia cells via a graft-versus-leukemia effect (GvL, caused either spontaneously post-HSCT or via donor lymphocyte infusion. GvL effects can also be initiated by allogenic mismatched natural killer cells, antigen-specific T cells, and activated dendritic cells of leukemic origin. The history and further application of this GvL effect and the main mechanisms will be discussed and reviewed in this chapter.

  3. Identification of a High Affinity Nucleocapsid Protein Binding Element from The Bovine Leukemia Virus Genome

    Science.gov (United States)

    Yildiz, F. Zehra; Babalola, Kathleen; Summers, Michael F.

    2012-01-01

    Retroviral genome recognition is mediated by interactions between the nucleocapsid (NC) domain of the virally encoded Gag polyprotein and cognate RNA packaging elements that, for most retroviruses, appear to reside primarily within the 5′-untranslated region (5′-UTR) of the genome. Recent studies suggest that a major packaging determinant of Bovine Leukemia Virus (BLV), a member of the human T-cell leukemia virus (HTLV)/BLV family and a non-primate animal model for HTLV-induced leukemogenesis, resides within the gag open reading frame. We have prepared and purified the recombinant BLV NC protein and conducted electrophoretic mobility shift and isothermal titration calorimetry studies with RNA fragments corresponding to these proposed packaging elements. The gag-derived RNAs did not exhibit significant affinity for NC, suggesting an alternate role in packaging. However, an 83-nucleotide fragment of the 5′-UTR that resides just upstream of the gag start codon binds NC stoichiometrically and with high affinity (Kd = 136 ± 21 nM). These nucleotides were predicted to form tandem hairpin structures, and studies with smaller fragments indicate that the NC binding site resides exclusively within the distal hairpin (residues G369- U399, Kd = 67 ± 8 nM at physiological ionic strength). Unlike all other structurally characterized retroviral NC binding RNAs, this fragment is not expected to contain exposed guanosines, suggesting that RNA binding may be mediated by a previously uncharacterized mechanism. PMID:22846919

  4. Adult T-cell leukemia/lymphoma. Report of a case in Uruguay

    Directory of Open Access Journals (Sweden)

    Matilde Boada

    2017-06-01

    Full Text Available Adult T-cell leukemia/lymphoma belongs to the group of mature T-cell malignancies according to the WHO classification. It constitutes a rare entity and has a strong association with infection by human T-lymphotropic virus 1. In Uruguay, this viral infection is very infrequent and, to our knowledge, no case of adult T-cell leukemia/lymphoma has been previously reported. We describe the case of a woman, immigrant from Peru, who presented with persistent lymphocytosis, intestinal parasitic diseases, and skin involvement. The diagnosis was delayed and the patient died before initiating oncological treatment. We therefore emphasize the relevance of an early clinical suspicion and serology for this virus, especially in patients coming from endemic countries like Peru.

  5. Dendritic Cell-Based Immunotherapy for Myeloid Leukemias

    Science.gov (United States)

    Schürch, Christian M.; Riether, Carsten; Ochsenbein, Adrian F.

    2013-01-01

    Acute and chronic myeloid leukemia (AML, CML) are hematologic malignancies arising from oncogene-transformed hematopoietic stem/progenitor cells known as leukemia stem cells (LSCs). LSCs are selectively resistant to various forms of therapy including irradiation or cytotoxic drugs. The introduction of tyrosine kinase inhibitors has dramatically improved disease outcome in patients with CML. For AML, however, prognosis is still quite dismal. Standard treatments have been established more than 20 years ago with only limited advances ever since. Durable remission is achieved in less than 30% of patients. Minimal residual disease (MRD), reflected by the persistence of LSCs below the detection limit by conventional methods, causes a high rate of disease relapses. Therefore, the ultimate goal in the treatment of myeloid leukemia must be the eradication of LSCs. Active immunotherapy, aiming at the generation of leukemia-specific cytotoxic T cells (CTLs), may represent a powerful approach to target LSCs in the MRD situation. To fully activate CTLs, leukemia antigens have to be successfully captured, processed, and presented by mature dendritic cells (DCs). Myeloid progenitors are a prominent source of DCs under homeostatic conditions, and it is now well established that LSCs and leukemic blasts can give rise to “malignant” DCs. These leukemia-derived DCs can express leukemia antigens and may either induce anti-leukemic T cell responses or favor tolerance to the leukemia, depending on co-stimulatory or -inhibitory molecules and cytokines. This review will concentrate on the role of DCs in myeloid leukemia immunotherapy with a special focus on their generation, application, and function and how they could be improved in order to generate highly effective and specific anti-leukemic CTL responses. In addition, we discuss how DC-based immunotherapy may be successfully integrated into current treatment strategies to promote remission and potentially cure myeloid leukemias

  6. Mutations of the kissing-loop dimerization sequence influence the site specificity of murine leukemia virus recombination in vivo

    DEFF Research Database (Denmark)

    Mikkelsen, J G; Lund, Anders Henrik; Duch, M

    2000-01-01

    synthesis in newly infected cells. We have previously shown that template shifts within the 5' leader of murine leukemia viruses occur preferentially within the kissing stem-loop motif, a cis element crucial for in vitro RNA dimer formation. By use of a forced recombination approach based on single......-cycle transfer of Akv murine leukemia virus-based vectors harboring defective primer binding site sequences, we now report that modifications of the kissing-loop structure, ranging from a deletion of the entire sequence to introduction of a single point mutation in the loop motif, significantly disturb site...... specificity of recombination within the highly structured 5' leader region. In addition, we find that an intact kissing-loop sequence favors optimal RNA encapsidation and vector transduction. Our data are consistent with the kissing-loop dimerization model and suggest that a direct intermolecular RNA...

  7. Expression of heterologous genes from an IRES translational cassette in replication competent murine leukemia virus vectors

    DEFF Research Database (Denmark)

    Jespersen, Thomas; Duch, Mogens R.; Carrasco, M L

    1999-01-01

    We describe replication competent retroviruses capable of expressing heterologous genes during multiple rounds of infection. An internal ribosome entry site (IRES) from encephalomyocarditis virus was inserted in the U3 region of Akv- and SL3-3-murine leukemia viruses (MLV) to direct translation...

  8. 75 FR 54496 - Diseases Associated With Exposure to Certain Herbicide Agents (Hairy Cell Leukemia and Other...

    Science.gov (United States)

    2010-09-08

    ... DEPARTMENT OF VETERANS AFFAIRS 38 CFR Part 3 RIN 2900-AN54 Diseases Associated With Exposure to Certain Herbicide Agents (Hairy Cell Leukemia and Other Chronic B-Cell Leukemias, Parkinson's Disease and... leukemia and other chronic B-cell leukemias, Parkinson's disease and ischemic heart disease to the list of...

  9. Determination of the minimal fusion peptide of bovine leukemia virus gp30

    International Nuclear Information System (INIS)

    Lorin, Aurelien; Lins, Laurence; Stroobant, Vincent; Brasseur, Robert; Charloteaux, Benoit

    2007-01-01

    In this study, we determined the minimal N-terminal fusion peptide of the gp30 of the bovine leukemia virus on the basis of the tilted peptide theory. We first used molecular modelling to predict that the gp30 minimal fusion peptide corresponds to the 15 first residues. Liposome lipid-mixing and leakage assays confirmed that the 15-residue long peptide induces fusion in vitro and that it is the shortest peptide inducing optimal fusion since longer peptides destabilize liposomes to the same extent but not shorter ones. The 15-residue long peptide can thus be considered as the minimal fusion peptide. The effect of mutations reported in the literature was also investigated. Interestingly, mutations related to glycoproteins unable to induce syncytia in cell-cell fusion assays correspond to peptides predicted as non-tilted. The relationship between obliquity and fusogenicity was also confirmed in vitro for one tilted and one non-tilted mutant peptide

  10. Role for protein geranylgeranylation in adult T-cell leukemia cell survival

    International Nuclear Information System (INIS)

    Nonaka, Mizuho; Uota, Shin; Saitoh, Yasunori; Takahashi, Mayumi; Sugimoto, Haruyo; Amet, Tohti; Arai, Ayako; Miura, Osamu; Yamamoto, Naoki; Yamaoka, Shoji

    2009-01-01

    Adult T-cell leukemia (ATL) is a fatal lymphoproliferative disease that develops in human T-cell leukemia virus type I (HTLV-I)-infected individuals. Despite the accumulating knowledge of the molecular biology of HTLV-I-infected cells, effective therapeutic strategies remain to be established. Recent reports showed that the hydroxyl-3-methylglutaryl (HMG)-CoA reductase inhibitor statins have anti-proliferative and apoptotic effects on certain tumor cells through inhibition of protein prenylation. Here, we report that statins hinder the survival of ATL cells and induce apoptotic cell death. Inhibition of protein geranylgeranylation is responsible for these effects, since simultaneous treatment with isoprenoid precursors, geranylgeranyl pyrophosphate or farnesyl pyrophosphate, but not a cholesterol precursor squalene, restored the viability of ATL cells. Simvastatin inhibited geranylgeranylation of small GTPases Rab5B and Rac1 in ATL cells, and a geranylgeranyl transferase inhibitor GGTI-298 reduced ATL cell viability more efficiently than a farnesyl transferase inhibitor FTI-277. These results not only unveil an important role for protein geranylgeranylation in ATL cell survival, but also implicate therapeutic potentials of statins in the treatment of ATL

  11. A novel human monoclonal antibody, TONO-1, reactive with T-lymphocytic leukemia cells.

    Science.gov (United States)

    Numasaki, M; Fukuoka, Y; Kudo, T; Saeki, H; Tachibana, T; Motomiya, M; Nukiwa, T

    1995-07-04

    Mononuclear cells from the peripheral blood of patients with systemic lupus erythematosus (SLE) were transformed with the Epstein-Barr virus (EBV) and the resultant polyclonal B-lymphoblastoid cell lines were tested for antibody activity to membrane antigens of certain T-cell lines. B lymphoblastoid cell lines secreting specific antibodies were fused with (mouse x human) heteromyeloma SHM-D33 cells. Among the large number of hybridomas generated, one which produced a human monoclonal antibody (MAb) TONO-1 (IgM, lambda) was selected. MAb TONO-1 proved to be reactive with 4 human T-cell lines, HPB-MLT, L-MAT, MOLT-3 and MOLT-4F, but not with B-leukemia, Burkitt's lymphoma, myelomonocytic leukemia, erythroleukemia or non-hematopoietic malignant cell lines. MAb TONO-1 reacted positively with fresh leukemia cells from 2 of 7 patients with acute T-lymphocytic leukemia, but no reaction was observed in non-T-cell leukemia cases. Normal lymphocytes, monocytes, granulocytes, red blood cells and platelets in the peripheral blood did not demonstrate remarkable binding. Neither thymocytes nor bone-marrow cells from healthy volunteers were reactive. The antigens defined by MAb TONO-1 were polypeptides of 57 kDa and 68 kDa. Immunohistological studies revealed no staining of thymocytes in the thymus of a 6-month-old child, but showed epithelial reticular cells and Hassall's corpuscles to stain positively. These results suggest that MAb TONO-1 is directed to T-leukemic cells and some components of thymus tissue.

  12. BRAF mutation in hairy cell leukemia

    Directory of Open Access Journals (Sweden)

    Ahmad Ahmadzadeh

    2014-09-01

    Full Text Available BRAF is a serine/threonine kinase with a regulatory role in the mitogen-activated protein kinase (MAPK signaling pathway. A mutation in the RAF gene, especially in BRAF protein, leads to an increased stimulation of this cascade, causing uncontrolled cell division and development of malignancy. Several mutations have been observed in the gene coding for this protein in a variety of human malignancies, including hairy cell leukemia (HCL. BRAF V600E is the most common mutation reported in exon15 of BRAF, which is observed in almost all cases of classic HCL, but it is negative in other B-cell malignancies, including the HCL variant. Therefore it can be used as a marker to differentiate between these B-cell disorders. We also discuss the interaction between miRNAs and signaling pathways, including MAPK, in HCL. When this mutation is present, the use of BRAF protein inhibitors may represent an effective treatment. In this review we have evaluated the role of the mutation of the BRAF gene in the pathogenesis and progression of HCL.

  13. Treating Multiply Relapsed or Refractory Hairy Cell Leukemia

    Science.gov (United States)

    In this trial, patients with hairy cell leukemia who have not responded or relapsed after initial chemotherapy will be randomly assigned to receive rituximab combined with either pentostatin or bendamustine.

  14. Bovine leukemia virus nucleocapsid protein is an efficient nucleic acid chaperone

    International Nuclear Information System (INIS)

    Qualley, Dominic F.; Sokolove, Victoria L.; Ross, James L.

    2015-01-01

    Nucleocapsid proteins (NCs) direct the rearrangement of nucleic acids to form the most thermodynamically stable structure, and facilitate many steps throughout the life cycle of retroviruses. NCs bind strongly to nucleic acids (NAs) and promote NA aggregation by virtue of their cationic nature; they also destabilize the NA duplex via highly structured zinc-binding motifs. Thus, they are considered to be NA chaperones. While most retroviral NCs are structurally similar, differences are observed both within and between retroviral genera. In this work, we compare the NA binding and chaperone activity of bovine leukemia virus (BLV) NC to that of two other retroviral NCs: human immunodeficiency virus type 1 (HIV-1) NC, which is structurally similar to BLV NC but from a different retrovirus genus, and human T-cell leukemia virus type 1 (HTLV-1) NC, which possesses several key structural differences from BLV NC but is from the same genus. Our data show that BLV and HIV-1 NCs bind to NAs with stronger affinity in relation to HTLV-1 NC, and that they also accelerate the annealing of complementary stem-loop structures to a greater extent. Analysis of kinetic parameters derived from the annealing data suggests that while all three NCs stimulate annealing by a two-step mechanism as previously reported, the relative contributions of each step to the overall annealing equilibrium are conserved between BLV and HIV-1 NCs but are different for HTLV-1 NC. It is concluded that while BLV and HTLV-1 belong to the same genus of retroviruses, processes that rely on NC may not be directly comparable. - Highlights: • BLV NC binds strongly to DNA and RNA. • BLV NC promotes mini-TAR annealing as well as HIV-1 NC. • Annealing kinetics suggest a low degree of similarity between BLV NC and HTLV-1 NC

  15. [Myeloid/natural killer cell precursor and myeloid/natural killer cell acute leukemia].

    Science.gov (United States)

    Ni, Ming; Chen, Bao-An

    2014-04-01

    With the popularity of flow cytometry, the classification of leukemia become more detailed. Myeloid/natural killer cell precursor acute leukemia and myeloid/natural killer cell acute leukemias are generally recognized as two kinds of rare leukemias and have poor prognosis. The cells expressed both myeloid and lymphatic antigens in these two leukemia and can not be diagnosed by morphology. The only basis to make a definite diagnosis is their unique Immunophenotyping. The role of CD7 and CD56 in these two leukemia are compelling, in the other hand, as the progress of cell differentiation research, there are many new awareness of NK cell differentiation. In this article, the biological origin, clinical manifestation, diagnosis, treatment and the role of CD7 and CD56 in these two leukemia are briefly summarized.

  16. Targeting the leukemia cell metabolism by the CPT1a inhibition: functional preclinical effects in leukemias.

    Science.gov (United States)

    Ricciardi, Maria Rosaria; Mirabilii, Simone; Allegretti, Matteo; Licchetta, Roberto; Calarco, Anna; Torrisi, Maria Rosaria; Foà, Robin; Nicolai, Raffaella; Peluso, Gianfranco; Tafuri, Agostino

    2015-10-15

    Cancer cells are characterized by perturbations of their metabolic processes. Recent observations demonstrated that the fatty acid oxidation (FAO) pathway may represent an alternative carbon source for anabolic processes in different tumors, therefore appearing particularly promising for therapeutic purposes. Because the carnitine palmitoyl transferase 1a (CPT1a) is a protein that catalyzes the rate-limiting step of FAO, here we investigated the in vitro antileukemic activity of the novel CPT1a inhibitor ST1326 on leukemia cell lines and primary cells obtained from patients with hematologic malignancies. By real-time metabolic analysis, we documented that ST1326 inhibited FAO in leukemia cell lines associated with a dose- and time-dependent cell growth arrest, mitochondrial damage, and apoptosis induction. Data obtained on primary hematopoietic malignant cells confirmed the FAO inhibition and cytotoxic activity of ST1326, particularly on acute myeloid leukemia cells. These data suggest that leukemia treatment may be carried out by targeting metabolic processes. © 2015 by The American Society of Hematology.

  17. Endogenous retroviruses mobilized during friend murine leukemia virus infection.

    Science.gov (United States)

    Boi, Stefano; Rosenke, Kyle; Hansen, Ethan; Hendrick, Duncan; Malik, Frank; Evans, Leonard H

    2016-12-01

    We have demonstrated in a mouse model that infection with a retrovirus can lead not only to the generation of recombinants between exogenous and endogenous gammaretrovirus, but also to the mobilization of endogenous proviruses by pseudotyping entire polytropic proviral transcripts and facilitating their infectious spread to new cells. However, the frequency of this occurrence, the kinetics, and the identity of mobilized endogenous proviruses was unclear. Here we find that these mobilized transcripts are detected after only one day of infection. They predominate over recombinant polytropic viruses early in infection, persist throughout the course of disease and are comprised of multiple different polytropic proviruses. Other endogenous retroviral elements such as intracisternal A particles (IAPs) were not detected. The integration of the endogenous transcripts into new cells could result in loss of transcriptional control and elevated expression which may facilitate pathogenesis, perhaps by contributing to the generation of polytropic recombinant viruses. Published by Elsevier Inc.

  18. Human T-cell leukemia virus type I tax protein induces the expression of anti-apoptotic gene Bcl-xL in human T-cells through nuclear factor-kappaB and c-AMP responsive element binding protein pathways.

    Science.gov (United States)

    Mori, N; Fujii, M; Cheng, G; Ikeda, S; Yamasaki, Y; Yamada, Y; Tomonaga, M; Yamamoto, N

    2001-06-01

    Human T-cell leukemia virus type I (HTLV-I) is the etiologic agent of adult T-cell leukemia (ATL), which is an aggressive form of human T-cell malignancy. The viral protein, Tax, immortalizes human T-cells and inhibits various types of apoptosis, and is thought to play crucial roles in the development of ATL. We have recently demonstrated that Tax induces the constitutive expression of the anti-apoptotic protein, Bcl-xL, in a mouse T-cell line. The mouse, however, is not a natural host of HTLV-I, and HTLV-I does not induce this malignancy in mice. We thus examined whether Tax also activates the expression of Bcl-xL in human T-cells. Expression of Tax in a human T-cell line, Jurkat, induced the expression of the Bcl-xL gene, but did not significantly affect the expression of the other apoptosis-related genes, Bcl-2 and Bax. Transient transfection assays showed that Tax stimulated human Bcl-xL promoter activity in Jurkat cells. Deletion of the two potential nuclear factor (NF)-kappaB binding sites in the human Bcl-xL promoter significantly decreased Tax-induced transactivation. In addition to NF-kappaB, Tax activates transcription through the c-AMP responsive element binding protein (CREB). Tax mutants segregating these two pathways showed that both the NF-kappaB and CREB pathways of Tax are required for maximum activation of a human Bcl-xL promoter, nevertheless, NF-kappaB alone was sufficient for that of a mouse Bcl-xL promoter. Northern blot analysis showed that all the human T-cell lines expressing Tax had higher levels of Bcl-xL mRNA than HTLV-I-uninfected ones. Furthermore, the sample from one patient with ATL expressed higher levels of Bcl-xL mRNA compared with levels from uninfected peripheral blood mononuclear cells. Our results suggest that Tax induces the expression of Bc-xL through the NF-kappaB and CREB pathways in HTLV-I-infected human T-cells, and then inhibits apoptosis, and such inhibition is necessary for the infected cells to advance to the

  19. Seroprevalence of Toxoplasma gondii and concurrent bartonella spp., feline immunodeficiency virus, and feline leukemia infections in cats from Grenada, West Indies

    Science.gov (United States)

    Toxoplasma gondii and Bartonella spp. are zoonotic pathogens of cats. Feline Immunodeficiency Virus (FIV), and Feline Leukemia Virus (FeLv) are related to Human Iimmunodeficiency Virus, and Human Leukemia Virus, respectively, and these viruses are immunosuppressive. In the present study, the prevale...

  20. Lapatinib induces autophagic cell death and differentiation in acute myeloblastic leukemia

    Directory of Open Access Journals (Sweden)

    Chen YJ

    2016-07-01

    Full Text Available Yu-Jen Chen,1–4 Li-Wen Fang,5 Wen-Chi Su,6,7 Wen-Yi Hsu,1 Kai-Chien Yang,1 Huey-Lan Huang8 1Department of Medical Research, 2Department of Radiation Oncology, Mackay Memorial Hospital, 3Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, 4Institute of Pharmacology, Taipei Medical University, Taipei, 5Department of Nutrition, I-Shou University, Kaohsiung, 6Research Center for Emerging Viruses, China Medical University Hospital, 7Graduate Institute of Clinical Medical Science, China Medical University, Taichung, 8Department of Bioscience Technology, College of Health Science, Chang Jung Christian University, Tainan, Taiwan, Republic of China Abstract: Lapatinib is an oral-form dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR or ErbB/Her superfamily members with anticancer activity. In this study, we examined the effects and mechanism of action of lapatinib on several human leukemia cells lines, including acute myeloid leukemia (AML, chronic myeloid leukemia (CML, and acute lymphoblastic leukemia (ALL cells. We found that lapatinib inhibited the growth of human AML U937, HL-60, NB4, CML KU812, MEG-01, and ALL Jurkat T cells. Among these leukemia cell lines, lapatinib induced apoptosis in HL-60, NB4, and Jurkat cells, but induced nonapoptotic cell death in U937, K562, and MEG-01 cells. Moreover, lapatinib treatment caused autophagic cell death as shown by positive acridine orange staining, the massive formation of vacuoles as seen by electronic microscopy, and the upregulation of LC3-II, ATG5, and ATG7 in AML U937 cells. Furthermore, autophagy inhibitor 3-methyladenine and knockdown of ATG5, ATG7, and Beclin-1 using short hairpin RNA (shRNA partially rescued lapatinib-induced cell death. In addition, the induction of phagocytosis and ROS production as well as the upregulation of surface markers CD14 and CD68 was detected in lapatinib-treated U937 cells, suggesting the induction of

  1. Endophilins interact with Moloney murine leukemia virus Gag and modulate virion production

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    De Camilli Pietro

    2003-12-01

    Full Text Available Abstract Background The retroviral Gag protein is the central player in the process of virion assembly at the plasma membrane, and is sufficient to induce the formation and release of virus-like particles. Recent evidence suggests that Gag may co-opt the host cell's endocytic machinery to facilitate retroviral assembly and release. Results A search for novel partners interacting with the Gag protein of the Moloney murine leukemia virus (Mo-MuLV via the yeast two-hybrid protein-protein interaction assay resulted in the identification of endophilin 2, a component of the machinery involved in clathrin-mediated endocytosis. We demonstrate that endophilin interacts with the matrix or MA domain of the Gag protein of Mo-MuLV, but not of human immunodeficiency virus, HIV. Both exogenously expressed and endogenous endophilin are incorporated into Mo-MuLV viral particles. Titration experiments suggest that the binding sites for inclusion of endophilin into viral particles are limited and saturable. Knock-down of endophilin with small interfering RNA (siRNA had no effect on virion production, but overexpression of endophilin and, to a lesser extent, of several fragments of the protein, result in inhibition of Mo-MuLV virion production, but not of HIV virion production. Conclusions This study shows that endophilins interact with Mo-MuLV Gag and affect virion production. The findings imply that endophilin is another component of the large complex that is hijacked by retroviruses to promote virion production.

  2. Vaccination of adult and newborn mice of a resistant strain (C57BL/6J) against challenge with leukemias induced by Moloney murine leukemia virus

    International Nuclear Information System (INIS)

    Reif, A.E.

    1985-01-01

    Adult or newborn C57BL/6J mice were immunized with isogenic Moloney strain MuLV-induced leukemia cells irradiated with 10,000 rads or treated with low concentrations of formalin. Groups of immunized and control mice were challenged with a range of doses of viable leukemia cells, and tumor deaths were recorded for 90 days after challenge. Then, the doses of challenge cells which produced 50% tumor deaths were calculated for immunized and control mice. The logarithm of their ratio quantified the degree of protection provided by immunization. For adult C57BL/6J mice, a single immunization with MuLV-induced leukemia cells was not effective; either cells plus Bacillus Calmette-Guerin or Corynebacterium parvum, or else two immunizations with irradiated leukemia cells were needed to produce statistically significant increases in the values of the doses of challenge cells which produced 50% tumor deaths. Cross-protection was obtained by immunization with other isogenic MuLV-induced leukemias, but not by immunization with isogenic carcinogen-induced tumors or with an isogenic spontaneous leukemia. For newborn mice, a single injection of irradiated leukemia cells provided 1.3 to 1.5 logs of protection, and admixture of B. Calmette-Guerin or C. parvum increased this protection to 2.4 to 2.7 logs. Since irradiated and frozen-thawed MuLV-induced leukemia cells contained viable MuLV, leukemia cells treated with 0.5 or 1.0% formalin were tested as an alternative. A single injection of formalin-treated isogenic leukemia cells admixed with C. parvum provided between 1.7 and 2.8 logs of protection. These results demonstrate that a single vaccination of newborn animals against a highly antigenic virally induced leukemia produces strong protection against a subsequent challenge with viable leukemia cells

  3. Bilateral proliferative retinopathy in B-cell acute lymphoblastic leukemia

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    Devesh Kumawat

    2018-01-01

    Full Text Available A 4-year-old child with B-cell acute lymphoblastic leukemia presented with vitreous hemorrhage due to proliferative retinopathy in both eyes. Pars plana vitrectomy was performed in both eyes to clear nonresolving vitreous hemorrhage after systemic stabilization. Visual recovery was limited by the disc drag in the right eye and subfoveal exudation in the left eye. Etiopathogenesis and management of proliferative retinopathy in acute leukemias are discussed.

  4. FoxP3+ regulatory T cells are distinct from leukemia cells in HTLV-1-associated adult T-cell leukemia.

    Science.gov (United States)

    Toulza, Frederic; Nosaka, Kisato; Takiguchi, Masafumi; Pagliuca, Tony; Mitsuya, Hiroaki; Tanaka, Yuetsu; Taylor, Graham P; Bangham, Charles R M

    2009-11-15

    Human T-lymphotropic virus type 1 (HTLV-1) is the causative agent of adult T-cell leukemia/lymphoma (ATLL). It has been postulated that ATLL cells might act as regulatory T cells (T(regs)) which, in common with ATLL cells, express both CD25 and FoxP3, and so contribute to the severe immune suppression typical of ATLL. We report here that the frequency of CD25(+) cells varied independently of the frequency of FoxP3(+) cells in both a cross-sectional study and in a longitudinal study of 2 patients with chronic ATLL. Furthermore, the capacity of ATLL cells to suppress proliferation of heterologous CD4(+)CD25(-) cells correlated with the frequency of CD4(+) FoxP3(+) cells but was independent of CD25 expression. Finally, the frequency of CD4(+)FoxP3(+) cells was inversely correlated with the lytic activity of HTLV-1-specific CTLs in patients with ATLL. We conclude that ATLL is not a tumor of FoxP3(+) regulatory T cells, and that a population of FoxP3(+) cells distinct from ATLL cells has regulatory functions and may impair the cell-mediated immune response to HTLV-1 in patients with ATLL.

  5. Mutational library analysis of selected amino acids in the receptor binding domain of envelope of Akv murine leukemia virus by conditionally replication competent bicistronic vectors

    DEFF Research Database (Denmark)

    Bahrami, Shervin; Jespersen, Thomas; Pedersen, Finn Skou

    2003-01-01

    envelope expression. This vector functions as a replication competent mini-virus in a culture of NIH 3T3 derived semi-packaging cells that express the viral Gag and Pol proteins. Titers comparable to those of wild type virus were achieved by this system. To test this vector system, we created a random...... mutational library of Arg 85 and Asp 86 in the first variable region of Akv envelope protein. Homologous amino acids to Asp 86 in Moloney and Friend murine leukemia viruses are thought to be directly involved in receptor binding. Subsequent selection of mutants capable of infecting murine NIH 3T3 cells...

  6. Immune inhibition of virus release from human and nonhuman cells by antibody to viral and host cell determinants.

    Science.gov (United States)

    Shariff, D M; Davies, J; Desperbasques, M; Billstrom, M; Geerligs, H J; Welling, G W; Welling-Wester, S; Buchan, A; Skinner, G R

    1991-01-01

    Immune inhibition of release of the DNA viruses, herpes simplex virus types 1 and 2 and pseudorabies virus by anti-viral and anti-host cell sera occurred while two RNA viruses, influenza and encephalomyocarditis, were inhibited only by anti-viral sera (not anti-host cell sera). Simian virus 40 and surprisingly two herpes viruses, bovine mamillitis and equine abortion, were not inhibited by either anti-viral or anti-host sera. Using the herpes simplex virus model, inhibition of virus release was detected in different cells of human and nonhuman origin with cross-inhibition between cell lines of different origin; thus, this form of immunotherapy may not require antibody to be tissue or organ specific. Evidence of inhibition of virus release from neoplastic and leukemic cell lines suggests possible application of this approach to control of virus-mediated leukoproliferative pathology (e.g. Burkitt's lymphoma or adult T cell leukemia).

  7. Feline immunodeficiency virus and feline leukemia virus: frequency and associated factors in cats in northeastern Brazil.

    Science.gov (United States)

    Lacerda, L C; Silva, A N; Freitas, J S; Cruz, R D S; Said, R A; Munhoz, A D

    2017-05-10

    Our aims were to determine the frequencies of feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) in owned and stray cats in the northeastern region of Brazil, ascertain the status of FeLV infection, and investigate potential associated factors among the owned cats. Blood samples from 200 asymptomatic owned cats and 30 stray cats were processed using nested PCR and commercial immunochromatographic tests to diagnose infections. To evaluate the factors associated with FIV and/or FeLV in owned cats, a semi-structured interview was conducted with each owner about the animal's environment, and these data were subjected to unconditional logistic regression. The frequencies for owned cats were 6% (12/200) and 3% (6/200) for FIV and FeLV, respectively. No owned cat was positive for both viruses. Stray cats showed frequencies of 6.66% (2/30) and 0% (0/30) for FIV and FeLV, respectively. Contact with other cats and living in peri-urban areas were considered to be risk factors (P < 0.05) for FIV. We did not identify any factors associated with infections with FeLV. Our results confirm the presence of these two retroviruses in the region under study. Our use of different diagnostic techniques allowed us to determine the frequency of retroviruses in the feline population more accurately, particularly with regard to infections by FeLV, which have complex pathogenesis.

  8. Adult T-cell leukemia/lymphoma treatment in Bahia, Brazil

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    Pedro Dantas Oliveira

    Full Text Available Abstract Background: Adult T-cell leukemia/lymphoma is a peripheral disease associated with human T-cell lymphotropic virus type 1. Treatment is carried out according to clinical type with watchful waiting being recommended for less aggressive types. Aggressive adult T-cell leukemia/lymphoma is generally treated with chemotherapy and/or antivirals. The objective of this study was to correlate the survival of patients diagnosed in Bahia, Brazil, with the therapeutic approaches employed and to evaluate what issues existed in their treatment processes. Methods: Eighty-three adult T-cell leukemia/lymphoma patients (26 smoldering, 23 chronic, 16 acute, 13 lymphoma and five primary cutaneous tumoral with available data were included in this study. Results: Complete response was achieved in seven smoldering patients with symptomatic treatment, in two with chronic disease using antivirals/chemotherapy, in one with acute disease using antivirals and in one lymphoma using the LSG15 regimen [vincristine, cyclophosphamide, doxorubicin, and prednisolone (VCAP; doxorubicin, ranimustine, and prednisolone (AMP; and vindesine, etoposide, carboplatin, and prednisolone (VECP]. Smoldering patients who received symptomatic treatment presented longer survival. Favorable chronic patients treated with antivirals presented longer survival compared to the unfavorable subtype. However, for the acute form, first-line chemotherapy was better, albeit without significance, than antivirals. Only one of the patients with lymphoma and primary cutaneous tumors responded. Conclusions: Watchful waiting associated with phototherapy represents the best option for smoldering adult T-cell leukemia/lymphoma with survival in Bahia being superior to that described in Japan. There was a trend of better results with zidovudine/interferon-alpha in favorable chronic disease. Excellent results were achieved in the lymphoma type treated with the LSG15 protocol. Patients are diagnosed late

  9. The enhancing effect of fractionated whole-body x-irradiation on replication of endogenous leukemia viruses in BALB/c mice

    International Nuclear Information System (INIS)

    Takamori, Yasuhiko; Okumoto, Masaaki; Iwai, Mineko; Iwai, Yoshiaki

    1976-01-01

    The incidence of leukemia, changes in the tissue weight of spleen and thymus, and the expression of endogenous viruses were examined with BALB/c mice following 4 weekly fractionated whole-body x-irradiation of 170 R each, starting at 4 weeks of age. The leukemia incidence was quite low for the unirradiated controls, while 60% of the irradiated male mice developed thymic lymphoma. The virus-positive cells appeared earlier in the spleen than in the thymus and bone marrow, and increased with aging. The time of appearance of virus-positive cells in these tissues was remarkably promoted by the fractionated x-irradiation, and its frequency was also enhanced. (auth.)

  10. PCR and serology find no association between xenotropic murine leukemia virus-related virus (XMRV and autism

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    Satterfield Brent C

    2010-10-01

    Full Text Available Abstract Xenotropic murine leukemia virus-related virus (XMRV is a retrovirus implicated in prostate cancer and chronic fatigue syndrome (CFS. Press releases have suggested that it could contribute to autism spectrum disorder (ASD. In this study we used two PCR assays and one antibody assay to screen 25 blood samples from autistic children born to mothers with CFS and from 20 mixed controls including family members of the children assayed, people with fibromyalgia and people with chronic Lyme disease. Using a real-time PCR assay, we screened an additional 48 South Carolina autism disorder samples, 96 Italian ASD samples, 61 South Carolina ASD samples and 184 healthy controls. Despite having the ability to detect low copy number XMRV DNA in a large background of cellular DNA, none of the PCR assays found any evidence of XMRV infection in blood cells from patients or controls. Further, no anti-XMRV antibodies were detected, ruling out possible low level or abortive infections in blood or in other reservoirs. These results imply that XMRV is not associated with autism.

  11. Oncogenic Viruses and Breast Cancer: Mouse Mammary Tumor Virus (MMTV, Bovine Leukemia Virus (BLV, Human Papilloma Virus (HPV, and Epstein–Barr Virus (EBV

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    James S. Lawson

    2018-01-01

    Full Text Available BackgroundAlthough the risk factors for breast cancer are well established, namely female gender, early menarche and late menopause plus the protective influence of early pregnancy, the underlying causes of breast cancer remain unknown. The development of substantial recent evidence indicates that a handful of viruses may have a role in breast cancer. These viruses are mouse mammary tumor virus (MMTV, bovine leukemia virus (BLV, human papilloma viruses (HPVs, and Epstein–Barr virus (EBV-also known as human herpes virus type 4. Each of these viruses has documented oncogenic potential. The aim of this review is to inform the scientific and general community about this recent evidence.The evidenceMMTV and human breast cancer—the evidence is detailed and comprehensive but cannot be regarded as conclusive. BLV and human breast cancer—the evidence is limited. However, in view of the emerging information about BLV in human breast cancer, it is prudent to encourage the elimination of BLV in cattle, particularly in the dairy industry. HPVs and breast cancer—the evidence is substantial but not conclusive. The availability of effective preventive vaccines is a major advantage and their use should be encouraged. EBV and breast cancer—the evidence is also substantial but not conclusive. Currently, there are no practical means of either prevention or treatment. Although there is evidence of genetic predisposition, and cancer in general is a culmination of events, there is no evidence that inherited genetic traits are causal.ConclusionThe influence of oncogenic viruses is currently the major plausible hypothesis for a direct cause of human breast cancer.

  12. Oncogenic Viruses and Breast Cancer: Mouse Mammary Tumor Virus (MMTV), Bovine Leukemia Virus (BLV), Human Papilloma Virus (HPV), and Epstein-Barr Virus (EBV).

    Science.gov (United States)

    Lawson, James S; Salmons, Brian; Glenn, Wendy K

    2018-01-01

    Although the risk factors for breast cancer are well established, namely female gender, early menarche and late menopause plus the protective influence of early pregnancy, the underlying causes of breast cancer remain unknown. The development of substantial recent evidence indicates that a handful of viruses may have a role in breast cancer. These viruses are mouse mammary tumor virus (MMTV), bovine leukemia virus (BLV), human papilloma viruses (HPVs), and Epstein-Barr virus (EBV-also known as human herpes virus type 4). Each of these viruses has documented oncogenic potential. The aim of this review is to inform the scientific and general community about this recent evidence. MMTV and human breast cancer-the evidence is detailed and comprehensive but cannot be regarded as conclusive. BLV and human breast cancer-the evidence is limited. However, in view of the emerging information about BLV in human breast cancer, it is prudent to encourage the elimination of BLV in cattle, particularly in the dairy industry. HPVs and breast cancer-the evidence is substantial but not conclusive. The availability of effective preventive vaccines is a major advantage and their use should be encouraged. EBV and breast cancer-the evidence is also substantial but not conclusive. Currently, there are no practical means of either prevention or treatment. Although there is evidence of genetic predisposition, and cancer in general is a culmination of events, there is no evidence that inherited genetic traits are causal. The influence of oncogenic viruses is currently the major plausible hypothesis for a direct cause of human breast cancer.

  13. Distribution of 51Cr labeled leukemia cells in mice: Comparison with representative normal cells

    International Nuclear Information System (INIS)

    Boranic, M.; Radacic, M.

    1978-01-01

    Cells of two transplantable leukemias of mice, one myeloid and one lymphoid, were labeled with 51 Cr in order to follow their distribution in hemopoietic and parenchymatous organs and blood of syngeneic recipients. Distribution of myeloid leukemia cells was compared with that of regenerating bone marrow cells and normal spleen cells. The organ distribution of myeloid leukemia cells was essentially different from that of cells of regenerating bone marrow, and both were different from that of normal spleen cells. Cells of lymphoid leukemia, which are presumably of B-lymphocyte origin, were compared with a B-lymphocyte enriched population, obtained from the lymph nodes of so-called TIR mice (thymectomized, irradiated, and reconstituted with syngeneic bone marrow), and with spleen cells of normal mice. The three patterns of organ distribution were different. It is concluded that the two leukemias studied each have a specific and characteristic distribution. (author)

  14. Chronic lymphocytic leukemia cells are active participants in microenvironmental cross-talk

    NARCIS (Netherlands)

    van Attekum, Martijn H. A.; Eldering, Eric; Kater, Arnon P.

    2017-01-01

    The importance of the tumor microenvironment in chronic lymphocytic leukemia is widely accepted. Nevertheless, the understanding of the complex interplay between the various types of bystander cells and chronic lymphocytic leukemia cells is incomplete. Numerous studies have indicated that bystander

  15. Transgene stability for three replication-competent murine leukemia virus vectors

    DEFF Research Database (Denmark)

    Duch, Mogens R.; Carrasco, Maria L; Jespersen, Thomas

    2004-01-01

    cassette consisting of an internal ribosome entry site followed by the enhanced green fluorescent protein coding sequence inserted in different configurations into murine leukemia virus genomes. In two of the constructs, the insert was located in the upstream part of the U3 region while in the third...

  16. The xenotropic murine leukemia virus-related retrovirus debate continues at first international workshop

    NARCIS (Netherlands)

    J.P. Stoye (Jonathan); R.H. Silverman (Robert); C.A.B. Boucher (Charles); S.F.J. Le Grice

    2010-01-01

    textabstractThe 1stInternational Workshop on Xenotropic Murine Leukemia Virus-Related Retrovirus (XMRV), co-sponsored by the National Institutes of Health, The Department of Health and Human Services and Abbott Diagnostics, was convened on September 7/8, 2010 on the NIH campus, Bethesda, MD.

  17. Fungal phosphate transporter serves as a receptor backbone for gibbon ape leukemia virus

    DEFF Research Database (Denmark)

    Pedersen, Lene; van Zeijl, Marja; Johann, Stephen V

    1997-01-01

    Pit1, the receptor for gibbon ape leukemia virus (GALV), is proposed to be an integral membrane protein with five extracellular loops. Chimeras made between Pit1 homologs differing in permissivity for infection and between Pit1 and the related protein Pit2 have shown that the fourth extracellular...

  18. Bovine leukemia virus seroprevalence among cattle presented for slaughter in the United States

    Science.gov (United States)

    Infection with bovine leukemia virus (BLV) results in economic loss due reduced productivity, especially the reduction of milk production and early culling. In the USA.,USA, previous studies in 1996, 1999 and 2007 showed BLV infections widespread, especially in the dairy herds. The goal of this stud...

  19. Chronic lymphocytic leukemia cells are active participants in microenvironmental cross-talk

    OpenAIRE

    van Attekum, Martijn HA; Eldering, Eric; Kater, Arnon P

    2017-01-01

    The importance of the tumor microenvironment in chronic lymphocytic leukemia is widely accepted. Nevertheless, the understanding of the complex interplay between the various types of bystander cells and chronic lymphocytic leukemia cells is incomplete. Numerous studies have indicated that bystander cells provide chronic lymphocytic leukemia-supportive functions, but it has also become clear that chronic lymphocytic leukemia cells actively engage in the formation of a supportive tumor microenv...

  20. Phosphorylation of bovine leukemia virus Tax protein is required for in vitro transformation but not for transactivation.

    Science.gov (United States)

    Willems, L; Grimonpont, C; Kerkhofs, P; Capiau, C; Gheysen, D; Conrath, K; Roussef, R; Mamoun, R; Portetelle, D; Burny, A; Adam, E; Lefèbvre, L; Twizere, J C; Heremans, H; Kettmann, R

    1998-04-30

    The Tax proteins of the oncovirinae viruses are phosphorylated transcriptional activators that exhibit oncogenic potential. The role of phosphorylation in their functional activities remains unknown. As a model for the Human T-cell leukemia virus type I (HTLV-I), Bovine Leukemia Virus (BLV) permits the characterization of viral replication and leukemogenesis in vivo. Here, we show that the BLV Tax protein is phosphorylated on serine residues 106 and 293 both in insect and in mammalian cells. These sites can also be efficiently phosphorylated by the cdc2 and MAP kinases in vitro. Mutation of these residues does not affect the capacity of the Tax protein to function as a transactivator. Indeed, the Tax proteins mutated at one or both serines increase LTR-directed viral transcription at levels similar to those obtained with wild-type Tax in cell culture. Moreover, inhibition of Tax phosphorylation by W7, a calmodulin antagonist, does not alter its transactivation activity. Thus, phosphorylation on serines 106 and 293 is not required for transactivation by Tax. However, simultaneous substitution of both serines into alanine residues destroys the capacity of Tax to cooperate with the Ha-ras oncogene to transform primary rat embryo fibroblasts and induce tumors in nude mice. When the serines were replaced with aspartic acid residues, the oncogenic potential of Tax was maintained indicating that the negative charge rather than the phosphate group itself was required for Tax oncogenicity. Finally, to assess the role of the serine residues in vivo, recombinant viruses which express the Tax mutants were constructed and injected into sheep. It appeared that the mutated proviruses replicate at levels similar to the wild-type virus in vivo. We conclude that Tax phosphorylation is dispensable for transactivation and viral replication in vivo but is required for its oncogenic potential in vitro.

  1. Determinants of the Bovine Leukemia Virus Envelope Glycoproteins Involved in Infectivity, Replication and Pathogenesis

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    Alix de Brogniez

    2016-03-01

    Full Text Available Interaction of viral envelope proteins with host cell membranes has been extensively investigated in a number of systems. However, the biological relevance of these interactions in vivo has been hampered by the absence of adequate animal models. Reverse genetics using the bovine leukemia virus (BLV genome highlighted important functional domains of the envelope protein involved in the viral life cycle. For example, immunoreceptor tyrosine-based activation motifs (ITAM of the envelope transmembrane protein (TM are essential determinants of infection. Although cell fusion directed by the aminoterminal end of TM is postulated to be essential, some proviruses expressing fusion-deficient envelope proteins unexpectedly replicate at wild-type levels. Surprisingly also, a conserved N-linked glycosylation site of the extracellular envelope protein (SU inhibits cell-to-cell transmission suggesting that infectious potential has been limited during evolution. In this review, we summarize the knowledge pertaining to the BLV envelope protein in the context of viral infection, replication and pathogenesis.

  2. Determinants of the Bovine Leukemia Virus Envelope Glycoproteins Involved in Infectivity, Replication and Pathogenesis

    Science.gov (United States)

    de Brogniez, Alix; Mast, Jan; Willems, Luc

    2016-01-01

    Interaction of viral envelope proteins with host cell membranes has been extensively investigated in a number of systems. However, the biological relevance of these interactions in vivo has been hampered by the absence of adequate animal models. Reverse genetics using the bovine leukemia virus (BLV) genome highlighted important functional domains of the envelope protein involved in the viral life cycle. For example, immunoreceptor tyrosine-based activation motifs (ITAM) of the envelope transmembrane protein (TM) are essential determinants of infection. Although cell fusion directed by the aminoterminal end of TM is postulated to be essential, some proviruses expressing fusion-deficient envelope proteins unexpectedly replicate at wild-type levels. Surprisingly also, a conserved N-linked glycosylation site of the extracellular envelope protein (SU) inhibits cell-to-cell transmission suggesting that infectious potential has been limited during evolution. In this review, we summarize the knowledge pertaining to the BLV envelope protein in the context of viral infection, replication and pathogenesis. PMID:27023592

  3. Laparoscopic Splenectomy for Hairy Cell Leukemia in Pregnancy

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    Beni Adegoke Adeniji

    2010-01-01

    Conclusion. Hairy cell leukemia is a clonal B-Cell malignancy, for which there is very limited experience worldwide for its management when it occurs during pregnancy. Laparoscopic splenectomy should be considered as a therapeutic option, even with a significantly enlarged spleen, in order to avoid the risks of fetal exposure to chemotherapeutic agents. Unique considerations relating to pregnancy are highlighted.

  4. Mutations that abrogate transactivational activity of the feline leukemia virus long terminal repeat do not affect virus replication

    International Nuclear Information System (INIS)

    Abujamra, Ana L.; Faller, Douglas V.; Ghosh, Sajal K.

    2003-01-01

    The U3 region of the LTR of oncogenic Moloney murine leukemia virus (Mo-MuLV) and feline leukemia viruses (FeLV) have been previously reported to activate expression of specific cellular genes in trans, such as MHC class I, collagenase IV, and MCP-1, in an integration-independent manner. It has been suggested that transactivation of these specific cellular genes by leukemia virus U3-LTR may contribute to the multistage process of leukemogenesis. The U3-LTR region, necessary for gene transactivational activity, also contains multiple transcription factor-binding sites that are essential for normal virus replication. To dissect the promoter activity and the gene transactivational activity of the U3-LTR, we conducted mutational analysis of the U3-LTR region of FeLV-A molecular clone 61E. We identified minimal nucleotide substitution mutants on the U3 LTR that did not disturb transcription factor-binding sites but abrogated its ability to transactivate the collagenase gene promoter. To determine if these mutations actually have altered any uncharacterized important transcription factor-binding site, we introduced these U3-LTR mutations into the full-length infectious molecular clone 61E. We demonstrate that the mutant virus was replication competent but could not transactivate cellular gene expression. These results thus suggest that the gene transactivational activity is a distinct property of the LTR and possibly not related to its promoter activity. The cellular gene transactivational activity-deficient mutant FeLV generated in this study may also serve as a valuable reagent for testing the biological significance of LTR-mediated cellular gene activation in the tumorigenesis caused by leukemia viruses

  5. Alantolactone selectively ablates acute myeloid leukemia stem and progenitor cells

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    Yahui Ding

    2016-09-01

    Full Text Available Abstract Background The poor outcomes for patients diagnosed with acute myeloid leukemia (AML are largely attributed to leukemia stem cells (LSCs which are difficult to eliminate with conventional therapy and responsible for relapse. Thus, new therapeutic strategies which could selectively target LSCs in clinical leukemia treatment and avoid drug resistance are urgently needed. However, only a few small molecules have been reported to show anti-LSCs activity. Methods The aim of the present study was to identify alantolactone as novel agent that can ablate acute myeloid leukemia stem and progenitor cells from AML patient specimens and evaluate the anticancer activity of alantolactone in vitro and in vivo. Results The present study is the first to demonstrate that alantolactone, a prominent eudesmane-type sesquiterpene lactone, could specifically ablate LSCs from AML patient specimens. Furthermore, in comparison to the conventional chemotherapy drug, cytosine arabinoside (Ara-C, alantolactone showed superior effects of leukemia cytotoxicity while sparing normal hematopoietic cells. Alantolactone induced apoptosis with a dose-dependent manner by suppression of NF-kB and its downstream target proteins. DMA-alantolactone, a water-soluble prodrug of alantolactone, could suppress tumor growth in vivo. Conclusions Based on these results, we propose that alantolactone may represent a novel LSCs-targeted therapy and eudesmane-type sesquiterpene lactones offer a new scaffold for drug discovery towards anti-LSCs agents.

  6. Molecular and phylogenetic analyses of a new Amphotropic murine leukemia virus (MuLV-1313

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    Wang Mingwu

    2006-12-01

    Full Text Available Abstract Background The amphotropic murine leukemia viruses (MuLV-A's are naturally occurring, exogenously acquired gammaretroviruses that are indigenous to the Southern California wild mice. These viruses replicate in a wide range of cell types including human cells in vitro and they can cause both hematological and neurological disorders in feral as well as in the inbred laboratory mice. Since MuLV-A's also exhibit discrete interference and neutralization properties, the envelope proteins of these viruses have been extremely useful for studying virus-host cell interactions and as vehicles for transfer of foreign genes into a variety of hosts including human cells. However, the genomic structure of any of the several known MuLV-A's has not been established and the evolutionary relationship of amphotropic retroviruses to the numerous exogenous or endogenous MuLV strains remains elusive. Herein we present a complete genetic structure of a novel amphotropic virus designated MuLV-1313 and demonstrate that this retrovirus together with other MuLV-A's belongs to a distinct molecular, biological and phylogenetic class among the MuLV strains isolated from a large number of the laboratory inbred or feral mice. Results The host range of MuLV-1313 is similar to the previously isolated MuLV-A's except that this virus replicates efficiently in mammalian as well as in chicken cells. Compared to ENV proteins of other MuLV-A's (4070A, 1504A and 10A-1, the gp70 protein of MuLV-1313 exhibits differences in its signal peptides and the proline-rich hinge regions. However, the MuLV-1313 envelope protein is totally unrelated to those present in a broad range of murine retroviruses that have been isolated from various inbred and feral mice globally. Genetic analysis of the entire MuLV-1313 genome by dot plot analyses, which compares each nucleotide of one genome with the corresponding nucleotide of another, revealed that the genome of this virus, with the exception

  7. Advanced Data Mining of Leukemia Cells Micro-Arrays

    OpenAIRE

    Richard S. Segall; Ryan M. Pierce

    2009-01-01

    This paper provides continuation and extensions of previous research by Segall and Pierce (2009a) that discussed data mining for micro-array databases of Leukemia cells for primarily self-organized maps (SOM). As Segall and Pierce (2009a) and Segall and Pierce (2009b) the results of applying data mining are shown and discussed for the data categories of microarray databases of HL60, Jurkat, NB4 and U937 Leukemia cells that are also described in this article. First, a background section is pro...

  8. Development Refractoriness of MLL-Rearranged Human B Cell Acute Leukemias to Reprogramming into Pluripotency

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    Alvaro Muñoz-López

    2016-10-01

    Full Text Available Induced pluripotent stem cells (iPSCs are a powerful tool for disease modeling. They are routinely generated from healthy donors and patients from multiple cell types at different developmental stages. However, reprogramming leukemias is an extremely inefficient process. Few studies generated iPSCs from primary chronic myeloid leukemias, but iPSC generation from acute myeloid or lymphoid leukemias (ALL has not been achieved. We attempted to generate iPSCs from different subtypes of B-ALL to address the developmental impact of leukemic fusion genes. OKSM(L-expressing mono/polycistronic-, retroviral/lentiviral/episomal-, and Sendai virus vector-based reprogramming strategies failed to render iPSCs in vitro and in vivo. Addition of transcriptomic-epigenetic reprogramming “boosters” also failed to generate iPSCs from B cell blasts and B-ALL lines, and when iPSCs emerged they lacked leukemic fusion genes, demonstrating non-leukemic myeloid origin. Conversely, MLL-AF4-overexpressing hematopoietic stem cells/B progenitors were successfully reprogrammed, indicating that B cell origin and leukemic fusion gene were not reprogramming barriers. Global transcriptome/DNA methylome profiling suggested a developmental/differentiation refractoriness of MLL-rearranged B-ALL to reprogramming into pluripotency.

  9. HUMAN NK CELLS: FROM SURFACE RECEPTORS TO THE THERAPY OF LEUKEMIAS AND SOLID TUMORS

    Directory of Open Access Journals (Sweden)

    LORENZO eMORETTA

    2014-03-01

    Full Text Available Natural Killer (NK cells are major effector cells of the innate immunity. The discovery, over two decades ago, of MHC-class I specific NK receptors and subsequently of activating receptors, recognizing ligands expressed by tumor or virus-infected cells, paved the way to our understanding of the mechanisms of selective recognition and killing of tumor cells. Although NK cells can efficiently kill tumor cells of different histotypes in vitro, their activity may be limited in vivo by their inefficient trafficking to tumor lesions and by the inhibition of their function induced by tumor cells themselves and by the tumor microenvironment. On the other hand, the important role of NK cells has been clearly demonstrated in the therapy of high risk leukemias in the haploidentical hematopoietic cell (HSC transplantation setting. NK cells derived from donor HSC kill leukemic cells residual after the conditioning regimen, thus preventing leukemia relapses. In addition, they also kill residual dendritic cells and T lymphocytes, thus preventing both GvHD and graft rejection.

  10. Resistance of human and mouse myeloid leukemia cells to UV radiation

    International Nuclear Information System (INIS)

    Poljak-Blazi, M.; Osmak, M.; Hadzija, M.

    1989-01-01

    Sensitivity of mouse bone marrow and myeloid leukemia cells and sensitivity of human myeloid leukemia cells to UV light was tested. Criteria were the in vivo colony-forming ability of UV exposed cells and the inhibition of DNA synthesis during post-irradiation incubation for 24 h in vitro. Mouse bone marrow cells irradiated with a small dose of UV light (5 J/m 2 ) and injected into x-irradiated animals did not form hemopoietic colonies on recipient's spleens, and recipients died. However, mouse leukemia cells, after irradiation with higher doses of UV light, retained the ability to form colonies on the spleens, and all recipient mice died with typical symptoms of leukemia. In vitro, mouse bone marrow cells exhibited high sensitivity to UV light compared to mouse myeloid leukemia cells. Human leukemia cells were also resistant to UV light, but more sensitive than mouse leukemia cells. (author)

  11. T Cell Receptor Vβ Staining Identifies the Malignant Clone in Adult T cell Leukemia and Reveals Killing of Leukemia Cells by Autologous CD8+ T cells.

    Directory of Open Access Journals (Sweden)

    Aileen G Rowan

    2016-11-01

    Full Text Available There is growing evidence that CD8+ cytotoxic T lymphocyte (CTL responses can contribute to long-term remission of many malignancies. The etiological agent of adult T-cell leukemia/lymphoma (ATL, human T lymphotropic virus type-1 (HTLV-1, contains highly immunogenic CTL epitopes, but ATL patients typically have low frequencies of cytokine-producing HTLV-1-specific CD8+ cells in the circulation. It remains unclear whether patients with ATL possess CTLs that can kill the malignant HTLV-1 infected clone. Here we used flow cytometric staining of TCRVβ and cell adhesion molecule-1 (CADM1 to identify monoclonal populations of HTLV-1-infected T cells in the peripheral blood of patients with ATL. Thus, we quantified the rate of CD8+-mediated killing of the putative malignant clone in ex vivo blood samples. We observed that CD8+ cells from ATL patients were unable to lyse autologous ATL clones when tested directly ex vivo. However, short in vitro culture restored the ability of CD8+ cells to kill ex vivo ATL clones in some donors. The capacity of CD8+ cells to lyse HTLV-1 infected cells which expressed the viral sense strand gene products was significantly enhanced after in vitro culture, and donors with an ATL clone that expressed the HTLV-1 Tax gene were most likely to make a detectable lytic CD8+ response to the ATL cells. We conclude that some patients with ATL possess functional tumour-specific CTLs which could be exploited to contribute to control of the disease.

  12. Increased bovine Tim-3 and its ligand expressions during bovine leukemia virus infection

    Directory of Open Access Journals (Sweden)

    Okagawa Tomohiro

    2012-05-01

    Full Text Available Abstract The immunoinhibitory receptor T cell immunoglobulin domain and mucin domain-3 (Tim-3 and its ligand, galectin-9 (Gal-9, are involved in the immune evasion mechanisms for several pathogens causing chronic infections. However, there is no report concerning the role of Tim-3 in diseases of domestic animals. In this study, cDNA encoding for bovine Tim-3 and Gal-9 were cloned and sequenced, and their expression and role in immune reactivation were analyzed in bovine leukemia virus (BLV-infected cattle. Predicted amino acid sequences of Tim-3 and Gal-9 shared high homologies with human and mouse homologues. Functional domains, including tyrosine kinase phosphorylation motif in the intracellular domain of Tim-3 were highly conserved among cattle and other species. Quantitative real-time PCR analysis showed that bovine Tim-3 mRNA is mainly expressed in T cells such as CD4+ and CD8+ cells, while Gal-9 mRNA is mainly expressed in monocyte and T cells. Tim-3 mRNA expression in CD4+ and CD8+ cells was upregulated during disease progression of BLV infection. Interestingly, expression levels for Tim-3 and Gal-9 correlated positively with viral load in infected cattle. Furthermore, Tim-3 expression level closely correlated with up-regulation of IL-10 in infected cattle. The expression of IFN-γ and IL-2 mRNA was upregulated when PBMC from BLV-infected cattle were cultured with Cos-7 cells expressing Tim-3 to inhibit the Tim-3/Gal-9 pathway. Moreover, combined blockade of the Tim-3/Gal-9 and PD-1/PD-L1 pathways significantly promoted IFN-γ mRNA expression compared with blockade of the PD-1/PD-L1 pathway alone. These results suggest that Tim-3 is involved in the suppression of T cell function during BLV infection.

  13. Cytotoxic effect of Spirulina platensis extracts on human acute leukemia Kasumi-1 and chronic myelogenous leukemia K-562 cell lines

    OpenAIRE

    Flores Hernandez, Flor Yohana; Khandual, Sanghamitra; Ramírez López, Inocencia Guadalupe

    2017-01-01

    Objective: To evaluate the cytotoxic effects of Spirulina platensis extracts on acute leukemia Kasumi-1 and chronic leukemia K-562 cancer cell lines. Methods: Various concentrations of Spirulina platensis extracts (0.25–50.00 mg/mL) obtained with different solvents were used to treat cell lines for 72 h. For cytotoxic effect studies, cell viability test with trypan blue solution, MTT assay and microscopic cytomorphological assessment were done. Results: Spirulina extract obtained with 7...

  14. Lysosomal disruption preferentially targets acute myeloid leukemia cells and progenitors

    Science.gov (United States)

    Sukhai, Mahadeo A.; Prabha, Swayam; Hurren, Rose; Rutledge, Angela C.; Lee, Anna Y.; Sriskanthadevan, Shrivani; Sun, Hong; Wang, Xiaoming; Skrtic, Marko; Seneviratne, Ayesh; Cusimano, Maria; Jhas, Bozhena; Gronda, Marcela; MacLean, Neil; Cho, Eunice E.; Spagnuolo, Paul A.; Sharmeen, Sumaiya; Gebbia, Marinella; Urbanus, Malene; Eppert, Kolja; Dissanayake, Dilan; Jonet, Alexia; Dassonville-Klimpt, Alexandra; Li, Xiaoming; Datti, Alessandro; Ohashi, Pamela S.; Wrana, Jeff; Rogers, Ian; Sonnet, Pascal; Ellis, William Y.; Corey, Seth J.; Eaves, Connie; Minden, Mark D.; Wang, Jean C.Y.; Dick, John E.; Nislow, Corey; Giaever, Guri; Schimmer, Aaron D.

    2012-01-01

    Despite efforts to understand and treat acute myeloid leukemia (AML), there remains a need for more comprehensive therapies to prevent AML-associated relapses. To identify new therapeutic strategies for AML, we screened a library of on- and off-patent drugs and identified the antimalarial agent mefloquine as a compound that selectively kills AML cells and AML stem cells in a panel of leukemia cell lines and in mice. Using a yeast genome-wide functional screen for mefloquine sensitizers, we identified genes associated with the yeast vacuole, the homolog of the mammalian lysosome. Consistent with this, we determined that mefloquine disrupts lysosomes, directly permeabilizes the lysosome membrane, and releases cathepsins into the cytosol. Knockdown of the lysosomal membrane proteins LAMP1 and LAMP2 resulted in decreased cell viability, as did treatment of AML cells with known lysosome disrupters. Highlighting a potential therapeutic rationale for this strategy, leukemic cells had significantly larger lysosomes compared with normal cells, and leukemia-initiating cells overexpressed lysosomal biogenesis genes. These results demonstrate that lysosomal disruption preferentially targets AML cells and AML progenitor cells, providing a rationale for testing lysosomal disruption as a novel therapeutic strategy for AML. PMID:23202731

  15. Expression profile of CREB knockdown in myeloid leukemia cells

    International Nuclear Information System (INIS)

    Pellegrini, Matteo; Cheng, Jerry C; Voutila, Jon; Judelson, Dejah; Taylor, Julie; Nelson, Stanley F; Sakamoto, Kathleen M

    2008-01-01

    The cAMP Response Element Binding Protein, CREB, is a transcription factor that regulates cell proliferation, differentiation, and survival in several model systems, including neuronal and hematopoietic cells. We demonstrated that CREB is overexpressed in acute myeloid and leukemia cells compared to normal hematopoietic stem cells. CREB knockdown inhibits leukemic cell proliferation in vitro and in vivo, but does not affect long-term hematopoietic reconstitution. To understand downstream pathways regulating CREB, we performed expression profiling with RNA from the K562 myeloid leukemia cell line transduced with CREB shRNA. By combining our expression data from CREB knockdown cells with prior ChIP data on CREB binding we were able to identify a list of putative CREB regulated genes. We performed extensive analyses on the top genes in this list as high confidence CREB targets. We found that this list is enriched for genes involved in cancer, and unexpectedly, highly enriched for histone genes. Furthermore, histone genes regulated by CREB were more likely to be specifically expressed in hematopoietic lineages. Decreased expression of specific histone genes was validated in K562, TF-1, and primary AML cells transduced with CREB shRNA. We have identified a high confidence list of CREB targets in K562 cells. These genes allow us to begin to understand the mechanisms by which CREB contributes to acute leukemia. We speculate that regulation of histone genes may play an important role by possibly altering the regulation of DNA replication during the cell cycle

  16. Impact of Donor Epstein-Barr Virus Serostatus on the Incidence of Graft-Versus-Host Disease in Patients With Acute Leukemia After Hematopoietic Stem-Cell Transplantation: A Study From the Acute Leukemia and Infectious Diseases Working Parties of the European Society for Blood and Marrow Transplantation.

    Science.gov (United States)

    Styczynski, Jan; Tridello, Gloria; Gil, Lidia; Ljungman, Per; Hoek, Jennifer; Iacobelli, Simona; Ward, Katherine N; Cordonnier, Catherine; Einsele, Hermann; Socie, Gerard; Milpied, Noel; Veelken, Hendrik; Chevallier, Patrice; Yakoub-Agha, Ibrahim; Maertens, Johan; Blaise, Didier; Cornelissen, Jan; Michallet, Mauricette; Daguindau, Etienne; Petersen, Eefke; Passweg, Jakob; Greinix, Hildegard; Duarte, Rafael F; Kröger, Nicolaus; Dreger, Peter; Mohty, Mohamad; Nagler, Arnon; Cesaro, Simone

    2016-07-01

    We investigated the effect of Epstein-Barr virus (EBV) serostatus on the overall outcome of allogeneic hematopoietic stem-cell transplantation (allo-HSCT). The study included 11,364 patients who underwent allogeneic peripheral-blood or bone marrow transplantation for acute leukemia between 1997 and 2012. We analyzed the impact of donor and recipient EBV serologic status on overall survival, relapse-free survival, relapse incidence, nonrelapse mortality, and incidence of graft-versus-host disease (GVHD) after allo-HSCT. Patients receiving grafts from EBV-seropositive donors had the same overall survival as patients who received grafts from EBV-seronegative donors (hazard ratio [HR], 1.05; 95% CI, 0.97 to 1.12; P = .23). Seropositive donors also had no influence on relapse-free survival (HR, 1.04; 95% CI, 0.97 to 1.11; P = 0.31), relapse incidence (HR, 1.03; 95% CI, 0.94 to 1.12; P = .58), and nonrelapse mortality (HR, 1.05; 95% CI, 0.94 to 1.17; P = .37). However, in univariate analysis, recipients receiving grafts from seropositive donors had a higher risk of chronic GVHD than those with seronegative donors (40.8% v 31.0%, respectively; P < .001; HR, 1.42; 95% CI, 1.30 to 1.56). When adjusting for confounders, higher risk was identified for both acute and chronic GVHD. In seronegative patients with seropositive donors, the HR for chronic GVHD was 1.30 (95% CI, 1.06 to 1.59; P = .039). In seropositive patients with seropositive donors, the HR was 1.24 (95% CI, 1.07 to 1.45; P = .016) for acute GVHD and 1.43 (95% CI, 1.23 to 1.67; P < .001) for chronic GVHD. Seropositive patients with seronegative donors did not have an increased risk of GVHD. Our data suggest that donor EBV status significantly influences development of acute and chronic GVHD after allo-HSCT. © 2016 by American Society of Clinical Oncology.

  17. Advanced Data Mining of Leukemia Cells Micro-Arrays

    Directory of Open Access Journals (Sweden)

    Ryan M. Pierce

    2009-12-01

    Full Text Available This paper provides continuation and extensions of previous research by Segall and Pierce (2009a that discussed data mining for micro-array databases of Leukemia cells for primarily self-organized maps (SOM. As Segall and Pierce (2009a and Segall and Pierce (2009b the results of applying data mining are shown and discussed for the data categories of microarray databases of HL60, Jurkat, NB4 and U937 Leukemia cells that are also described in this article. First, a background section is provided on the work of others pertaining to the applications of data mining to micro-array databases of Leukemia cells and micro-array databases in general. As noted in predecessor article by Segall and Pierce (2009a, micro-array databases are one of the most popular functional genomics tools in use today. This research in this paper is intended to use advanced data mining technologies for better interpretations and knowledge discovery as generated by the patterns of gene expressions of HL60, Jurkat, NB4 and U937 Leukemia cells. The advanced data mining performed entailed using other data mining tools such as cubic clustering criterion, variable importance rankings, decision trees, and more detailed examinations of data mining statistics and study of other self-organized maps (SOM clustering regions of workspace as generated by SAS Enterprise Miner version 4. Conclusions and future directions of the research are also presented.

  18. Blastic Plasmacytoid Dendritic Cell Leukemia in a Black Malian

    African Journals Online (AJOL)

    2017-06-28

    Jun 28, 2017 ... (BPDCN) is an acute myeloblastic leukemia (AML) characterized by the clonal proliferation of precursors of plasmacytoid dendritic cells. It is categorized as an acute myeloid neoplasm by the 2008 world health organization classification of neoplasms. Over 90% of cases present with skin lesions in the form ...

  19. An animal model of adult T-cell leukemia: humanized mice with HTLV-1-specific immunity.

    Science.gov (United States)

    Tezuka, Kenta; Xun, Runze; Tei, Mami; Ueno, Takaharu; Tanaka, Masakazu; Takenouchi, Norihiro; Fujisawa, Jun-ichi

    2014-01-16

    Human T-cell leukemia virus type 1 (HTLV-1) is causally associated with adult T-cell leukemia (ATL), an aggressive T-cell malignancy with a poor prognosis. To elucidate ATL pathogenesis in vivo, a variety of animal models have been established; however, the mechanisms driving this disorder remain poorly understood due to deficiencies in each of these animal models. Here, we report a novel HTLV-1-infected humanized mouse model generated by intra-bone marrow injection of human CD133(+) stem cells into NOD/Shi-scid/IL-2Rγc null (NOG) mice (IBMI-huNOG mice). Upon infection, the number of CD4(+) human T cells in the periphery increased rapidly, and atypical lymphocytes with lobulated nuclei resembling ATL-specific flower cells were observed 4 to 5 months after infection. Proliferation was seen in both CD25(-) and CD25(+) CD4 T cells with identical proviral integration sites; however, a limited number of CD25(+)-infected T-cell clones eventually dominated, indicating an association between clonal selection of infected T cells and expression of CD25. Additionally, HTLV-1-specific adaptive immune responses were induced in infected mice and might be involved in the control of HTLV-1-infected cells. Thus, the HTLV-1-infected IBMI-huNOG mouse model successfully recapitulated the development of ATL and may serve as an important tool for investigating in vivo mechanisms of ATL leukemogenesis and evaluating anti-ATL drug and vaccine candidates.

  20. A preferred region for recombinational patch repair in the 5' untranslated region of primer binding site-impaired murine leukemia virus vectors

    DEFF Research Database (Denmark)

    Mikkelsen, J G; Lund, Anders Henrik; Kristensen, K D

    1996-01-01

    Transduction of primer binding site-impaired Akv murine leukemia virus-based retroviral vectors from the murine packaging cell lines psi-2 and omega E was studied. The efficiency of transduction of the neo marker of all mutated constructs was found to decrease by 5 to 6 orders of magnitude compared......, suggesting the involvement of a specific endogenous virus-like sequence in patch repair rescue of the primer binding site mutants. The putative recombination partner RNA was found in virions from psi-2 cells as detected by analysis of glutamine tRNA-initiated cDNA and by sequence analysis of regions...

  1. NALP3 inflammasome upregulation and CASP1 cleavage of the glucocorticoid receptor cause glucocorticoid resistance in leukemia cells

    NARCIS (Netherlands)

    S.W. Paugh (Steven); E.J. Bonten (Erik J.); D. Savic (Daniel); L.B. Ramsey (Laura B.); W.E. Thierfelder (William E.); P. Gurung (Prajwal); R.K.S. Malireddi (R. K. Subbarao); M. Actis (Marcelo); A. Mayasundari (Anand); J. Min (Jaeki); D.R. Coss (David R.); L.T. Laudermilk (Lucas T.); J.C. Panetta (John); J.R. McCorkle (J. Robert); Y. Fan (Yiping); K.R. Crews (Kristine R.); G. Stocco (Gabriele); M.R. Wilkinson (Mark R.); A.M. Ferreira (Antonio M.); C. Cheng (Cheng); W. Yang (Wenjian); S.E. Karol (Seth E.); C.A. Fernandez (Christian A.); B. Diouf (Barthelemy); C. Smith (Colton); J.K. Hicks (J Kevin); A. Zanut (Alessandra); A. Giordanengo (Audrey); D.J. Crona; J.J. Bianchi (Joy J.); L. Holmfeldt (Linda); C.G. Mullighan (Charles); M.L. den Boer (Monique); R. Pieters (Rob); S. Jeha (Sima); T.L. Dunwell (Thomas L.); F. Latif (Farida); D. Bhojwani (Deepa); W.L. Carroll (William L.); C.-H. Pui (Ching-Hon); R.M. Myers (Richard M.); R.K. Guy (R Kiplin); T.-D. Kanneganti (Thirumala-Devi); M.V. Relling (Mary); W.E. Evans (William)

    2015-01-01

    textabstractGlucocorticoids are universally used in the treatment of acute lymphoblastic leukemia (ALL), and resistance to glucocorticoids in leukemia cells confers poor prognosis. To elucidate mechanisms of glucocorticoid resistance, we determined the prednisolone sensitivity of primary leukemia

  2. Heterogeneous leukemia stem cells in myeloid blast phase chronic myeloid leukemia

    Science.gov (United States)

    Goardon, Nicolas; Morrison, Heather; Hamblin, Mike; Robinson, Lisa; Clark, Richard E.

    2016-01-01

    Chronic myeloid leukemia (CML) is an excellent model of the multistep processes in cancer. Initiating BCR-ABL mutations are required for the initial phase of the disease (chronic phase, CP-CML). Some CP-CML patients acquire additional mutation(s) that transforms CP-CML to poor prognosis, hard to treat, acute myeloid or lymphoid leukemia or blast phase CML (BP-CML). It is unclear where in the hemopoietic hierarchy additional mutations are acquired in BP-CML, how the hemopoietic hierarchy is altered as a consequence, and the cellular identity of the resulting leukemia-propagating stem cell (LSC) populations. Here, we show that myeloid BP-CML is associated with expanded populations that have the immunophenotype of normal progenitor populations that vary between patients. Serial transplantation in immunodeficient mice demonstrated functional LSCs reside in multiple populations with the immunophenotype of normal progenitor as well as stem cells. Multicolor fluorescence in situ hybridization detected serial acquisition of cytogenetic abnormalities of chromosome 17, associated with transformation to BP-CML, that is detected with equal frequency in all functional LSC compartments. New effective myeloid BP-CML therapies will likely have to target all these LSC populations. PMID:29296933

  3. Childhood Leukemia

    Science.gov (United States)

    Leukemia is cancer of the white blood cells. It is the most common type of childhood cancer. ... blood cells help your body fight infection. In leukemia, the bone marrow produces abnormal white blood cells. ...

  4. Cinnamon effectively inhibits the activity of leukemia stem cells.

    Science.gov (United States)

    Guan, X; Su, M C; Zhao, R B; Ouyang, H M; Dong, X D; Hu, P; Pei, Q; Lu, J; Li, Z F; Zhang, C R; Yang, T-H

    2016-08-19

    Cinnamon is the main component of Sanyangxuedai, which is one of the effective traditional Chinese medicines for treating malignancies. Leukemia is a prevalent malignant disease that Sanyangxuedai has been used to treat. Although successful in several studies, there is a lack of solid evidence as to why Sanyangxuedai has an effect on leukemia, and little is known about the underlying mechanisms. In this study, the active ingredients of cinnamon were isolated, purified, and identified. The transwell transport pool formed with the Caco-2 cell model was used to filter the active ingredients of cinnamon by simulating the gastrointestinal barrier in vitro. Moreover, the cell morphology, cell cycle status, apoptosis status, and antigenic variation of the cell surface antigens were observed and measured in K562 cells after treatment with the active ingredients of cinnamon. Our results showed that 50-75 μM was a safe concentration of cinnamon extract for treatment of K562 cells for 72 h. The cinnamon extract caused growth inhibition of K562 cells. Cinnamon extract seemed to arrest the cells at the G1 stage and increased the apoptosis rate significantly. Interestingly, cinnamon extract treatment upregulated the expression of erythroid and myeloid differentiation antigens and downregulated that of the megakaryocytic differentiation antigens in a dose-dependent manner. Our findings indicate that cinnamon extract from Sanyangxuedai may be effective for treating leukemia.

  5. Massive depletion of bovine leukemia virus proviral clones located in genomic transcriptionally active sites during primary infection.

    Science.gov (United States)

    Gillet, Nicolas A; Gutiérrez, Gerónimo; Rodriguez, Sabrina M; de Brogniez, Alix; Renotte, Nathalie; Alvarez, Irene; Trono, Karina; Willems, Luc

    2013-01-01

    Deltaretroviruses such as human T-lymphotropic virus type 1 (HTLV-1) and bovine leukemia virus (BLV) induce a persistent infection that remains generally asymptomatic but can also lead to leukemia or lymphoma. These viruses replicate by infecting new lymphocytes (i.e. the infectious cycle) or via clonal expansion of the infected cells (mitotic cycle). The relative importance of these two cycles in viral replication varies during infection. The majority of infected clones are created early before the onset of an efficient immune response. Later on, the main replication route is mitotic expansion of pre-existing infected clones. Due to the paucity of available samples and for ethical reasons, only scarce data is available on early infection by HTLV-1. Therefore, we addressed this question in a comparative BLV model. We used high-throughput sequencing to map and quantify the insertion sites of the provirus in order to monitor the clonality of the BLV-infected cells population (i.e. the number of distinct clones and abundance of each clone). We found that BLV propagation shifts from cell neoinfection to clonal proliferation in about 2 months from inoculation. Initially, BLV proviral integration significantly favors transcribed regions of the genome. Negative selection then eliminates 97% of the clones detected at seroconversion and disfavors BLV-infected cells carrying a provirus located close to a promoter or a gene. Nevertheless, among the surviving proviruses, clone abundance positively correlates with proximity of the provirus to a transcribed region. Two opposite forces thus operate during primary infection and dictate the fate of long term clonal composition: (1) initial integration inside genes or promoters and (2) host negative selection disfavoring proviruses located next to transcribed regions. The result of this initial response will contribute to the proviral load set point value as clonal abundance will benefit from carrying a provirus in transcribed

  6. Massive depletion of bovine leukemia virus proviral clones located in genomic transcriptionally active sites during primary infection.

    Directory of Open Access Journals (Sweden)

    Nicolas A Gillet

    Full Text Available Deltaretroviruses such as human T-lymphotropic virus type 1 (HTLV-1 and bovine leukemia virus (BLV induce a persistent infection that remains generally asymptomatic but can also lead to leukemia or lymphoma. These viruses replicate by infecting new lymphocytes (i.e. the infectious cycle or via clonal expansion of the infected cells (mitotic cycle. The relative importance of these two cycles in viral replication varies during infection. The majority of infected clones are created early before the onset of an efficient immune response. Later on, the main replication route is mitotic expansion of pre-existing infected clones. Due to the paucity of available samples and for ethical reasons, only scarce data is available on early infection by HTLV-1. Therefore, we addressed this question in a comparative BLV model. We used high-throughput sequencing to map and quantify the insertion sites of the provirus in order to monitor the clonality of the BLV-infected cells population (i.e. the number of distinct clones and abundance of each clone. We found that BLV propagation shifts from cell neoinfection to clonal proliferation in about 2 months from inoculation. Initially, BLV proviral integration significantly favors transcribed regions of the genome. Negative selection then eliminates 97% of the clones detected at seroconversion and disfavors BLV-infected cells carrying a provirus located close to a promoter or a gene. Nevertheless, among the surviving proviruses, clone abundance positively correlates with proximity of the provirus to a transcribed region. Two opposite forces thus operate during primary infection and dictate the fate of long term clonal composition: (1 initial integration inside genes or promoters and (2 host negative selection disfavoring proviruses located next to transcribed regions. The result of this initial response will contribute to the proviral load set point value as clonal abundance will benefit from carrying a provirus in

  7. The cell polarity determinant CDC42 controls division symmetry to block leukemia cell differentiation.

    Science.gov (United States)

    Mizukawa, Benjamin; O'Brien, Eric; Moreira, Daniel C; Wunderlich, Mark; Hochstetler, Cindy L; Duan, Xin; Liu, Wei; Orr, Emily; Grimes, H Leighton; Mulloy, James C; Zheng, Yi

    2017-09-14

    As a central regulator of cell polarity, the activity of CDC42 GTPase is tightly controlled in maintaining normal hematopoietic stem and progenitor cell (HSC/P) functions. We found that transformation of HSC/P to acute myeloid leukemia (AML) is associated with increased CDC42 expression and activity in leukemia cells. In a mouse model of AML, the loss of Cdc42 abrogates MLL-AF9 -induced AML development. Furthermore, genetic ablation of CDC42 in both murine and human MLL-AF9 (MA9) cells decreased survival and induced differentiation of the clonogenic leukemia-initiating cells. We show that MLL-AF9 leukemia cells maintain cell polarity in the context of elevated Cdc42-guanosine triphosphate activity, similar to nonmalignant, young HSC/Ps. The loss of Cdc42 resulted in a shift to depolarized AML cells that is associated with a decrease in the frequency of symmetric and asymmetric cell divisions producing daughter cells capable of self-renewal. Importantly, we demonstrate that inducible CDC42 suppression in primary human AML cells blocks leukemia progression in a xenograft model. Thus, CDC42 loss suppresses AML cell polarity and division asymmetry, and CDC42 constitutes a useful target to alter leukemia-initiating cell fate for differentiation therapy. © 2017 by The American Society of Hematology.

  8. A Unique T-Cell Receptor Amino Acid Sequence Selected by Human T-Cell Lymphotropic Virus Type 1 Tax301-309-Specific Cytotoxic T Cells in HLA-A24:02-Positive Asymptomatic Carriers and Adult T-Cell Leukemia/Lymphoma Patients.

    Science.gov (United States)

    Ishihara, Yuko; Tanaka, Yukie; Kobayashi, Seiichiro; Kawamura, Koji; Nakasone, Hideki; Gomyo, Ayumi; Hayakawa, Jin; Tamaki, Masaharu; Akahoshi, Yu; Harada, Naonori; Kusuda, Machiko; Kameda, Kazuaki; Ugai, Tomotaka; Wada, Hidenori; Sakamoto, Kana; Sato, Miki; Terasako-Saito, Kiriko; Kikuchi, Misato; Kimura, Shun-Ichi; Tanihara, Aki; Kako, Shinichi; Uchimaru, Kaoru; Kanda, Yoshinobu

    2017-10-01

    We previously reported that the T-cell receptor (TCR) repertoire of human T-cell lymphotropic virus type 1 (HTLV-1) Tax 301-309 -specific CD8 + cytotoxic T cells (Tax 301-309 -CTLs) was highly restricted and a particular amino acid sequence motif, the PDR motif, was conserved among HLA-A*24:02-positive (HLA-A*24:02 + ) adult T-cell leukemia/lymphoma (ATL) patients who had undergone allogeneic hematopoietic cell transplantation (allo-HSCT). Furthermore, we found that donor-derived PDR + CTLs selectively expanded in ATL long-term HSCT survivors with strong CTL activity against HTLV-1. On the other hand, the TCR repertoires in Tax 301-309 -CTLs of asymptomatic HTLV-1 carriers (ACs) remain unclear. In this study, we directly identified the DNA sequence of complementarity-determining region 3 (CDR3) of the TCR-β chain of Tax 301-309 -CTLs at the single-cell level and compared not only the TCR repertoires but also the frequencies and phenotypes of Tax 301-309 -CTLs between ACs and ATL patients. We did not observe any essential difference in the frequencies of Tax 301-309 -CTLs between ACs and ATL patients. In the single-cell TCR repertoire analysis of Tax 301-309 -CTLs, 1,458 Tax 301-309 -CTLs and 140 clones were identified in this cohort. Tax 301-309 -CTLs showed highly restricted TCR repertoires with a strongly biased usage of BV7, and PDR, the unique motif in TCR-β CDR3, was exclusively observed in all ACs and ATL patients. However, there was no correlation between PDR + CTL frequencies and HTLV-1 proviral load (PVL). In conclusion, we have identified, for the first time, a unique amino acid sequence, PDR, as a public TCR-CDR3 motif against Tax in HLA-A*24:02 + HTLV-1-infected individuals. Further investigations are warranted to elucidate the role of the PDR + CTL response in the progression from carrier state to ATL. IMPORTANCE ATL is an aggressive T-cell malignancy caused by HTLV-1 infection. The HTLV-1 regulatory protein Tax aggressively promotes the

  9. Mutated primer binding sites interacting with different tRNAs allow efficient murine leukemia virus replication

    DEFF Research Database (Denmark)

    Lund, Anders Henrik; Duch, M; Lovmand, J

    1993-01-01

    Two Akv murine leukemia virus-based retroviral vectors with primer binding sites matching tRNA(Gln-1) and tRNA(Lys-3) were constructed. The transduction efficiency of these mutated vectors was found to be comparable to that of a vector carrying the wild-type primer binding site matching t......RNA(Pro). Polymerase chain reaction amplification and sequence analysis of transduced proviruses confirmed the transfer of vectors with mutated primer binding sites and further showed that tRNA(Gln-2) may act efficiently in conjunction with the tRNA(Gln-1) primer binding site. We conclude that murine leukemia virus...... can replicate by using various tRNA molecules as primers and propose primer binding site-tRNA primer interactions to be of major importance for tRNA primer selection. However, efficient primer selection does not require perfect Watson-Crick base pairing at all 18 positions of the primer binding site....

  10. Evidence for Hox and E2A-PBX1 collaboration in mouse T-cell leukemia.

    Science.gov (United States)

    Bijl, J; Krosl, J; Lebert-Ghali, C-E; Vacher, J; Mayotte, N; Sauvageau, G

    2008-10-23

    Using murine Moloney leukemia virus (MMLV)-based proviral insertional mutagenesis, we previously showed a preferential targeting of a small region in the Hoxa gene locus in E2A-PBX1-induced lymphoid leukemia resulting in the overexpression of several Hoxa genes including Hoxa10, Hoxa9 and Hoxa7. This observation suggested a functional interaction between Hox gene overexpression and E2A-PBX1 in lymphoid tumors. To further explore this possibility, we generated a series of compound E2A-PBX1 x Hox transgenic mice and tested the genetic interaction between these genes in the generation of lymphoid leukemia in vivo. Results presented in this report show that the onset of T-cell leukemia is significantly accelerated in E2A-PBX1 x Hoxb4 compound transgenic animals when compared with control E2A-PBX1 or Hoxb4 littermates. Hoxa9 appears less potent than Hoxb4 to accelerate E2A-PBX1-induced T-cell leukemia in mice. E2A-PBX1-induced T-cell leukemias express much higher levels of Hoxa genes than MMLV-induced counterparts, possibly suggesting a contribution of these genes to T-cell transformation by E2A-PBX1. Collectively, these data provide the first genetic evidence showing oncogenic collaboration between E2A-PBX1 and a Hox gene in lymphoid malignancies in vivo and document the specific deregulation of a subgroup of Hoxa genes in these leukemias.

  11. Replacement of the murine leukemia virus (MLV) envelope gene with a truncated HIV envelope gene in MLV generates a virus with impaired replication capacity

    International Nuclear Information System (INIS)

    Nack, Ursula; Schnierle, Barbara S.

    2003-01-01

    Murine leukemia virus (MLV) capsid particles can be efficiently pseudotyped with a variant of the HIV-1 envelope protein (Env) containing the surface glycoprotein gp120-SU and a carboxyl-terminally truncated transmembrane (TM) protein, with only seven cytoplasmic amino acids. MLV/HIV pseudotyped vector particles acquire the natural host tropism of HIV-1 and their entry is dependent on the presence of CD4 and an appropriate co-receptor on the surface of the target cell. We describe here the construction of chimeric MLV/HIV proviruses containing the truncated HIV envelope gene. The MLV/HIV provirus was generated by direct replacement of the MLV envelope gene with HIV Env coding sequences either with or without the additional inclusion of the woodchuck hepatitis virus posttranscriptional regulatory element (WPRE). Chimeric MLV/HIV particles could be generated from transfected 293T cells and were able to infect CD4/CXCR4-positive target cells. However, the second round of infection of target cells was severely impaired, despite the fact that the WPRE element enhanced the amount of viral mRNA detected. Viral particles released from infected cells showed reduced HIV Env incorporation, indicating that additional factors required for efficient replication of MLV/HIV pseudotyped viruses are missing

  12. Mantle cell leukemia as a cause of leukostasis

    Directory of Open Access Journals (Sweden)

    Rappaport E

    2011-04-01

    Full Text Available Daniel Smith1, Christian Cable2, Cary Chisholm1, Walter Linz1, William Koss1, Sheila Dobin1, Edward Rappaport11Department of Pathology, 2Internal Medicine, Scott and White Healthcare/Texas A & M Health Science Center College of Medicine, Temple, TX, USAAbstract: A 72-year-old man was admitted with hypoxemic respiratory distress. Given a white blood cell count of 600 × 109/L and symptoms of leukostasis, emergency leukapheresis was initiated. The white blood cell count immediately after the first leukapheresis was paradoxically increased to over 700 × 109/L. Peripheral blood smear findings showed morphologically immature mononuclear cells and numerous circulating mitotic figures. Initial flow cytometry results showed a lambda light chain-restricted B lymphoid population positive for CD20, CD19, CD5, and FMC-7, and negative for TdT, CD10, CD23, CD34, CD117, and myeloid markers, suggesting classification as a blastoid variant of mantle cell lymphoma in a leukemic phase. Subsequent testing using DNA fluorescence in situ hybridization was positive for t(11;14, confirming the diagnosis of mantle cell leukemia. Although mantle cell lymphoma occasionally transforms or can even present as leukemia (leukocytes >40 × 109/L, it is rare for it to present with such profound leukocytosis and an overwhelming number of pleomorphic/blastoid forms. Although morphology suggested acute lymphoblastic leukemia, a more specific diagnosis of blastoid variant mantle cell lymphoma was obtained in 12 hours by applying complementary techniques of flow cytometry and rapid cytogenetics.Keywords: mantle cell lymphoma, chemotherapy, leukapheresis, lymphocytic leukemia

  13. Oxidative stress in normal hematopoietic stem cells and leukemia.

    Science.gov (United States)

    Samimi, Azin; Kalantari, Heybatullah; Lorestani, Marzieh Zeinvand; Shirzad, Reza; Saki, Najmaldin

    2018-04-01

    Leukemia is developed following the abnormal proliferation of immature hematopoietic cells in the blood when hematopoietic stem cells lose the ability to turn into mature cells at different stages of maturation and differentiation. Leukemia initiating cells are specifically dependent upon the suppression of oxidative stress in the hypoglycemic bone marrow (BM) environment to be able to start their activities. Relevant literature was identified by a PubMed search (2000-2017) of English-language literature using the terms 'oxidative stress,' 'reactive oxygen species,' 'hematopoietic stem cell,' and 'leukemia.' The generation and degradation of free radicals is a main component of the metabolism in aerobic organisms. A certain level of ROS is required for proper cellular function, but values outside this range will result in oxidative stress (OS). Long-term overactivity of reactive oxygen species (ROS) has harmful effects on the function of cells and their vital macromolecules, including the transformation of proteins into autoantigens and increased degradation of protein/DNA, which eventually leads to the change in pathways involved in the development of cancer and several other disorders. According to the metabolic disorders of cancer, the relationship between OS changes, the viability of cancer cells, and their response to chemotherapeutic agents affecting this pathway are undeniable. Recently, studies have been conducted to determine the effect of herbal agents and cancer chemotherapy drugs on oxidative stress pathways. By emphasizing the role of oxidative stress on stem cells in the incidence of leukemia, this paper attempts to state and summarize this subject. © 2018 APMIS. Published by John Wiley & Sons Ltd.

  14. Cannabinoids induce incomplete maturation of cultured human leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Murison, G.; Chubb, C.B.H.; Maeda, S.; Gemmell, M.A.; Huberman, E.

    1987-08-01

    Monocyte maturation markers were induced in cultured human myeloblastic ML-2 leukemia cells after treatment for 1-6 days with 0.03-30 ..mu..M ..delta../sup 9/-tetrahydrocannabinol (THC), the major psychoactive component of marijuana. After a 2-day or longer treatment, 2- to 5-fold increases were found in the percentages of cells exhibiting reactivity with either the murine OKM1 monoclonal antibody of the Leu-M5 monoclonal antibody, staining positively for nonspecific esterase activity, and displaying a promonocyte morphology. The increases in these differentiation markers after treatment with 0.03-1 ..mu..M THC were dose dependent. At this dose range, THC did not cause an inhibition of cell growth. The THC-induced cell maturation was also characterized by specific changes in the patterns of newly synthesized proteins. The THC-induced differentiation did not, however, result in cells with a highly developed mature monocyte phenotype. However, treatment of these incompletely matured cells with either phorbol 12-myristate 13-acetate of 1..cap alpha..,25-dihydroxycholecalciferol, which are inducers of differentiation in myeloid leukemia cells (including ML-2 cells), produced cells with a mature monocyte morphology. The ML-2 cell system described here may be a useful tool for deciphering critical biochemical events that lead to the cannabinoid-induced incomplete cell differentiation of ML-2 cells and other related cell types. Findings obtained from this system may have important implications for studies of cannabinoid effects on normal human bone-marrow progenitor cells.

  15. Report on Influenza A and B Viruses: Their Coinfection in a Saudi Leukemia Patient

    Directory of Open Access Journals (Sweden)

    Fahad N. Almajhdi

    2013-01-01

    Full Text Available Purpose. Influenza A and B viruses are the leading cause of respiratory infections in children worldwide, particularly in developing countries. There is a lack of data on coinfection of influenza A and B viruses circulating in Saudi Arabia. In this study, we aimed to identify the circulation of influenza viruses that contribute to respiratory tract infections in Saudi children. Methods. We collected 80 nasopharyngeal aspirates (NPAs from hospitalized children with acute respiratory illness (ARI at Riyadh during the period extended from October 2010 till April 2011. Samples were tested for the common respiratory viruses including influenza viruses by RT-PCR. Results. Overall, 6 samples were found positive for influenza A and/or B viruses. Among these positive clinical samples, only one collected sample from a female one-year-old immunocompromised child with leukemia showed a coinfection with influenza A and B viruses. In present study coinfection was confirmed by inoculation of the clinical specimen in specific pathogenfree embryonating chicken eggs and identification of the virus isolates by hemagglutination and one-step RT-PCR. Conclusion. This study opens the scene for studying the role of influenza virus’s coinfection in disease severity and virus evolution. Further studies are required to better understand the clinical importance of viral coinfection.

  16. Allogeneic hematopoietic stem cell transplantation as immunotherapy : B lymphocytes versus leukemia

    NARCIS (Netherlands)

    Gillissen, M.A.

    2018-01-01

    Research described in this thesis focuses on the role of B lymphocytes in graft versus leukemia responses following allogeneic hematopoietic stem cell transplantation (HSCT) as treatment of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Acute myeloid leukemia (AML) and high-risk

  17. Functional Interplay Between Murine Leukemia Virus Glycogag, Serinc5, and Surface Glycoprotein Governs Virus Entry, with Opposite Effects on Gammaretroviral and Ebolavirus Glycoproteins

    Directory of Open Access Journals (Sweden)

    Yadvinder S. Ahi

    2016-11-01

    Full Text Available Gammaretroviruses, such as murine leukemia viruses (MLVs, encode, in addition to the canonical Gag, Pol, and Env proteins that will form progeny virus particles, a protein called “glycogag” (glycosylated Gag. MLV glycogag contains the entire Gag sequence plus an 88-residue N-terminal extension. It has recently been reported that glycogag, like the Nef protein of HIV-1, counteracts the antiviral effects of the cellular protein Serinc5. We have found, in agreement with prior work, that glycogag strongly enhances the infectivity of MLVs with some Env proteins but not those with others. In contrast, however, glycogag was detrimental to MLVs carrying Ebolavirus glycoprotein. Glycogag could be replaced, with respect to viral infectivity, by the unrelated S2 protein of equine infectious anemia virus. We devised an assay for viral entry in which virus particles deliver the Cre recombinase into cells, leading to the expression of a reporter. Data from this assay showed that both the positive and the negative effects of glycogag and S2 upon MLV infectivity are exerted at the level of virus entry. Moreover, transfection of the virus-producing cells with a Serinc5 expression plasmid reduced the infectivity and entry capability of MLV carrying xenotropic MLV Env, particularly in the absence of glycogag. Conversely, Serinc5 expression abrogated the negative effects of glycogag upon the infectivity and entry capability of MLV carrying Ebolavirus glycoprotein. As Serinc5 may influence cellular phospholipid metabolism, it seems possible that all of these effects on virus entry derive from changes in the lipid composition of viral membranes.

  18. Adaptive immunity to leukemia is inhibited by cross-reactive induced regulatory T cells

    OpenAIRE

    Manlove, Luke S.; Berquam-Vrieze, Katherine E.; Pauken, Kristen E.; Williams, Richard T.; Jenkins, Marc K.; Farrar, Michael A.

    2015-01-01

    BCR-ABL+ acute lymphoblastic leukemia patients have transient responses to current therapies. However, the fusion of BCR to ABL generates a potential leukemia-specific antigen that could be a target for immunotherapy. We demonstrate that the immune system can limit BCR-ABL+ leukemia progression although ultimately this immune response fails. To address how BCR-ABL+ leukemia escapes immune surveillance, we developed a peptide: MHC-II tetramer that labels endogenous BCR-ABL-specific CD4+ T cell...

  19. The cell cycle checkpoint inhibitors in the treatment of leukemias.

    Science.gov (United States)

    Ghelli Luserna di Rora', A; Iacobucci, I; Martinelli, G

    2017-03-29

    The inhibition of the DNA damage response (DDR) pathway in the treatment of cancers has recently reached an exciting stage with several cell cycle checkpoint inhibitors that are now being tested in several clinical trials in cancer patients. Although the great amount of pre-clinical and clinical data are from the solid tumor experience, only few studies have been done on leukemias using specific cell cycle checkpoint inhibitors. This review aims to summarize the most recent data found on the biological mechanisms of the response to DNA damages highlighting the role of the different elements of the DDR pathway in normal and cancer cells and focusing on the main genetic alteration or aberrant gene expression that has been found on acute and chronic leukemias. This review, for the first time, outlines the most important pre-clinical and clinical data available on the efficacy of cell cycle checkpoint inhibitors in single agent and in combination with different agents normally used for the treatment of acute and chronic leukemias.

  20. Skin manifestations of adult T-cell leukemia/lymphoma: clinical, cytological and immunological features.

    Science.gov (United States)

    Tokura, Yoshiki; Sawada, Yu; Shimauchi, Takatoshi

    2014-01-01

    Adult T-cell leukemia/lymphoma (ATLL) is a malignancy of mature T cells caused by human T-cell leukemia virus type I. The endemic areas include Japan, especially in Kyushu, the Caribbean, Papua New Guinea, South America and Africa. Approximately 50% of ATLL patients exhibit skin manifestations. Cytologically, ATLL tumor cells are characterized by CD4(+) CD25(+) regulatory T-cell phenotype, high expressions of CCR4, and programmed cell death (PD)-1 and PD-ligand 1. The skin eruptions are categorized into six types: patch, plaque, multipapular, nodulotumoral, erythrodermic and purpuric. The overall survival of the eruption-bearing patients was poorer than that of the non-eruption-bearing patients in acute, chronic and smoldering types, but the survival levels of both groups were comparable in lymphoma type. The prognosis was poor in the order of: erythrodermic, nodulotumoral, multipapular/purpuric, plaque, then patch. Multivariate analysis revealed that the eruption type is an independent prognostic factor for ATLL. Patients may have other skin manifestations, secondary and infective lesions. © 2014 Japanese Dermatological Association.

  1. Molecular pathway activation features of pediatric acute myeloid leukemia (AML) and acute lymphoblast leukemia (ALL) cells.

    Science.gov (United States)

    Petrov, Ivan; Suntsova, Maria; Mutorova, Olga; Sorokin, Maxim; Garazha, Andrew; Ilnitskaya, Elena; Spirin, Pavel; Larin, Sergey; Kovalchuk, Olga; Prassolov, Vladimir; Zhavoronkov, Alex; Roumiantsev, Alexander; Buzdin, Anton

    2016-11-19

    Acute lymphoblast leukemia (ALL) is characterized by overproduction of immature white blood cells in the bone marrow. ALL is most common in the childhood and has high (>80%) cure rate. In contrast, acute myeloid leukemia (AML) has far greater mortality rate than the ALL and is most commonly affecting older adults. However, AML is a leading cause of childhood cancer mortality. In this study, we compare gene expression and molecular pathway activation patterns in three normal blood, seven pediatric ALL and seven pediatric AML bone marrow samples. We identified 172/94 and 148/31 characteristic gene expression/pathway activation signatures, clearly distinguishing pediatric ALL and AML cells, respectively, from the normal blood. The pediatric AML and ALL cells differed by 139/34 gene expression/pathway activation biomarkers. For the adult 30 AML and 17 normal blood samples, we found 132/33 gene expression/pathway AML-specific features, of which only 7/2 were common for the adult and pediatric AML and, therefore, age-independent. At the pathway level, we found more differences than similarities between the adult and pediatric forms. These findings suggest that the adult and pediatric AMLs may require different treatment strategies.

  2. Gene expression profiling of microglia infected by a highly neurovirulent murine leukemia virus: implications for neuropathogenesis

    Directory of Open Access Journals (Sweden)

    DeLucia Angelo L

    2006-05-01

    Full Text Available Abstract Background Certain murine leukemia viruses (MLVs are capable of inducing progressive spongiform motor neuron disease in susceptible mice upon infection of the central nervous system (CNS. The major CNS parenchymal target of these neurovirulent retroviruses (NVs are the microglia, whose infection is largely coincident with neuropathological changes. Despite this close association, the role of microglial infection in disease induction is still unknown. In this paper, we investigate the interaction of the highly virulent MLV, FrCasE, with microglia ex vivo to evaluate whether infection induces specific changes that could account for neurodegeneration. Specifically, we compared microglia infected with FrCasE, a related non-neurovirulent virus (NN F43/Fr57E, or mock-infected, both at a basic virological level, and at the level of cellular gene expression using quantitative real time RT-PCR (qRT-PCR and Afffymetrix 430A mouse gene chips. Results Basic virological comparison of NN, NV, and mock-infected microglia in culture did not reveal differences in virus expression that provided insight into neuropathogenesis. Therefore, microglial analysis was extended to ER stress gene induction based on previous experiments demonstrating ER stress induction in NV-infected mouse brains and cultured fibroblasts. Analysis of message levels for the ER stress genes BiP (grp78, CHOP (Gadd153, calreticulin, and grp58 in cultured microglia, and BiP and CHOP in microglia enriched fractions from infected mouse brains, indicated that FrCasE infection did not induce these ER stress genes either in vitro or in vivo. To broadly identify physiological changes resulting from NV infection of microglia in vitro, we undertook a gene array screen of more than 14,000 well-characterized murine genes and expressed sequence tags (ESTs. This analysis revealed only a small set of gene expression changes between infected and uninfected cells ( Conclusion The results from this

  3. Allogeneic stem cell transplantation in acute myeloid leukemia

    Directory of Open Access Journals (Sweden)

    Natasha Ali

    2012-11-01

    Full Text Available We report a case series of 12 patients with acute myeloid leukemia who underwent allogeneic stem cell transplant with a matched related donor. Male to female ratio was 1:1. The main complication post-transplant was graft-versus-host disease (n=7 patients. Transplant-related mortality involved one patient; cause of death was multi-organ failure. After a median follow up of 36.0±11.3 months, overall survival was 16%.

  4. RESULTS OF HEMATOPOIETIC CELL TRANSPLANTATION IN PEDIATRIC LEUKEMIA

    Directory of Open Access Journals (Sweden)

    A. Mousavi

    2008-05-01

    Full Text Available Hematopoietic cell transplantation (HCT is an accepted treatment for acute myeloid leukemia (AML in first remission, the treatment of choice for chronic myeloid leukemia (CML and high risk groups of ALL who relapse with conventional chemotherapy. We assessed results of HCT for pediatric leukemia in our center. A total of 92 children, 63 with diagnose of AML, 23 with ALL and 6 with CML received allogeneic transplantation from HLA full matched siblings (57.6% and autologous transplantation (42.4%. Source of hematopoietic cells were peripheral blood 83.7%, bone marrow 15.2% and cord blood 1.6%. The median transplanted nucleated cells were 6.4 ± 4.7 ×108 /Kg (body weight of patients and mononuclear cells were 5.5 ± 2.9×108/Kg. The most common conditioning regimens were cyclophosphamide + busulfan. Prophylaxis regimen for GVHD was cyclosporin ± methotrexate. GVHD occurred in 50 (54.3% patients. Eighty five of children had engraftment, 26 (28.6% relapsed and 57 (62% are alive. The most common cause of death was relapse (68.6%. Five years overall survival of patients with AML and ALL were 49% and 44% respectively and disease free survival of them were 52% and 49%. One year overall survival and disease free survival of CML was 57%. Overall survival increased with increasing age of patients at transplantation time (P = 0.06. Longer survival significantly related to earlier WBC and platelet recovery (P < 0.0001 and P = 0.006 respectively. Considering acceptable overall and disease free survival of patients after HCT, we concluded that is a good modality in treatment of leukemia of children.

  5. Serological survey of Toxoplasma gondii, Dirofilaria immitis, Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) infections in pet cats in Bangkok and vicinities, Thailand

    Science.gov (United States)

    The seroprevalence of Toxoplasma gondii, Dirofilaria immitis (heartworm), feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infections was examined using serum or plasma samples from 746 pet cats collected between May and July 2009 from clinics and hospitals located in and around ...

  6. High frequencies of leukemia stem cells in poor-outcome childhood precursor-B acute lymphoblastic leukemias.

    Science.gov (United States)

    Morisot, S; Wayne, A S; Bohana-Kashtan, O; Kaplan, I M; Gocke, C D; Hildreth, R; Stetler-Stevenson, M; Walker, R L; Davis, S; Meltzer, P S; Wheelan, S J; Brown, P; Jones, R J; Shultz, L D; Civin, C I

    2010-11-01

    In order to develop a xenograft model to determine the efficacy of new therapies against primary human precursor-B acute lymphoblastic leukemia (ALL) stem cells (LSCs), we used the highly immunodeficient non-obese diabetic (NOD).Cg-Prkdc(scid)IL2rg(tmlWjl)/SzJ (NOD-severe combined immune deficient (scid) IL2rg(-/-)) mouse strain. Intravenous transplantation of 2 of 2 ALL cell lines and 9 of 14 primary ALL cases generated leukemia-like proliferations in recipient mice by 1-7 months after transplant. Leukemias were retransplantable, and the immunophenotypes, gene rearrangements and expression profiles were identical or similar to those of the original primary samples. NOD-scid mice transplanted with the same primary samples developed similar leukemias with only a slightly longer latency than did NOD-scid-IL2Rg(-/-) mice. In this highly sensitive NOD-scid-IL2Rg(-/-)-based assay, 1-100 unsorted primary human ALL cells from five of five tested patients, four of whom eventually experienced leukemia relapse, generated leukemias in recipient mice. This very high frequency of LSCs suggests that a hierarchical LSC model is not valuable for poor-outcome ALL.

  7. Tax unleashed: fulminant Tax-positive Adult T-cell Leukemia/Lymphoma after failed allogeneic stem cell transplantation.

    Science.gov (United States)

    Ghez, David; Renand, Amédée; Lepelletier, Yves; Sibon, David; Suarez, Felipe; Rubio, Marie-Thérèse; Delarue, Richard; Buzyn, Agnès; Beljord, Kheira; Tanaka, Yuetsu; Varet, Bruno; Hermine, Olivier

    2009-12-01

    The human retrovirus HTLV-1 causes Adult T-cell Leukemia/Lymphoma (ATLL), a malignant lymphoproliferative disease of CD4+ T cells of dismal prognosis, in 3-5% of the 20 million infected individuals (Proietti et al.(1) and Bazarbachi et al.(2)). Infection with HTLV-1 represents a prototypical model of virus-mediated oncogenesis by virtue of the viral transactivator Tax, a potent oncogenic protein that exerts pleiotropic effects through its ability to deregulate the transcription of various cellular genes and signal transduction pathways and inhibit DNA repair enzymes, which are critical for T-cell homeostasis and genetic stability (Matsuoka and Jeang(3)) (et Boxus Retrovirology 2009). However, the oncogenic potential of Tax remains a conundrum. Tax protein expression is undetectable using conventional methods in freshly harvested ATLL cells and in non-malignant infected CD4+ T cells (Furukawa et al.(4)) but is up regulated after only a few hours of culture in vitro (Hanon et al.(5)). These observations strongly suggest that a host-derived mechanism is able to either actively repress the transcription of viral proteins in vivo or refrain the emergence of Tax-expressing cells, which would have a growth advantage. We report herein a unique case of CD4+ T-cell leukemia highly expressing Tax following rejection of an allogenic peripheral blood stem cell graft for an HTLV-1 associated lymphoma.

  8. Chronic mast cell leukemia: a novel leukemia-variant with distinct morphological and clinical features.

    Science.gov (United States)

    Valent, Peter; Sotlar, Karl; Sperr, Wolfgang R; Reiter, Andreas; Arock, Michel; Horny, Hans-Peter

    2015-01-01

    Mast cell leukemia (MCL) is a rare form of systemic mastocytosis characterized by leukemic expansion of mostly immature mast cells, organ damage, drug-resistance, and a poor prognosis. Even when treated with chemotherapy, most patients have a life-expectancy of less than one year. However, there are rare patients with MCL in whom the condition is less aggressive and does not cause organ damage within a short time. In these patients, mast cells exhibit a more mature morphology when compared to acute MCL. A recently proposed classification suggests that these cases are referred to as chronic MCL. In the present article, we discuss clinical, histopathological and morphological aspects of acute and chronic MCL. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Macropinocytosis is the Entry Mechanism of Amphotropic Murine Leukemia Virus

    DEFF Research Database (Denmark)

    Rasmussen, Izabela; Vilhardt, Frederik

    2015-01-01

    expression of dominant positive or negative mutants of Rac1, PAK1, and RhoG, to increase or decrease macropinocytosis, similarly correlated with an augmented or inhibited infection with A-MLV, respectively. The same experimental perturbations only mildly or not at all affected the infection of viruses...

  10. Perspectives on avian and bovine leukemia virus immunological studies

    International Nuclear Information System (INIS)

    Higuchi, T.; Souza, J.M.M. de; Nogueira, Z.M.; Ogata, H.

    1984-01-01

    The avian and bovine RNA virus are studied. The mechanism of replication, the genome, the ultrastructural composition, the immunogens reactivity, the class of determinants and affinity are presented. Purification techniques of viral proteins and immunoassay proceeding are reported. (M.A.C.) [pt

  11. TLX1 and NOTCH coregulate transcription in T cell acute lymphoblastic leukemia cells

    OpenAIRE

    Riz, Irene; Hawley, Teresa S; Luu, Truong V; Lee, Norman H; Hawley, Robert G

    2010-01-01

    Abstract Background The homeobox gene TLX1 (for T-cell leukemia homeobox 1, previously known as HOX11) is inappropriately expressed in a major subgroup of T cell acute lymphoblastic leukemia (T-ALL) where it is strongly associated with activating NOTCH1 mutations. Despite the recognition that these genetic lesions cooperate in leukemogenesis, there have been no mechanistic studies addressing how TLX1 and NOTCH1 functionally interact to promote the leukemic phenotype. Results Global gene expre...

  12. Decreased cisplatin uptake by resistant L1210 leukemia cells

    International Nuclear Information System (INIS)

    Hromas, R.A.; North, J.A.; Burns, C.P.

    1987-01-01

    Cisplatin resistance remains poorly understood compared to other forms of anti-neoplastic drug resistance. In this report radiolabelled cisplatin and rapid separation techniques were used to compare drug uptake by L1210 leukemia cells that are sensitive (K25) or resistant (SCR9) to cisplatin. Uptake of cisplatin by both cell lines was linear without saturation kinetics up to 100 μM. The resistant ZCR9 cells had 36-60% reduced drug uptake as compared to its sensitive parent line, K25. In contrast, there was no difference in the rate of efflux. We conclude that a decreased rate of uptake is one possible mechanism of cellular cisplatin resistance. (Author)

  13. AMPK Protects Leukemia-Initiating Cells in Myeloid Leukemias from Metabolic Stress in the Bone Marrow.

    Science.gov (United States)

    Saito, Yusuke; Chapple, Richard H; Lin, Angelique; Kitano, Ayumi; Nakada, Daisuke

    2015-11-05

    How cancer cells adapt to metabolically adverse conditions in patients and strive to proliferate is a fundamental question in cancer biology. Here we show that AMP-activated protein kinase (AMPK), a metabolic checkpoint kinase, confers metabolic stress resistance to leukemia-initiating cells (LICs) and promotes leukemogenesis. Upon dietary restriction, MLL-AF9-induced murine acute myeloid leukemia (AML) activated AMPK and maintained leukemogenic potential. AMPK deletion significantly delayed leukemogenesis and depleted LICs by reducing the expression of glucose transporter 1 (Glut1), compromising glucose flux, and increasing oxidative stress and DNA damage. LICs were particularly dependent on AMPK to suppress oxidative stress in the hypoglycemic bone marrow environment. Strikingly, AMPK inhibition synergized with physiological metabolic stress caused by dietary restriction and profoundly suppressed leukemogenesis. Our results indicate that AMPK protects LICs from metabolic stress and that combining AMPK inhibition with physiological metabolic stress potently suppresses AML by inducing oxidative stress and DNA damage. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Detection and molecular characterization of bovine leukemia virus in Philippine cattle.

    Science.gov (United States)

    Polat, Meripet; Ohno, Ayumu; Takeshima, Shin-Nosuke; Kim, Jiyun; Kikuya, Mari; Matsumoto, Yuki; Mingala, Claro Niegos; Onuma, Misao; Aida, Yoko

    2015-01-01

    Bovine leukemia virus (BLV) is the etiological agent of enzootic bovine leukosis, which is the most common neoplastic disease of cattle. BLV infects cattle worldwide, imposing a severe economic impact on the dairy cattle industry. However, there are no comprehensive studies on the distribution of BLV in the Philippines, and the genetic characteristics of Philippine BLV strains are unknown. Therefore, the aim of this study was to detect BLV infections in the Philippines and determined their genetic variability. Blood samples were obtained from 1116 cattle from different farms on five Philippine islands, and BLV provirus was detected by BLV-CoCoMo-qPCR-2 and nested PCR targeting BLV long terminal repeats. Out of 1116 samples, 108 (9.7 %) and 54 (4.8 %) were positive for BLV provirus, as determined by BLV-CoCoMo-qPCR-2 and nested PCR, respectively. Of the five islands, Luzon Island showed the highest prevalence of BLV infection (23.1 %). Partial env gp51 genes from 43 samples, which were positive for BLV provirus by both methods, were sequenced for phylogenetic analysis. Phylogenetic analysis based on a 423-bp fragment of the env gene revealed that Philippine BLV strains clustered into either genotype 1 or genotype 6. Substitutions were mainly found in antigenic determinants, such as the CD4(+) T-cell epitope, the CD8(+) T-cell epitope, the second neutralizing domain, B and E epitopes, and these substitutions varied according to genotype. This study provides comprehensive information regarding BLV infection levels in the Philippines and documents the presence of two BLV genotypes, genotypes 1 and 6, in this population.

  15. Virus manipulation of cell cycle.

    Science.gov (United States)

    Nascimento, R; Costa, H; Parkhouse, R M E

    2012-07-01

    Viruses depend on host cell resources for replication and access to those resources may be limited to a particular phase of the cell cycle. Thus manipulation of cell cycle is a commonly employed strategy of viruses for achieving a favorable cellular environment. For example, viruses capable of infecting nondividing cells induce S phase in order to activate the host DNA replication machinery and provide the nucleotide triphosphates necessary for viral DNA replication (Flemington in J Virol 75:4475-4481, 2001; Sullivan and Pipas in Microbiol Mol Biol Rev 66:179-202, 2002). Viruses have developed several strategies to subvert the cell cycle by association with cyclin and cyclin-dependent kinase complexes and molecules that regulate their activity. Viruses tend to act on cellular proteins involved in a network of interactions in a way that minimal protein-protein interactions lead to a major effect. The complex and interactive nature of intracellular signaling pathways controlling cell division affords many opportunities for virus manipulation strategies. Taking the maxim "Set a thief to catch a thief" as a counter strategy, however, provides us with the very same virus evasion strategies as "ready-made tools" for the development of novel antivirus therapeutics. The most obvious are attenuated virus vaccines with critical evasion genes deleted. Similarly, vaccines against viruses causing cancer are now being successfully developed. Finally, as viruses have been playing chess with our cell biology and immune responses for millions of years, the study of their evasion strategies will also undoubtedly reveal new control mechanisms and their corresponding cellular intracellular signaling pathways.

  16. Studies on emerging radiation leukemia virus variants in C57BL/Ka mice

    International Nuclear Information System (INIS)

    Rassart, E.; Shang, M.; Boie, Y.; Jolicoeur, P.

    1986-01-01

    To analyze the emergence of radiation leukemia virus (RadLV) variants in primary X-ray-induced C57BL/Ka thymoma and to identify the virus responsible for the very high leukemogenic potential of passaged Kaplan strain BL/VL3 preparation, we cloned several primary and passaged ecotropic RadLV infectious genomes. By restriction analysis, we found that BL/VL3 cells harbor three related but different ecotropic RadLVs. Their restriction map differs significantly from those of primary RadLVs. Hybridization analysis also indicated that BL/VL3 and primary RadLVs differ in their p15E and long terminal repeat (LTR) regions. The LTR sequence of primary weakly leukemogenic RadLV has only one change, a C-rich sequence, generating a 6-base-pair direct repeat just in front of the promotor. The LTR of the primary nonleukemogenic RadLV only showed few base changes, mainly clustered in R and U5. The LTR from a moderately leukemogenic passaged BL/VL3 RadLV had conserved the C-rich sequence and acquired a 43-base-pair direct repeat in U3 and several other point mutations, small insertions, and deletions scattered in U3, R, and U5. All cloned primary RadLVs were fibrotropic, and some were weakly leukemogenic. All cloned BL/VL3 RadLVs were thymotropic and nonfibrotropic. The block of their replication was found to be after the synthesis of unintegrated linear and supercoiled viral DNA. Most of the BL/VL3 RadLVs were moderately leukemogenic, and one (V-13) was highly leukemogenic, being as virulent as the Moloney strain. We propose a model for the emergence of the RadLV variants and show that the virus responsible for the high leukemogenic potential of BL/VL3 preparation is a nondefective, ecotropic, lymphotropic, nonfibrotropic, unique retrovirus which most likely arose from a parental primary RadLV similar to those studied here

  17. EBI2 overexpression in mice leads to B1 B cell expansion and chronic lymphocytic leukemia-(CLL)-like B cell malignancies

    DEFF Research Database (Denmark)

    Niss Arfelt, Kristine; Barington, Line; Benned-Jensen, Tau

    2017-01-01

    Human and mouse chronic lymphocytic leukemia (CLL) develop from CD5+ B cells that in mice and macaques are known to define the distinct B1a B cell lineage. B1a cells are characterized by lack of germinal center development and the B1a cell population is increased in mice with reduced germinal...... center formation. As a major mediator of follicular B cell migration, the G protein-coupled receptor (GPCR) Epstein Barr virus-induced gene 2 (EBI2 or GPR183) directs B cell migration in the lymphoid follicles in response to its endogenous ligands, oxysterols. Thus, upregulation of EBI2 drives the B...

  18. Transcription from a spleen necrosis virus 5' long terminal repeat is suppressed in mouse cells.

    OpenAIRE

    Embretson, J E; Temin, H M

    1987-01-01

    To determine the block(s) to spleen necrosis virus (SNV) replication in mouse cells, we studied the expression of a dominant selectable marker, neo, or a gene whose product is easily assayed, the chloramphenicol acetyltransferase (cat) gene, in SNV-derived and murine leukemia virus-derived vectors. Using transient (CAT) and stable (Neor phenotype) transfection assays, we showed that the SNV promoter was used in mouse cells only when the 3' SNV long terminal repeat (LTR) was absent. Infection ...

  19. Tumefactive intracranial presentation of precursor B-cell acute lymphoblastic leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Forester, Craig M. [University of Utah, Salt Lake City, UT (United States); Braunreiter, Chi L. [University of Utah, Division of Pediatric Hematology Oncology, Primary Children' s Medical Center, Salt Lake City, UT (United States); Helen DeVos Children' s Hospital, Department of Pediatric Hematology Oncology, Grand Rapids, MI (United States); Yaish, Hasan; Afify, Zeinab [University of Utah, Division of Pediatric Hematology Oncology, Primary Children' s Medical Center, Salt Lake City, UT (United States); Hedlund, Gary L. [Primary Children' s Medical Center, Department of Pediatric Radiology, Salt Lake City, UT (United States)

    2009-11-15

    In children, leukemia is the most common malignancy, and approximately 75% of leukemias are acute lymphoblastic leukemia (ALL). Central nervous system leukemia is found at diagnosis in fewer than 5% of children with ALL. Leukemic intracranial masses have been described with acute myeloid leukemia, but ALL presenting as a mass lesion is rare. We describe a unique case of an intracranial confirmed precursor B cell (pre-B) ALL mass in a 13-year-old girl that was diagnosed by brain CT, MRI and cerebral angiography, and confirmed by biopsy. This report details pertinent history and distinguishing imaging features of an intracranial ALL tumefaction. (orig.)

  20. Tumefactive intracranial presentation of precursor B-cell acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Forester, Craig M.; Braunreiter, Chi L.; Yaish, Hasan; Afify, Zeinab; Hedlund, Gary L.

    2009-01-01

    In children, leukemia is the most common malignancy, and approximately 75% of leukemias are acute lymphoblastic leukemia (ALL). Central nervous system leukemia is found at diagnosis in fewer than 5% of children with ALL. Leukemic intracranial masses have been described with acute myeloid leukemia, but ALL presenting as a mass lesion is rare. We describe a unique case of an intracranial confirmed precursor B cell (pre-B) ALL mass in a 13-year-old girl that was diagnosed by brain CT, MRI and cerebral angiography, and confirmed by biopsy. This report details pertinent history and distinguishing imaging features of an intracranial ALL tumefaction. (orig.)

  1. Blastic Transformation in a Case of Hairy Cell Leukemia.

    Science.gov (United States)

    Friedline; Crisan; Chen

    1998-09-01

    Background: Hairy cell leukemia (HCL) is a slowly progressive lymphoproliferative disorder that tends to afflict middle-aged adults, especially men. Blastic transformation of this form of leukemia is extremely rare. To date, a single case has been reported. Methods and Results: A case of HCL, evolving with blastic transformation after a 9- year clinical course, is reported. Routine histology, cytochemistry, flow cytometry immunophenotyping, and Southern blot analysis for B- and T-cell gene rearrangements were used in the evaluation. Although morphology at the time of presentation was characteristic of HCL, the cells were initially tartrate-resistant acid phosphatase (TRAP) negative. During a clinical course over several years, the hairy cells became progressively TRAP positive. The morphology of the leukemic cells changed 9 years after initial diagnosis, with blastic transformation and retaining strong TRAP positivity. Immunophenotypic analysis showed evolution from a characteristic hairy cell leukemic phenotype to a phenotype indicative of marked immaturity. Genotypic analysis showed an evolving pattern of immunoglobulin gene rearrangements, paralleling the morphology and phenotypic evolution and ruling out a second B-cell malignancy. Conclusions: This case report of blastic transformation in a patient with HCL is only the second such case identified in the medical literature to date.

  2. Flow cytometric immunophenotyping of adult T-cell leukemia/lymphoma using CD3 gating.

    Science.gov (United States)

    Yokote, Taiji; Akioka, Toshikazu; Oka, Satoko; Hara, Satoshi; Kobayashi, Kichinosuke; Nakajima, Hideto; Yamano, Takeshi; Ikemoto, Toshiyuki; Shimizu, Akira; Tsuji, Motomu; Hanafusa, Toshiaki

    2005-08-01

    Adult T-cell leukemia/lymphoma (ATLL) is a lymphoproliferative neoplasm of helper T lymphocytes caused by human T-cell leukemia virus type-1 (HTLV-1). The disease was first described in Kyushu, in southwestern Japan, and most frequently occurs in endemic areas, such as Japan, the Caribbean basin, West Africa, Brazil, and northern Iran. ATLL is essentially a disease of adults, characterized clinically by generalized lymphadenopathy, hepatosplenomegaly, skin lesions, and hypercalcemia. The prognosis of most patients is quite poor, with a median survival time of only 13 months, even if multiagent combination chemotherapy is given. In the present study, flow cytometric immunophenotyping with CD3 gating was performed on 30 samples from 26 patients who had been given a diagnosis of ATLL. The records of these patients also were reviewed retrospectively. In 14 of the 30 samples, an abnormal CD3(low) T-cell population was distinguishable from the normal T-cell populations by flow cytometric analysis. Herein we report a novel strategy for flow cytometric immunophenotyping of ATLL facilitated by CD3(low) gating.

  3. Single Amino Acid Insertion in Loop 4 Confers Amphotropic Murine Leukemia Virus Receptor Function upon Murine Pit1

    DEFF Research Database (Denmark)

    Lundorf, Mikkel D.; Pedersen, Finn Skou; O'Hara, Bryan

    1998-01-01

    Pit1 is the human receptor for gibbon ape leukemia virus (GALV) and feline leukemia virus subgroup B (FeLV-B), while the related human protein Pit2 is a receptor for amphotropic murine leukemia virus (A-MuLV). The A-MuLV-related isolate 10A1 can utilize both Pit1 and Pit2 as receptors. A stretch...... of amino acids named region A was identified in Pit1 (residues 550 to 558 in loop 4) as critical for GALV and FeLV-B receptor function. We have here investigated the role of region A in A-MuLV and 10A1 entry. Insertion of a single amino acid in region A of mouse Pit1 resulted in a functional A...

  4. Apoptosis of bone marrow leukemia cells in mice after low dose radiation at different time

    International Nuclear Information System (INIS)

    Li Guangyu; Yu Mingming; Li Xianjun; Liu Zhixiang

    2007-01-01

    Objective: To investigate the apoptosis of bone marrow leukemia cell in mice after low dose radiation (LDR) at different time and the experimental basis for LDR auxiliary therapy on leukemia. Methods: WEHI-3 cells were injected into BALB/c mice through tail veins to make an experimental mice model of myelornonocytic leukemia. 60 leukemia mice models were divided half-and half. 30 mice models in experimental group were irradiated with LDR of 75mGy at the same time while the others 30 in the control group were not. 6 mice models with LDR and 6 mice models without LDR would be killed at the time the 1st day, the 2nd day, the 3rd day, the 5th day- and the l0th day after LDR in order to extract bone marrow samples. The apoptosis percentage of leukemia cells in bone marrow was examined. Results: The apoptosis percentage of leukemia cells in experimental group was increasing after LDR and went to top on the 2nd day and the 3rd day. The apoptosis percentage of leukemia cells was remarkably different between experimental and control group, all P<0.05. Conclusion: LDR could significantly increase the apoptosis percentage of bone marrow leukemia cells in mice. Its mechanism is remarkably different in kill and wound of big dose radiation to tumour cells. It is probably related to of the increase immune exciting response as to promote some cytokine secretion, in leukemia mice. (authors)

  5. Increased regulatory T cells in acute lymphoblastic leukemia patients.

    Science.gov (United States)

    Idris, Siti-Zuleha; Hassan, Norfarazieda; Lee, Le-Jie; Md Noor, Sabariah; Osman, Raudhawati; Abdul-Jalil, Marsitah; Nordin, Abdul-Jalil; Abdullah, Maha

    2015-10-01

    Regulation in adaptive immune response balances a fine line that prevents instigation of self-damage or fall into unresponsiveness permitting abnormal cell growth. Mechanisms that keep this balance in check include regulatory T cells (Tregs). Tregs consist of a small but heterogeneous population which may be identified by the phenotype, CD3+CD4+CD25+CD127-. Role of Tregs in pathogenesis of cancers is thus far supported by evidence of increased Tregs in various cancers and may contribute to poorer prognosis. Tregs may also be important in acute leukemias. A review of the literature on Tregs in acute leukemias was conducted and Tregs were determined in B-cell acute lymphoblastic leukemias (ALLs). Studies on Tregs in B-cell ALL are few and controversial. We observed a significantly increased percentage of Tregs (mean ± SD, 9.72 ± 3.79% vs. 7.05 ± 1.74%; P = 0.047) in the bone marrow/peripheral blood of ALL (n = 17) compared to peripheral blood of normal controls (n = 35). A positive trend between Tregs and age (R = 0.474, P = 0.055, n = 17) implicates this factor of poor prognosis in B-cell ALL. Tregs in cancer are particularly significant in immunotherapy. The manipulation of the immune system to treat cancer has for a long time ignored regulatory mechanisms inducible or in place. In lymphoma studies tumor-specific mechanisms that are unlike conventional methods in the induction of Tregs have been hypothesized. In addition, tumor-infiltrating Tregs may present different profiles from peripheral blood pictures. Tregs will continue to be dissected to reveal their mysteries and their impact on clinical significance.

  6. Refined diagnostic criteria and classification of mast cell leukemia (MCL) and myelomastocytic leukemia (MML) : a consensus proposal

    NARCIS (Netherlands)

    Valent, P.; Sotlar, K.; Sperr, W. R.; Escribano, L.; Yavuz, S.; Reiter, A.; George, T. I.; Kluin-Nelemans, H. C.; Hermine, O.; Butterfield, J. H.; Hagglund, H.; Ustun, C.; Hornick, J. L.; Triggiani, M.; Radia, D.; Akin, C.; Hartmann, K.; Gotlib, J.; Schwartz, L. B.; Verstovsek, S.; Orfao, A.; Metcalfe, D. D.; Arock, M.; Horny, H. -P.

    Mast cell leukemia (MCL), the leukemic manifestation of systemic mastocytosis (SM), is characterized by leukemic expansion of immature mast cells (MCs) in the bone marrow (BM) and other internal organs; and a poor prognosis. In a subset of patients, circulating MCs are detectable. A major

  7. T-cell transcription factor GATA-3 is an immunophenotypic marker of acute leukemias with T-cell differentiation.

    Science.gov (United States)

    Dorfman, David M; Morgan, Elizabeth A; Pelton, Ashley; Unitt, Christine

    2017-07-01

    T-cell transcription factor GATA-3, known to play a role in early T-cell development and in the development of T-cell neoplasms, is expressed at high levels in fetal and adult thymus, as well as in acute leukemias with T-cell differentiation, including T-lymphoblastic leukemia/lymphoma (22/22 cases), early T-cell precursor lymphoblastic leukemia (11/11 cases), and mixed-phenotype acute leukemia, T/myeloid (4/5 cases), but only rarely in acute myeloid leukemia/myeloid sarcoma (1/36 cases), and not in B-lymphoblastic leukemia (0/16 cases). In contrast, T-bet, the other T-cell transcription factor that controls Th1/Th2 T-cell fate, is not expressed to any significant extent in immature thymocytes or in cases of T-lymphoblastic leukemia or acute myeloid leukemia/myeloid sarcoma, but is expressed in most cases (15/16) of B-lymphoblastic leukemia and in mixed-phenotype acute leukemia, B/myeloid. GATA-3-positive acute leukemias with T-cell differentiation were also found to express proto-oncogene C-MYC, in an average of 52% of neoplastic cells, which, along with GATA-3, may contribute to leukemogenesis, as suggested by transgenic mouse models. We conclude that GATA-3 is a sensitive and specific marker for the diagnosis of acute leukemias with T-cell differentiation and may be a useful addition to the panel of immunophenotypic markers for the diagnostic evaluation of acute leukemias. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Altered plasma concentrations of sex hormones in cats infected by feline immunodeficiency virus or feline leukemia virus.

    Science.gov (United States)

    Tejerizo, G; Doménech, A; Illera, J-C; Silván, G; Gómez-Lucía, E

    2012-02-01

    Gender differences may affect human immunodeficiency virus (HIV) infection in humans and may be related to fluctuations in sex hormone concentration. The different percentage of male and female cats observed to be infected by feline leukemia virus (FeLV) or feline immunodeficiency virus (FIV) has been traditionally explained through the transmission mechanisms of both viruses. However, sexual hormones may also play a role in this different distribution. To study this possibility, 17β-estradiol, progesterone, testosterone, and dehydroepiandrosterone (DHEA) concentrations were analyzed using a competitive enzyme immunoassay in the plasma of 258 cats naturally infected by FIV (FIV(+)), FeLV (FeLV(+)), or FeLV and FIV (F(-)F(+)) or negative for both viruses, including both sick and clinically healthy animals. Results indicated that the concentrations of 17β-estradiol and testosterone were significantly higher in animals infected with FIV or FeLV (P FIV(+) females had higher DHEA concentrations than the corresponding males (P FIV and FeLV infections are associated with an important deregulation of steroids, possibly from early in the infection process, which might have decisive consequences for disease progression. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Evidence of feline immunodeficiency virus, feline leukemia virus, and Toxoplasma gondii in feral cats on Mauna Kea, Hawaii

    Science.gov (United States)

    Danner, R.M.; Goltz, Dan M.; Hess, S.C.; Banko, P.C.

    2007-01-01

    We determined prevalence to feline immunodeficiency virus (FIV) antibodies, feline leukemia virus (FeLV) antigen, and Toxoplasma gondii antibodies in feral cats (Felis catus) on Mauna Kea Hawaii from April 2002 to May 2004. Six of 68 (8.8%) and 11 of 68 (16.2%) cats were antibody positive to FIV and antigen positive for FeLV, respectively; 25 of 67 (37.3%) cats were seropositive to T. gondii. Antibodies to FeLV and T. gondii occurred in all age and sex classes, but FIV occurred only in adult males. Evidence of current or previous infections with two of these infectious agents was detected in eight of 64 cats (12.5%). Despite exposure to these infectious agents, feral cats remain abundant throughout the Hawaiian Islands. ?? Wildlife Disease Association 2007.

  10. EPIZOOTIOLOGY AND MANAGEMENT OF FELINE LEUKEMIA VIRUS IN THE FLORIDA PUMA

    OpenAIRE

    Cunningham, Mark W.; Brown, Meredith A.; Shindle, David B.; Terrell, Scott P.; Hayes, Kathleen A.; Ferree, Bambi C.; McBride, R. T.; Blankenship, Emmett L.; Jansen, Deborah; Citino, Scott B.; Roelke, Melody E.; Kiltie, Richard A.; Troyer, Jennifer L.; O’Brien, Stephen J.

    2008-01-01

    Feline leukemia virus (FeLV) was not detected in Florida pumas (Puma concolor coryi) in almost 20 yr of surveillance; however, the finding of two FeLV antigen-positive pumas during the 2002–2003 capture season led to an investigation of FeLV in the population. Between January 1990 and April 2007, the proportion of pumas testing FeLV antibody positive increased, with antibody-positive pumas concentrated in the northern portion of puma range. Five of 131 (4%) pumas sampled between July 2000 and...

  11. Epigenetic deregulation of Ellis Van Creveld confers robust Hedgehog signaling in adult T-cell leukemia.

    Science.gov (United States)

    Takahashi, Ryutaro; Yamagishi, Makoto; Nakano, Kazumi; Yamochi, Toshiko; Yamochi, Tadanori; Fujikawa, Dai; Nakashima, Makoto; Tanaka, Yuetsu; Uchimaru, Kaoru; Utsunomiya, Atae; Watanabe, Toshiki

    2014-09-01

    One of the hallmarks of cancer, global gene expression alteration, is closely associated with the development and malignant characteristics associated with adult T-cell leukemia (ATL) as well as other cancers. Here, we show that aberrant overexpression of the Ellis Van Creveld (EVC) family is responsible for cellular Hedgehog (HH) activation, which provides the pro-survival ability of ATL cells. Using microarray, quantitative RT-PCR and immunohistochemistry we have demonstrated that EVC is significantly upregulated in ATL and human T-cell leukemia virus type I (HTLV-1)-infected cells. Epigenetic marks, including histone H3 acetylation and Lys4 trimethylation, are specifically accumulated at the EVC locus in ATL samples. The HTLV-1 Tax participates in the coordination of EVC expression in an epigenetic fashion. The treatment of shRNA targeting EVC, as well as the transcription factors for HH signaling, diminishes the HH activation and leads to apoptotic death in ATL cell lines. We also showed that a HH signaling inhibitor, GANT61, induces strong apoptosis in the established ATL cell lines and patient-derived primary ATL cells. Therefore, our data indicate that HH activation is involved in the regulation of leukemic cell survival. The epigenetically deregulated EVC appears to play an important role for HH activation. The possible use of EVC as a specific cell marker and a novel drug target for HTLV-1-infected T-cells is implicated by these findings. The HH inhibitors are suggested as drug candidates for ATL therapy. Our findings also suggest chromatin rearrangement associated with active histone markers in ATL. © 2014 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.

  12. An activating mutation of interferon regulatory factor 4 (IRF4) in adult T cell leukemia.

    Science.gov (United States)

    Cherian, Mathew A; Olson, Sydney; Sundaramoorthi, Hemalatha; Cates, Kitra; Cheng, Xiaogang; Harding, John; Martens, Andrew; Challen, Grant A; Tyagi, Manoj; Ratner, Lee; Rauch, Daniel

    2018-03-14

    The human T cell leukemia virus-1 (HTLV-1) oncoprotein Tax drives cell proliferation and resistance to apoptosis early in the pathogenesis of adult T-cell leukemia (ATL). Subsequently, likely as a result of specific immuno-editing, Tax expression is downregulated and functionally replaced by somatic driver mutations of the host genome. Both amplification and point mutations of interferon regulatory factor 4 (IRF4) have been previously detected in ATL, and the K59R mutation is the most common single-nucleotide variation in IRF4 and is found exclusively in ATL. Here high throughput whole-exome sequencing revealed recurrent activating genetic alterations in the T cell receptor, CD28, and NF-kB pathways. Moreover, we found that IRF4, which is transcriptionally activated downstream of these pathways, is frequently mutated in ATL. IRF4 RNA, protein, and IRF4 transcriptional targets are uniformly elevated in HTLV transformed cells and ATL cell lines, and IRF4 was bound to genomic regulatory DNA of many of these transcriptional targets in HTLV-1 transformed cell lines. We further noted that the K59R IRF4 mutant is expressed at higher levels in the nucleus than is wild-type IRF4, and is transcriptionally more active. Expression of both wild-type and the K59R mutant of IRF4 from a constitutive promoter in retrovirally transduced murine bone marrow cells increased the abundance of T lymphocytes but not myeloid cells or B lymphocytes in mice. IRF4 may represent a therapeutic target in ATL since ATL cells select for a mutant of IRF4 with higher nuclear expression and transcriptional activity, and over-expression of IRF4 induces the expansion of T lymphocytes in vivo. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Canthin-6-one induces cell death, cell cycle arrest and differentiation in human myeloid leukemia cells.

    Science.gov (United States)

    Vieira Torquato, Heron F; Ribeiro-Filho, Antonio C; Buri, Marcus V; Araújo Júnior, Roberto T; Pimenta, Renata; de Oliveira, José Salvador R; Filho, Valdir C; Macho, Antonio; Paredes-Gamero, Edgar J; de Oliveira Martins, Domingos T

    2017-04-01

    Canthin-6-one is a natural product isolated from various plant genera and from fungi with potential antitumor activity. In the present study, we evaluate the antitumor effects of canthin-6-one in human myeloid leukemia lineages. Kasumi-1 lineage was used as a model for acute myeloid leukemia. Cells were treated with canthin-6-one and cell death, cell cycle and differentiation were evaluated in both total cells (Lin + ) and leukemia stem cell population (CD34 + CD38 - Lin -/low ). Among the human lineages tested, Kasumi-1 was the most sensitive to canthin-6-one. Canthin-6-one induced cell death with apoptotic (caspase activation, decrease of mitochondrial potential) and necrotic (lysosomal permeabilization, double labeling of annexin V/propidium iodide) characteristics. Moreover, canthin-6-one induced cell cycle arrest at G 0 /G 1 (7μM) and G 2 (45μM) evidenced by DNA content, BrdU incorporation and cyclin B1/histone 3 quantification. Canthin-6-one also promoted differentiation of Kasumi-1, evidenced by an increase in the expression of myeloid markers (CD11b and CD15) and the transcription factor PU.1. Furthermore, a reduction of the leukemic stem cell population and clonogenic capability of stem cells were observed. These results show that canthin-6-one can affect Kasumi-1 cells by promoting cell death, cell cycle arrest and cell differentiation depending on concentration used. Canthin-6-one presents an interesting cytotoxic activity against leukemic cells and represents a promising scaffold for the development of molecules for anti-leukemic applications, especially by its anti-leukemic stem cell activity. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Biology and relevance of human acute myeloid leukemia stem cells.

    Science.gov (United States)

    Thomas, Daniel; Majeti, Ravindra

    2017-03-23

    Evidence of human acute myeloid leukemia stem cells (AML LSCs) was first reported nearly 2 decades ago through the identification of rare subpopulations of engrafting cells in xenotransplantation assays. These AML LSCs were shown to reside at the apex of a cellular hierarchy that initiates and maintains the disease, exhibiting properties of self-renewal, cell cycle quiescence, and chemoresistance. This cancer stem cell model offers an explanation for chemotherapy resistance and disease relapse and implies that approaches to treatment must eradicate LSCs for cure. More recently, a number of studies have both refined and expanded our understanding of LSCs and intrapatient heterogeneity in AML using improved xenotransplant models, genome-scale analyses, and experimental manipulation of primary patient cells. Here, we review these studies with a focus on the immunophenotype, biological properties, epigenetics, genetics, and clinical associations of human AML LSCs and discuss critical questions that need to be addressed in future research. © 2017 by The American Society of Hematology.

  15. Anti-adult T-cell leukemia/lymphoma effects of indole-3-carbinol

    Directory of Open Access Journals (Sweden)

    Okudaira Taeko

    2009-01-01

    Full Text Available Abstract Background Adult T-cell leukemia/lymphoma (ATLL is a malignancy derived from T cells infected with human T-cell leukemia virus type 1 (HTLV-1, and it is known to be resistant to standard anticancer therapies. Indole-3-carbinol (I3C, a naturally occurring component of Brassica vegetables such as cabbage, broccoli and Brussels sprout, is a promising chemopreventive agent as it is reported to possess antimutagenic, antitumorigenic and antiestrogenic properties in experimental studies. The aim of this study was to determine the potential anti-ATLL effects of I3C both in vitro and in vivo. Results In the in vitro study, I3C inhibited cell viability of HTLV-1-infected T-cell lines and ATLL cells in a dose-dependent manner. Importantly, I3C did not exert any inhibitory effect on uninfected T-cell lines and normal peripheral blood mononuclear cells. I3C prevented the G1/S transition by reducing the expression of cyclin D1, cyclin D2, Cdk4 and Cdk6, and induced apoptosis by reducing the expression of XIAP, survivin and Bcl-2, and by upregulating the expression of Bak. The induced apoptosis was associated with activation of caspase-3, -8 and -9, and poly(ADP-ribose polymerase cleavage. I3C also suppressed IκBα phosphorylation and JunD expression, resulting in inactivation of NF-κB and AP-1. Inoculation of HTLV-1-infected T cells in mice with severe combined immunodeficiency resulted in tumor growth. The latter was inhibited by treatment with I3C (50 mg/kg/day orally, but not the vehicle control. Conclusion Our preclinical data suggest that I3C could be potentially a useful chemotherapeutic agent for patients with ATLL.

  16. ATF3, an HTLV-1 bZip factor binding protein, promotes proliferation of adult T-cell leukemia cells

    Directory of Open Access Journals (Sweden)

    Ohshima Koichi

    2011-03-01

    Full Text Available Abstract Background Adult T-cell leukemia (ATL is an aggressive malignancy of CD4+ T-cells caused by human T-cell leukemia virus type 1 (HTLV-1. The HTLV-1 bZIP factor (HBZ gene, which is encoded by the minus strand of the viral genome, is expressed as an antisense transcript in all ATL cases. By using yeast two-hybrid screening, we identified activating transcription factor 3 (ATF3 as an HBZ-interacting protein. ATF3 has been reported to be expressed in ATL cells, but its biological significance is not known. Results Immunoprecipitation analysis confirmed that ATF3 interacts with HBZ. Expression of ATF3 was upregulated in ATL cell lines and fresh ATL cases. Reporter assay revealed that ATF3 could interfere with the HTLV-1 Tax's transactivation of the 5' proviral long terminal repeat (LTR, doing so by affecting the ATF/CRE site, as well as HBZ. Suppressing ATF3 expression inhibited proliferation and strongly reduced the viability of ATL cells. As mechanisms of growth-promoting activity of ATF3, comparative expression profiling of ATF3 knockdown cells identified candidate genes that are critical for the cell cycle and cell death, including cell division cycle 2 (CDC2 and cyclin E2. ATF3 also enhanced p53 transcriptional activity, but this activity was suppressed by HBZ. Conclusions Thus, ATF3 expression has positive and negative effects on the proliferation and survival of ATL cells. HBZ impedes its negative effects, leaving ATF3 to promote proliferation of ATL cells via mechanisms including upregulation of CDC2 and cyclin E2. Both HBZ and ATF3 suppress Tax expression, which enables infected cells to escape the host immune system.

  17. Combined treatment of 3-hydroxyflavone and imatinib mesylate increases apoptotic cell death of imatinib mesylate-resistant leukemia cells.

    Science.gov (United States)

    Kim, Jung-Hyun; Song, Minjung; Kang, Geun-Ho; Lee, Eung-Ryoung; Choi, Hye-Yeon; Lee, Chung; Kim, Jin-Hoi; Kim, Youngsoo; Koo, Bon-Nyeo; Cho, Ssang-Goo

    2012-09-01

    Imatinib mesylate, a Bcr/Abl tyrosine kinase inhibitor, is widely used in treating chronic myeloid leukemia. However, drug-resistance of leukemia cells becomes an emergent problem. Herein, various flavonoids were screened for applicability in leukemia treatment, and 3-hydroxyflavone (3-HF) was found to be most effective in reducing cancer cell viability. The combination of 3-HF and imatinib mesylate resulted in significant apoptotic cell death in imatinib mesylate-resistant leukemia cells. Combined treatment resulted in apparent activation of caspases and decrease of the oncoprotein phosphor-Bcr/Abl in leukemia cells. Our results suggest that this combined treatment is beneficial in imatinib mesylate-resistant chronic myelogenous leukemia. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. CD117 expression on blast cells in acute myeloid leukemia

    Directory of Open Access Journals (Sweden)

    Goryainova N.V.

    2015-09-01

    Full Text Available The aim of the present work was to analyze the frequency of CD117 (c-KIT antigen expression on the blast cells in acute myeloid leukemia (AML, evaluation of the presence of the relationship between the expression of the c-KIT and leukemia according to the FAB classification and definition of co-expression of the antigen CD117, antigens CD33 and CD34. The data of 47 patients with AML were diagnosed. M0 AML variant was established in 3 (6% patients, M1 – in 2 (4%, M2 – in 9 (20%, M4 – in 22 (47% and M5 – in 11 (23%. For immunophenotypic stu¬dies monoclonal antibodies (mAb that detect antigens of anti-CD34, anti-CD33 and anti-CD117 (Becton Dickinson, USA were used. The presence of the antigen CD117 was detected in 39 people, accounting for 83% of all surveyed. Antigen c-KIT was present in 48.117.0% cells on average: in all 3 cases – AML M0, in2 cases of AML M1, in 6 cases – AML M2, 20 of 22 cases – AML M4 and in 8 of 11 AML M5 cases. Average levels of CD117 in investigated leukemia cases statistically differed significantly (p=0.0067. Among 39 CD117- positive patients in 25 (53% co-expression of CD117+/CD34+ was revealed. Expression of CD117+/CD34- was observed in 14 cases (30%, CD117-/CD34+ – in 4 cases (8,5%, CD117-/CD34- – in 4 cases (8.5%. CD34 had of 64% of cells of myeloid origin. A high positive cor¬relation between expression of CD117 and CD34 (r=+0,5169 was determined, being statistically significant (p0,0067.

  19. Targeted Elimination of Leukemia Stem Cells; a New Therapeutic Approach in Hemato-Oncology

    NARCIS (Netherlands)

    ten Cate, B.; de Bruyn, M.; Wei, Y.; Bremer, E.; Helfrich, W.

    Despite recent advances, treatment of leukemia is often not curative. New insights indicate that this may be attributable to a small population of therapy-resistant malignant cells with self-renewal capacity and the ability to generate large numbers of more differentiated leukemia cells. These

  20. Protothecosis in a patient with T cell lymphocytic leukemia.

    Science.gov (United States)

    Fernández, Mariana S; Rojas, Florencia D; Cattana, María E; Mussin, Javier E; de Los Ángeles Sosa, María; Benzoni, Carlos D; Giusiano, Gustavo E

    Human protothecosis is a rare infection caused by algae of the genus Prototheca. Prototheca wickerhamii has been recognized as the main species that causes infection in immunocompromised hosts with deficits in innate or cellular immunity. We report a case of persisting subcutaneous protothecosis in a patient with T-cell large granular lymphocyte leukemia, who also presented a history of disseminated histoplasmosis. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Current status of haploidentical stem cell transplantation for leukemia

    Directory of Open Access Journals (Sweden)

    Huang Xiao-jun

    2008-12-01

    Full Text Available Abstract Haploidentical hematopoietic stem cell transplantation has made tremendous progress over the past 20 years and has become a feasible option for leukemia patients without a HLA identical sibling donor. The early complications of severe graft-versus-host disease (GVHD, graft failure and delayed engraftment, as well as disease recurrence have limited the use of this approach. Newer strategies have been applied and overcome some of the problems, including the use of T-cell depleted graft, "mega" dose of stem cells, intensive post-transplant immunosuppression and manipulation of the graft. These have decreased the transplant related mortality and GVHD associated with haploidentical transplantation, however, the major problems of disease relapse and infection, which related to late immune reconstitution, limit the development of haploidentical HSCT. Future challenges remain in improving post-transplant immune reconstitution and finding the best approach to reduce the incidence and severity of GVHD, while preserving graft-versus-leukemia effect to prevent the recurrence of underlying malignancy.

  2. Pathogenesis of Metastatic Calcification and Acute Pancreatitis in Adult T-Cell Leukemia under Hypercalcemic State

    Directory of Open Access Journals (Sweden)

    Masachika Senba

    2012-01-01

    Full Text Available Human T-cell leukemia virus type-1 (HTLV-1 is the causative agent of adult T-cell leukemia (ATL. Hypercalcemia is common in patients with ATL. These patients rarely develop metastatic calcification and acute pancreatitis. The underlying pathogenesis of this condition is osteoclast hyperactivity with associated overproduction of parathyroid hormone-related protein, which results in hypercalcemia in association with bone demineralization. The discovery of the osteoclast differentiation factor receptor activator of nuclear factor-κB ligand (RANKL, its receptor RANK, and its decoy receptor osteoprotegerin (OPG, enhanced our understanding of the mechanisms of ATL-associated hypercalcemia. Macrophage inflammatory protein-1-α, tumor necrosis factor-α, interleukin-1, and interleukin-6 are important molecules that enhance the migration and differentiation of osteoclasts and the associated enhanced production of RANKL for osteoblast formation. In this paper, we focus on metastatic calcification and acute pancreatitis in ATL, highlighting recent advances in the understanding of the molecular role of the RANKL/RANK/OPG system including its interaction with various cytokines and calciotropic hormones in the regulation of osteoclastogenesis for bone resorption in hypercalcemic ATL patients.

  3. The nucleocapsid domain is responsible for the ability of spleen necrosis virus (SNV) Gag polyprotein to package both SNV and murine leukemia virus RNA.

    Science.gov (United States)

    Certo, J L; Kabdulov, T O; Paulson, M L; Anderson, J A; Hu, W S

    1999-11-01

    Murine leukemia virus (MLV)-based vector RNA can be packaged and propagated by the proteins of spleen necrosis virus (SNV). We recently demonstrated that MLV proteins cannot support the replication of an SNV-based vector; RNA analysis revealed that MLV proteins cannot efficiently package SNV-based vector RNA. The domain in Gag responsible for the specificity of RNA packaging was identified using chimeric gag-pol expression constructs. A competitive packaging system was established by generating a cell line that expresses one viral vector RNA containing the MLV packaging signal (Psi) and another viral vector RNA containing the SNV packaging signal (E). The chimeric gag-pol expression constructs were introduced into the cells, and vector titers as well as the efficiency of RNA packaging were examined. Our data confirm that Gag is solely responsible for the selection of viral RNAs. Furthermore, the nucleocapsid (NC) domain in the SNV Gag is responsible for its ability to interact with both SNV E and MLV Psi. Replacement of the SNV NC with the MLV NC generated a chimeric Gag that could not package SNV RNA but retained its ability to package MLV RNA. A construct expressing SNV gag-MLV pol supported the replication of both MLV and SNV vectors, indicating that the gag and pol gene products from two different viruses can functionally cooperate to perform one cycle of retroviral replication. Viral titer data indicated that SNV cis-acting elements are not ideal substrates for MLV pol gene products since infectious viruses were generated at a lower efficiency. These results indicate that the nonreciprocal recognition between SNV and MLV extends beyond the Gag-RNA interaction and also includes interactions between Pol and other cis-acting elements.

  4. High-resolution Antibody Array Analysis of Childhood Acute Leukemia Cells

    Czech Academy of Sciences Publication Activity Database

    Kanderová, V.; Kuzilkova, D.; Stuchlý, J.; Vašková, M.; Brdička, Tomáš; Fišer, K.; Hrušák, O.; Lund-Johansen, F.; Kalina, T.

    2016-01-01

    Roč. 15, č. 4 (2016), s. 1246-1261 ISSN 1535-9476 R&D Projects: GA MŠk 2B06064 Institutional support: RVO:68378050 Keywords : acute lymphoblastic-leukemia * acute promyelocytic leukemia * cytometric immunobead assay * caspase-dependent cleavage * acute myeloid-leukemia * gene-expression * fusion proteins * flow-cytometry * pcr data * b-cells Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.540, year: 2016

  5. Paraptosis cell death induction by the thiamine analog benfotiamine in leukemia cells.

    Directory of Open Access Journals (Sweden)

    Naomi Sugimori

    Full Text Available Benfotiamine is a synthetic thiamine analogue that stimulates transketolase, a cellular enzyme essential for glucose metabolism. Currently, benfotiamine is used to treat diabetic neuropathy. We recently reported that oral benfotiamine induced a temporary but remarkable recovery from acute myeloid leukemia in an elderly patient who was ineligible for standard chemotherapy due to dementia and renal failure. In the present study we present evidences that benfotiamine possess antitumor activity against leukemia cells. In a panel of nine myeloid leukemia cell lines benfotiamine impaired the viability of HL-60, NB4, K562 and KG1 cells and also inhibited the growing of primary leukemic blasts. The antitumor activity of benfotiamine is not mediated by apoptosis, necrosis or autophagy, but rather occurs though paraptosis cell death induction. Mechanistic studies revealed that benfotiamine inhibited the activity of constitutively active ERK1/2 and concomitantly increased the phosphorylation of JNK1/2 kinase in leukemic cells. In addition, benfotiamine induced the down regulation of the cell cycle regulator CDK3 which resulted in G1 cell cycle arrest in the sensitive leukemic cells. Moreover, combination index studies showed that benfotiamine enhanced the antiproliferative activities of cytarabine against leukemia cells. These findings suggest that benfotiamine has antitumor therapeutic potential.

  6. Epstein–Barr Virus MicroRNAs are Expressed in Patients with Chronic Lymphocytic Leukemia and Correlate with Overall Survival

    Directory of Open Access Journals (Sweden)

    Alessandra Ferrajoli

    2015-06-01

    Full Text Available Although numerous studies highlighted the role of Epstein–Barr Virus (EBV in B-cell transformation, the involvement of EBV proteins or genome in the development of the most frequent adult leukemia, chronic lymphocytic leukemia (CLL, has not yet been defined. We hypothesized that EBV microRNAs contribute to progression of CLL and demonstrated the presence of EBV miRNAs in B-cells, in paraffin-embedded bone marrow biopsies and in the plasma of patients with CLL by using three different methods (small RNA-sequencing, quantitative reverse transcription PCR [q-RT-PCR] and miRNAs in situ hybridization [miRNA-ISH]. We found that EBV miRNA BHRF1-1 expression levels were significantly higher in the plasma of patients with CLL compared with healthy individuals (p < 0 · 0001. Notably, BHRF1-1 as well as BART4 expression were detected in the plasma of either seronegative or seropositive (anti-EBNA-1 IgG and EBV DNA tested patients; similarly, miRNA-ISH stained positive in bone marrow specimens while LMP1 and EBER immunohistochemistry failed to detect viral proteins and RNA. We also found that BHRF1-1 plasma expression levels were positively associated with elevated beta-2-microglobulin levels and advanced Rai stages and observed a correlation between higher BHRF1-1 expression levels and shorter survival in two independent patients' cohorts. Furthermore, in the majority of CLL cases where BHRF1-1 was exogenously induced in primary malignant B cells the levels of TP53 were reduced. Our findings suggest that EBV may have a role in the process of disease progression in CLL and that miRNA RT-PCR and miRNAs ISH could represent additional methods to detect EBV miRNAs in patients with CLL.

  7. Diagnostic problems among chronic lymphocytic leukemia and other indolent B-cell leukemias in a Japanese population.

    Science.gov (United States)

    Isobe, Yasushi; Tomomatsu, Junichi; Tsukune, Yutaka; Tsukada, Nobuhiro; Sasaki, Makoto; Sugimoto, Koichi; Komatsu, Norio

    2012-01-01

    Japanese chronic lymphocytic leukemia (CLL) provides a diagnostic dilemma due to the low incidence and the heterogeneity shown in its morphology and immunophenotype. We clarified the diagnostic problems in Japanese CLL through our retrospective observation. Between 2006 and 2011, we found a total of 48 cases with CLL and other indolent B-cell leukemias. We made a diagnosis of true CLL based on clinical, laboratory, immunophenotypic and cytogenetic data. Among the 48 cases, only 28 cases (58.3%) were diagnosed with true CLL. Morphologic evaluation using a forced-air dried preparation alone is not helpful to distinguish CLL from other indolent B-cell leukemias, including hairy cell leukemia, mantle cell lymphoma, lymphoplasmacytic lymphoma, and splenic marginal zone lymphoma. CLL immunophenotypic score should be more strictly applied in Japan than in Western countries. Fluorescence in situ hybridization for CCND1/IGH, the presence of leukocytosis and lymphadenopathy at diagnosis, and the morphological evaluation using naturally air dried preparations are important clues to make a correct diagnosis of Japanese CLL.

  8. Liver and spleen MRI findings in virus-associated hemophagocytic syndrome in a patient with acute lymphocytic leukemia

    International Nuclear Information System (INIS)

    Zilkha, A.; Madan, V.; Leonidas, J.C.; Valderrama, E.

    1998-01-01

    Virus-associated hemophagocytic syndrome is characterized by the phagocytosis of erthythrocytes and other blood elements in multiple organ systems, especially the liver and spleen. Magnetic resonance imaging (MRI) can suggest this diagnosis in the proper clinical setting by demonstrating multiple, rounded signal voids in the spleen corresponding to hemosiderin deposition. We report a patient with virus-associated hemophagocytic syndrome during the course of acute lymphocytic leukemia and MRI findings that suggested the preoperative diagnosis. (orig.)

  9. Liver and spleen MRI findings in virus-associated hemophagocytic syndrome in a patient with acute lymphocytic leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Zilkha, A.; Madan, V.; Leonidas, J.C. [Division of Pediatric Radiology, Island Jewish Medical Center, New Hyde Park, NY (United States); Valderrama, E. [Department of Pathology, Long Island Jewish Medical Center, New Hyde Park, NY (United States)

    1998-12-01

    Virus-associated hemophagocytic syndrome is characterized by the phagocytosis of erthythrocytes and other blood elements in multiple organ systems, especially the liver and spleen. Magnetic resonance imaging (MRI) can suggest this diagnosis in the proper clinical setting by demonstrating multiple, rounded signal voids in the spleen corresponding to hemosiderin deposition. We report a patient with virus-associated hemophagocytic syndrome during the course of acute lymphocytic leukemia and MRI findings that suggested the preoperative diagnosis. (orig.) With 1 fig., 4 refs.

  10. Docosahexaenoic acid induces apoptosis in primary chronic lymphocytic leukemia cells

    Directory of Open Access Journals (Sweden)

    Romain Guièze

    2015-12-01

    Full Text Available Chronic lymphocytic leukemia is an indolent disorder with an increased infectious risk remaining one of the main causes of death. Development of therapies with higher safety profile is thus a challenging issue. Docosahexaenoic acid (DHA, 22:6 is an omega-3 fatty acid, a natural compound of normal cells, and has been shown to display antitumor potency in cancer. We evaluated the potential in vitro effect of DHA in primary CLL cells. DHA induces high level of in vitro apoptosis compared to oleic acid in a dose-dependent and time-dependent manner. Estimation of IC50 was only of 4.813 μM, which appears lower than those reported in solid cancers. DHA is highly active on CLL cells in vitro. This observation provides a rationale for further studies aiming to understand its mechanisms of action and its potent in vivo activity.

  11. REGULATORY T-CELLS IN CHRONIC LYMPHOCYTIC LEUKEMIA

    Directory of Open Access Journals (Sweden)

    Giovanni D'arena

    2012-08-01

    Full Text Available Regulatory T-cells (Tregs constitute a small subset of cells that are actively involved in maintaining self-tolerance, in immune homeostasis and in antitumor immunity. They are thought to play a significant role in the progression of cancer and are generally increased in patient with chronic lymphocytic leukemia (CLL. Their number correlates with more aggressive disease status and is predictive of the time to treatment, as well. Moreover, it is now clear that dysregulation in Tregs cell frequency and/or function may result in a plethora of autoimmune diseases, including multiple sclerosis, type 1 diabetes mellitus, myasthenia gravis, systemic lupus erythematosis, autoimmune lymphoproliferative disorders, rheumatoid arthritis, and psoriasis. Efforts are made aiming to develop approaches to deplete Tregs or inhibit their function in either cancer and autoimmune disorders.

  12. Plasma cell leukemia: update on biology and therapy.

    Science.gov (United States)

    Mina, Roberto; D'Agostino, Mattia; Cerrato, Chiara; Gay, Francesca; Palumbo, Antonio

    2017-07-01

    Plasma cell leukemia (PCL) is a rare, but very aggressive, plasma cell dyscrasia, representing a distinct clinicopathological entity as compared to multiple myeloma (MM), with peculiar biological and clinical features. A hundred times rarer than MM, the disease course is characterized by short remissions and poor survival. PCL is defined by an increased percentage (>20%) and absolute number (>2 × 10 9 /l) of plasma cells in the peripheral blood. PCL is defined as 'primary' when peripheral plasmacytosis is detected at diagnosis, 'secondary' when leukemization occurs in a patient with preexisting MM. Novel agents have revolutionized the outcomes of MM patients and have been introduced also for the treatment of PCL. Here, we provide an update on biology and treatment options for PCL.

  13. Expression of HER2/Neu in B-Cell Acute Lymphoblastic Leukemia.

    Science.gov (United States)

    Rodriguez-Rodriguez, Sergio; Pomerantz, Alan; Demichelis-Gomez, Roberta; Barrera-Lumbreras, Georgina; Barrales-Benitez, Olga; Aguayo-Gonzalez, Alvaro

    2016-01-01

    The expression of HER2/neu in B-cell acute lymphoblastic leukemia has been reported in previous studies. The objective of this research was to study the expression of HER2/neu on the blasts of patients with acute leukemia from the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran. From June 2015 to February 2016, a HER2/neu monoclonal antibody was added to the panel of antibodies that we routinely use in patients with acute leukemia. An expression of ≥ 30% was considered positive. We studied 33 patients: 19 had de novo leukemia (57.6%), three (9.1%) were in relapse, and in 11 (33.3%) their status could not be specified. Seventeen patients (51.5%) were classified as B-cell acute lymphoblastic leukemia with a median expression of HER2/neu of 0.3% (range 0-90.2). Three patients with B-cell acute lymphoblastic leukemia were positive for HER2/neu: 89.4%, 90.9%, and 62.4%. The first and third patient had de novo B-cell acute lymphoblastic leukemia. The second patient was in second relapse after allogeneic stem cell transplant. All three patients were categorized as high-risk at the time of diagnosis. In the studied Mexican population, we found a positive expression of HER2/neu in 17% of the B-cell acute lymphoblastic leukemia patients, similar to previous studies in which the expression was found in 15-50%.

  14. Targeting of the BLT2 in chronic myeloid leukemia inhibits leukemia stem/progenitor cell function

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Meifang; Ai, Hongmei; Li, Tao [Department of Laboratory Medicine, JingZhou Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Jingzhou (China); Rajoria, Pasupati; Shahu, Prakash [Department of Clinical Medicine, Medical School of Yangtze University, Jingzhou (China); Li, Xiansong, E-mail: lixiansongjz@hotmail.com [Department of Neurosurgery, JingZhou Hospital, Tongji Medical College, Huazhong University of Science and Technology (HUST), Jingzhou (China)

    2016-04-15

    Imatinib, a tyrosine kinase inhibitor (TKI) has significantly improved clinical outcome for chronic myeloid leukemia (CML) patients. However, patients develop resistance when the disease progresses to the blast phase (BP) and the mechanisms are not well understood. Here we show that BCR-ABL activates BLT2 in hematopoietic stem/progenitor cells to promote leukemogenesis and this involves the p53 signaling pathway. Compared to normal bone marrow (NBM), the mRNA and protein levels of BLT2 are significantly increased in BP-CML CD34{sup +} stem/progenitor cells. This is correlated with increasing BCR-ABL expression. In contrast, knockdown of BCR-ABL or inhibition of its tyrosine kinase activity decreases Blt2 protein level. BLT2 inhibition induces apoptosis, inhibits proliferation, colony formation and self-renewal capacity of CD34{sup +} cells from TKI-resistant BP-CML patients. Importantly, the inhibitory effects of BCR-ABL TKI on CML stem/progenitor cells are further enhanced upon combination with BLT2 inhibition. We further show that BLT2 activation selectively suppresses p53 but not Wnt or BMP-mediated luciferase activity and transcription. Our results demonstrate that BLT2 is a novel pathway activated by BCR-ABL and critically involved in the resistance of BP-CML CD34{sup +} stem/progenitors to TKIs treatment. Our findings suggest that BLT2 and p53 can serve as therapeutic targets for CML treatment. - Highlights: • BCR-ABL regulates BLT2 expression to promote leukemogenesis. • BLT2 is essential to maintain CML cell function. • Activation of BLT2 suppresses p53 signaling pathway in CML cells. • Inhibition of BLT2 and BCR-ABL synergize in eliminating CML CD34{sup +} stem/progenitors.

  15. Targeting of the BLT2 in chronic myeloid leukemia inhibits leukemia stem/progenitor cell function

    International Nuclear Information System (INIS)

    Xiao, Meifang; Ai, Hongmei; Li, Tao; Rajoria, Pasupati; Shahu, Prakash; Li, Xiansong

    2016-01-01

    Imatinib, a tyrosine kinase inhibitor (TKI) has significantly improved clinical outcome for chronic myeloid leukemia (CML) patients. However, patients develop resistance when the disease progresses to the blast phase (BP) and the mechanisms are not well understood. Here we show that BCR-ABL activates BLT2 in hematopoietic stem/progenitor cells to promote leukemogenesis and this involves the p53 signaling pathway. Compared to normal bone marrow (NBM), the mRNA and protein levels of BLT2 are significantly increased in BP-CML CD34 + stem/progenitor cells. This is correlated with increasing BCR-ABL expression. In contrast, knockdown of BCR-ABL or inhibition of its tyrosine kinase activity decreases Blt2 protein level. BLT2 inhibition induces apoptosis, inhibits proliferation, colony formation and self-renewal capacity of CD34 + cells from TKI-resistant BP-CML patients. Importantly, the inhibitory effects of BCR-ABL TKI on CML stem/progenitor cells are further enhanced upon combination with BLT2 inhibition. We further show that BLT2 activation selectively suppresses p53 but not Wnt or BMP-mediated luciferase activity and transcription. Our results demonstrate that BLT2 is a novel pathway activated by BCR-ABL and critically involved in the resistance of BP-CML CD34 + stem/progenitors to TKIs treatment. Our findings suggest that BLT2 and p53 can serve as therapeutic targets for CML treatment. - Highlights: • BCR-ABL regulates BLT2 expression to promote leukemogenesis. • BLT2 is essential to maintain CML cell function. • Activation of BLT2 suppresses p53 signaling pathway in CML cells. • Inhibition of BLT2 and BCR-ABL synergize in eliminating CML CD34 + stem/progenitors.

  16. Activation of the PI3K-Akt pathway by human T cell leukemia virus type 1 (HTLV-1) oncoprotein Tax increases Bcl3 expression, which is associated with enhanced growth of HTLV-1-infected T cells

    International Nuclear Information System (INIS)

    Saito, Kousuke; Saito, Mineki; Taniura, Naoko; Okuwa, Takako; Ohara, Yoshiro

    2010-01-01

    Bcl3 is a member of the IκB family that regulates genes involved in cell proliferation and apoptosis. Recent reports indicated that Bcl3 is overexpressed in HTLV-1-infected T cells via Tax-mediated transactivation, and acts as a negative regulator of viral transcription. However, the role of Bcl3 in cellular signal transduction and the growth of HTLV-1-infected T cells have not been reported. In this study, we showed that the knockdown of Bcl3 by short hairpin RNA inhibited the growth of HTLV-1-infected T cells. Although phosphatidylinositol-3 kinase (PI3K) inhibitor reduced Bcl3 expression, inactivation of glycogen synthase kinase 3 (GSK3), an effector kinase of the PI3K/Akt signaling pathway, restored Bcl3 expression in Tax-negative but not in Tax-positive T cells. Our results indicate that the overexpression of Bcl3 in HTLV-1-infected T cells is regulated not only by transcriptional but also by post-transcriptional mechanisms, and is involved in overgrowth of HTLV-1-infected T cells.

  17. Activated allogeneic NK cells preferentially kill poor prognosis B-cell chronic lymphocytic leukemia cells

    Directory of Open Access Journals (Sweden)

    Diego Sanchez-Martinez

    2016-10-01

    Full Text Available Mutational status of TP53 together with expression of wild type (wt IGHV represents the most widely accepted biomarkers, establishing a very poor prognosis in B-cell chronic lymphocytic leukemia (B-CLL patients. Adoptive cell therapy using allogeneic HLA mismatched Natural Killer (NK cells has emerged as an effective and safe alternative in the treatment of acute myeloid and lymphoid leukemias that do not respond to traditional therapies. We have described that allogeneic activated NK cells eliminate hematological cancer cell lines with multidrug resistance acquired by mutations in the apoptotic machinery. This effect depends on the activation protocol, being B-lymphoblastoid cell lines (LCLs the most effective stimulus to activate NK cells. Here we have further analyzed the molecular determinants involved in allogeneic NK cell recognition and elimination of B-CLL cells, including the expression of ligands of the main NK cell activating receptors (NKG2D and NCRs and HLA mismatch. We present preliminary data suggesting that B-CLL susceptibility significantly correlates with HLA mismatch between NK cell donor and B-CLL patient. Moreover, we show that the sensitivity of B-CLL cells to NK cells depends on the prognosis based on TP53 and IGHV mutational status. Cells from patients with worse prognosis (mutated TP53 and wt IGHV are the most susceptible to activated NK cells. Hence, B-CLL prognosis may predict the efficacy of allogenic activated NK cells and, thus, NK cell transfer represents a good alternative to treat poor prognosis B-CLL patients who present a very short life expectancy due to lack of effective treatments.□

  18. The Nucleocapsid Domain Is Responsible for the Ability of Spleen Necrosis Virus (SNV) Gag Polyprotein To Package both SNV and Murine Leukemia Virus RNA

    OpenAIRE

    Certo, Jeanine L.; Kabdulov, Timur O.; Paulson, Michelle L.; Anderson, Jeffrey A.; Hu, Wei-Shau

    1999-01-01

    Murine leukemia virus (MLV)-based vector RNA can be packaged and propagated by the proteins of spleen necrosis virus (SNV). We recently demonstrated that MLV proteins cannot support the replication of an SNV-based vector; RNA analysis revealed that MLV proteins cannot efficiently package SNV-based vector RNA. The domain in Gag responsible for the specificity of RNA packaging was identified using chimeric gag-pol expression constructs. A competitive packaging system was established by generati...

  19. Establishment of cell lines from adult T-cell leukemia cells dependent on negatively charged polymers.

    Science.gov (United States)

    Kagami, Yoshitoyo; Uchiyama, Susumu; Kato, Harumi; Okada, Yasutaka; Seto, Masao; Kinoshita, Tomohiro

    2017-07-05

    Growing adult T-cell leukemia/lymphoma (ATLL) cells in vitro is difficult. Here, we examined the effects of static electricity in the culture medium on the proliferation of ATLL cells. Six out of 10 ATLL cells did not proliferate in vitro and thus had to be cultured in a medium containing negatively charged polymers. In the presence of poly-γ-glutamic acid (PGA) or chondroitin sulfate (CDR), cell lines (HKOX3-PGA, HKOX3-CDR) were established from the same single ATLL case using interleukin (IL)-2, IL-4, and feeder cells expressing OX40L (OX40L + HK). Dextran sulfate inhibited growth in both HKOX3 cell lines. Both PGA and OX40L + HK were indispensable for HKOX3-PGA growth, but HKOX3-CDR could proliferate in the presence of CDR or OX40L + HK alone. Thus, the specific action of each negatively charged polymer promoted the growth of specific ATLL cells in vitro.

  20. Prognostic significance of cell surface phenotype in acute lymphoblastic leukemia

    Directory of Open Access Journals (Sweden)

    Shiek Aejaz Aziz

    2015-01-01

    Full Text Available Context: To find out the phenotypic character of lymphoblasts of acute lymphoblastic leukemia (ALL patients in our study cohort and their possible effect on the prognosis. Aims: To investigate the phenotype in ALL in our demographic population and to prognosticate various upfront current protocols employed in our hospital. Settings and Design: The study spanned over a period of 4 years with retrospective and prospective data of January 2008 through December 2011. Materials and Methods: 159 patients of all age groups were enrolled for the study, of which flow cytometry was done in 144 patients. Statistical Analysis Used: Analysis was done using the variables on SPSS (statistical package for social sciences software on computer. Survival curves were estimated by method of Kaplan-Meir. Results: Majority of the patients were of B-cell (68.1% and 30.6% patients were of T-cell lineage. Of these, 80.6% patients were having cALLa positivity. Complete remission (CR was achieved in 59.1%, 16.4% relapsed, and 20.1% patients died. Conclusions: Phenotyping has become an important and integral part of diagnosis, classification, management and prognosticating in ALL. B-cell has been found to have a better survival over T-cell lymphoblastic leukemia. cALLa antigen positivity has good impact in achieving CR in only B-cell lineage, myeloid coexpression has no significant effect on the outcome. BFM (Berlin-Frankfurt-Münster based protocols though showed a higher CR and survival vis-a-vis UKALL-XII. However, patients enrolled in former group being of low risk category and lesser in numbers cannot be compared statistically with a fair degree of confidence.

  1. Aberrant Expression of Functional BAFF-System Receptors by Malignant B-Cell Precursors Impacts Leukemia Cell Survival

    Science.gov (United States)

    Maia, Sara; Pelletier, Marc; Ding, Jixin; Hsu, Yen-Ming; Sallan, Stephen E.; Rao, Sambasiva P.; Nadler, Lee M.; Cardoso, Angelo A.

    2011-01-01

    Despite exhibiting oncogenic events, patient's leukemia cells are responsive and dependent on signals from their malignant bone marrow (BM) microenvironment, which modulate their survival, cell cycle progression, trafficking and resistance to chemotherapy. Identification of the signaling pathways mediating this leukemia/microenvironment interplay is critical for the development of novel molecular targeted therapies. We observed that primary leukemia B-cell precursors aberrantly express receptors of the BAFF-system, BAFF-R, BCMA, and TACI. These receptors are functional as their ligation triggers activation of NF-κB, MAPK/JNK, and Akt signaling. Leukemia cells express surface BAFF and APRIL ligands, and soluble BAFF is significantly higher in leukemia patients in comparison to age-matched controls. Interestingly, leukemia cells also express surface APRIL, which seems to be encoded by APRIL-δ, a novel isoform that lacks the furin convertase domain. Importantly, we observed BM microenvironmental cells express the ligands BAFF and APRIL, including surface and secreted BAFF by BM endothelial cells. Functional studies showed that signals through BAFF-system receptors impact the survival and basal proliferation of leukemia B-cell precursors, and support the involvement of both homotypic and heterotypic mechanisms. This study shows an unforeseen role for the BAFF-system in the biology of precursor B-cell leukemia, and suggests that the target disruption of BAFF signals may constitute a valid strategy for the treatment of this cancer. PMID:21687682

  2. Aberrant expression of functional BAFF-system receptors by malignant B-cell precursors impacts leukemia cell survival.

    Directory of Open Access Journals (Sweden)

    Sara Maia

    Full Text Available Despite exhibiting oncogenic events, patient's leukemia cells are responsive and dependent on signals from their malignant bone marrow (BM microenvironment, which modulate their survival, cell cycle progression, trafficking and resistance to chemotherapy. Identification of the signaling pathways mediating this leukemia/microenvironment interplay is critical for the development of novel molecular targeted therapies.We observed that primary leukemia B-cell precursors aberrantly express receptors of the BAFF-system, BAFF-R, BCMA, and TACI. These receptors are functional as their ligation triggers activation of NF-κB, MAPK/JNK, and Akt signaling. Leukemia cells express surface BAFF and APRIL ligands, and soluble BAFF is significantly higher in leukemia patients in comparison to age-matched controls. Interestingly, leukemia cells also express surface APRIL, which seems to be encoded by APRIL-δ, a novel isoform that lacks the furin convertase domain. Importantly, we observed BM microenvironmental cells express the ligands BAFF and APRIL, including surface and secreted BAFF by BM endothelial cells. Functional studies showed that signals through BAFF-system receptors impact the survival and basal proliferation of leukemia B-cell precursors, and support the involvement of both homotypic and heterotypic mechanisms.This study shows an unforeseen role for the BAFF-system in the biology of precursor B-cell leukemia, and suggests that the target disruption of BAFF signals may constitute a valid strategy for the treatment of this cancer.

  3. Evaluation of rapid diagnostic test kits for feline leukemia virus infection using samples from naturally infected cats

    Directory of Open Access Journals (Sweden)

    Jiayou Liu

    2016-09-01

    Full Text Available Objectives Feline leukemia virus (FeLV is a potentially life-threatening oncogenic retrovirus. The p27 viral core protein is produced by the virus in infected feline cells, is found in the cytoplasm in several blood cells and can be free in the serum and plasma. ELISA or particle-based immunoassay are commonly used to detect the presence of the p27 core protein in samples obtained from blood. The objective of this study was to compare the performance of several in-clinic tests: the SNAP Feline Triple Test (IDEXX Laboratories, the WITNESS FeLV-FIV Test (Zoetis and the VetScan Feline FeLV/FIV Rapid Test (Abaxis. Methods The sample population (100 positive, 105 negative samples consisted of serum and plasma samples submitted to IDEXX’s worldwide reference laboratory for feline retrovirus testing. Virus isolation and reverse transcriptase PCR results were not available and so samples were judged to be positive or negative based on the results of the ViraCHEK FeLV (Zoetis microtiter plate assay. Results The percentage of samples positive and negative for FeLV p27 antigen using the three in-clinic tests compared with the ViraCHEK method were as follows: IDEXX Feline Triple (positive 98.0%, negative 100%; Zoetis WITNESS (positive 79.0%, negative 97.1%; Abaxis VetScan (positive 73.0%, negative 97.1%. Conclusions and relevance The SNAP Feline Triple Test demonstrated a high level of agreement for FeLV-positive and FeLV-negative samples when assessed in this model. Results of FeLV assays can vary among tests.

  4. Infection of CD4+ T lymphocytes by the human T cell leukemia virus type 1 is mediated by the glucose transporter GLUT-1: Evidence using antibodies specific to the receptor's large extracellular domain

    International Nuclear Information System (INIS)

    Jin, Qingwen; Agrawal, Lokesh; VanHorn-Ali, Zainab; Alkhatib, Ghalib

    2006-01-01

    To analyze HTLV-1 cytotropism, we developed a highly sensitive vaccinia virus-based assay measuring activation of a reporter gene upon fusion of two distinct cell populations. We used this system in a functional cDNA screening to isolate and confirm that the glucose transporter protein 1 (GLUT-1) is a receptor for HTLV-1. GLUT-1 is a ubiquitously expressed plasma membrane glycoprotein with 12 transmembrane domains and 6 extracellular loops (ECL). We demonstrate for the first time that peptide antibodies (GLUT-IgY) raised in chicken to the large extracellular loop (ECL1) detect GLUT-1 at the cell surface and inhibit envelope (Env)-mediated fusion and infection. Efficient GLUT-IgY staining was detected with peripheral blood CD4 + lymphocytes purified by positive selection. Further, GLUT-IgY caused efficient inhibition of Env-mediated fusion and infection of CD4 + T and significantly lower inhibition of CD8 + T lymphocytes. The specificity of GLUT-IgY antibodies to GLUT-1 was demonstrated by ECL1 peptide competition studies. Grafting ECL1 of GLUT-1 onto the receptor-negative GLUT-3 conferred significant receptor activity. In contrast, grafting ECL1 of GLUT-3 onto GLUT-1 resulted in a significant loss of the receptor activity. The ECL1-mediated receptor activity was efficiently blocked with four different human monoclonal antibody (HMab) to HTLV-1 Env. The ECL1-derived peptide blocked HTLV-1 Env-mediated fusion with several nonhuman mammalian cell lines. The results demonstrate the utilization of cell surface GLUT-1 in HTLV-1 infection of CD4 + T lymphocytes and implicate a critical role for the ECL1 region in viral tropism

  5. CD19/CD22 Chimeric Antigen Receptor T Cells and Chemotherapy in Treating Patients With Recurrent or Refractory CD19 Positive Diffuse Large B-Cell Lymphoma or B Acute Lymphoblastic Leukemia

    Science.gov (United States)

    2018-01-25

    B Acute Lymphoblastic Leukemia; CD19 Positive; Diffuse Large B-Cell Lymphoma Associated With Chronic Inflammation; Diffuse Large B-Cell Lymphoma, Not Otherwise Specified; Epstein-Barr Virus Positive Diffuse Large B-Cell Lymphoma of the Elderly; Minimal Residual Disease; Philadelphia Chromosome Positive; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma; T-Cell/Histiocyte-Rich Large B-Cell Lymphoma

  6. Red cell ferritin and iron stores in chronic granulocytic leukemia

    International Nuclear Information System (INIS)

    Cermak, J.; Neuwirth, J.; Voglova, J.; Brabec, V.; Chrobak, L.

    1994-01-01

    Basic red cell ferritin was investigated in 28 patients with different phases of chronic granulocytic leukemia (GCL). Red cell ferritin was significantly decreased in remission after busulphan treatment and significantly elevated in the blast crisis as compared to healthy controls. Bone marrow stainable iron was decreased or absent in 86% of patients in the initial phase at the time of diagnosis and in 92% of those in remission. Red cell ferritin correlated with serum ferritin, however, serum ferritin level remained above normal range during all phases of the disease. A negative correlation between red cell ferritin and hemoglobin (Hb) (r = -0.605, p < 0.001) suggested that red cell ferritin level reflected the rate of iron utilization for heme synthesis. Decrease red cell iron observed in the remission may be explained by regression of dyserythropoiesis and by restoration of normal Hb synthesis after busulphan treatment. A progressive dyserythropoiesis in the blast crisis may lead to an increased red cell ferritin level. (author)

  7. Defective immunoregulatory T-cell function in chronic lymphocytic leukemia

    International Nuclear Information System (INIS)

    Han, T.; Ozer, H.; Henderson, E.S.; Dadey, B.; Nussbaum-Blumenson, A.; Barcos, M.

    1981-01-01

    Chronic lymphocytic leukemia (CLL) of B-cell origin results in the malignant proliferation of small immunoglobulin-bearing lymphocytes. There is currently a controversy in the literature regarding both the ability of this leukemic population to differentiate into mature plasma cells, as well as the ability of apparently normal T cells from these patients to regulate allogeneic B-cell differentiation. In the present study we have examined the lymphocytes of CLL patients in various clinical stages of their disease and with different surface phenotypes of their leukemic B-cell population. Our results show that leukemic CLL B cells from all 20 patients (including one patient with a monoclonal IgM paraprotein and another with a monoclonal IgG paraprotein) are incapable of further differentiation even in the absence of suppressor T cells and the presence of helper T lymphocytes. This lack of capacity to differentiate is unaffected by clinical stage, by therapy, or by the phenotype of the malignant population. Since the leukemic B population did not suppress normal allogeneic B-cell differentiation, the maturation deficit is evidently intrinsic to the leukemic clone rather than a result of activity of non-T suppressor cells. T helper function was also variably depressed in the blood of some patients with CLL, and this depression did not correlate with clinical stage, with therapy, or with the degree of lymphocytosis. Dysfunction of radiosensitive T suppressor cells was found to be the most consistent regulatory deficit of CLL T cells. Each of 11 patients whose leukemic cell population was of the μdelta, μα, or μ phenotype had both helper and suppressor cell defects

  8. MLL leukemia induction by genome editing of human CD34+ hematopoietic cells

    Science.gov (United States)

    Buechele, Corina; Breese, Erin H.; Schneidawind, Dominik; Lin, Chiou-Hong; Jeong, Johan; Duque-Afonso, Jesus; Wong, Stephen H. K.; Smith, Kevin S.; Negrin, Robert S.; Porteus, Matthew

    2015-01-01

    Chromosomal rearrangements involving the mixed-lineage leukemia (MLL) gene occur in primary and treatment-related leukemias and confer a poor prognosis. Studies based primarily on mouse models have substantially advanced our understanding of MLL leukemia pathogenesis, but often use supraphysiological oncogene expression with uncertain implications for human leukemia. Genome editing using site-specific nucleases provides a powerful new technology for gene modification to potentially model human disease, however, this approach has not been used to re-create acute leukemia in human cells of origin comparable to disease observed in patients. We applied transcription activator-like effector nuclease–mediated genome editing to generate endogenous MLL-AF9 and MLL-ENL oncogenes through insertional mutagenesis in primary human hematopoietic stem and progenitor cells (HSPCs) derived from human umbilical cord blood. Engineered HSPCs displayed altered in vitro growth potentials and induced acute leukemias following transplantation in immunocompromised mice at a mean latency of 16 weeks. The leukemias displayed phenotypic and morphologic similarities with patient leukemia blasts including a subset with mixed phenotype, a distinctive feature seen in clinical disease. The leukemic blasts expressed an MLL-associated transcriptional program with elevated levels of crucial MLL target genes, displayed heightened sensitivity to DOT1L inhibition, and demonstrated increased oncogenic potential ex vivo and in secondary transplant assays. Thus, genome editing to create endogenous MLL oncogenes in primary human HSPCs faithfully models acute MLL-rearranged leukemia and provides an experimental platform for prospective studies of leukemia initiation and stem cell biology in a genetic subtype of poor prognosis leukemia. PMID:26311362

  9. Complete suppression of in vivo growth of human leukemia cells by specific immunotoxins: nude mouse models

    International Nuclear Information System (INIS)

    Hara, H.; Seon, B.K.

    1987-01-01

    In this study, immunotoxins containing monoclonal anti-human T-cell leukemia antibodies are shown to be capable of completely suppressing the tumor growth of human T-cell leukemia cells in vivo without any overt undersirable toxicity. These immunotoxins were prepared by conjugating ricin A chain (RA) with our monoclonal antibodies, SN1 and SN2, directed specifically to the human T-cell leukemia cell surface antigens TALLA and GP37, respectively. The authors have shown that these monoclonal antibodies are highly specific for human T-cell leukemia cells and do not react with various normal cells including normal T and B cells, thymocytes, and bone marrow cells. Ascitic and solid human T-cell leukemia cell tumors were generated in nude mice. The ascitic tumor was generated by transplanting Ichikawa cells (a human T-cell leukemia cell) i.p. into nude mice, whereas the solid tumor was generated by transplanting s.c. MOLT-4 cells (a human T-cell leukemia cell line) and x-irradiated human fibrosarcoma cells into x-irradiated nude mice. To investigate the efficacy of specific immunotoxins in suppression the in vivo growth of the ascitic tumor, they divided 40 nude mice that were injected with Ichikawa cells into four groups. None of the mice in group 4 that were treated with SN1-RA and SN2-RA showed any signs of a tumor or undesirable toxic effects for the 20 weeks that they were followed after the transplantation. Treatment with SN1-RA plus SN2-RA completely suppressed solid tumor growth in 4 of 10 nude mice carrying solid tumors and partially suppressed the tumor growth in the remaining 6 nude mice. These results strongly suggest that SN1-RA and SN2-RA may be useful for clinical treatment

  10. What You Need to Know about Leukemia

    Science.gov (United States)

    ... Publications Reports What You Need To Know About™ Leukemia This booklet is about leukemia. Leukemia is cancer of the blood and bone marrow ( ... This book covers: Basics about blood cells and leukemia Types of doctors who treat leukemia Treatments for ...

  11. Adaptive Immunity to Leukemia Is Inhibited by Cross-Reactive Induced Regulatory T Cells.

    Science.gov (United States)

    Manlove, Luke S; Berquam-Vrieze, Katherine E; Pauken, Kristen E; Williams, Richard T; Jenkins, Marc K; Farrar, Michael A

    2015-10-15

    BCR-ABL(+) acute lymphoblastic leukemia patients have transient responses to current therapies. However, the fusion of BCR to ABL generates a potential leukemia-specific Ag that could be a target for immunotherapy. We demonstrate that the immune system can limit BCR-ABL(+) leukemia progression although ultimately this immune response fails. To address how BCR-ABL(+) leukemia escapes immune surveillance, we developed a peptide: MHC class II tetramer that labels endogenous BCR-ABL-specific CD4(+) T cells. Naive mice harbored a small population of BCR-ABL-specific T cells that proliferated modestly upon immunization. The small number of naive BCR-ABL-specific T cells was due to negative selection in the thymus, which depleted BCR-ABL-specific T cells. Consistent with this observation, we saw that BCR-ABL-specific T cells were cross-reactive with an endogenous peptide derived from ABL. Despite this cross-reactivity, the remaining population of BCR-ABL reactive T cells proliferated upon immunization with the BCR-ABL fusion peptide and adjuvant. In response to BCR-ABL(+) leukemia, BCR-ABL-specific T cells proliferated and converted into regulatory T (Treg) cells, a process that was dependent on cross-reactivity with self-antigen, TGF-β1, and MHC class II Ag presentation by leukemic cells. Treg cells were critical for leukemia progression in C57BL/6 mice, as transient Treg cell ablation led to extended survival of leukemic mice. Thus, BCR-ABL(+) leukemia actively suppresses antileukemia immune responses by converting cross-reactive leukemia-specific T cells into Treg cells. Copyright © 2015 by The American Association of Immunologists, Inc.

  12. Targeting acute myeloid leukemia stem cells: a review and principles for the development of clinical trials.

    Science.gov (United States)

    Pollyea, Daniel A; Gutman, Jonathan A; Gore, Lia; Smith, Clayton A; Jordan, Craig T

    2014-08-01

    Despite an increasingly rich understanding of its pathogenesis, acute myeloid leukemia remains a disease with poor outcomes, overwhelmingly due to disease relapse. In recent years, work to characterize the leukemia stem cell population, the disease compartment most difficult to eliminate with conventional therapy and most responsible for relapse, has been undertaken. This, in conjunction with advances in drug development that have allowed for increasingly targeted therapies to be engineered, raises the hope that we are entering an era in which the leukemia stem cell population can be eliminated, resulting in therapeutic cures for acute myeloid leukemia patients. For these therapies to become available, they must be tested in the setting of clinical trials. A long-established clinical trials infrastructure has been employed to shepherd new therapies from proof-of-concept to approval. However, due to the unique features of leukemia stem cells, drugs that are designed to specifically eliminate this population may not be adequately tested when applied to this model. Therefore, in this review article, we seek to identify the relevant features of acute myeloid leukemia stem cells for clinical trialists, discuss potential strategies to target leukemia stem cells, and propose a set of guidelines outlining the necessary elements of clinical trials to allow for the successful testing of stem cell-directed therapies. Copyright© Ferrata Storti Foundation.

  13. Complete suppression of viral gene expression is associated with the onset and progression of lymphoid malignancy: observations in Bovine Leukemia Virus-infected sheep

    Directory of Open Access Journals (Sweden)

    Burny Arsène

    2007-07-01

    Full Text Available Abstract Background During malignant progression, tumor cells need to acquire novel characteristics that lead to uncontrolled growth and reduced immunogenicity. In the Bovine Leukemia Virus-induced ovine leukemia model, silencing of viral gene expression has been proposed as a mechanism leading to immune evasion. However, whether proviral expression in tumors is completely suppressed in vivo was not conclusively demonstrated. Therefore, we studied viral expression in two selected experimentally-infected sheep, the virus or the disease of which had features that made it possible to distinguish tumor cells from their nontransformed counterparts. Results In the first animal, we observed the emergence of a genetically modified provirus simultaneously with leukemia onset. We found a Tax-mutated (TaxK303 replication-deficient provirus in the malignant B-cell clone while functional provirus (TaxE303 had been consistently monitored over the 17-month aleukemic period. In the second case, both non-transformed and transformed BLV-infected cells were present at the same time, but at distinct sites. While there was potentially-active provirus in the non-leukemic blood B-cell population, as demonstrated by ex-vivo culture and injection into naïve sheep, virus expression was completely suppressed in the malignant B-cells isolated from the lymphoid tumors despite the absence of genetic alterations in the proviral genome. These observations suggest that silencing of viral genes, including the oncoprotein Tax, is associated with tumor onset. Conclusion Our findings suggest that silencing is critical for tumor progression and identify two distinct mechanisms-genetic and epigenetic-involved in the complete suppression of virus and Tax expression. We demonstrate that, in contrast to systems that require sustained oncogene expression, the major viral transforming protein Tax can be turned-off without reversing the transformed phenotype. We propose that suppression

  14. In Vitro Assembly of Virus-Like Particles of a Gammaretrovirus, the Murine Leukemia Virus XMRV

    Czech Academy of Sciences Publication Activity Database

    Hadravová, Romana; de Marco, A.; Ulbrich, P.; Štokrová, Jitka; Doležal, Michal; Pichová, Iva; Ruml, T.; Briggs, J. A. G.; Rumlová, Michaela

    2012-01-01

    Roč. 86, č. 3 (2012), s. 1297-1306 ISSN 0022-538X R&D Projects: GA ČR GA204/09/1388; GA MŠk 1M0508 Grant - others:GA MŠk(CZ) 1M0520 Program:1M Institutional research plan: CEZ:AV0Z40550506 Keywords : human-immunodeficiency-virus * Rous sarcoma virus * chronic-fatigue-syndrome * Pfizer monkey virus * N-terminal domain Subject RIV: CE - Biochemistry Impact factor: 5.076, year: 2012

  15. Expression of tumor invasion factors determines systemic engraftment and induction of humoral hypercalcemia in a mouse model of adult T-cell leukemia.

    Science.gov (United States)

    Parrula, C; Zimmerman, B; Nadella, P; Shu, S; Rosol, T; Fernandez, S; Lairmore, M; Niewiesk, S

    2009-09-01

    Infection with human T-cell leukemia virus type 1 (HTLV-1) leads sometimes to the development of adult T-cell lymphoma/leukemia (ATL), which is invariably fatal and often associated with humoral hypercalcemia of malignancy. The transformation of infected CD4 T cells and the pathogenesis of leukemia have been studied with great limitation in tissue culture and patients. To better understand the pathogenesis and perform preclinical drug studies, animal models of ATL are urgently needed. In mice, inoculation of HTLV-1 cell lines mostly leads to development of localized lymphomas. To develop an ATL animal model with leukemic spread of ATL cells, mouse strains with different well-defined immune deficiencies were inoculated intraperitoneally with different HTLV-1-infected cell lines (ACH.2, C8166, MT-2, MET-1). Inoculation of MET-1 cells into NOD/SCID mice provided the best model system for slowly developing T-cell leukemia with multiple organ involvement. In leukemic mice, an increase in serum calcium levels correlated with expression of receptor activator of nuclear factor kappa-light-chain-enhancer of activated B cells ligand on leukemic cells and secretion of parathyroid hormone-related protein and interleukin-6. In contrast to the other cell lines that did not spread systemically, MET-1 expressed both the adhesion molecules CD11a (LFA-1alpha) and CD49d (VLA-4alpha) and produced or induced expression of matrix metalloproteinases 1, 2, 3, and 9, thus underlining the importance of these molecules in the spread of adult T-cell leukemia cells. The MET-1/NOD/SCID model will be useful for developing interventions against invasion and spread of leukemic cells and subsequent humoral hypercalcemia of malignancy.

  16. New hematological key for bovine leukemia virus-infected Japanese Black cattle.

    Science.gov (United States)

    Mekata, Hirohisa; Yamamoto, Mari; Kirino, Yumi; Sekiguchi, Satoshi; Konnai, Satoru; Horii, Yoichiro; Norimine, Junzo

    2018-02-20

    The European Community's (EC) Key, which is also called Bendixen's Key, is a well-established bovine leukemia virus (BLV) diagnostic method that classifies cattle according to the absolute lymphocyte count and age. The EC Key was originally designed for dairy cattle and is not necessarily suitable for Japanese Black (JB) beef cattle. This study revealed the lymphocyte counts in the BLV-free and -infected JB cattle were significantly lower than those in the Holstein cattle. Therefore, applying the EC Key to JB cattle could result in a large number of undetected BLV-infected cattle. Our proposed hematological key, which was designed for JB cattle, improves the detection of BLV-infected cattle by approximately 20%. We believe that this study could help promote BLV control.

  17. [Gene Expression Profile of Apoptosis in Leukemia Cells Induced by Hsp90 Selective inhibitor 17-AAG].

    Science.gov (United States)

    Wang, Na-Na; Li, Zhi-Heng; Tao, Yan-Fang; Xu, Li-Xiao; Pan, Jian; Hu, Shao-Yan

    2016-06-01

    To investigate the apoptotic effects of Hsp90 selective inhibitor 17-AAG on human leukemia HL-60 and NB4 cells and analyse its possible mechanism. CCK-8 assay was used to quantify the growth inhibition of cells after exposure to 17-AAG for 24 hours. Flow cytometrve with annexin V/propidium iodide staining was used to detect apoptosis of leukemia cells. Then Western blot was used to detect the activation of apoptosis related protein caspase-3 and PARP level. Gene expression profile of NB4 cells treated with 17-AAG was analyzed with real-time PCR arrays. The inhibition of leukemia cell proliferation displayed a dose-dependent manner. Annexin V assay, cell cycle analysis and activation of PARP demonstrate that 17-AAG induced apoptosis leukemia cells. Real-time PCR array analysis showed that expression of 56 genes significantly up-regulated and expression of 23 genes were significantly down-regulated after 17-AAG treatment. The 17-AAG can inhibit the proliferation and induce the apoptosis of leukemia cells. After leukemia cells are treated with 17-AAG, the significant changes of apoptosis-related genes occured, and the cell apoptosis occurs via activating apoptosis related signaling pathway.

  18. Diffuse omental cake as an initial presentation of plasma cell leukemia

    Directory of Open Access Journals (Sweden)

    Po-Shen Ko

    2017-03-01

    Full Text Available Omental cake is a term to describe peritoneal thickening caused by different processes. Metastatic malignancy is the most common cause. Plasma cell leukemia is a rare hematological malignancy involving plasma cells and differ from multiple myeloma in its aggressiveness, initial presentation, and dismal prognosis. Herein, we reported a case of primary plasma cell leukemia initially presented with diffuse omental cake and ascites and subsequent systemic capillary leak syndrome.

  19. Leukemia mortality by cell type in petroleum workers with potential exposure to benzene.

    OpenAIRE

    Raabe, G K; Wong, O

    1996-01-01

    Workers in the petroleum industry are potentially exposed to a variety of petrochemicals, including benzene or benzene-containing liquids. Although a large number of studies of petroleum workers have been conducted to examine leukemia and other cancer risks, few existing studies have investigated cell-type-specific leukemias. One of the major reasons for the lack of cell-type-specific analysis was the small number of deaths by cell type in individual studies. In the present investigation, all...

  20. High-resolution Antibody Array Analysis of Childhood Acute Leukemia Cells*

    Science.gov (United States)

    Kanderova, Veronika; Kuzilkova, Daniela; Stuchly, Jan; Vaskova, Martina; Brdicka, Tomas; Fiser, Karel; Hrusak, Ondrej; Lund-Johansen, Fridtjof

    2016-01-01

    Acute leukemia is a disease pathologically manifested at both genomic and proteomic levels. Molecular genetic technologies are currently widely used in clinical research. In contrast, sensitive and high-throughput proteomic techniques for performing protein analyses in patient samples are still lacking. Here, we used a technology based on size exclusion chromatography followed by immunoprecipitation of target proteins with an antibody bead array (Size Exclusion Chromatography-Microsphere-based Affinity Proteomics, SEC-MAP) to detect hundreds of proteins from a single sample. In addition, we developed semi-automatic bioinformatics tools to adapt this technology for high-content proteomic screening of pediatric acute leukemia patients. To confirm the utility of SEC-MAP in leukemia immunophenotyping, we tested 31 leukemia diagnostic markers in parallel by SEC-MAP and flow cytometry. We identified 28 antibodies suitable for both techniques. Eighteen of them provided excellent quantitative correlation between SEC-MAP and flow cytometry (p leukemia. In this assay, we used 632 different antibodies and detected 501 targets. Of those, 47 targets were differentially expressed between at least two of the three acute leukemia subgroups. The CD markers correlated with immunophenotypic categories as expected. From non-CD markers, we found DBN1, PAX5, or PTK2 overexpressed in B-cell precursor acute lymphoblastic leukemias, LAT, SH2D1A, or STAT5A overexpressed in T-cell acute lymphoblastic leukemias, and HCK, GLUD1, or SYK overexpressed in acute myeloid leukemias. In addition, OPAL1 overexpression corresponded to ETV6-RUNX1 chromosomal translocation. In summary, we demonstrated that SEC-MAP technology is a powerful tool for detecting hundreds of proteins in clinical samples obtained from pediatric acute leukemia patients. It provides information about protein size and reveals differences in protein expression between particular leukemia subgroups. Forty-seven of SEC-MAP identified

  1. TIGAR cooperated with glycolysis to inhibit the apoptosis of leukemia cells and associated with poor prognosis in patients with cytogenetically normal acute myeloid leukemia.

    Science.gov (United States)

    Qian, Sixuan; Li, Jianyong; Hong, Ming; Zhu, Yu; Zhao, Huihui; Xie, Yue; Huang, Jiayu; Lian, Yun; Li, Yanru; Wang, Shuai; Mao, Jianping; Chen, Yaoyu

    2016-11-25

    Cancer cells show increased glycolysis and take advantage of this metabolic pathway to generate ATP. The TP53-induced glycolysis and apoptosis regulator (TIGAR) inhibits aerobic glycolysis and protects tumor cells from intracellular reactive oxygen species (ROS)-associated apoptosis. However, the function of TIGAR in glycolysis and survival of acute myeloid leukemia cells remains unclear. We analyzed TIGAR expression in cytogenetically normal (CN-) AML patients and the correlations with clinical and biological parameters. In vivo and in vitro, we tested whether glycolysis may induce TIGAR expression and evaluated the combination effect of glycolysis inhibitor and TIGAR knockdown on human leukemia cell proliferation. High TIGAR expression was an independent predictor of poor survival and high incidence of relapse in adult patients with CN-AML. TIGAR also showed high expression in multiple human leukemia cell lines and knockdown of TIGAR activated glycolysis through PFKFB3 upregulation in human leukemia cells. Knockdown of TIGAR inhibited the proliferation of human leukemia cells and sensitized leukemia cells to glycolysis inhibitor both in vitro and in vivo. Furthermore, TIGAR knockdown in combination with glycolysis inhibitor 2-DG led leukemia cells to apoptosis. In addition, the p53 activator Nutlin-3α showed a significant combinational effect with TIGAR knockdown in leukemia cells. However, TIGAR expression and its anti-apoptotic effects were uncoupled from overexpression of exogenous p53 in leukemia cells. TIGAR might be a predictor of poor survival and high incidence of relapse in AML patients, and the combination of TIGAR inhibitors with anti-glycolytic agents may be novel therapies for the future clinical use in AML patients.

  2. Efficacy of immunization against hepatitis B virus infection in acute leukemia

    Directory of Open Access Journals (Sweden)

    Tuphan Kanti Dolai

    2010-09-01

    Full Text Available Objective: The aim of this study was to assess the antibody response to combined passive-active immunization versus active immunization against hepatitis B in 71 patients with acute leukemia with negative hepatitis B virus serology at presentation. Materials and Methods: The first group (n=28 received a double dose of hepatitis B vaccine at 0, 1, 2 and 6 months and immunoglobin (HBIG at 0 and 1 month concurrently with vaccine but at a different intramuscular site. The second group (n=43 received double dose of hepatitis B vaccine at 0, 1, 2, and 6 months. HBsAg and anti-HBs titers were determined one month after the 1st, 2nd, 3rd and 4th doses of vaccine. Results: In the vaccine-only group, 2.56%, 8.33%, 14.28% and 34.29% of patients developed anti-HBs titer ≥10 IU/L after the 1st, 2nd, 3rd and 4th doses of vaccine, respectively. In the HBIG group, 91.30%, 91.30%, 69.56% and 73.91% of patients developed anti-HBs titer ≥10 IU/L after the 1st, 2nd, 3rd and 4th doses of vaccine, respectively. Those in the vaccine-HBIG group maintained their anti-HBs titer ≥10 IU/L from the 1st to the 4th doses. In the vaccine-only group, 34.29% of patients gained protective antibody titer after receiving the 4th dose of vaccine. Subgroup analysis of age (pediatric vs adult and disease (acute lymphoblastic leukemia vs acute myeloid leukemia groups showed no effect of either on the development of protective antibody titer. The incidence of HBsAg positivity one month after the 4th dose of vaccine was 8.62%. No patient became positive for anti-HCV or HIV antibody before or after chemo therapy.Conclusion: Combined HBIG and vaccine may protect acute leukemia patients during the intensive chemotherapy period.

  3. Identification of an MLC suppressor cell population in acute leukemia

    International Nuclear Information System (INIS)

    Bryan, C.F.; Broxmeyer, H.E.; Hansen, J.; Pollack, M.; Dupont, B.

    1978-01-01

    The MLC data from the 20 nonsuppressing patients and the 10 suppressing leukemia patients were analyzed with regard to HLA-A, -B, and -C antigens in the leukemia patients and compared with the presence or absence of suppression. These results demonstrate a significant increase (p < 0.02, Mann-Whitney U test) of HLA antigens Al, A3, and A11 in the leukemia suppressor group. Seven of the 10 leukemia patients showing suppression were A1, A3, or A11, while only 4 of the 20 nonsuppressing leukemia patients carried any of these three HLA-A antigens. The studies demonstrate that a nonspecific suppression of MLC responses is observed in 33% of the patients with acute leukemia

  4. Maintenance of leukemia-initiating cells is regulated by the CDK inhibitor Inca1.

    Directory of Open Access Journals (Sweden)

    Nicole Bäumer

    Full Text Available Functional differences between healthy progenitor and cancer initiating cells may provide unique opportunities for targeted therapy approaches. Hematopoietic stem cells are tightly controlled by a network of CDK inhibitors that govern proliferation and prevent stem cell exhaustion. Loss of Inca1 led to an increased number of short-term hematopoietic stem cells in older mice, but Inca1 seems largely dispensable for normal hematopoiesis. On the other hand, Inca1-deficiency enhanced cell cycling upon cytotoxic stress and accelerated bone marrow exhaustion. Moreover, AML1-ETO9a-induced proliferation was not sustained in Inca1-deficient cells in vivo. As a consequence, leukemia induction and leukemia maintenance were severely impaired in Inca1-/- bone marrow cells. The re-initiation of leukemia was also significantly inhibited in absence of Inca1-/- in MLL-AF9- and c-myc/BCL2-positive leukemia mouse models. These findings indicate distinct functional properties of Inca1 in normal hematopoietic cells compared to leukemia initiating cells. Such functional differences might be used to design specific therapy approaches in leukemia.

  5. Ayanin diacetate-induced cell death is amplified by TRAIL in human leukemia cells

    International Nuclear Information System (INIS)

    Marrero, María Teresa; Estévez, Sara; Negrín, Gledy; Quintana, José; López, Mariana; Pérez, Francisco J.; Triana, Jorge; León, Francisco; Estévez, Francisco

    2012-01-01

    Highlights: ► Ayanin diacetate as apoptotic inducer in leukemia cells. ► Cell death was prevented by caspase inhibitors and by the overexpression of Bcl-x L . ► The intrinsic and the extrinsic pathways are involved in the mechanism of action. ► Death receptors are up-regulated and TRAIL enhances apoptotic cell death. -- Abstract: Here we demonstrate that the semi-synthetic flavonoid ayanin diacetate induces cell death selectively in leukemia cells without affecting the proliferation of normal lymphocytes. Incubation of human leukemia cells with ayanin diacetate induced G 2 -M phase cell cycle arrest and apoptosis which was prevented by the non-specific caspase inhibitor z-VAD-fmk and reduced by the overexpression of Bcl-x L . Ayanin diacetate-induced cell death was found to be associated with: (i) loss of inner mitochondrial membrane potential, (ii) the release of cytochrome c, (iii) the activation of multiple caspases, (iv) cleavage of poly(ADP-ribose) polymerase and (v) the up-regulation of death receptors for TRAIL, DR4 and DR5. Moreover, the combined treatment with ayanin diacetate and TRAIL amplified cell death, compared to single treatments. These results provide a basis for further exploring the potential applications of this combination for the treatment of cancer.

  6. Ayanin diacetate-induced cell death is amplified by TRAIL in human leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Marrero, Maria Teresa; Estevez, Sara; Negrin, Gledy; Quintana, Jose [Departamento de Bioquimica, Unidad Asociada al Consejo Superior de Investigaciones Cientificas, Universidad de Las Palmas de Gran Canaria, Plaza Dr. Pasteur s/n, 35016 Las Palmas de Gran Canaria (Spain); Lopez, Mariana; Perez, Francisco J.; Triana, Jorge [Departamento de Quimica, Universidad de Las Palmas de Gran Canaria, Instituto Canario de Investigacion del Cancer, 35017 Las Palmas de Gran Canaria (Spain); Leon, Francisco [Instituto de Productos Naturales y Agrobiologia, Consejo Superior de Investigaciones Cientificas, Avda. Astrofisico F. Sanchez 3, 38206 La Laguna, Tenerife (Spain); Estevez, Francisco, E-mail: festevez@dbbf.ulpgc.es [Departamento de Bioquimica, Unidad Asociada al Consejo Superior de Investigaciones Cientificas, Universidad de Las Palmas de Gran Canaria, Plaza Dr. Pasteur s/n, 35016 Las Palmas de Gran Canaria (Spain)

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer Ayanin diacetate as apoptotic inducer in leukemia cells. Black-Right-Pointing-Pointer Cell death was prevented by caspase inhibitors and by the overexpression of Bcl-x{sub L}. Black-Right-Pointing-Pointer The intrinsic and the extrinsic pathways are involved in the mechanism of action. Black-Right-Pointing-Pointer Death receptors are up-regulated and TRAIL enhances apoptotic cell death. -- Abstract: Here we demonstrate that the semi-synthetic flavonoid ayanin diacetate induces cell death selectively in leukemia cells without affecting the proliferation of normal lymphocytes. Incubation of human leukemia cells with ayanin diacetate induced G{sub 2}-M phase cell cycle arrest and apoptosis which was prevented by the non-specific caspase inhibitor z-VAD-fmk and reduced by the overexpression of Bcl-x{sub L}. Ayanin diacetate-induced cell death was found to be associated with: (i) loss of inner mitochondrial membrane potential, (ii) the release of cytochrome c, (iii) the activation of multiple caspases, (iv) cleavage of poly(ADP-ribose) polymerase and (v) the up-regulation of death receptors for TRAIL, DR4 and DR5. Moreover, the combined treatment with ayanin diacetate and TRAIL amplified cell death, compared to single treatments. These results provide a basis for further exploring the potential applications of this combination for the treatment of cancer.

  7. Seroprevalence of feline leukemia virus, feline immunodeficiency virus and heartworm infection among owned cats in tropical Mexico.

    Science.gov (United States)

    Ortega-Pacheco, Antonio; Aguilar-Caballero, Armando J; Colin-Flores, Rafael F; Acosta-Viana, Karla Y; Guzman-Marin, Eugenia; Jimenez-Coello, Matilde

    2014-06-01

    Several infectious agents may be distributed within a healthy population of cats where diverse risk factors predispose them to come into contact with pathogens. Blood samples from 227 owned cats in Merida, Mexico, were collected with the objective of determining the seroprevalence and associated risk factors of feline leukemia virus (FeLV) and Dirofilaria immitis antigen, and feline immunodeficiency virus (FIV) antibody. Serological detection of FeLV and D immitis antigens, and FIV antibodies was performed using the commercial kit SNAP Feline Triple Test. The prevalence was found to be 7.5% for FeLV, 2.5% for FIV and 0% for D immitis. Adult cats were at a higher risk of coming into contact with FeLV (P FIV. The prevalence of retroviral infections found in this study was low, but within the limits reported in the different geographical areas of the world. Cases of filariosis in the domestic cats of Merida, Mexico, may be absent or very low; however, the low sample size may have influenced these results. © ISFM and AAFP 2013.

  8. Viral diagnostic criteria for Feline immunodeficiency virus and Feline leukemia virus infections in domestic cats from Buenos Aires, Argentina.

    Science.gov (United States)

    Galdo Novo, Sabrina; Bucafusco, Danilo; Diaz, Leandro M; Bratanich, Ana Cristina

    A cross-sectional study was carried out on cats attending the Small Animal Hospital at the Faculty of Veterinary Sciences of the University of Buenos Aires to assess the prevalence and associated risk factors of Feline immunodeficiency virus (FIV) and Feline leukemia virus (FeLV) in the city of Buenos Aires, Argentina. Blood samples from 255 cats with symptoms compatible with FIV or FeLV infection, collected between 2009 and 2013 were analyzed by serology (immunochromatography, IA) and by hemi-nested PCR (n-PCR). The IA and n-PCR assays showed similar percentages of positivity for FIV while the n-PCR test was more sensitive for FeLV. Differences between the diagnostic tests and their choice according to the age of the animal are discussed. The clinical histories of ninety of the 255 cats showed blood profiles similar to others previously reported and revealed a higher risk of infection in male adult cats with outdoor access. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Dietary Intakes and Risk of Lymphoid and Myeloid Leukemia in the European Prospective Investigation into Cancer and Nutrition (EPIC)

    NARCIS (Netherlands)

    Saberi Hosnijeh, F.; Peeters, P.H.M.; Romieu, I.; Kelly, R.; Riboli, E.; Olsen, A.; Tjonneland, A.; Fagherazzi, g.; Clavel Chapelon, F.; Dossus, L.; Nieters, A.; Teucher, B.; Trichopoulo, A.; Naska, A.; Valanou, E.; Mattiello, A.; Sieri, S.; Parr, C.L.; Engeset, D.; Bueno de Mesquita, H.B.; Ros, M.M.; Travis, R.C.; Key, T.J.; Vineis, P.; Vermeulen, R.C.H.

    2014-01-01

    The etiology of leukemias cannot entirely be explained by known risk factors, including ionizing radiation, benzene exposure, and infection with human T cell leukemia virus. A number of studies suggested that diet influences the risk of adult leukemias. However, results have been largely

  10. ESAM is a novel human hematopoietic stem cell marker associated with a subset of human leukemias.

    Science.gov (United States)

    Ishibashi, Tomohiko; Yokota, Takafumi; Tanaka, Hirokazu; Ichii, Michiko; Sudo, Takao; Satoh, Yusuke; Doi, Yukiko; Ueda, Tomoaki; Tanimura, Akira; Hamanaka, Yuri; Ezoe, Sachiko; Shibayama, Hirohiko; Oritani, Kenji; Kanakura, Yuzuru

    2016-04-01

    Reliable markers are essential to increase our understanding of the biological features of human hematopoietic stem cells and to facilitate the application of hematopoietic stem cells in the field of transplantation and regenerative medicine. We previously identified endothelial cell-selective adhesion molecule (ESAM) as a novel functional marker of hematopoietic stem cells in mice. Here, we found that ESAM can also be used to purify human hematopoietic stem cells from all the currently available sources (adult bone marrow, mobilized peripheral blood, and cord blood). Multipotent colony-forming units and long-term hematopoietic-reconstituting cells in immunodeficient mice were found exclusively in the ESAM(High) fraction of CD34(+)CD38(-) cells. The CD34(+)CD38(-) fraction of cord blood and collagenase-treated bone marrow contained cells exhibiting extremely high expression of ESAM; these cells are likely to be related to the endothelial lineage. Leukemia cell lines of erythroid and megakaryocyte origin, but not those of myeloid or lymphoid descent, were ESAM positive. However, high ESAM expression was observed in some primary acute myeloid leukemia cells. Furthermore, KG-1a myeloid leukemia cells switched from ESAM negative to ESAM positive with repeated leukemia reconstitution in vivo. Thus, ESAM is a useful marker for studying both human hematopoietic stem cells and leukemia cells. Copyright © 2016 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

  11. The toxicity of aromatic nitrocompounds to bovine leukemia virus-transformed fibroblasts: the role of single-electron reduction.

    Science.gov (United States)

    Cènas, N; Nemeikaitè, A; Dickancaitè, E; Anusevicius, Z; Nivinskas, H; Bironaitè, D

    1995-08-31

    Bovine leukemia virus-transformed lamb embryo fibroblasts (line FLK) possess activity of DT-diaphorase of ca. 260 U/mg protein and similar levels of other NADP(H)-oxidizing enzymes: NADH:oxidase, 359 U/mg; NADPH:oxidase, 43 U/mg; NADH:cytochrome-c reductase, 141 U/mg; NADPH:cytochrome-c reductase, 43 U/mg. In general, the toxicity of aromatic nitrocompounds towards FLK cells increases on increase of single-electron reduction potentials (E1(1)) of nitrocompounds or the log of their reduction rate constants by single-electron-transferring enzymes, microsomal NADPH:cytochrome P-450 reductase (EC 1.6.2.4) and mitochondrial NADH:ubiquinone reductase (EC 1.6.99.3). No correlation between the toxicity and reduction rate of nitrocompounds by rat liver DT-diaphorase (EC 1.6.99.2) was observed. The toxicity is not significantly affected by dicumarol, an inhibitor of DT-diaphorase. Nitrocompounds examined were poor substrates for DT-diaphorase, being 10(4) times less active than menadione. Their poor reactivity is most probably determined by their preferential binding to a NADPH binding site, but not to menadione binding site of diaphorase. These data indicate that at comparable activities of DT-diaphorase and single-electron-transferring NAD(P)H dehydrogenases in the cell, the toxicity of nitrocompounds will be determined mainly by their single-electron reduction reactions.

  12. WRN-targeted therapy using inhibitors NSC 19630 and NSC 617145 induce apoptosis in HTLV-1-transformed adult T-cell leukemia cells

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    R. Moles

    2016-11-01

    Full Text Available Abstract Background Human T-cell leukemia virus type 1 (HTLV-1 infection is associated with adult T-cell leukemia/lymphoma (ATLL, a lymphoproliferative malignancy with a dismal prognosis and limited therapeutic options. Recent evidence shows that HTLV-1-transformed cells present defects in both DNA replication and DNA repair, suggesting that these cells might be particularly sensitive to treatment with a small helicase inhibitor. Because the “Werner syndrome ATP-dependent helicase” encoded by the WRN gene plays important roles in both cellular proliferation and DNA repair, we hypothesized that inhibition of WRN activity could be used as a new strategy to target ATLL cells. Methods Our analysis demonstrates an apoptotic effect induced by the WRN helicase inhibitor in HTLV-1-transformed cells in vitro and ATL-derived cell lines. Inhibition of cellular proliferation and induction of apoptosis were demonstrated with cell cycle analysis, XTT proliferation assay, clonogenic assay, annexin V staining, and measurement of mitochondrial transmembrane potential. Results Targeted inhibition of the WRN helicase induced cell cycle arrest and apoptosis in HTLV-1-transformed leukemia cells. Treatment with NSC 19630 (WRN inhibitor induces S-phase cell cycle arrest, disruption of the mitochondrial membrane potential, and decreased expression of anti-apoptotic factor Bcl-2. These events were associated with activation of caspase-3-dependent apoptosis in ATL cells. We identified some ATL cells, ATL-55T and LMY1, less sensitive to NSC 19630 but sensitive to another WRN inhibitor, NSC 617145. Conclusions WRN is essential for survival of ATL cells. Our studies suggest that targeting the WRN helicase with small inhibitors is a novel promising strategy to target HTLV-1-transformed ATL cells.

  13. A novel cell growth-promoting factor identified in a B cell leukemia cell line, BALL-1

    International Nuclear Information System (INIS)

    Dao, T.; Holan, V.; Minowada, J.

    1993-01-01

    A novel leukemia cell growth-promoting activity has been identified in the culture supernatant from a human B cell leukemia cell line, BALL-1. The supernatant from unstimulated cultures of the BALL-1 cells significantly promoted the growth of 16 out of 24 leukemia/lymphoma cell lines of different lineages (T, B and non-lymphoid) in a minimal concentration of fetal bovine serum (FBS), and 5 out of 12 cases of fresh leukemia cells in FBS-free medium. The growth-promoting sieve filtration and dialysis. The MW of the factor was less than 10 kDa. The growth-promoting activity was heat and acid stable and resistant to trypsin treatment. The factor isolated from the BALL-1 supernatant was distinct from known polypeptide growth factors with MW below 10 kDa, such as epidermal growth factor, transforming growth factor α, insulin-like growth factor I (IGF-I), IGF-II and insulin, as determine by specific antibodies and by cell-growth-promoting tests. The factor is the BALL-1 supernatant did not promote the proliferation of normal human fresh peripheral blood lymphocytes or mouse fibroblast cell line, BALB/C 3T3. In addition to the BALL-1 supernatant, a similar growth-promoting activity was found in the culture supernatant from 13 of 17 leukemia/lymphoma cell lines tested. The activity in these culture supernatant promoted the growth of leukemia/lymphoma cell lines in autocrine and/or paracrine fashions. These observations suggest that the low MW cell growth-promoting activity found in the BALL-1 culture supernatant is mediated by a novel factor which may be responsible for the clonal expansion of particular leukemic clones. (author)

  14. In vivo imaging enables high resolution preclinical trials on patients' leukemia cells growing in mice.

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    Nadia Terziyska

    Full Text Available Xenograft mouse models represent helpful tools for preclinical studies on human tumors. For modeling the complexity of the human disease, primary tumor cells are by far superior to established cell lines. As qualified exemplary model, patients' acute lymphoblastic leukemia cells reliably engraft in mice inducing orthotopic disseminated leukemia closely resembling the disease in men. Unfortunately, disease monitoring of acute lymphoblastic leukemia in mice is hampered by lack of a suitable readout parameter.Patients' acute lymphoblastic leukemia cells were lentivirally transduced to express the membrane-bound form of Gaussia luciferase. In vivo imaging was established in individual patients' leukemias and extensively validated.Bioluminescence in vivo imaging enabled reliable and continuous follow-up of individual mice. Light emission strictly correlated to post mortem quantification of leukemic burden and revealed a logarithmic, time and cell number dependent growth pattern. Imaging conveniently quantified frequencies of leukemia initiating cells in limiting dilution transplantation assays. Upon detecting a single leukemia cell within more than 10,000 bone marrow cells, imaging enabled monitoring minimal residual disease, time to tumor re-growth and relapse. Imaging quantified therapy effects precisely and with low variances, discriminating treatment failure from partial and complete responses.For the first time, we characterized in detail how in vivo imaging reforms preclinical studies on patient-derived tumors upon increasing monitoring resolution. In the future, in vivo imaging will enable performing precise preclinical studies on a broad range of highly demanding clinical challenges, such as treatment failure, resistance in leukemia initiating cells, minimal residual disease and relapse.

  15. Synergistic interactions between HDAC and sirtuin inhibitors in human leukemia cells.

    Science.gov (United States)

    Cea, Michele; Soncini, Debora; Fruscione, Floriana; Raffaghello, Lizzia; Garuti, Anna; Emionite, Laura; Moran, Eva; Magnone, Mirko; Zoppoli, Gabriele; Reverberi, Daniele; Caffa, Irene; Salis, Annalisa; Cagnetta, Antonia; Bergamaschi, Micaela; Casciaro, Salvatore; Pierri, Ivana; Damonte, Gianluca; Ansaldi, Filippo; Gobbi, Marco; Pistoia, Vito; Ballestrero, Alberto; Patrone, Franco; Bruzzone, Santina; Nencioni, Alessio

    2011-01-01

    Aberrant histone deacetylase (HDAC) activity is frequent in human leukemias. However, while classical, NAD(+)-independent HDACs are an established therapeutic target, the relevance of NAD(+)-dependent HDACs (sirtuins) in leukemia treatment remains unclear. Here, we assessed the antileukemic activity of sirtuin inhibitors and of the NAD(+)-lowering drug FK866, alone and in combination with traditional HDAC inhibitors. Primary leukemia cells, leukemia cell lines, healthy leukocytes and hematopoietic progenitors were treated with sirtuin inhibitors (sirtinol, cambinol, EX527) and with FK866, with or without addition of the HDAC inhibitors valproic acid, sodium butyrate, and vorinostat. Cell death was quantified by propidium iodide cell staining and subsequent flow-cytometry. Apoptosis induction was monitored by cell staining with FITC-Annexin-V/propidium iodide or with TMRE followed by flow-cytometric analysis, and by measuring caspase3/7 activity. Intracellular Bax was detected by flow-cytometry and western blotting. Cellular NAD(+) levels were measured by enzymatic cycling assays. Bax was overexpressed by retroviral transduction. Bax and SIRT1 were silenced by RNA-interference. Sirtuin inhibitors and FK866 synergistically enhanced HDAC inhibitor activity in leukemia cells, but not in healthy leukocytes and hematopoietic progenitors. In leukemia cells, HDAC inhibitors were found to induce upregulation of Bax, a pro-apoptotic Bcl2 family-member whose translocation to mitochondria is normally prevented by SIRT1. As a result, leukemia cells become sensitized to sirtuin inhibitor-induced apoptosis. In conclusion, NAD(+)-independent HDACs and sirtuins cooperate in leukemia cells to avoid apoptosis. Combining sirtuin with HDAC inhibitors results in synergistic antileukemic activity that could be therapeutically exploited.

  16. Synergistic interactions between HDAC and sirtuin inhibitors in human leukemia cells.

    Directory of Open Access Journals (Sweden)

    Michele Cea

    Full Text Available Aberrant histone deacetylase (HDAC activity is frequent in human leukemias. However, while classical, NAD(+-independent HDACs are an established therapeutic target, the relevance of NAD(+-dependent HDACs (sirtuins in leukemia treatment remains unclear. Here, we assessed the antileukemic activity of sirtuin inhibitors and of the NAD(+-lowering drug FK866, alone and in combination with traditional HDAC inhibitors. Primary leukemia cells, leukemia cell lines, healthy leukocytes and hematopoietic progenitors were treated with sirtuin inhibitors (sirtinol, cambinol, EX527 and with FK866, with or without addition of the HDAC inhibitors valproic acid, sodium butyrate, and vorinostat. Cell death was quantified by propidium iodide cell staining and subsequent flow-cytometry. Apoptosis induction was monitored by cell staining with FITC-Annexin-V/propidium iodide or with TMRE followed by flow-cytometric analysis, and by measuring caspase3/7 activity. Intracellular Bax was detected by flow-cytometry and western blotting. Cellular NAD(+ levels were measured by enzymatic cycling assays. Bax was overexpressed by retroviral transduction. Bax and SIRT1 were silenced by RNA-interference. Sirtuin inhibitors and FK866 synergistically enhanced HDAC inhibitor activity in leukemia cells, but not in healthy leukocytes and hematopoietic progenitors. In leukemia cells, HDAC inhibitors were found to induce upregulation of Bax, a pro-apoptotic Bcl2 family-member whose translocation to mitochondria is normally prevented by SIRT1. As a result, leukemia cells become sensitized to sirtuin inhibitor-induced apoptosis. In conclusion, NAD(+-independent HDACs and sirtuins cooperate in leukemia cells to avoid apoptosis. Combining sirtuin with HDAC inhibitors results in synergistic antileukemic activity that could be therapeutically exploited.

  17. Diagnostic performances of two rapid tests for detection of feline leukemia virus antigen in sera of experimentally feline leukemia virus-infected cats

    Directory of Open Access Journals (Sweden)

    Matthew R Krecic

    2017-12-01

    Full Text Available Objectives The objective of this study was to compare the diagnostic sensitivities and specificities of WITNESS FeLV-FIV (Zoetis and SNAP FIV/FeLV Combo Test (IDEXX for the detection of FeLV p27 antigen in the sera of experimentally feline leukemia virus (FeLV-infected cats. Methods Diagnostic sensitivities of WITNESS and SNAP were determined through testing of 47 serum samples collected from cats day 56 post-experimental infection with a virulent FeLV Rickard strain. Successful experimental infection was confirmed based on observation of FeLV antigen and proviral DNA in anti-coagulated (EDTA whole-blood samples by immunofluorescent antibody (IFA test and PCR, respectively. Diagnostic specificities of both tests were determined through testing of sera of 92 laboratory-housed, non-FeLV-exposed specific pathogen-free (SPF cats. Results Forty-one of 47 blood samples were IFA positive, whereas all 47 samples were PCR positive. All 92 non-FeLV-infected SPF cats were IFA and PCR negative. In comparison to IFA as the reference method, both WITNESS and SNAP tests yielded equivalent sensitivities and specificities of 100% and 97.8%, respectively. In comparison to PCR as the reference method, both WITNESS and SNAP tests likewise performed equivalently, with sensitivities and specificities of 91.5% and 100%, respectively. Conclusions and relevance Sensitivity and specificity of WITNESS FeLV-FIV for identifying FeLV p27 antigen in the sera of these experimentally FeLV-infected and non-FeLV-exposed SPF cats equaled those of the SNAP FIV/FeLV Combo Test. However, all positive results, regardless of the point-of-care test used, should be confirmed before making clinical decisions such as segregation from other cats or euthanasia.

  18. Acute interstitial nephritis in T-cell leukemia in a pediatric patient.

    Science.gov (United States)

    Biro, Erika; Szikszay, Edit; Pethő-Orosz, Petronella; Bigida, László; Balla, György; Szabó, Tamás

    2016-09-01

    Acute lymphoid leukemia is the most frequently occurring malignancy in childhood, but acute tubulointerstitial nephritis with associated acute renal failure as the leading manifestation of leukemia is extremely rare. Only a few pediatric cases have been described in the literature. We present a surprising case in which physical examination and initial investigation were not typical for leukemia. Ultrasound showed only modest kidney enlargement while laboratory results indicated acute renal failure. Renal biopsy indicated tubulointerstitial nephritis, and subsequent steroid treatment led to sudden clinical improvement. One month later, however, the patient returned with typical clinical features of leukemia. Re-evaluation of the original kidney biopsy block indicated T-cell acute lymphoid leukemia. The present case highlights the importance of renal biopsy. © 2016 Japan Pediatric Society.

  19. Successful hematopoietic cell transplantation in a patient with X-linked agammaglobulinemia and acute myeloid leukemia.

    Science.gov (United States)

    Abu-Arja, Rolla F; Chernin, Leah R; Abusin, Ghada; Auletta, Jeffery; Cabral, Linda; Egler, Rachel; Ochs, Hans D; Torgerson, Troy R; Lopez-Guisa, Jesus; Hostoffer, Robert W; Tcheurekdjian, Haig; Cooke, Kenneth R

    2015-09-01

    X-linked agammaglobulinemia (XLA) is a primary immunodeficiency characterized by marked reduction in all classes of serum immunoglobulins and the near absence of mature CD19(+) B-cells. Although malignancy has been observed in patients with XLA, we present the first reported case of acute myeloid leukemia (AML) in a patient with XLA. We also demonstrate the complete correction of the XLA phenotype following allogeneic hematopoietic cell transplantation for treatment of the patient's leukemia. © 2015 Wiley Periodicals, Inc.

  20. REGULATORY T-CELLS IN CHRONIC LYMPHOCYTIC LEUKEMIA

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    Giovanni D'arena

    2012-01-01

    Full Text Available

    Regulatory T-cells (Tregs constitute a small subset of cells that are actively involved in maintaining self-tolerance, in immune homeostasis and in antitumor immunity. They are thought to play a significant role in the progression of cancer and are generally increased in patient with chronic lymphocytic leukemia (CLL. Their number correlates with more aggressive disease status and is predictive of the time to treatment, as well. Moreover, it is now clear that dysregulation in Tregs cell frequency and/or function may result in a plethora of autoimmune diseases, including multiple sclerosis, type 1 diabetes mellitus, myasthenia gravis, systemic lupus erythematosis, autoimmune lymphoproliferative disorders, rheumatoid arthritis, and psoriasis. Efforts are made aiming to develop approaches to deplete Tregs or inhibit their function in either cancer and autoimmune disorders.

  1. Epizootiology and management of feline leukemia virus in the Florida puma.

    Science.gov (United States)

    Cunningham, Mark W; Brown, Meredith A; Shindle, David B; Terrell, Scott P; Hayes, Kathleen A; Ferree, Bambi C; McBride, R T; Blankenship, Emmett L; Jansen, Deborah; Citino, Scott B; Roelke, Melody E; Kiltie, Richard A; Troyer, Jennifer L; O'Brien, Stephen J

    2008-07-01

    Feline leukemia virus (FeLV) was not detected in Florida pumas (Puma concolor coryi) in almost 20 yr of surveillance; however, the finding of two FeLV antigen-positive pumas during the 2002-2003 capture season led to an investigation of FeLV in the population. Between January 1990 and April 2007, the proportion of pumas testing FeLV antibody positive increased, with antibody-positive pumas concentrated in the northern portion of puma range. Five of 131 (4%) pumas sampled between July 2000 and April 2007 were viremic, with all cases clustered in Okaloacoochee Slough (OKS). Clinical signs and clinical pathology at capture were absent or included lymphadenopathy, moderate-to-severe anemia, and lymphopenia. All viremic pumas died; causes of death were septicemia (n=2), intraspecific aggression (n=2), and anemia/dehydration (n=1). Outcome after FeLV exposure in pumas was similar to that in domestic cats, with evidence of regressive, latent, and persistent infections. Management of the epizootic included vaccination, and as of April 2007, 52 free-ranging pumas had received one or more inoculations. Vaccinations were concentrated in OKS and in a band between OKS and the remainder of the puma population. There have been no new cases since July 2004; however, the potential for reintroduction of the virus remains.

  2. Mast Cell Leukemia: Review of a Rare Disease and Case Report of Prolonged Survival after Allogeneic Stem Cell Transplant

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    James Bauer, MD, PhD

    2017-11-01

    Full Text Available Mast cell leukemia is a rare and aggressive form of mastocytosis characterized by >20% mast cells found in the bone marrow aspirates of patients with signs of systemic mastocytosis-related organ damage. The prognosis for patients with mast cell leukemia is extremely poor, with resistance to both cytoreductive therapies and tyrosine kinase inhibitors being relatively common. While allogeneic hematopoietic stem cell transplantation has been associated with long-term survival in patients with advanced systemic mastocytosis, reports regarding its effectiveness in mast cell leukemia are limited to fewer than 20 cases described in the literature. Here, we report a patient with mast cell leukemia who remains in complete remission 24 months after allogeneic HSCT at the time of this writing, and briefly review the clinical, diagnostic, and therapeutic approaches to this rare disease.

  3. Mogamulizumab for the treatment of adult T-cell leukemia/lymphoma

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    Yoshimitsu M

    2014-12-01

    Full Text Available Makoto Yoshimitsu, Naomichi Arima Division of Hematology and Immunology, Center for Chronic Viral Diseases, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan Abstract: Adult T-cell leukemia/lymphoma (ATLL is a peripheral T-cell lymphoma caused by latent infection of human T-cell lymphotropic virus type 1. The outcome for ATLL is very poor, with a 3-year overall survival of approximately 24% with conventional chemotherapy; thus, there is an unmet need for developing new treatment options. Defucosylated humanized anti-CC chemokine receptor 4 (CCR4 antibody (KW-0761, mogamulizumab has been clinically available for the treatment of relapsed or refractory ATLL in Japan since 2012, and a Phase II study of mogamulizumab for patients with relapsed CCR4+ ATLL demonstrated a 50% objective response, a 30.8% complete response, and an acceptable safety profile. Allogeneic hematopoietic stem cell transplantation has been used to treat patients with ATLL, and mogamulizumab in combination with allogeneic hematopoietic stem cell transplantation has been used successfully in a limited number of patients to treat refractory or relapsed ATLL. The efficacy of combining mogamulizumab with standard chemotherapy (mLSG15 for patients with ATLL has also been examined, and the results have shown higher rates of complete response with the combined therapy (52% compared with for chemotherapy alone (33%. Mogamulizumab also has potential application in the treatment of human T-cell lymphotropic virus type 1-associated myelopathy/tropical paraparesis, Epstein–Barr virus-associated T-cell and natural killer-cell lymphoproliferative diseases, and peripheral and cutaneous T-cell lymphomas. Possible adverse events of mogamulizumab have been reported, such as cutaneous adverse reactions (including Stevens–Johnson syndrome, diffuse panbronchiolitis, reactivation of hepatitis B, and opportunistic infections. The treatment outcome of patients

  4. Chronic Lymphocytic Leukemia

    Science.gov (United States)

    Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, the bone marrow produces abnormal white blood cells. ...

  5. Coexistence of chronic myeloid leukemia and diffuse large B-cell lymphoma with antecedent chronic lymphocytic leukemia: a case report and review of the literature.

    Science.gov (United States)

    Abuelgasim, Khadega A; Rehan, Hinna; Alsubaie, Maha; Al Atwi, Nasser; Al Balwi, Mohammed; Alshieban, Saeed; Almughairi, Areej

    2018-03-11

    Chronic lymphocytic leukemia and chronic myeloid leukemia are the most common types of adult leukemia. However, it is rare for the same patient to suffer from both. Richter's transformation to diffuse large B-cell lymphoma is frequently observed in chronic lymphocytic leukemia. Purine analog therapy and the presence of trisomy 12, and CCND1 gene rearrangement have been linked to increased risk of Richter's transformation. The coexistence of chronic myeloid leukemia and diffuse large B-cell lymphoma in the same patient is extremely rare, with only nine reported cases. Here, we describe the first reported case of concurrent chronic myeloid leukemia and diffuse large B-cell lymphoma in a background of chronic lymphocytic leukemia. A 60-year-old Saudi man known to have diabetes, hypertension, and chronic active hepatitis B was diagnosed as having Rai stage II chronic lymphocytic leukemia, with trisomy 12 and rearrangement of the CCND1 gene in December 2012. He required no therapy until January 2016 when he developed significant anemia, thrombocytopenia, and constitutional symptoms. He received six cycles of fludarabine, cyclophosphamide, and rituximab, after which he achieved complete remission. One month later, he presented with progressive leukocytosis (mostly neutrophilia) and splenomegaly. Fluorescence in situ hybridization from bone marrow aspirate was positive for translocation (9;22) and reverse transcription polymerase chain reaction detected BCR-ABL fusion gene consistent with chronic myeloid leukemia. He had no morphologic or immunophenotypic evidence of chronic lymphocytic leukemia at the time. Imatinib, a first-line tyrosine kinase inhibitor, was started. Eight months later, a screening imaging revealed new liver lesions, which were confirmed to be diffuse large B-cell lymphoma. In chronic lymphocytic leukemia, progressive leukocytosis and splenomegaly caused by emerging chronic myeloid leukemia can be easily overlooked. It is unlikely that chronic myeloid

  6. Targeting peroxiredoxin I potentiates 1,25-dihydroxyvitamin D3-induced cell differentiation in leukemia cells.

    Science.gov (United States)

    Wei, Wei; Liu, Chuanxu; Qin, Dongjun; Song, Lili; Xia, Li; Lei, Hu; Yu, Yun; Wang, Weiwei; Pu, Jianxin; Sun, Handong; Wu, Yingli; Xu, Hanzhang; Hao, Siguo

    2016-03-01

    Although 1,25‑dihydroxyvitamin D3 (VD3) is regarded as a promising inducing agent for leukemia cell differentiation, it is not as effective an agent as all‑trans‑retinoic acid, and its usefulness is also limited by the adverse effects of hypercalcemia. The aim of the present study was to determine whether combining VD3 with adenanthin, a peroxiresoxin I (Prx I)‑targeting natural compound, improves the efficacy of VD3. Cell viability was assessed using a trypan blue exclusion assay and flow cytometry was used to evaluate the expression of cell surface markers, CD11b/CD14, and the level of reactive oxygen species (ROS). Wright's staining was used to examine morphological changes and RNA‑interference was used to knockdown Prx I and p65 gene expression. Protein expression was determined by western blot analysis. The results demonstrated that adenanthin markedly enhanced VD3‑induced cell differentiation of leukemia NB4 cells, as evidenced by the increased percentage of CD11b‑ and CD14‑positive cells, the mature morphology of the monocytes and the increased phagocytic ability. Consistent with these results, knockdown of Prx I, but not nuclear factor‑κB (p65), enhanced VD3‑induced cell differentiation. The combinatorial effects of adenanthin and VD3 were shown to be associated with the ROS‑CCAAT‑enhancer‑binding protein (C/EBP)β axis, since N‑acetylcysteine, a ROS scavenger, was able to abrogate the differentiation‑enhancing effects of adenanthin, and the knockdown of C/EBPβ also inhibited the combinatorial effects of adenanthin and VD3. In addition, co‑treatment with adenanthin and VD3 was able to induce differentiation in other non‑acute promyelocytic leukemia cells and primary leukemia cells. In conclusion, the results of the present study revealed a novel role for Prx I in VD3‑induced cell differentiation, and suggested that targeting Prx I may represent a novel strategy to enhance VD3‑induced leukemia cell differentiation.

  7. Absence of Bovine leukemia virus (BLV) infection in buffaloes from Amazon and southeast region in Brazil.

    Science.gov (United States)

    De Oliveira, Cairo H S; Resende, Cláudia F; Oliveira, Carlos M C; Barbosa, José D; Fonseca, Antônio A; Leite, Rômulo C; Reis, Jenner K P

    2016-07-01

    Enzootic bovine leucosis is an infectious disease caused by Bovine leukemia virus (BLV) and is well described in bovines. The majority of infected animals are asymptomatic, one to five percent develop lymphoma and from 30 to 50% present a persistent lymphocytosis. The virus occurs naturally in cattle and experimentally in buffaloes, capybaras and rabbits. The occurrence of lymphoma in buffaloes has been attributed to BLV infection by some authors in India and Venezuela, but not confirmed by other studies and little information on natural BLV infection in buffaloes is available. The aim of this study was to evaluate the occurrence of BLV in a sub-sample of buffalo from Amazon and southeast regions in Brazil. Three hundred and fifteen serum samples were negative using commercial AGID and ELISA (ELISA-gp51) which detect anti-BLV glycoprotein gp51 antibodies. The same samples were also evaluated for antibodies to whole virus through a commercial ELISA (ELISA-BLV) in which 77 (24.44%) were found seropositive and two (0.63%) inconclusive. On the other hand, all animals were negative by PCR to BLV targeted to the env and tax genes. These results suggest that ELISA-BLV produces false positive results in buffalo serum (p<0.001). In addition, one buffalo lymphoma sample was negative in both PCR assays used in this study. BLV was not detected in buffaloes from the Amazon basin and the southeast region of Brazil. Serological tests, like ELISA-BLV, usually used for cattle may produce false-positive results for BLV in buffaloes and direct detection tests such as PCR should be chosen in these surveys. The occurrence of lymphoma in buffalo was not associated with BLV infection in the one case analyzed in this work and the etiology and pathogenesis of this disease should be clarified. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Metformin inhibits cell cycle progression of B-cell chronic lymphocytic leukemia cells

    Science.gov (United States)

    Bruno, Silvia; Ledda, Bernardetta; Tenca, Claudya; Ravera, Silvia; Orengo, Anna Maria; Mazzarello, Andrea Nicola; Pesenti, Elisa; Casciaro, Salvatore; Racchi, Omar; Ghiotto, Fabio; Marini, Cecilia; Sambuceti, Gianmario; DeCensi, Andrea; Fais, Franco

    2015-01-01

    B-cell chronic lymphocytic leukemia (CLL) was believed to result from clonal accumulation of resting apoptosis-resistant malignant B lymphocytes. However, it became increasingly clear that CLL cells undergo, during their life, iterative cycles of re-activation and subsequent clonal expansion. Drugs interfering with CLL cell cycle entry would be greatly beneficial in the treatment of this disease. 1, 1-Dimethylbiguanide hydrochloride (metformin), the most widely prescribed oral hypoglycemic agent, inexpensive and well tolerated, has recently received increased attention for its potential antitumor activity. We wondered whether metformin has apoptotic and anti-proliferative activity on leukemic cells derived from CLL patients. Metformin was administered in vitro either to quiescent cells or during CLL cell activation stimuli, provided by classical co-culturing with CD40L-expressing fibroblasts. At doses that were totally ineffective on normal lymphocytes, metformin induced apoptosis of quiescent CLL cells and inhibition of cell cycle entry when CLL were stimulated by CD40-CD40L ligation. This cytostatic effect was accompanied by decreased expression of survival- and proliferation-associated proteins, inhibition of signaling pathways involved in CLL disease progression and decreased intracellular glucose available for glycolysis. In drug combination experiments, metformin lowered the apoptotic threshold and potentiated the cytotoxic effects of classical and novel antitumor molecules. Our results indicate that, while CLL cells after stimulation are in the process of building their full survival and cycling armamentarium, the presence of metformin affects this process. PMID:26265439

  9. Drug screen in patient cells suggests quinacrine to be repositioned for treatment of acute myeloid leukemia

    International Nuclear Information System (INIS)

    Eriksson, A; Österroos, A; Hassan, S; Gullbo, J; Rickardson, L; Jarvius, M; Nygren, P; Fryknäs, M; Höglund, M; Larsson, R

    2015-01-01

    To find drugs suitable for repositioning for use against leukemia, samples from patients with chronic lymphocytic, acute myeloid and lymphocytic leukemias as well as peripheral blood mononuclear cells (PBMC) were tested in response to 1266 compounds from the LOPAC 1280 library (Sigma). Twenty-five compounds were defined as hits with activity in all leukemia subgroups (<50% cell survival compared with control) at 10 μM drug concentration. Only one of these compounds, quinacrine, showed low activity in normal PBMCs and was therefore selected for further preclinical evaluation. Mining the NCI-60 and the NextBio databases demonstrated leukemia sensitivity and the ability of quinacrine to reverse myeloid leukemia gene expression. Mechanistic exploration was performed using the NextBio bioinformatic software using gene expression analysis of drug exposed acute myeloid leukemia cultures (HL-60) in the database. Analysis of gene enrichment and drug correlations revealed strong connections to ribosomal biogenesis nucleoli and translation initiation. The highest drug–drug correlation was to ellipticine, a known RNA polymerase I inhibitor. These results were validated by additional gene expression analysis performed in-house. Quinacrine induced early inhibition of protein synthesis supporting these predictions. The results suggest that quinacrine have repositioning potential for treatment of acute myeloid leukemia by targeting of ribosomal biogenesis

  10. Ezrin dephosphorylation/downregulation contributes to ursolic acid-mediated cell death in human leukemia cells

    International Nuclear Information System (INIS)

    Li, G; Zhou, T; Liu, L; Chen, J; Zhao, Z; Peng, Y; Li, P; Gao, N

    2013-01-01

    Ezrin links the actin filaments with the cell membrane and has a functional role in the apoptotic process. It appears clear that ezrin is directly associated with Fas, leading to activation of caspase cascade and cell death. However, the exact role of ezrin in ursolic acid (UA)-induced apoptosis remains unclear. In this study, we show for the first time that UA induces apoptosis in both transformed and primary leukemia cells through dephosphorylation/downregulation of ezrin, association and polarized colocalization of Fas and ezrin, as well as formation of death-inducing signaling complex. These events are dependent on Rho-ROCK1 signaling pathway. Knockdown of ezrin enhanced cell death mediated by UA, whereas overexpression of ezrin attenuated UA-induced apoptosis. Our in vivo study also showed that UA-mediated inhibition of tumor growth of mouse leukemia xenograft model is in association with the dephosphorylation/downregulation of ezrin. Such findings suggest that the cytoskeletal protein ezrin may represent an attractive target for UA-mediated lethality in human leukemia cells

  11. Helios expression in regulatory T cells promotes immunosuppression, angiogenesis and the growth of leukemia cells in pediatric acute lymphoblastic leukemia.

    Science.gov (United States)

    Li, Xue; Li, Dong; Huang, Xiaoyang; Zhou, Panpan; Shi, Qing; Zhang, Bing; Ju, Xiuli

    2018-04-01

    Regulatory T cells (Tregs) characterized by the transcription factor forkhead box P3 (FoxP3) are crucial for maintaining immune tolerance and preventing autoimmunity. However, FoxP3 does not function alone and Helios is considered a potential candidate for defining Treg subsets. In this study, we investigated the expression and function of Helios for identifying Tregs in childhood precursor B-cell acute lymphoblastic leukemia (pre-B ALL). Our results demonstrated that patients with pre-B ALL had a higher percentage of Helios + FoxP3 + CD4 + Tregs. And there was a positive correlation between the expression of Helios and the suppressive function of Tregs, the risk gradation of ALL. Helios in combination with CD4 and FoxP3 may be an effective way to detect functional Tregs in pre-B ALL by promoting the secretion of transforming growth factor (TGF)-β1. Furthermore, Helios + Tregs could regulate angiogenesis in the BM niche of pre-B ALL via the VEGFA/VEGFR2 pathway. We also found Helios + Tregs decreased apoptosis rate of nalm-6 cells by up-regulating the expression of anti-apoptosis protein Bcl-2. In summary, these data strongly imply the physiological importance of Helios expression in Tregs, and suggest that the manipulation of Helios may serve as a novel strategy for cancer immunotherapy. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Iron and Ferritin Levels in the Serum and Milk of Bovine Leukemia Virus-Infected Dairy Cows

    OpenAIRE

    Schnell, Star A.; Ohtsuka, Hiromichi; Kakinuma, Seiichi; Yoshikawa, Yasunaga; Watanabe, Kiyotaka; Orino, Koichi

    2015-01-01

    Iron metabolism was examined in 15 bovine leukemia virus (BLV)-infected dairy cows (2.6–7.8 years old). BLV infection was detected by measuring serum antibody titer against BLV virus antigen (gp51). The anti-BLV antibody titers of the BLV-infected cows were significantly higher in serum than in milk; a single serum-positive animal lacked detectable anti-BLV antibodies in its milk. Iron and ferritin concentrations also were significantly higher in serum than in milk. Although most of the BLV-i...

  13. Chronic adult T-cell Leukemia in a young male after blood transfusion as a newborn

    Directory of Open Access Journals (Sweden)

    Magali Colucci

    2016-06-01

    Full Text Available Human T-cell Lymphotropic virus type 1 (HTLV-1 is the etiological agent of Adult T-cell Leukemia/Lymphoma (ATLL and HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HTM/TSP. Areas of extremely high HTLV-1 prevalence are surrounded by areas of middle or very low prevalence. ATLL is an aggressive lymphoproliferative malignancy of peripheral T cells, with an incidence of less than 5% in HTLV-1-infected individuals. ATLL developed in the majority of cases in individuals who were infected with HTLV-1 by their mothers due to prolonged breastfeeding. In non-endemic areas, ATLL is usually limited to immigrants, their sexual partners and descendants from endemic regions. Very few cases of ATLL have been diagnosed in recipient patients few years after an organ transplantation or blood transfusion worldwide. Achieving an accurate and fast diagnosis of ATLL can be challenging due to the lack of professional experience, delayed consultation and difficulty in its sub-classification. We present a case of a delayed onset of a chronic ATLL in an 18-years-old male who was transfused with blood components as a premature newborn in Buenos Aires, a non-endemic city of South America.

  14. Inhibition of serotonin receptor type 1 in acute myeloid leukemia impairs leukemia stem cell functionality: a promising novel therapeutic target.

    Science.gov (United States)

    Etxabe, A; Lara-Castillo, M C; Cornet-Masana, J M; Banús-Mulet, A; Nomdedeu, M; Torrente, M A; Pratcorona, M; Díaz-Beyá, M; Esteve, J; Risueño, R M

    2017-11-01

    Acute myeloid leukemia (AML) is a clinically and molecularly heterogeneous neoplasia with poor outcome, organized as a hierarchy initiated and maintained by a sub-population with differentiation and self-renewal capacities called leukemia stem cells (LSCs). Although currently used chemotherapy is capable of initially reducing the tumor burden producing a complete remission, most patients will ultimately relapse and will succumb to their disease. As such, new therapeutic strategies are needed. AML cells differentially expressed serotonin receptor type 1 (HTR1) compared with healthy blood cells and the most primitive hematopoietic fraction; in fact, HTR1B expression on AML patient samples correlated with clinical outcome. Inhibition of HTR1s activated the apoptosis program, induced differentiation and reduced the clonogenic capacity, while minimal effect was observed on healthy blood cells. In vivo regeneration capacity of primary AML samples was disrupted upon inhibition of HTR1. The self-renewal capacity remaining in AML cells upon in vivo treatment was severely reduced as demonstrated by serial transplantation. Thus, treatment with HTR1 antagonists showed antileukemia effect, especially anti-LSC activity while sparing healthy blood cells. Our results highlight the importance of HTR1 in leukemogenesis and LSC survival and identify this receptor family as a new target for therapy in AML with prognostic value.

  15. Development of sugar chain-binding single-chain variable fragment antibody to adult T-cell leukemia cells using glyco-nanotechnology and phage display method.

    Science.gov (United States)

    Muchima, Kaname; Todaka, Taro; Shinchi, Hiroyuki; Sato, Ayaka; Tazoe, Arisa; Aramaki, Rikiya; Kakitsubata, Yuhei; Yokoyama, Risa; Arima, Naomichi; Baba, Masanori; Wakao, Masahiro; Ito, Yuji; Suda, Yasuo

    2018-04-01

    Adult T-cell leukemia (ATL) is an intractable blood cancer caused by the infection of human T-cell leukemia virus type-1, and effective medical treatment is required. It is known that the structure and expression levels of cell surface sugar chains vary depending on cell states such as inflammation and cancer. Thus, it is expected that the antibody specific for ATL cell surface sugar chain would be an effective diagnostic tool and a strong candidate for the development of an anti-ATL drug. Here, we developed a stable sugar chain-binding single-chain variable fragment antibody (scFv) that can bind to ATL cells using a fibre-type Sugar Chip and phage display method. The fiber-type Sugar Chips were prepared using O-glycans released from ATL cell lines. The scFv-displaying phages derived from human B cells (diversity: 1.04 × 108) were then screened using the fiber-type Sugar Chips, and an O-glycan-binding scFv was obtained. The flow cytometry analysis revealed that the scFv predominantly bound to ATL cell lines. The sugar chain-binding properties of the scFv was evaluated by array-type Sugar Chip immobilized with a library of synthetic glycosaminoglycan disaccharide structures. Highly sulphated disaccharide structures were found to have high affinity to scFv.

  16. Replication and pathogenicity of primer binding site mutants of SL3-3 murine leukemia viruses

    DEFF Research Database (Denmark)

    Lund, Anders Henrik; Schmidt, J; Luz, A

    1999-01-01

    ) in undifferentiated embryonic cells. In this study we test whether SL3-3 MLV can replicate stably using tRNA primers other than the cognate tRNAPro and analyze the effect of altering the primer binding site sequence to match the 3' end of tRNA1Gln, tRNA3Lys, or tRNA1,2Arg in a mouse pathogenicity model. Contrary...... delayed relative to that of the wild-type virus, molecular tumor analysis indicated that all the primer binding site-modified viruses induce T-cell lymphomas similar to those induced by the wild-type virus in terms of frequencies of genomic rearrangements within the T-cell receptor beta......, recombination with endogenous viruses resulting in the generation of recombinant viruses carrying a glutamine primer binding site was detected in the majority of the tumors induced by the SL3-3 Lys3 mutant as well as in two tumors induced by wild-type SL3-3 and the SL3-3 Arg1,2 mutant....

  17. RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells

    International Nuclear Information System (INIS)

    Wang, Houcai; Yu, Jing; Zhang, Lixia; Xiong, Yuanyuan; Chen, Shuying; Xing, Haiyan; Tian, Zheng; Tang, Kejing; Wei, Hui; Rao, Qing; Wang, Min; Wang, Jianxiang

    2014-01-01

    Highlights: • RPS27a expression was up-regulated in advanced-phase CML and AL patients. • RPS27a knockdown changed biological property of K562 and K562/G01 cells. • RPS27a knockdown affected Raf/MEK/ERK, P21 and BCL-2 signaling pathways. • RPS27a knockdown may be applicable for new combination therapy in CML patients. - Abstract: Ribosomal protein S27a (RPS27a) could perform extra-ribosomal functions besides imparting a role in ribosome biogenesis and post-translational modifications of proteins. The high expression level of RPS27a was reported in solid tumors, and we found that the expression level of RPS27a was up-regulated in advanced-phase chronic myeloid leukemia (CML) and acute leukemia (AL) patients. In this study, we explored the function of RPS27a in leukemia cells by using CML cell line K562 cells and its imatinib resistant cell line K562/G01 cells. It was observed that the expression level of RPS27a was high in K562 cells and even higher in K562/G01 cells. Further analysis revealed that RPS27a knockdown by shRNA in both K562 and K562G01 cells inhibited the cell viability, induced cell cycle arrest at S and G2/M phases and increased cell apoptosis induced by imatinib. Combination of shRNA with imatinib treatment could lead to more cleaved PARP and cleaved caspase-3 expression in RPS27a knockdown cells. Further, it was found that phospho-ERK(p-ERK) and BCL-2 were down-regulated and P21 up-regulated in RPS27a knockdown cells. In conclusion, RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells. It appears that drugs targeting RPS27a combining with tyrosine kinase inhibitor (TKI) might represent a novel therapy strategy in TKI resistant CML patients

  18. RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Houcai; Yu, Jing; Zhang, Lixia; Xiong, Yuanyuan; Chen, Shuying; Xing, Haiyan; Tian, Zheng; Tang, Kejing; Wei, Hui; Rao, Qing; Wang, Min; Wang, Jianxiang, E-mail: wangjx@ihcams.ac.cn

    2014-04-18

    Highlights: • RPS27a expression was up-regulated in advanced-phase CML and AL patients. • RPS27a knockdown changed biological property of K562 and K562/G01 cells. • RPS27a knockdown affected Raf/MEK/ERK, P21 and BCL-2 signaling pathways. • RPS27a knockdown may be applicable for new combination therapy in CML patients. - Abstract: Ribosomal protein S27a (RPS27a) could perform extra-ribosomal functions besides imparting a role in ribosome biogenesis and post-translational modifications of proteins. The high expression level of RPS27a was reported in solid tumors, and we found that the expression level of RPS27a was up-regulated in advanced-phase chronic myeloid leukemia (CML) and acute leukemia (AL) patients. In this study, we explored the function of RPS27a in leukemia cells by using CML cell line K562 cells and its imatinib resistant cell line K562/G01 cells. It was observed that the expression level of RPS27a was high in K562 cells and even higher in K562/G01 cells. Further analysis revealed that RPS27a knockdown by shRNA in both K562 and K562G01 cells inhibited the cell viability, induced cell cycle arrest at S and G2/M phases and increased cell apoptosis induced by imatinib. Combination of shRNA with imatinib treatment could lead to more cleaved PARP and cleaved caspase-3 expression in RPS27a knockdown cells. Further, it was found that phospho-ERK(p-ERK) and BCL-2 were down-regulated and P21 up-regulated in RPS27a knockdown cells. In conclusion, RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells. It appears that drugs targeting RPS27a combining with tyrosine kinase inhibitor (TKI) might represent a novel therapy strategy in TKI resistant CML patients.

  19. Differential effects of antofine N-oxide on solid tumor and leukemia cells.

    Science.gov (United States)

    Bour, Tania; Yang, Xianwen; Li, Weihong; Bernardin, Francois; Kaoma, Tony; Muller, Arnaud; Vallar, Laurent; Steinmetz, André

    2014-01-01

    We have studied the anti-cancer activities of antofine N-oxide isolated and purified from the medicinal plant Cynanchum vincetoxicum. Antofine N-oxide displayed a strong inhibitory effect on several solid tumor cell lines (glioblastoma, breast carcinoma and lung carcinoma) and on a T-cell leukemia cell line. Remarkably, its cytotoxic effect was considerably weaker in non-cancer cells. Antofine N-oxide was found to inhibit proliferation of the solid tumor cells whereas it caused apoptotic cell death in the leukemia cells. A microarray analysis after a short treatment revealed that the number of differentially expressed genes was considerably higher in solid tumor than in leukemia cells. Up-regulated genes in the three solid tumor cell lines include genes related to TNFα signaling, of which TNFα was among the most significantly induced. A functional analysis revealed that TNFR1 signaling was most likely activated in the solid tumor cells. The increased mRNA levels of several genes of this pathway (namely TNFα, TNFAIP3 and BIRC3) were confirmed by real-time quantitative PCR after different treatment durations. Finally a slight inhibition of NFκB-mediated transcription was observed in the same cells. Together our results suggest that inhibition of cell proliferation in solid tumor cells essentially occurs through TNFα signaling whereas this pathway is not activated in leukemia cells. Apoptotic cell death in the latter is induced by a distinct yet unknown pathway.

  20. Evaluation of a new in-clinic test system to detect feline immunodeficiency virus and feline leukemia virus infection.

    Science.gov (United States)

    Sand, Christina; Englert, Theresa; Egberink, Herman; Lutz, Hans; Hartmann, Katrin

    2010-06-01

    Many in-house tests for the diagnosis of feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infection are licensed for use in veterinary practice. A new test with unknown performance has recently appeared on the market. The aims of this study were to define the efficacy of a new in-clinic test system, the Anigen Rapid FIV Ab/FeLV Ag Test, and to compare it with the current leading in-clinic test, the SNAP Kombi Plus FeLV Antigen/FIB Antibody Test. Three-hundred serum samples from randomly selected healthy and diseased cats presented to the Clinic of Small Animal Medicine at Ludwig Maximilian University were tested using both the Anigen Rapid Test and the SNAP Kombi Plus Test. Diagnostic sensitivity, specificity, and positive and negative predictive values were calculated for both tests using Western blot as the gold standard for verification of FIV infection and PCR as the gold standard for FeLV infection. The presence of antibodies against FIV was confirmed by Western blot in 9/300 samples (prevalence 3%). FeLV DNA was detected by PCR in 15/300 samples (prevalence 5%). For FIV infection the Anigen Rapid Test had a sensitivity of 88.9%, specificity of 99.7%, positive predictive value of 88.9%, and negative predictive value of 99.7%. For FeLV infection, the Anigen Rapid Test had a sensitivity of 40.0%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 96.9%. Diagnostic accuracy was similar to that of the SNAP Kombi Plus Test. The new Anigen Rapid FIV Ab/FeLV Ag Test performed very well and can be recommended for use in veterinary practice.

  1. Radotinib Induces Apoptosis of CD11b+ Cells Differentiated from Acute Myeloid Leukemia Cells.

    Directory of Open Access Journals (Sweden)

    Sook-Kyoung Heo

    Full Text Available Radotinib, developed as a BCR/ABL tyrosine kinase inhibitor (TKI, is approved for the second-line treatment of chronic myeloid leukemia (CML in South Korea. However, therapeutic effects of radotinib in acute myeloid leukemia (AML are unknown. In the present study, we demonstrate that radotinib significantly decreases the viability of AML cells in a dose-dependent manner. Kasumi-1 cells were more sensitive to radotinib than NB4, HL60, or THP-1 cell lines. Furthermore, radotinib induced CD11b expression in NB4, THP-1, and Kasumi-1 cells either in presence or absence of all trans-retinoic acid (ATRA. We found that radotinib promoted differentiation and induced CD11b expression in AML cells by downregulating LYN. However, CD11b expression induced by ATRA in HL60 cells was decreased by radotinib through upregulation of LYN. Furthermore, radotinib mainly induced apoptosis of CD11b+ cells in the total population of AML cells. Radotinib also increased apoptosis of CD11b+ HL60 cells when they were differentiated by ATRA/dasatinib treatment. We show that radotinib induced apoptosis via caspase-3 activation and the loss of mitochondrial membrane potential (ΔΨm in CD11b+ cells differentiated from AML cells. Our results suggest that radotinib may be used as a candidate drug in AML or a chemosensitizer for treatment of AML by other therapeutics.

  2. Re-evaluation of various molecular targets located on CD34+CD38-Lin-leukemia stem cells and other cell subsets in pediatric acute myeloid leukemia.

    Science.gov (United States)

    Cheng, Yuping; Jia, Ming; Chen, Yuanyuan; Zhao, Haizhao; Luo, Zebin; Tang, Yongmin

    2016-01-01

    Leukemia stem cells (LSCs) are hypothesized to be capable of driving the development of leukemia, and are responsible for disease relapse. Antibody therapy targeting cell surface antigens has significantly improved the treatment outcomes of leukemia. Therefore, it is important to identify cell surface markers that are expressed on LSCs, and that are unexpressed or expressed at reduced levels on normal hematopoietic stem cells (HSCs), in order to establish novel therapeutic targets. In the present study, the immunophenotypic characteristics of cluster of differentiation (CD)34 + CD38 - lineage (Lin) - stem cells were analyzed, and antigen expression levels were compared with the expression of other cell components, using multicolor flow cytometry, in 54 patients with newly diagnosed acute myeloid leukemia (AML) and 11 control patients with immune thrombocytopenia. The findings indicated that CD133 and human leukocyte antigen (HLA)-DR were expressed on normal HSCs and on AML LSCs, with no significant difference (P>0.05). By contrast, CD33, CD123 and CD44 were highly expressed on AML LSCs, and demonstrated significant differences compared with their expression on normal HSCs (CD33, 81.7 vs. 18.3%; CD123, 75.8 vs. 19.1%; CD44, 97.7 vs. 84.4%). Among the aforementioned antigens, CD33 and CD123 were promising candidates for targeted therapy for the treatment of AML. This was particularly evident for CD123 in immature AML subtype cells, which may require additional investigation within a clinical trial setting. CD44, CD133 and HLA-DR may not be suitable for leukemia targeting due to their broad and high expression levels on normal HSCs and other tissues.

  3. Nanomechanical measurement of adhesion and migration of leukemia cells with phorbol 12-myristate 13-acetate treatment.

    Science.gov (United States)

    Zhou, Zhuo Long; Ma, Jing; Tong, Ming-Hui; Chan, Barbara Pui; Wong, Alice Sze Tsai; Ngan, Alfonso Hing Wan

    The adhesion and traction behavior of leukemia cells in their microenvironment is directly linked to their migration, which is a prime issue affecting the release of cancer cells from the bone marrow and hence metastasis. In assessing the effectiveness of phorbol 12-myristate 13-acetate (PMA) treatment, the conventional batch-cell transwell-migration assay may not indicate the intrinsic effect of the treatment on migration, since the treatment may also affect other cellular behavior, such as proliferation or death. In this study, the pN-level adhesion and traction forces between single leukemia cells and their microenvironment were directly measured using optical tweezers and traction-force microscopy. The effects of PMA on K562 and THP1 leukemia cells were studied, and the results showed that PMA treatment significantly increased cell adhesion with extracellular matrix proteins, bone marrow stromal cells, and human fibroblasts. PMA treatment also significantly increased the traction of THP1 cells on bovine serum albumin proteins, although the effect on K562 cells was insignificant. Western blots showed an increased expression of E-cadherin and vimentin proteins after the leukemia cells were treated with PMA. The study suggests that PMA upregulates adhesion and thus suppresses the migration of both K562 and THP1 cells in their microenvironment. The ability of optical tweezers and traction-force microscopy to measure directly pN-level cell-protein or cell-cell contact was also demonstrated.

  4. Seroprevalence of feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) in shelter cats on the island of Newfoundland, Canada.

    Science.gov (United States)

    Munro, Hannah J; Berghuis, Lesley; Lang, Andrew S; Rogers, Laura; Whitney, Hugh

    2014-04-01

    Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses found within domestic and wild cat populations. These viruses cause severe illnesses that eventually lead to death. Housing cats communally for long periods of time makes shelters at high risk for virus transmission among cats. We tested 548 cats from 5 different sites across the island of Newfoundland for FIV and FeLV. The overall seroprevalence was 2.2% and 6.2% for FIV and FeLV, respectively. Two sites had significantly higher seroprevalence of FeLV infection than the other 3 sites. Analysis of sequences from the FeLV env gene (envelope gene) from 6 positive cats showed that 4 fell within the FeLV subtype-A, while 2 sequences were most closely related to FeLV subtype-B and endogenous feline leukemia virus (en FeLV). Varying seroprevalence and the variation in sequences at different sites demonstrate that some shelters are at greater risk of FeLV infections and recombination can occur at sites of high seroprevalence.

  5. Hypomethylation of the Treg-Specific Demethylated Region in FOXP3 Is a Hallmark of the Regulatory T-cell Subtype in Adult T-cell Leukemia.

    Science.gov (United States)

    Shimazu, Yayoi; Shimazu, Yutaka; Hishizawa, Masakatsu; Hamaguchi, Masahide; Nagai, Yuya; Sugino, Noriko; Fujii, Sumie; Kawahara, Masahiro; Kadowaki, Norimitsu; Nishikawa, Hiroyoshi; Sakaguchi, Shimon; Takaori-Kondo, Akifumi

    2016-02-01

    Adult T-cell leukemia (ATL) is an aggressive T-cell malignancy caused by human T-cell leukemia virus type 1. Because of its immunosuppressive property and resistance to treatment, patients with ATL have poor prognoses. ATL cells possess the regulatory T cell (Treg) phenotype, such as CD4 and CD25, and usually express forkhead box P3 (FOXP3). However, the mechanisms of FOXP3 expression and its association with Treg-like characteristics in ATL remain unclear. Selective demethylation of the Treg-specific demethylated region (TSDR) in the FOXP3 gene leads to stable FOXP3 expression and defines natural Tregs. Here, we focus on the functional and clinical relationship between the epigenetic pattern of the TSDR and ATL. Analysis of DNA methylation in specimens from 26 patients with ATL showed that 15 patients (58%) hypomethylated the TSDR. The FOXP3(+) cells were mainly observed in the TSDR-hypomethylated cases. The TSDR-hypomethylated ATL cells exerted more suppressive function than the TSDR-methylated ATL cells. Thus, the epigenetic analysis of the FOXP3 gene identified a distinct subtype with Treg properties in heterogeneous ATL. Furthermore, we observed that the hypomethylation of TSDR was associated with poor outcomes in ATL. These results suggest that the DNA methylation status of the TSDR is an important hallmark to define this heterogeneous disease and to predict ATL patient prognosis. ©2015 American Association for Cancer Research.

  6. Leukemia stem cells in T-ALL require active Hif1α and Wnt signaling

    Science.gov (United States)

    Giambra, Vincenzo; Jenkins, Catherine E.; Lam, Sonya H.; Hoofd, Catherine; Belmonte, Miriam; Wang, Xuehai; Gusscott, Sam; Gracias, Deanne

    2015-01-01

    The Wnt signaling pathway has been shown to play important roles in normal hematopoietic stem cell biology and in the development of both acute and chronic myelogenous leukemia. Its role in maintaining established leukemia stem cells, which are more directly relevant to patients with disease, however, is less clear. To address what role Wnt signaling may play in T-cell acute lymphoblastic leukemia (T-ALL), we used a stably integrated fluorescent Wnt reporter construct to interrogate endogenous Wnt signaling activity in vivo. In this study, we report that active Wnt signaling is restricted to minor subpopulations within bulk tumors, that these Wnt-active subsets are highly enriched for leukemia-initiating cells (LICs), and that genetic inactivation of β-catenin severely reduces LIC frequency. We show further that β-catenin transcription is upregulated by hypoxia through hypoxia-inducible factor 1α (Hif1α) stabilization, and that deletion of Hif1α also severely reduces LIC frequency. Of note, the deletion of β-catenin or Hif1α did not impair the growth or viability of bulk tumor cells, suggesting that elements of the Wnt and Hif pathways specifically support leukemia stem cells. We also confirm the relevance of these findings to human disease using cell lines and patient-derived xenografts, suggesting that targeting these pathways could benefit patients with T-ALL. PMID:25934477

  7. Acute Lymphocytic Leukemia

    Science.gov (United States)

    Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, however, the bone marrow produces abnormal white blood ...

  8. Acute Myeloid Leukemia

    Science.gov (United States)

    Leukemia is cancer of the white blood cells. White blood cells help your body fight infection. Your blood cells form in your bone marrow. In leukemia, however, the bone marrow produces abnormal white blood ...

  9. Chimeric Antigen Receptor T-Cells for the Treatment of B-Cell Acute Lymphoblastic Leukemia

    Directory of Open Access Journals (Sweden)

    Ciprian Tomuleasa

    2018-02-01

    Full Text Available Chimeric antigen receptor (CAR T-cell technology has seen a rapid development over the last decade mostly due to the potential that these cells may have in treating malignant diseases. It is a generally accepted principle that very few therapeutic compounds deliver a clinical response without treatment-related toxicity, and studies have shown that CAR T-cells are not an exception to this rule. While large multinational drug companies are currently investigating the potential role of CAR T-cells in hematological oncology, the potential of such cellular therapies are being recognized worldwide as they are expected to expand in the patient to support the establishment of the immune memory, provide a continuous surveillance to prevent and/or treat a relapse, and keep the targeted malignant cell subpopulation in check. In this article, we present the possible advantages of using CAR T-cells in treating acute lymphoblastic leukemia, presenting the technology and the current knowledge in their preclinical and early clinical trial use. Thus, this article first presents the main present-day knowledge on the standard of care for acute lymphoblastic leukemia. Afterward, current knowledge is presented about the use of CAR T-cells in cancer immunotherapy, describing their design, the molecular constructs, and the preclinical data on murine models to properly explain the background for their clinical use. Last, but certainly not least, this article presents the use of CAR T-cells for the immunotherapy of B-cell acute lymphoblastic leukemia, describing both their potential clinical advantages and the possible side effects.

  10. Hollow core photonic crystal fiber for monitoring leukemia cells using surface enhanced Raman scattering (SERS).

    Science.gov (United States)

    Khetani, Altaf; Momenpour, Ali; Alarcon, Emilio I; Anis, Hanan

    2015-11-01

    The present paper demonstrates an antibody-free, robust, fast, and portable platform for detection of leukemia cells using Raman spectroscopy with a 785-nm laser diode coupled to a hollow core photonic crystal (HC-PCF) containing silver nanoparticles. Acute myeloid leukemia is one of the most common bone marrow cancers in children and youths. Clinical studies suggest that early diagnosis and remission evaluation of myoblasts in the bone marrow are pivotal for improving patient survival. However, the current protocols for leukemic cells detection involve the use of expensive antibodies and flow cytometers. Thus, we have developed a new technology for detection of leukemia cells up to 300 cells/ml using a compact fiber HC-PCF, which offers a novel alternative to existing clinical standards. Furthermore, we were also able to accurately distinguish live, apoptotic and necrotic leukemic cells.

  11. Non-seminomatous mediastinal germ cell tumor and acute megakaryoblastic leukemia.

    Science.gov (United States)

    Mukherjee, Sarbajit; Ibrahimi, Sami; John, Sonia; Adnan, Mohammed Muqeet; Scordino, Teresa; Khalil, Mohammad O; Cherry, Mohamad

    2017-09-01

    The association between mediastinal germ cell tumors (MGCT) and acute megakaryoblastic (M7) leukemia has been known for many years. We hereby present this review to better characterize the coexistence of these entities as well as the salient features, the treatment options, and the overall prognosis. A search of PUBMED, Medline, and EMBASE databases via OVID engine for primary articles and case reports under keywords "germ cell tumors" and "acute myeloid leukemia" revealed a total of 26 cases in English that reported MGCT and M7 leukemia. The median age at diagnosis of MGCT was 24 (13-36) years. All cases were stage III. All cases of MGCT were of non-seminomatous origin and one case was unclassified. MGCT occurred prior to the diagnosis of leukemia in 46% of cases and concomitantly in 31% of cases. M7 leukemia was never reported prior to the appearance of MGCT. Complex cytogenetics and hyperdiploidy were the most commonly reported cytogenetic abnormalities. In the 23 cases where the treatment regimen was available, platinum-based chemotherapy directed towards management of the germ cell tumors was used initially in 21 cases and leukemia-directed treatment was used initially in 2 cases only. The median time from diagnosis of MGCT to development of M7 leukemia was 5 (2.25-39) months. Median time to death from the initial diagnosis of MGCT was 6 (0.5-60) months. Patients with a history of MGCT are at higher risk of developing M7 leukemia. They need long-term follow-up with a particular attention to the development of hematological malignancies. The overall prognosis remains poor.

  12. Molecular characterization of neoplastic and normal "sister" lymphoblastoid B-cell lines from chronic lymphocytic leukemia

    DEFF Research Database (Denmark)

    Lanemo Myhrinder, Anna; Hellqvist, Eva; Bergh, Ann-Charlotte

    2013-01-01

    Chronic lymphocytic leukemia (CLL) B-cells resemble self-renewing CD5 + B-cells carrying auto/xeno-antigen-reactive B-cell receptors (BCRs) and multiple innate pattern-recognition receptors, such as Toll-like receptors and scavenger receptors. Integration of signals from BCRs with multiple surface...

  13. Synergistic effect of green tea EGCG treatment with gamma radiation in leukemia cell necrosis

    International Nuclear Information System (INIS)

    Lee, Hong Soo; Kim, Jae Man

    2006-01-01

    During cancer therapy, gamma-ray irradiation and treatment of anti-cancer chemicals destroy the normal cells as well as cancer cells. In this study, we investigated the effect of epigallocathechin-gallate (EGCG) extracted from green tea, which is known to have anti-cancer and anti-oxident activities, in order to find out the feasible method to protect the normal cells and to kill the cancer cells efficiently. We investigated the effect of EGCG on the leukemia cell growth and cell necrosis, especially when treated along with gamma radiation. The EGCG inhibited the leukemia cell, HL-60, growth at the appropriate concentration while it exhibited no influence on the normal cell growth. More significantly, it enhanced leukemia cell necrosis when its treatment was combined with gamma irradiation. Simultaneous treatment of EGCG and gamma radiation increased leukemia cell necrosis up to 35% compared with separate treatments. These results suggest that drinking of green tea or co-treatment of EGCG during gamma irradiation therapy may result in better prognosis through enhancement of the tumor cell necrosis and protection of the normal cells

  14. Prevalence and clinical significance of resistance to perforin- and FAS-mediated cell death in leukemia

    NARCIS (Netherlands)

    Otten, H. G.; van Ginkel, W. G. J.; Hagenbeek, A.; Petersen, E. J.

    2004-01-01

    Killer lymphocytes play a central therapeutic role in graft-versus-leukemia following allogeneic hematopoietic stem cell transplantation (HSCT). The Perforin/Granzyme and FAS/CD95 pathways are of crucial importance in tumor cell elimination by killer cells. In this study, we have examined whether

  15. Proteomic analysis of human acute leukemia cells: insight into their classification.

    Science.gov (United States)

    Cui, Jiu-Wei; Wang, Jie; He, Kun; Jin, Bao-Feng; Wang, Hong-Xia; Li, Wei; Kang, Li-Hua; Hu, Mei-Ru; Li, Hui-Yan; Yu, Ming; Shen, Bei-Fen; Wang, Guan-Jun; Zhang, Xue-Min

    2004-10-15

    French-American-British (FAB) classification of acute leukemia with genetic heterogeneity is important for treatment and prognosis. However, the distinct protein profiles that contribute to the subtypes and facilitate molecular definition of acute leukemia classification are still unclear. The proteins of leukemic cells from 61 cases of acute leukemia characterized by FAB classification were separated by two-dimensional electrophoresis, and the differentially expressed protein spots were identified by both matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) and tandem electrospray ionization MS (ESI-MS/MS). The distinct protein profiles of acute leukemia FAB types or subtypes were successfully explored, including acute myeloid leukemia (AML), its subtypes (M2, M3, and M5) and acute lymphoid leukemia (ALL), which were homogeneous within substantial samples of the respective subgroups but clearly differed from all other subgroups. We found a group of proteins that were highly expressed in M2 and M3, rather than other subtypes. Among them, myeloid-related proteins 8 and 14 were first reported to mark AML differentiation and to differentiate AML from ALL. Heat shock 27 kDa protein 1 and other proteins that are highly expressed in ALL may play important roles in clinically distinguishing AML from ALL. Another set of proteins up-regulated was restricted to granulocytic lineage leukemia. High-level expression of NM23-H1 was found in all but the M3a subtype, with favorable prognosis. These data have implications in delineating the pathways of aberrant gene expression underlying the pathogenesis of acute leukemia and could facilitate molecular definition of FAB classification. The extension of the present analysis to currently less well-defined acute leukemias will identify additional subgroups.

  16. Pseudotyped murine leukemia virus for schistosome transgenesis: approaches, methods and perspectives.

    Science.gov (United States)

    Mann, Victoria H; Suttiprapa, Sutas; Skinner, Danielle E; Brindley, Paul J; Rinaldi, Gabriel

    2014-06-01

    Draft genome sequences for the human schistosomes, Schistosoma japonicum, S. mansoni and S. haematobium are now available. The schistosome genome contains ~11,000 protein encoding genes for which the functions of few are well understood. Nonetheless, the newly described gene products and novel non-coding RNAs represent potential intervention targets, and molecular tools are being developed to determine their importance. Over the past decade, noteworthy advances has been reported towards development of tools for gene manipulation of schistosomes, including gene expression perturbation by RNAi, and transient and stable transfection including transgenesis mediated by genome integration competent vectors. Retrovirus-mediated transgenesis is an established functional genomic approach for model species. It offers the means to establish gain- or loss-of-function phenotypes, supports vector-based RNA interference, and represents a powerful forward genetics tool for insertional mutagenesis. Murine leukemia virus (MLV) pseudotyped with vesicular stomatitis virus glycoprotein mediates somatic transgenesis in S. mansoni, and vertical transmission of integrated transgenes in S. mansoni has been demonstrated, leading the establishment of transgenic lines. In addition, MLV transgenes encoding antibiotic resistance allow the selection of MLV-transduced parasites with the appropriate antibiotics. Here we describe detailed methods to produce and quantify pseudotyped MLV particles for use in transducing developmental stages of schistosomes. Approaches to analyze MLV-transduced schistosomes, including qPCR and high throughput approaches to verify and map genome integration of transgenes are also presented. We anticipate these tools should find utility in genetic investigations in other laboratories and for other helminth pathogens of important neglected tropical diseases.

  17. Characterization of miRNomes in acute and chronic myeloid leukemia cell lines.

    Science.gov (United States)

    Xiong, Qian; Yang, Yadong; Wang, Hai; Li, Jie; Wang, Shaobin; Li, Yanming; Yang, Yaran; Cai, Kan; Ruan, Xiuyan; Yan, Jiangwei; Hu, Songnian; Fang, Xiangdong

    2014-04-01

    Myeloid leukemias are highly diverse diseases and have been shown to be associated with microRNA (miRNA) expression aberrations. The present study involved an in-depth miRNome analysis of two human acute myeloid leukemia (AML) cell lines, HL-60 and THP-1, and one human chronic myeloid leukemia (CML) cell line, K562, via massively parallel signature sequencing. mRNA expression profiles of these cell lines that were established previously in our lab facilitated an integrative analysis of miRNA and mRNA expression patterns. miRNA expression profiling followed by differential expression analysis and target prediction suggested numerous miRNA signatures in AML and CML cell lines. Some miRNAs may act as either tumor suppressors or oncomiRs in AML and CML by targeting key genes in AML and CML pathways. Expression patterns of cell type-specific miRNAs could partially reflect the characteristics of K562, HL-60 and THP-1 cell lines, such as actin filament-based processes, responsiveness to stimulus and phagocytic activity. miRNAs may also regulate myeloid differentiation, since they usually suppress differentiation regulators. Our study provides a resource to further investigate the employment of miRNAs in human leukemia subtyping, leukemogenesis and myeloid development. In addition, the distinctive miRNA signatures may be potential candidates for the clinical diagnosis, prognosis and treatment of myeloid leukemias. Copyright © 2014. Production and hosting by Elsevier Ltd.

  18. Lineage Switching in Acute Leukemias: A Consequence of Stem Cell Plasticity?

    Directory of Open Access Journals (Sweden)

    Elisa Dorantes-Acosta

    2012-01-01

    Full Text Available Acute leukemias are the most common cancer in childhood and characterized by the uncontrolled production of hematopoietic precursor cells of the lymphoid or myeloid series within the bone marrow. Even when a relatively high efficiency of therapeutic agents has increased the overall survival rates in the last years, factors such as cell lineage switching and the rise of mixed lineages at relapses often change the prognosis of the illness. During lineage switching, conversions from lymphoblastic leukemia to myeloid leukemia, or vice versa, are recorded. The central mechanisms involved in these phenomena remain undefined, but recent studies suggest that lineage commitment of plastic hematopoietic progenitors may be multidirectional and reversible upon specific signals provided by both intrinsic and environmental cues. In this paper, we focus on the current knowledge about cell heterogeneity and the lineage switch resulting from leukemic cells plasticity. A number of hypothetical mechanisms that may inspire changes in cell fate decisions are highlighted. Understanding the plasticity of leukemia initiating cells might be fundamental to unravel the pathogenesis of lineage switch in acute leukemias and will illuminate the importance of a flexible hematopoietic development.

  19. Lineage Switching in Acute Leukemias: A Consequence of Stem Cell Plasticity?

    Science.gov (United States)

    Dorantes-Acosta, Elisa; Pelayo, Rosana

    2012-01-01

    Acute leukemias are the most common cancer in childhood and characterized by the uncontrolled production of hematopoietic precursor cells of the lymphoid or myeloid series within the bone marrow. Even when a relatively high efficiency of therapeutic agents has increased the overall survival rates in the last years, factors such as cell lineage switching and the rise of mixed lineages at relapses often change the prognosis of the illness. During lineage switching, conversions from lymphoblastic leukemia to myeloid leukemia, or vice versa, are recorded. The central mechanisms involved in these phenomena remain undefined, but recent studies suggest that lineage commitment of plastic hematopoietic progenitors may be multidirectional and reversible upon specific signals provided by both intrinsic and environmental cues. In this paper, we focus on the current knowledge about cell heterogeneity and the lineage switch resulting from leukemic cells plasticity. A number of hypothetical mechanisms that may inspire changes in cell fate decisions are highlighted. Understanding the plasticity of leukemia initiating cells might be fundamental to unravel the pathogenesis of lineage switch in acute leukemias and will illuminate the importance of a flexible hematopoietic development. PMID:22852088

  20. Bovine leukemia virus seroprevalence among cattle presented for slaughter in the United States.

    Science.gov (United States)

    Bauermann, Fernando V; Ridpath, Julia F; Dargatz, David A

    2017-09-01

    Infection with bovine leukemia virus (BLV) results in economic loss because of reduced productivity, especially reduced milk production, and early culling. In the United States, studies in 1996, 1999, and 2007 showed BLV infection to be widespread, especially in dairy herds. We updated information herein on BLV seroprevalence in the United States, using samples submitted for testing and found negative for antibodies for Brucella by the Kentucky Eastern Regional Federal Brucellosis Laboratory. From October 2014 through August 2015, 2,000 samples from all regions of the contiguous United States were selected and tested for BLV antibodies by enzyme-linked immunosorbent assay. The overall percentage of samples positive for BLV antibody was 38.6%. Based on the animal's origin, the percent positive by region ranged from 32.5% (Mountain West region) to 54.3% (Northeast region; p animals (dairy plants; 47.6%) was higher than the positive rate at slaughter plants that processed mainly beef animals (beef plants; 33.6%; p < 0.05). The results suggest that BLV infection remains widespread in all regions of the United States and that rates may differ between beef and dairy cattle.

  1. Survey of feline leukemia virus and feline coronaviruses in captive neotropical wild felids from Southern Brazil.

    Science.gov (United States)

    Guimaraes, Ana M S; Brandão, Paulo E; de Moraes, Wanderlei; Cubas, Zalmir S; Santos, Leonilda C; Villarreal, Laura Y B; Robes, Rogério R; Coelho, Fabiana M; Resende, Mauricio; Santos, Renata C F; Oliveira, Rosangela C; Yamaguti, Mauricio; Marques, Lucas M; Neto, Renata L; Buzinhani, Melissa; Marques, Regina; Messick, Joanne B; Biondo, Alexander W; Timenetsky, Jorge

    2009-06-01

    A total of 57 captive neotropical felids (one Leopardus geoffroyi, 14 Leopardus pardalis, 17 Leopardus wiedii, 22 Leopardus tigrinus, and three Puma yagouaroundi) from the Itaipu Binacional Wildlife Research Center (Refúgio Bela Vista, Southern Brazil) were anesthetized for blood collection. Feces samples were available for 44 animals, including one L. geoffroyi, eight L. pardalis, 14 L. wiedii, 20 L. tigrinus, and one P. yagouaroundi. Total DNA and RNA were extracted from blood and feces, respectively, using commercial kits. Blood DNA samples were evaluated by polymerase chain reaction (PCR) for feline leukemia virus (FeLV) proviral DNA, whereas reverse transcriptase-PCR was run on fecal samples for detection of coronavirus RNA. None of the samples were positive for coronaviruses. A male L. pardalis and a female L. tigrinus were positive for FeLV proviral DNA, and identities of PCR products were confirmed by sequencing. This is the first evidence of FeLV proviral DNA in these species in Southern Brazil.

  2. Murine Leukemia Virus Uses TREX Components for Efficient Nuclear Export of Unspliced Viral Transcripts

    Directory of Open Access Journals (Sweden)

    Toshie Sakuma

    2014-03-01

    Full Text Available Previously we reported that nuclear export of both unspliced and spliced murine leukemia virus (MLV transcripts depends on the nuclear export factor (NXF1 pathway. Although the mRNA export complex TREX, which contains Aly/REF, UAP56, and the THO complex, is involved in the NXF1-mediated nuclear export of cellular mRNAs, its contribution to the export of MLV mRNA transcripts remains poorly understood. Here, we studied the involvement of TREX components in the export of MLV transcripts. Depletion of UAP56, but not Aly/REF, reduced the level of both unspliced and spliced viral transcripts in the cytoplasm. Interestingly, depletion of THO components, including THOC5 and THOC7, affected only unspliced viral transcripts in the cytoplasm. Moreover, the RNA immunoprecipitation assay showed that only the unspliced viral transcript interacted with THOC5. These results imply that MLV requires UAP56, THOC5 and THOC7, in addition to NXF1, for nuclear export of viral transcripts. Given that naturally intronless mRNAs, but not bulk mRNAs, require THOC5 for nuclear export, it is plausible that THOC5 plays a key role in the export of unspliced MLV transcripts.

  3. Evolutionary dynamics of endogenous feline leukemia virus proliferation among species of the domestic cat lineage

    International Nuclear Information System (INIS)

    Polani, Sagi; Roca, Alfred L.; Rosensteel, Bryan B.; Kolokotronis, Sergios-Orestis; Bar-Gal, Gila Kahila

    2010-01-01

    Endogenous feline leukemia viruses (enFeLVs) occur in the germ lines of the domestic cat and related wild species (genus Felis). We sequenced the long terminal repeats and part of the env region of enFeLVs in domestic cats and five wild species. A total of 305 enFeLV sequences were generated across 17 individuals, demonstrating considerable diversity within two major clades. Distinct proliferations of enFeLVs occurred before and after the black-footed cat diverged from the other species. Diversity of enFeLVs was limited for the sand cat and jungle cat suggesting that proliferation of enFeLVs occurred within these species after they diverged. Relationships among enFeLVs were congruent with host species relationships except for the jungle cat, which carried only enFeLVs from a lineage that recently invaded the germline (enFeLV-AGTT). Comparison of wildcat and domestic cat enFeLVs indicated that a distinctive germ line invasion of enFeLVs has not occurred since the cat was domesticated.

  4. Allogeneic stem cell transplantation for patients harboring T315I BCR-ABL mutated leukemias

    DEFF Research Database (Denmark)

    Nicolini, Franck Emmanuel; Basak, Grzegorz W; Soverini, Simona

    2011-01-01

    T315I(+) Philadelphia chromosome-positive leukemias are inherently resistant to all licensed tyrosine kinase inhibitors, and therapeutic options remain limited. We report the outcome of allogeneic stem cell transplantation in 64 patients with documented BCR-ABL(T315I) mutations. Median follow......-up was 52 months from mutation detection and 26 months from transplantation. At transplantation, 51.5% of patients with chronic myeloid leukemia were in the chronic phase and 4.5% were in advanced phases. Median overall survival after transplantation was 10.3 months (range 5.7 months to not reached [ie......, still alive]) for those with chronic myeloid leukemia in the blast phase and 7.4 months (range 1.4 months to not reached [ie, still alive]) for those with Philadelphia chromosome-positive acute lymphoblastic leukemia but has not yet been reached for those in the chronic and accelerated phases of chronic...

  5. Inverse relationship of tumors and mononuclear cell leukemia infiltration in the lungs of F344 rats

    Energy Technology Data Exchange (ETDEWEB)

    Lundgren, D.L.; Griffith, W.C.; Hahn, F.F.

    1995-12-01

    In 1970 and F344 rat, along with the B6C3F{sub 1} mouse, were selected as the standard rodents for the National Cancer Institute Carcinogenic Bioassay program for studies of potentially carcinogenic chemicals. The F344 rat has also been used in a variety of other carcinogenesis studies, including numerous studies at ITRI. A major concern to be considered in evaluating carcinogenic bioassay studies using the F344 rat is the relatively high background incidence of mononuclear cell leukemia (MCL) (also referred to as large granular lymphocytic leukemia, Fischer rat leukemia, or monocytic leukemia). Incidences of MCL ranging from 10 to 72% in male F344 rats to 6 to 31% in female F344 rats have been reported. Gaining the understanding of the mechanisms involved in the negative correlations noted should enhance our understanding of the mechanisms involved in the development of lung cancer.

  6. Mutational analyses of the core domain of Avian Leukemia and Sarcoma Viruses integrase: critical residues for concerted integration and multimerization

    International Nuclear Information System (INIS)

    Moreau, Karen; Faure, Claudine; Violot, Sebastien; Gouet, Patrice; Verdier, Gerard; Ronfort, Corinne

    2004-01-01

    During replicative cycle of retroviruses, the reverse-transcribed viral DNA is integrated into the cell DNA by the viral integrase (IN) enzyme. The central core domain of IN contains the catalytic site of the enzyme and is involved in binding viral ends and cell DNA as well as dimerization. We previously performed single amino acid substitutions in the core domain of an Avian Leukemia and Sarcoma Virus (ALSV) IN [Arch. Virol. 147 (2002) 1761]. Here, we modeled the resulting IN mutants and analyzed the ability of these mutants to mediate concerted DNA integration in an in vitro assay, and to form dimers by protein-protein cross-linking and size exclusion chromatography. The N197C mutation resulted in the inability of the mutant to perform concerted integration that was concomitant with a loss of IN dimerization. Surprisingly, mutations Q102G and A106V at the dimer interface resulted in mutants with higher efficiencies than the wild-type IN in performing two-ended concerted integration of viral DNA ends. The G139D and A195V mutants had a trend to perform one-ended DNA integration of viral ends instead of two-ended integration. More drastically, the I88L and L135G mutants preferentially mediated nonconcerted DNA integration although the proteins form dimers. Therefore, these mutations may alter the formation of IN complexes of higher molecular size than a dimer that would be required for concerted integration. This study points to the important role of core domain residues in the concerted integration of viral DNA ends as well as in the oligomerization of the enzyme

  7. Biguanides sensitize leukemia cells to ABT-737-induced apoptosis by inhibiting mitochondrial electron transport

    Science.gov (United States)

    Velez, Juliana; Pan, Rongqing; Lee, Jason T.C.; Enciso, Leonardo; Suarez, Marta; Duque, Jorge Eduardo; Jaramillo, Daniel; Lopez, Catalina; Morales, Ludis; Bornmann, William; Konopleva, Marina; Krystal, Gerald; Andreeff, Michael; Samudio, Ismael

    2016-01-01

    Metformin displays antileukemic effects partly due to activation of AMPK and subsequent inhibition of mTOR signaling. Nevertheless, Metformin also inhibits mitochondrial electron transport at complex I in an AMPK-independent manner, Here we report that Metformin and rotenone inhibit mitochondrial electron transport and increase triglyceride levels in leukemia cell lines, suggesting impairment of fatty acid oxidation (FAO). We also report that, like other FAO inhibitors, both agents and the related biguanide, Phenformin, increase sensitivity to apoptosis induction by the bcl-2 inhibitor ABT-737 supporting the notion that electron transport antagonizes activation of the intrinsic apoptosis pathway in leukemia cells. Both biguanides and rotenone induce superoxide generation in leukemia cells, indicating that oxidative damage may sensitize toABT-737 induced apoptosis. In addition, we demonstrate that Metformin sensitizes leukemia cells to the oligomerization of Bak, suggesting that the observed synergy with ABT-737 is mediated, at least in part, by enhanced outer mitochondrial membrane permeabilization. Notably, Phenformin was at least 10-fold more potent than Metformin in abrogating electron transport and increasing sensitivity to ABT-737, suggesting that this agent may be better suited for targeting hematological malignancies. Taken together, our results suggest that inhibition of mitochondrial metabolism by Metformin or Phenformin is associated with increased leukemia cell susceptibility to induction of intrinsic apoptosis, and provide a rationale for clinical studies exploring the efficacy of combining biguanides with the orally bioavailable derivative of ABT-737, Venetoclax. PMID:27283492

  8. Cell size variations of large granular lymphocyte leukemia: Implication of a small cell subtype of granular lymphocyte leukemia with STAT3 mutations.

    Science.gov (United States)

    Tanahashi, Takahiro; Sekiguchi, Nodoka; Matsuda, Kazuyuki; Takezawa, Yuka; Ito, Toshiro; Kobayashi, Hikaru; Ichikawa, Naoaki; Nishina, Sayaka; Senoo, Noriko; Sakai, Hitoshi; Nakazawa, Hideyuki; Ishida, Fumihiro

    2016-06-01

    Large granular lymphocyte leukemia (LGL-L) has been morphologically defined as a group of lymphoproliferative disorders, including T-cell large granular lymphocytic leukemia (T-LGL-L), chronic lymphoproliferative disorders of NK cells (CLPD-NK) and aggressive NK cell leukemia. We investigated the morphological features of LGL leukemic cells in 26 LGL-L patients in order to elucidate relationships with current classifications and molecular backgrounds. LGL-L cells were mostly indistinguishable from normal LGL. Patients with STAT3 SH2 domain mutations showed significantly smaller cells compared with patients without STAT3 mutations. Four patients with T-LGL-L showed smaller granular lymphocytes with a median diameter of less than 13μm, which were rarely seen in normal subjects. This small subtype of T-LGL-L was recognized among rather young patients and was associated with D661Y mutations in the STAT3 gene SH2 domain. In addition, all of them showed anemia including two cases with pure red cell aplasia. These results suggest the heterogeneity of T-LGL-L and a specific subtype with small variants of T-LGL-L. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Differential protective effects of immune lymphoid cells against transplanted line Ib leukemia and immune polioencephalomyelitis

    International Nuclear Information System (INIS)

    Duffey, P.S.; Lukasewycz, O.A.; Olson, D.S.; Murphy, W.H.

    1978-01-01

    The capacity of immune cells obtained from the major lymphoid compartments to protect C58 mice from transplanted line Ib leukemia, and from an age-dependent autoimmune CNS disease (immune polioencephalomyelitis = IPE) elicited by immunizing old C58 mice with inactivated Ib cells was quantified. Cells used for comparative adoptive protection tests were harvested from the major lymphoid compartments 14 to 15 days after young C58 mice were immunized with inactivated Ib cell preparations. Regression curves were plotted from survival data and the log 10 PD 50 values were determined. Immune spleen (ISC) and peritoneal cells (IPEC) were significantly more protective against transplanted Ib cells than immune lymph node (ILNC), thymic (ITC), and marrow cells (IMC). In contrast, IPEC and IMC were not protective against IPE and ITC were only marginally protective. ILNC afforded significant protection to transplantable leukemia but were only marginally protective to IPE. When ISC were treated with anti-thy 1.2 serum and complement, protection against transplanted leukemia and IPE was reduced > 99%. When donors of immune lymphoid cells were treated with 12.5 mg of cortisone acetate daily for 2 days before lymphoid cells were harvested, protection against transplanted Ib cells by ISC was reduced by approximately 90% whereas protection against IPE was totally eliminated. Considered together, these results indicate that the protective mechanisms to transplantable leukemia and IPE differ significantly in the same indicator mouse strain

  10. Differential mechanisms of cell death induction via delivery of therapeutic nanoliposomal ceramide in leukemias

    Science.gov (United States)

    Ryland, Lindsay K.

    Large granular lymphocyte (LGL) leukemia is a rare lymphoproliferative malignancy that involves blood, bone marrow and spleen infiltration. Clinically, LGL leukemia can manifest as a chronic lymphocytosis or as an aggressive leukemia that is fatal within a short period of time. A segment of LGL leukemia patients are unresponsive to immunosuppressive therapy and currently there is no known curative treatment for this disease. Another hematological malignancy, chronic lymphocytic leukemia (CLL) is the most prevalent leukemia in adults in Western countries and accounts for approximately 30% of all diagnosed leukemia cases. Around 95% of all CLL cases involve clonal expansion and abnormal proliferation of neoplastic B lymphocytes in lymphoid organs, bone marrow and peripheral blood. Similar to LGL leukemia, CLL is also incurable with current therapies. Therefore, this represents a need for new therapeutic approaches for treatment of these diseases. Recent advances in nanotechnology have illustrated the feasibility of generating nanoliposomes that encapsulate hydrophobic compounds, like ceramide, to facilitate treatment of LGL leukemia and CLL. Ceramide is an anti-proliferative sphingolipid metabolite that has been shown to selectively induce cell death in cancer cells. However, the use of ceramide as a chemotherapeutic agent is limited due to hydrophobicity. While it is understood how nanoliposomal ceramide induces cell death in several types of cancers and hematological malignancies, the effect of nanoliposomal ceramide treatment in LGL leukemia and CLL remains unclear. In this study, we investigate the differential mechanisms of cell death induction following nanoliposomal C6-ceramide treatment in both LGL leukemia and CLL. We show that nanoliposomal C6-ceramide displays minimal cytotoxicity in normal donors. peripheral blood mononuclear cells (PBMCs) and is a well-tolerated therapy during in vivo treatment in these leukemia models. To further examine this mechanism

  11. Indoleamine 2,3-dioxygenase-expressing leukemic dendritic cells impair a leukemia-specific immune response by inducing potent T regulatory cells

    OpenAIRE

    Curti, A; Trabanelli, S; Onofri, C; Aluigi, M; Salvestrini, V; Ocadlikova, D; Evangelisti, C; Rutella, S; De Cristofaro, R; Ottaviani, E; Baccarani, M; Lemoli, RM

    2010-01-01

    Background: The immunoregulatory enzyme indoleamine 2,3-dioxygenase, which catalyzes the conversion of tryptophan into kynurenine, is expressed in a significant subset of patients with acute myeloid leukemia, resulting in the inhibition of T-cell proliferation and the induction of regulatory T cells. Acute myeloid leukemia cells can be differentiated into dendritic cells, which have increased immunogenicity and have been proposed as vaccines against leukemia.\\ud Design and Methods: Leukemic d...

  12. 3D/4D multiscale imaging in acute lymphoblastic leukemia cells: visualizing dynamics of cell death

    Science.gov (United States)

    Sarangapani, Sreelatha; Mohan, Rosmin Elsa; Patil, Ajeetkumar; Lang, Matthew J.; Asundi, Anand

    2017-06-01

    Quantitative phase detection is a new methodology that provides quantitative information on cellular morphology to monitor the cell status, drug response and toxicity. In this paper the morphological changes in acute leukemia cells treated with chitosan were detected using d'Bioimager a robust imaging system. Quantitative phase image of the cells was obtained with numerical analysis. Results show that the average area and optical volume of the chitosan treated cells is significantly reduced when compared with the control cells, which reveals the effect of chitosan on the cancer cells. From the results it can be attributed that d'Bioimager can be used as a non-invasive imaging alternative to measure the morphological changes of the living cells in real time.

  13. Adult T cell leukemia aggressivenness correlates with loss of both 5-hydroxymethylcytosine and TET2 expression.

    Science.gov (United States)

    Marçais, Ambroise; Waast, Laetitia; Bruneau, Julie; Hanssens, Katia; Asnafi, Vahid; Gaulard, Philippe; Suarez, Felipe; Dubreuil, Patrice; Gessain, Antoine; Hermine, Olivier; Pique, Claudine

    2017-08-08

    Mutations in TET2 , encoding one of the TET members responsible for the conversion of DNA cytosine methylation to hydroxymethylation (5-hmc), have been recently described in Human T-lymphotropic virus type 1-associated adult T-cell leukemia/lymphoma (ATLL). However, neither the amount of genomic 5-hmc in ATLL tumor cells nor TET2 expression has been studied yet. In this study, we analyzed these two parameters as well as the mutational status of TET2 in ATLL patients. By employing a direct in situ approach, we documented that tumor T cells infiltrating lymph nodes exhibit low level of 5-hmc compared to residual normal T cells. Furthermore, this 5-hmc defect was more pronounced in tumor T cells from acute patients than from chronic ones and correlated with reduced expression of TET2 protein. TET2 variations were found in 14 patients (20%), including 13 with aggressive forms. Strikingly, 9 of the 14 patients showed the same variation (SNP rs72963007), whose frequency in ATLL patients was significantly higher than that of an ethnically matched control population (13% vs. 5%). However, no reduction of 5-hmc was found in PBMC from individuals possessing the variant rs72963007 TET2 allele, as compared to wild-type individuals. In contrast, a robust correlation was observed between 5-hmc and the levels of TET2 mRNA. Finally, loss of 5-hmc and TET2 downregulation both correlated with poor survival. These findings demonstrate that ATLL progression coincides with loss of genomic 5-hmc and indicate that downregulation of TET2 , rather than TET2 mutations, is the key mechanism involved in 5-hmc modulation during ATLL progression.

  14. Ref-1/APE1 as a Transcriptional Regulator and Novel Therapeutic Target in Pediatric T-cell Leukemia.

    Science.gov (United States)

    Ding, Jixin; Fishel, Melissa L; Reed, April M; McAdams, Erin; Czader, Magdalena B; Cardoso, Angelo A; Kelley, Mark R

    2017-07-01

    The increasing characterization of childhood acute lymphoblastic leukemia (ALL) has led to the identification of multiple molecular targets but has yet to translate into more effective targeted therapies, particularly for high-risk, relapsed T-cell ALL. Searching for master regulators controlling multiple signaling pathways in T-ALL, we investigated the multifunctional protein redox factor-1 (Ref-1/APE1), which acts as a signaling "node" by exerting redox regulatory control of transcription factors important in leukemia. Leukemia patients' transcriptome databases showed increased expression in T-ALL of Ref-1 and other genes of the Ref-1/SET interactome. Validation studies demonstrated that Ref-1 is expressed in high-risk leukemia T cells, including in patient biopsies. Ref-1 redox function is active in leukemia T cells, regulating the Ref-1 target NF-κB, and inhibited by the redox-selective Ref-1 inhibitor E3330. Ref-1 expression is not regulated by Notch signaling, but is upregulated by glucocorticoid treatment. E3330 disrupted Ref-1 redox activity in functional studies and resulted in marked inhibition of leukemia cell viability, including T-ALL lines representing different genotypes and risk groups. Potent leukemia cell inhibition was seen in primary cells from ALL patients, relapsed and glucocorticoid-resistant T-ALL cells, and cells from a murine model of Notch-induced leukemia. Ref-1 redox inhibition triggered leukemia cell apoptosis and downregulation of survival genes regulated by Ref-1 targets. For the first time, this work identifies Ref-1 as a novel molecular effector in T-ALL and demonstrates that Ref-1 redox inhibition results in potent inhibition of leukemia T cells, including relapsed T-ALL. These data also support E3330 as a specific Ref-1 small-molecule inhibitor for leukemia. Mol Cancer Ther; 16(7); 1401-11. ©2017 AACR . ©2017 American Association for Cancer Research.

  15. Frequent upregulation of MYC in plasma cell leukemia.

    Science.gov (United States)

    Chiecchio, Laura; Dagrada, Gian Paolo; White, Helen E; Towsend, Mark R; Protheroe, Rebecca K M; Cheung, Kan Luk; Stockley, David M; Orchard, Kim H; Cross, Nicholas C P; Harrison, Christine J; Ross, Fiona M

    2009-07-01

    Plasma cell leukemia (PCL) is a rare form of monoclonal gammopathy, which can originate de novo or evolve from multiple myeloma (MM) as a terminal leukemic phase. Previous cytogenetic studies of PCL have reported the presence of complex karyotypes with involvement of multiple unidentified chromosomal regions. We report here the analysis of 12 PCL (10 primary and two secondary) by metaphase and FISH analysis combined with oligonucleotide array data (244 k, Agilent). Interphase-FISH results were compared with those from a series of 861 newly diagnosed patients with MM. Cytogenetic analysis was successful on 11 patients, all of whom showed clonal chromosomal abnormalities. Compared with MM, t(11;14)(q13;q32) (42% versus 15%; P = 0.027) and t(14;16)(q32;q23) (25% versus 4%; P = 0.010) were more frequent in PCL, although neither the specific partner chromosome involved in the IgH translocation nor the ploidy status predicted for survival. Chromosomes 1, 8, 13, and 16 showed the highest number of copy number alterations with 8q24 being the chromosomal region most frequently involved. In eight of 12 patients we found abnormalities (translocations, one amplification, small deletions, and duplications) that directly targeted or were very close to MYC. Only four of these changes were detected by routine FISH analysis using commercial probes with the others exclusively detected by arrays. Quantitative reverse transcription polymerase chain reaction demonstrated that these different abnormalities were associated with increased levels of MYC mRNA. We conclude that MYC dysregulation by complex mechanisms is one of the major molecular events in the oncogenesis of PCL.

  16. The establishment of a cell line from an acute megakaryoblastic leukemia with evidence of emperipolesis

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, C.Y.; Pabello, P.; Skinnider, L.F. [Univ. of Saskatchewan, Saskatoon (Canada)

    1994-09-01

    Acute megakaryoblstic leukemia is uncommon and comprises about 5% of acute non-lymphoid leukemia in the Franco-American-British (FAB) classification. Cell lines from such leukemias are relatively rare with only 6 reported in the literature. We have established a cell line from a case of acute megakaryoblastic leukemia arising in a 2-year-old child. Surface marker studies of the cells confirm their megakaryoblastic nature with 54.1% of the cells being CD61-positive. The cells have a doubling time of 72 hours. Morphologically they appear blast-like with Wright Giemsa stain and electron microscopy and some have small cytoplasmic blebs. Emperipolesis of one blast into another large one is occasionally seen and review of the original bone marrow specimen also showed emperipolesis of neutrophils into the megakaryoblasts (emperipolesis is a phenomenon in which a cell, usually a lymphocyte or neutrophil, enters another cell, moves about and leaves without undergoing phagocytosis). Karyotyping of the cells showed 45,XX + marker chromosome. The marker chromosome is apparently chromosome 16 with a small segment of a chromosome translocated to the terminal portion of chromosome 16. The origin of the translocated material will be elucidated using fluorescence in situ hybridization (FISH). This cell line may be useful in studying factors that contribute to the phenomenon of emperipolesis.

  17. Proteasome inhibitor carfilzomib interacts synergistically with histone deacetylase inhibitor vorinostat in Jurkat T-leukemia cells.

    Science.gov (United States)

    Gao, Minjie; Gao, Lu; Tao, Yi; Hou, Jun; Yang, Guang; Wu, Xiaosong; Xu, Hongwei; Tompkins, Van S; Han, Ying; Wu, Huiqun; Zhan, Fenghuang; Shi, Jumei

    2014-06-01

    In the present study, we investigated the interactions between proteasome inhibitor carfilzomib (CFZ) and histone deacetylase inhibitor vorinostat in Jurkat T-leukemia cells. Coexposure of cells to minimally lethal concentrations of CFZ with very low concentration of vorinostat resulted in synergistic antiproliferative effects and enhanced apoptosis in Jurkat T-leukemia cells, accompanied with the sharply increased reactive oxygen species (ROS), the striking decrease in the mitochondrial membrane potential (MMP), the increased release of cytochrome c, the enhanced activation of caspase-9 and -3, and the cleavage of PARP. The combined treatment of Jurkat cells pre-treated with ROS scavengers N-acetylcysteine (NAC) significantly blocked the loss of mitochondrial membrane potential, suggesting that ROS generation was a former event of the loss of mitochondrial membrane potential. Furthermore, NAC also resulted in a marked reduction in apoptotic cells, indicating a critical role for increased ROS generation by combined treatment. In addition, combined treatment arrested the cell cycle in G2-M phase. These results imply that CFZ interacted synergistically with vorinostat in Jurkat T-leukemia cells, which raised the possibility that the combination of carfilzomib with vorinostat may represent a novel strategy in treating T-cell Leukemia. © The Author 2014. Published by ABBS Editorial Office in association with Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences.

  18. Identification of glycan structure alterations on cell membrane proteins in desoxyepothilone B resistant leukemia cells.

    Science.gov (United States)

    Nakano, Miyako; Saldanha, Rohit; Göbel, Anja; Kavallaris, Maria; Packer, Nicolle H

    2011-11-01

    Resistance to tubulin-binding agents used in cancer is often multifactorial and can include changes in drug accumulation and modified expression of tubulin isotypes. Glycans on cell membrane proteins play important roles in many cellular processes such as recognition and apoptosis, and this study investigated whether changes to the glycan structures on cell membrane proteins occur when cells become resistant to drugs. Specifically, we investigated the alteration of glycan structures on the cell membrane proteins of human T-cell acute lymphoblastic leukemia (CEM) cells that were selected for resistance to desoxyepothilone B (CEM/dEpoB). The glycan profile of the cell membrane glycoproteins was obtained by sequential release of N- and O-glycans from cell membrane fraction dotted onto polyvinylidene difluoride membrane with PNGase F and β-elimination respectively. The released glycan alditols were analyzed by liquid chromatography (graphitized carbon)-electrospray ionization tandem MS. The major N-glycan on CEM cell was the core fucosylated α2-6 monosialo-biantennary structure. Resistant CEM/dEpoB cells had a significant decrease of α2-6 linked sialic acid on N-glycans. The lower α2-6 sialylation was caused by a decrease in activity of β-galactoside α2-6 sialyltransferase (ST6Gal), and decreased expression of the mRNA. It is clear that the membrane glycosylation of leukemia cells changes during acquired resistance to dEpoB drugs and that this change occurs globally on all cell membrane glycoproteins. This is the first identification of a specific glycan modification on the surface of drug resistant cells and the mechanism of this downstream effect on microtubule targeting drugs may offer a route to new interventions to overcome drug resistance.

  19. Rearrangement of c-myc, pim-1 and Mlvi-1 and trisomy of chromosome 15 in MCF- and Moloney-MuLV-induced murine T-cell leukemias.

    Science.gov (United States)

    Wirschubsky, Z; Tsichlis, P; Klein, G; Sumegi, J

    1986-11-15

    Provirus insertion near the c-myc, pim-1 or Mlvi-1 genes occurred in 7 out of 59 virally induced T-cell leukemias. C-myc was exclusively rearranged in approximately 10% of MCF247-induced tumors while Mlvi-1 was rearranged to a similar frequency in Moloney-virus-induced lymphomas. Out of 25 karyotyped tumors, 9 (36%) showed trisomy of chromosome 15. Provirus insertion near c-myc, pim-1 or Mlvi-1 occurred both in diploid lymphomas and in tumors with trisomy 15. These results suggest that the molecular and cytogenetic changes observed in murine T-cell leukemias are independent tumor-associated events and that trisomy of chromosome 15 is a common tumor-progression-related event.

  20. Tumor suppressors BTG1 and IKZF1 cooperate during mouse leukemia development and increase relapse risk in B-cell precursor acute lymphoblastic leukemia patients.

    Science.gov (United States)

    Scheijen, Blanca; Boer, Judith M; Marke, René; Tijchon, Esther; van Ingen Schenau, Dorette; Waanders, Esmé; van Emst, Liesbeth; van der Meer, Laurens T; Pieters, Rob; Escherich, Gabriele; Horstmann, Martin A; Sonneveld, Edwin; Venn, Nicola; Sutton, Rosemary; Dalla-Pozza, Luciano; Kuiper, Roland P; Hoogerbrugge, Peter M; den Boer, Monique L; van Leeuwen, Frank N

    2017-03-01

    Deletions and mutations affecting lymphoid transcription factor IKZF1 (IKAROS) are associated with an increased relapse risk and poor outcome in B-cell precursor acute lymphoblastic leukemia. However, additional genetic events may either enhance or negate the effects of IKZF1 deletions on prognosis. In a large discovery cohort of 533 childhood B-cell precursor acute lymphoblastic leukemia patients, we observed that single-copy losses of BTG1 were significantly enriched in IKZF1 -deleted B-cell precursor acute lymphoblastic leukemia ( P =0.007). While BTG1 deletions alone had no impact on prognosis, the combined presence of BTG1 and IKZF1 deletions was associated with a significantly lower 5-year event-free survival ( P =0.0003) and a higher 5-year cumulative incidence of relapse ( P =0.005), when compared with IKZF1 -deleted cases without BTG1 aberrations. In contrast, other copy number losses commonly observed in B-cell precursor acute lymphoblastic leukemia, such as CDKN2A/B, PAX5, EBF1 or RB1 , did not affect the outcome of IKZF1 -deleted acute lymphoblastic leukemia patients. To establish whether the combined loss of IKZF1 and BTG1 function cooperate in leukemogenesis, Btg1 -deficient mice were crossed onto an Ikzf1 heterozygous background. We observed that loss of Btg1 increased the tumor incidence of Ikzf1 +/- mice in a dose-dependent manner. Moreover, murine B cells deficient for Btg1 and Ikzf1 +/- displayed increased resistance to glucocorticoids, but not to other chemotherapeutic drugs. Together, our results identify BTG1 as a tumor suppressor in leukemia that, when deleted, strongly enhances the risk of relapse in IKZF1 -deleted B-cell precursor acute lymphoblastic leukemia, and augments the glucocorticoid resistance phenotype mediated by the loss of IKZF1 function. Copyright© Ferrata Storti Foundation.

  1. Identification of a novel SEPT9-ABL1 fusion gene in a patient with T-cell prolymphocytic leukemia

    Directory of Open Access Journals (Sweden)

    Rikio Suzuki

    2014-01-01

    Full Text Available T-cell prolymphocytic leukemia (T-PLL, a rare type of peripheral T-cell leukemia, is characterized by marked splenomegaly with rapidly progressive lymphocytosis and a poor prognosis. Nine kinds of ABL1 chimeric genes have been identified in various kinds of hematological malignancies, such as chronic myeloid leukemia and B- or T-lymphoblastic leukemia. However, there have been no reports describing T-PLL cases with ABL1 rearrangements. We herein report a case of T-PLL with a novel SEPT9-ABL1 fusion gene which induced strong resistance to tyrosine kinase inhibitors such as imatinib and dasatinib.

  2. Targeting Jurkat T Lymphocyte Leukemia Cells by an Engineered Interferon-Alpha Hybrid Molecule.

    Science.gov (United States)

    Yu, Dehai; Du, Zhonghua; Li, Wei; Chen, Huaqiu; Ye, Songgen; Hoffman, Andrew R; Cui, Jiuwei; Hu, Ji-Fan

    2017-01-01

    Adult T-cell leukemia/lymphoma (ATL) is a very aggressive T cell malignancy that carries a poor prognosis, primarily due to its resistance to chemotherapy and to life-threatening infectious complications. Interferon-alpha (IFNα) has been used in combination with the anti-retroviral drug zidovudine to treat patients with ATL. However, the efficacy of long-term therapy is significantly limited due to the systemic toxicity of IFNα. We utilized phage display library screening to identify short peptides that specifically bind to Jurkat T lymphocyte leukemia cells. By fusing the Jurkat-binding peptide to the C-terminus of IFNα, we constructed an engineered chimeric IFNα molecule (IFNP) for the treatment of ATL. We found that IFNP exhibited significantly higher activity than wild type IFNα in inhibiting the growth of leukemia cells and inducing cell blockage at the G0/G1 phase. The synthetic IFNP molecule exerted its antitumor activity by upregulating the downstream genes involved in the STAT1 pathway and in apoptosis. Using a cell receptor binding assay, we showed that this Jurkat-binding peptide facilitated the binding affinity of IFNα to the cell surface type I IFN receptor. The isolated Jurkat-binding peptide significantly potentiates the therapeutic activity of IFNα in T lymphocyte leukemia cells. The engineered IFNP molecule may prove to a novel antitumor approach in the treatment of patients with ATL. © 2017 The Author(s). Published by S. Karger AG, Basel.

  3. Antagonism of B cell enhancer networks by STAT5 drives leukemia and poor patient survival

    NARCIS (Netherlands)

    Katerndahl, C.D.S.; Heltemes-Harris, L.M.; Willette, M.J.L.; Henzler, C.M.; Frietze, S.; Yang, R.; Schjerven, H.; Silverstein, K.A.T.; Ramsey, L.B.; Hubbard, G.; Wells, A.D.; Kuiper, R.P; Scheijen, B.; Leeuwen, F.N. van; Muschen, M.; Kornblau, S.M.; Farrar, M.A.

    2017-01-01

    The transcription factor STAT5 has a critical role in B cell acute lymphoblastic leukemia (B-ALL). How STAT5 mediates this effect is unclear. Here we found that activation of STAT5 worked together with defects in signaling components of the precursor to the B cell antigen receptor (pre-BCR),

  4. Targeting 6-phosphogluconate dehydrogenase in the oxidative PPP sensitizes leukemia cells to antimalarial agent dihydroartemisinin.

    Science.gov (United States)

    Elf, S; Lin, R; Xia, S; Pan, Y; Shan, C; Wu, S; Lonial, S; Gaddh, M; Arellano, M L; Khoury, H J; Khuri, F R; Lee, B H; Boggon, T J; Fan, J; Chen, J

    2017-01-12

    The oxidative pentose phosphate pathway (PPP) is crucial for cancer cell metabolism and tumor growth. We recently reported that targeting a key oxidative PPP enzyme, 6-phosphogluconate dehydrogenase (6PGD), using our novel small-molecule 6PGD inhibitors Physcion and its derivative S3, shows anticancer effects. Notably, humans with genetic deficiency of either 6PGD or another oxidative PPP enzyme, glucose-6-phosphate dehydrogenase, exhibit non-immune hemolytic anemia upon exposure to aspirin and various antimalarial drugs. Inspired by these clinical observations, we examined the anticancer potential of combined treatment with 6PGD inhibitors and antimalarial drugs. We found that stable knockdown of 6PGD sensitizes leukemia cells to antimalarial agent dihydroartemisinin (DHA). Combined treatment with DHA and Physcion activates AMP-activated protein kinase, leading to synergistic inhibition of human leukemia cell viability. Moreover, our combined therapy synergistically attenuates tumor growth in xenograft nude mice injected with human K562 leukemia cells and cell viability of primary leukemia cells from human patients, but shows minimal toxicity to normal hematopoietic cells in mice as well as red blood cells and mononucleocytes from healthy human donors. Our findings reveal the potential for combined therapy using optimized doses of Physcion and DHA as a novel antileukemia treatment without inducing hemolysis.

  5. Chronic lymphocytic leukemia cells display p53-dependent drug-induced Puma upregulation

    NARCIS (Netherlands)

    Mackus, W. J. M.; Kater, A. P.; Grummels, A.; Evers, L. M.; Hooijbrink, B.; Kramer, M. H. H.; Castro, J. E.; Kipps, T. J.; van Lier, R. A. W.; van Oers, M. H. J.; Eldering, E.

    2005-01-01

    We investigated the apoptosis gene expression profile of chronic lymphocytic leukemia (CLL) cells in relation to (1) normal peripheral and tonsillar B-cell subsets, (2) IgV(H) mutation status, and (3) effects of cytotoxic drugs. In accord with their noncycling, antiapoptotic status in vivo, CLL

  6. Induction of apoptosis by xanthones from mangosteen in human leukemia cell lines.

    Science.gov (United States)

    Matsumoto, Kenji; Akao, Yukihiro; Kobayashi, Emi; Ohguchi, Kenji; Ito, Tetsuro; Tanaka, Toshiyuki; Iinuma, Munekazu; Nozawa, Yoshinori

    2003-08-01

    We examined the effects of six xanthones from the pericarps of mangosteen, Garcinia mangostana, on the cell growth inhibition of human leukemia cell line HL60. All xanthones displayed growth inhibitory effects. Among them, alpha-mangostin showed complete inhibition at 10 microM through the induction of apoptosis.

  7. Sorafenib promotes graft-versus-leukemia activity in mice and humans through IL-15 production in FLT3-ITD-mutant leukemia cells.

    Science.gov (United States)

    Mathew, Nimitha R; Baumgartner, Francis; Braun, Lukas; O'Sullivan, David; Thomas, Simone; Waterhouse, Miguel; Müller, Tony A; Hanke, Kathrin; Taromi, Sanaz; Apostolova, Petya; Illert, Anna L; Melchinger, Wolfgang; Duquesne, Sandra; Schmitt-Graeff, Annette; Osswald, Lena; Yan, Kai-Li; Weber, Arnim; Tugues, Sonia; Spath, Sabine; Pfeifer, Dietmar; Follo, Marie; Claus, Rainer; Lübbert, Michael; Rummelt, Christoph; Bertz, Hartmut; Wäsch, Ralph; Haag, Johanna; Schmidts, Andrea; Schultheiss, Michael; Bettinger, Dominik; Thimme, Robert; Ullrich, Evelyn; Tanriver, Yakup; Vuong, Giang Lam; Arnold, Renate; Hemmati, Philipp; Wolf, Dominik; Ditschkowski, Markus; Jilg, Cordula; Wilhelm, Konrad; Leiber, Christian; Gerull, Sabine; Halter, Jörg; Lengerke, Claudia; Pabst, Thomas; Schroeder, Thomas; Kobbe, Guido; Rösler, Wolf; Doostkam, Soroush; Meckel, Stephan; Stabla, Kathleen; Metzelder, Stephan K; Halbach, Sebastian; Brummer, Tilman; Hu, Zehan; Dengjel, Joern; Hackanson, Björn; Schmid, Christoph; Holtick, Udo; Scheid, Christof; Spyridonidis, Alexandros; Stölzel, Friedrich; Ordemann, Rainer; Müller, Lutz P; Sicre-de-Fontbrune, Flore; Ihorst, Gabriele; Kuball, Jürgen; Ehlert, Jan E; Feger, Daniel; Wagner, Eva-Maria; Cahn, Jean-Yves; Schnell, Jacqueline; Kuchenbauer, Florian; Bunjes, Donald; Chakraverty, Ronjon; Richardson, Simon; Gill, Saar; Kröger, Nicolaus; Ayuk, Francis; Vago, Luca; Ciceri, Fabio; Müller, Antonia M; Kondo, Takeshi; Teshima, Takanori; Klaeger, Susan; Kuster, Bernhard; Kim, Dennis Dong Hwan; Weisdorf, Daniel; van der Velden, Walter; Dörfel, Daniela; Bethge, Wolfgang; Hilgendorf, Inken; Hochhaus, Andreas; Andrieux, Geoffroy; Börries, Melanie; Busch, Hauke; Magenau, John; Reddy, Pavan; Labopin, Myriam; Antin, Joseph H; Henden, Andrea S; Hill, Geoffrey R; Kennedy, Glen A; Bar, Merav; Sarma, Anita; McLornan, Donal; Mufti, Ghulam; Oran, Betul; Rezvani, Katayoun; Shah, Omid; Negrin, Robert S; Nagler, Arnon; Prinz, Marco; Burchert, Andreas; Neubauer, Andreas; Beelen, Dietrich; Mackensen, Andreas; von Bubnoff, Nikolas; Herr, Wolfgang; Becher, Burkhard; Socié, Gerard; Caligiuri, Michael A; Ruggiero, Eliana; Bonini, Chiara; Häcker, Georg; Duyster, Justus; Finke, Jürgen; Pearce, Erika; Blazar, Bruce R; Zeiser, Robert

    2018-03-01

    Individuals with acute myeloid leukemia (AML) harboring an internal tandem duplication (ITD) in the gene encoding Fms-related tyrosine kinase 3 (FLT3) who relapse after allogeneic hematopoietic cell transplantation (allo-HCT) have a 1-year survival rate below 20%. We observed that sorafenib, a multitargeted tyrosine kinase inhibitor, increased IL-15 production by FLT3-ITD + leukemia cells. This synergized with the allogeneic CD8 + T cell response, leading to long-term survival in six mouse models of FLT3-ITD + AML. Sorafenib-related IL-15 production caused an increase in CD8 + CD107a + IFN-γ + T cells with features of longevity (high levels of Bcl-2 and reduced PD-1 levels), which eradicated leukemia in secondary recipients. Mechanistically, sorafenib reduced expression of the transcription factor ATF4, thereby blocking negative regulation of interferon regulatory factor 7 (IRF7) activation, which enhanced IL-15 transcription. Both IRF7 knockdown and ATF4 overexpression in leukemia cells antagonized sorafenib-induced IL-15 production in vitro. Human FLT3-ITD + AML cells obtained from sorafenib responders following sorafenib therapy showed increased levels of IL-15, phosphorylated IRF7, and a transcriptionally active IRF7 chromatin state. The mitochondrial spare respiratory capacity and glycolytic capacity of CD8 + T cells increased upon sorafenib treatment in sorafenib responders but not in nonresponders. Our findings indicate that the synergism of T cells and sorafenib is mediated via reduced ATF4 expression, causing activation of the IRF7-IL-15 axis in leukemia cells and thereby leading to metabolic reprogramming of leukemia-reactive T cells in humans. Therefore, sorafenib treatment has the potential to contribute to an immune-mediated cure of FLT3-ITD-mutant AML relapse, an otherwise fatal complication after allo-HCT.

  8. Importance of glutamine metabolism in leukemia cells by energy production through TCA cycle and by redox homeostasis.

    Science.gov (United States)

    Goto, Mineaki; Miwa, Hiroshi; Shikami, Masato; Tsunekawa-Imai, Norikazu; Suganuma, Kazuto; Mizuno, Shohei; Takahashi, Miyuki; Mizutani, Motonori; Hanamura, Ichiro; Nitta, Masakazu

    2014-07-01

    Some cancer cells depend on glutamine despite of pronounced glycolysis. We examined the glutamine metabolism in leukemia cells, and found that HL-60 cells most depended on glutamine in the 4 acute myelogenous leukemia (AML) cell lines examined: growth of HL-60 cells was most suppressed by glutamine deprivation and by inhibition of glutaminolysis, which was rescued by tricarboxylic acid (TCA) cycle intermediate, oxaloacetic acid. Glutamine is also involved in antioxidant defense function by increasing glutathione. Glutamine deprivation suppressed the glutathione content and elevated reactive oxygen species most evidently in HL-60 cells. Glutamine metabolism might be a therapeutic target in some leukemia.

  9. Tyrosine kinase inhibitor therapy can cure chronic myeloid leukemia without hitting leukemic stem cells

    Science.gov (United States)

    Lenaerts, Tom; Pacheco, Jorge M.; Traulsen, Arne; Dingli, David

    2010-01-01

    Background Tyrosine kinase inhibitors, such as imatinib, are not considered curative for chronic myeloid leukemia – regardless of the significant reduction of disease burden during treatment – since they do not affect the leukemic stem cells. However, the stochastic nature of hematopoiesis and recent clinical observations suggest that this view must be revisited. Design and Methods We studied the natural history of a large cohort of virtual patients with chronic myeloid leukemia under tyrosine kinase inhibitor therapy using a computational model of hematopoiesis and chronic myeloid leukemia that takes into account stochastic dynamics within the hematopoietic stem and early progenitor cell pool. Results We found that in the overwhelming majority of patients the leukemic stem cell population undergoes extinction before disease diagnosis. Hence leukemic progenitors, susceptible to tyrosine kinase inhibitor attack, are the natural target for chronic myeloid leukemia treatment. Response dynamics predicted by the model closely match data from clinical trials. We further predicted that early diagnosis together with administration of tyrosine kinase inhibitor opens the path to eradication of chronic myeloid leukemia, leading to the wash out of the aberrant progenitor cells, ameliorating the patient’s condition while lowering the risk of blast transformation and drug resistance. Conclusions Tyrosine kinase inhibitor therapy can cure chronic myeloid leukemia, although it may have to be prolonged. The depth of response increases with time in the vast majority of patients. These results illustrate the importance of stochastic effects on the dynamics of acquired hematopoietic stem cell disorders and have direct relevance for other hematopoietic stem cell-derived diseases. PMID:20007137

  10. Differentiation status of primary chronic myeloid leukemia cells affects sensitivity to BCR-ABL1 inhibitors.

    Science.gov (United States)

    Pietarinen, Paavo O; Eide, Christopher A; Ayuda-Durán, Pilar; Potdar, Swapnil; Kuusanmäki, Heikki; Andersson, Emma I; Mpindi, John P; Pemovska, Tea; Kontro, Mika; Heckman, Caroline A; Kallioniemi, Olli; Wennerberg, Krister; Hjorth-Hansen, Henrik; Druker, Brian J; Enserink, Jorrit M; Tyner, Jeffrey W; Mustjoki, Satu; Porkka, Kimmo

    2017-04-04

    Tyrosine kinase inhibitors (TKI) are the mainstay treatment of BCR-ABL1-positive leukemia and virtually all patients with chronic myeloid leukemia in chronic phase (CP CML) respond to TKI therapy. However, there is limited information on the cellular mechanisms of response and particularly on the effect of cell differentiation state to TKI sensitivity in vivo and ex vivo/in vitro. We used multiple, independent high-throughput drug sensitivity and resistance testing platforms that collectively evaluated 295 oncology compounds to characterize ex vivo drug response profiles of primary cells freshly collected from newly-diagnosed patients with BCR-ABL1-positive leukemia (n = 40) and healthy controls (n = 12). In contrast to the highly TKI-sensitive cells from blast phase CML and Philadelphia chromosome-positive acute lymphoblastic leukemia, primary CP CML cells were insensitive to TKI therapy ex vivo. Despite maintaining potent BCR-ABL1 inhibitory activity, ex vivo viability of cells was unaffected by TKIs. These findings were validated in two independent patient cohorts and analysis platforms. All CP CML patients under study responded to TKI therapy in vivo. When CP CML cells were sorted based on CD34 expression, the CD34-positive progenitor cells showed good sensitivity to TKIs, whereas the more mature CD34-negative cells were markedly less sensitive. Thus in CP CML, TKIs predominantly target the progenitor cell population while the differentiated leukemic cells (mostly cells from granulocytic series) are insensitive to BCR-ABL1 inhibition. These findings have implications for drug discovery in CP CML and indicate a fundamental biological difference between CP CML and advanced forms of BCR-ABL1-positive leukemia.

  11. Preclinical validation: LV/IL-12 transduction of patient leukemia cells for immunotherapy of AML

    Directory of Open Access Journals (Sweden)

    Ju Huang

    2016-01-01

    Full Text Available Interleukin-12 (IL-12 is a potent cytokine that may be harnessed to treat cancer. To date, nearly 100 IL-12-based clinical trials have been initiated worldwide. Yet systemic administration of IL-12 is toxic. Different strategies are being developed to reduce such toxicities by restricting IL-12 distribution. Our previous studies employed lentivector-mediated expression of murine IL-12 in tumor cells and demonstrated effective protection in both mouse leukemia and solid tumor challenge models. In this study, we carried out preclinical validation studies using a novel lentivector to engineer expression of human IL-12 in acute myeloid leukemia blast cells isolated from 21 patients. Acute myeloid leukemia cells were transduced with a bicistronic lentivector that encodes the human IL-12 cDNA as a fusion, as well as a LNGFR (ΔLNGFR/mutant thymidylate kinase cassette as a marking and cell-fate control element. A range of 20–70% functional transduction efficiencies was achieved. Transduced acute myeloid leukemia cells produced bioactive IL-12 protein and displayed dose-dependent sensitivity to the prodrug 3′-azido-3′-deoxythymidine. In vitro immortalization assays using transduced mouse hematopoietic stem cells demonstrated minimal genotoxic risk from our IL-12 vector. Scale-up transduction and cell processing was subsequently validated in a GMP facility to support our (now approved Clinical Trial Application (CTA.

  12. Transcription factor networks in B-cell differentiation link development to acute lymphoid leukemia.

    Science.gov (United States)

    Somasundaram, Rajesh; Prasad, Mahadesh A J; Ungerbäck, Jonas; Sigvardsson, Mikael

    2015-07-09

    B-lymphocyte development in the bone marrow is controlled by the coordinated action of transcription factors creating regulatory networks ensuring activation of the B-lymphoid program and silencing of alternative cell fates. This process is tightly connected to malignant transformation because B-lineage acute lymphoblastic leukemia cells display a pronounced block in differentiation resulting in the expansion of immature progenitor cells. Over the last few years, high-resolution analysis of genetic changes in leukemia has revealed that several key regulators of normal B-cell development, including IKZF1, TCF3, EBF1, and PAX5, are genetically altered in a large portion of the human B-lineage acute leukemias. This opens the possibility of directly linking the disrupted development as well as aberrant gene expression patterns in leukemic cells to molecular functions of defined transcription factors in normal cell differentiation. This review article focuses on the roles of transcription factors in early B-cell development and their involvement in the formation of human leukemia. © 2015 by The American Society of Hematology.

  13. Catch me if you can: Leukemia Escape after CD19-Directed T Cell Immunotherapies

    Directory of Open Access Journals (Sweden)

    Marco Ruella

    2016-01-01

    Full Text Available Immunotherapy is the revolution in cancer treatment of this last decade. Among multiple approaches able to harness the power of the immune system against cancer, T cell based immunotherapies represent one of the most successful examples. In particular, biotechnological engineering of protein structures, like the T cell receptor or the immunoglobulins, allowed the generation of synthetic peptides like chimeric antigen receptors and bispecific antibodies that are able to redirect non-tumor specific T cells to recognize and kill leukemic cells. The anti-CD19/CD3 bispecific antibody blinatumomab and anti-CD19 chimeric antigen receptor T cells (CART19 have produced deep responses in patients with relapsed and refractory B-cell acute leukemias. However, although the majority of these patients responds to anti-CD19 immunotherapy, a subset of them still relapses. Interestingly, a novel family of leukemia escape mechanisms has been described, all characterized by the apparent loss of CD19 on the surface of leukemic blasts. This extraordinary finding demonstrates the potent selective pressure of CART19/blinatumomab that drives extreme and specific escape strategies by leukemic blasts. Patients with CD19-negative relapsed leukemia have very poor prognosis and novel approaches to treat and ideally prevent antigen-loss are direly needed. In this review we discuss the incidence, mechanisms and therapeutic approaches for CD19-negative leukemia relapses occuring after CD19-directed T cell immunotherapies and present our future perspective.

  14. Allogeneic hematopoietic stem-cell transplantation for acute myeloid leukemia in remission

    DEFF Research Database (Denmark)

    Nagler, Arnon; Rocha, Vanderson; Labopin, Myriam

    2013-01-01

    Cyclophosphamide (Cy) combined with total-body irradiation (TBI) or with busulfan (Bu) are currently the most common myeloablative regimens used in allogeneic stem-cell transplantation (alloSCT) in adults with acute myelogenous leukemia (AML). Intravenous (IV) Bu has more predictable bioavailabil......Cyclophosphamide (Cy) combined with total-body irradiation (TBI) or with busulfan (Bu) are currently the most common myeloablative regimens used in allogeneic stem-cell transplantation (alloSCT) in adults with acute myelogenous leukemia (AML). Intravenous (IV) Bu has more predictable...

  15. In vitro effect of imatinib mesylate loaded on polybutylcyanoacrylate nanoparticles on leukemia cell line K562.

    Science.gov (United States)

    Hasandoost, Leyla; Akbarzadeh, Azim; Attar, Hossein; Heydarinasab, Amir

    2017-05-01

    The study aimed to prepare imatinib mesylate-loaded polybutylcyanoacrylate (PBCA) nanoparticles and evaluate their efficacy on leukemia cell line K562. The formulation was prepared by miniemulsion polymerization technique. Nanoparticles were characterized by dynamic light scattering (DLS), spectrophotometry, Fourier transform infrared spectroscopy (FTIR), dialysis membrane, and 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) techniques. Nanoscale particles with high encapsulation efficiency (86%) and physical entrapment of drug were observed. In addition, nanoparticles showed suitable drug retention capability and potentiate the cytotoxicity effects of imatinib mesylate. Findings of study suggested PBCA nanoparticles are promising carrier for imatinib mesylate delivery to leukemia cell line K562.

  16. Trigeminal nerve involvement in T-cell acute lymphoblastic leukemia: value of MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Karadag, Demet; Karaguelle, Ayse Tuba; Erden, Ilhan; Erden, Ayse E-mail: erden@ada.net.tr

    2002-10-01

    A 30-year-old male with T-cell acute lymphoblastic leukemia presented with facial numbness. Neurological examination revealed paresthesia of the left trigeminal nerve. Cerebrospinal fluid (CSF) cytology showed no atypical cells. Gadolinium-enhanced magnetic resonance (MR) imaging demonstrated enlargement and enhancement of intracranial portions of the left trigeminal nerve. The abnormal MR imaging findings almost completely resolved after the chemotherapy. Gadolinium-enhanced MR imaging is not only a useful procedure for the early diagnosis of cranial nerve invasion by leukemia but it might be helpful to follow the changes after the treatment.

  17. Germline transgenesis and insertional mutagenesis in Schistosoma mansoni mediated by murine leukemia virus.

    Directory of Open Access Journals (Sweden)

    Gabriel Rinaldi

    Full Text Available Functional studies will facilitate characterization of role and essentiality of newly available genome sequences of the human schistosomes, Schistosoma mansoni, S. japonicum and S. haematobium. To develop transgenesis as a functional approach for these pathogens, we previously demonstrated that pseudotyped murine leukemia virus (MLV can transduce schistosomes leading to chromosomal integration of reporter transgenes and short hairpin RNA cassettes. Here we investigated vertical transmission of transgenes through the developmental cycle of S. mansoni after introducing transgenes into eggs. Although MLV infection of schistosome eggs from mouse livers was efficient in terms of snail infectivity, >10-fold higher transgene copy numbers were detected in cercariae derived from in vitro laid eggs (IVLE. After infecting snails with miracidia from eggs transduced by MLV, sequencing of genomic DNA from cercariae released from the snails also revealed the presence of transgenes, demonstrating that transgenes had been transmitted through the asexual developmental cycle, and thereby confirming germline transgenesis. High-throughput sequencing of genomic DNA from schistosome populations exposed to MLV mapped widespread and random insertion of transgenes throughout the genome, along each of the autosomes and sex chromosomes, validating the utility of this approach for insertional mutagenesis. In addition, the germline-transmitted transgene encoding neomycin phosphotransferase rescued cultured schistosomules from toxicity of the antibiotic G418, and PCR analysis of eggs resulting from sexual reproduction of the transgenic worms in mice confirmed that retroviral transgenes were transmitted to the next (F1 generation. These findings provide the first description of wide-scale, random insertional mutagenesis of chromosomes and of germline transmission of a transgene in schistosomes. Transgenic lines of schistosomes expressing antibiotic resistance could advance

  18. Oncogenic STAT5 signaling promotes oxidative stress in chronic myeloid leukemia cells by repressing antioxidant defenses.

    Science.gov (United States)

    Bourgeais, Jerome; Ishac, Nicole; Medrzycki, Magdalena; Brachet-Botineau, Marie; Desbourdes, Laura; Gouilleux-Gruart, Valerie; Pecnard, Emmanuel; Rouleux-Bonnin, Florence; Gyan, Emmanuel; Domenech, Jorge; Mazurier, Frederic; Moriggl, Richard; Bunting, Kevin D; Herault, Olivier; Gouilleux, Fabrice

    2017-06-27

    STAT5 transcription factors are frequently activated in hematopoietic neoplasms and are targets of various tyrosine kinase oncogenes. Evidences for a crosstalk between STAT5 and reactive oxygen species (ROS) metabolism have recently emerged but mechanisms involved in STAT5-mediated regulation of ROS still remain elusive. We demonstrate that sustained activation of STAT5 induced by Bcr-Abl in chronic myeloid leukemia (CML) cells promotes ROS production by repressing expression of two antioxidant enzymes, catalase and glutaredoxin-1(Glrx1). Downregulation of catalase and Glrx1 expression was also observed in primary cells from CML patients. Catalase was shown not only to reduce ROS levels but also, to induce quiescence in Bcr-Abl-positive leukemia cells. Furthermore, reduction of STAT5 phosphorylation and upregulation of catalase and Glrx1 were also evidenced in leukemia cells co-cultured with bone marrow stromal cells to mimic a leukemic niche. This caused downregulation of ROS levels and enhancement of leukemic cell quiescence. These data support a role of persistent STAT5 signaling in the regulation of ROS production in myeloid leukemias and highlight the repression of antioxidant defenses as an important regulatory mechanism.

  19. Activity of the Type II JAK2 Inhibitor CHZ868 in B Cell Acute Lymphoblastic Leukemia.

    Science.gov (United States)

    Wu, Shuo-Chieh; Li, Loretta S; Kopp, Nadja; Montero, Joan; Chapuy, Bjoern; Yoda, Akinori; Christie, Amanda L; Liu, Huiyun; Christodoulou, Alexandra; van Bodegom, Diederik; van der Zwet, Jordy; Layer, Jacob V; Tivey, Trevor; Lane, Andrew A; Ryan, Jeremy A; Ng, Samuel Y; DeAngelo, Daniel J; Stone, Richard M; Steensma, David; Wadleigh, Martha; Harris, Marian; Mandon, Emeline; Ebel, Nicolas; Andraos, Rita; Romanet, Vincent; Dölemeyer, Arno; Sterker, Dario; Zender, Michael; Rodig, Scott J; Murakami, Masato; Hofmann, Francesco; Kuo, Frank; Eck, Michael J; Silverman, Lewis B; Sallan, Stephen E; Letai, Anthony; Baffert, Fabienne; Vangrevelinghe, Eric; Radimerski, Thomas; Gaul, Christoph; Weinstock, David M

    2015-07-13

    A variety of cancers depend on JAK2 signaling, including the high-risk subset of B cell acute lymphoblastic leukemias (B-ALLs) with CRLF2 rearrangements. Type I JAK2 inhibitors induce paradoxical JAK2 hyperphosphorylation in these leukemias and have limited activity. To improve the efficacy of JAK2 inhibition in B-ALL, we developed the type II inhibitor CHZ868, which stabilizes JAK2 in an inactive conformation. CHZ868 potently suppressed the growth of CRLF2-rearranged human B-ALL cells, abrogated JAK2 signaling, and improved survival in mice with human or murine B-ALL. CHZ868 and dexamethasone synergistically induced apoptosis in JAK2-dependent B-ALLs and further improved in vivo survival compared to CHZ868 alone. These data support the testing of type II JAK2 inhibition in patients with JAK2-dependent leukemias and other disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Differentiation of chronic lymphocytic leukemia B cells into immunoglobulin secreting cells decreases LEF-1 expression.

    Directory of Open Access Journals (Sweden)

    Albert Gutierrez

    Full Text Available Lymphocyte enhancer binding factor 1 (LEF-1 plays a crucial role in B lineage development and is only expressed in B cell precursors as B cell differentiation into mature B and plasma cells silences its expression. Chronic lymphocytic leukemia (CLL cells aberrantly express LEF-1 and its expression is required for cellular survival. We hypothesized that modification of the differentiation status of CLL cells would result in loss of LEF-1 expression and eliminate the survival advantage provided by its aberrant expression. In this study, we first established a methodology that induces CLL cells to differentiate into immunoglobulin (Ig secreting cells (ISC using the TLR9 agonist, CpG, together with cytokines (CpG/c. CpG/c stimulation resulted in dramatic CLL cell phenotypic and morphologic changes, expression of cytoplasmic Ig, and secretion of light chain restricted Ig. CpG/c stimulation also resulted in decreased CLL cell LEF-1 expression and increased Blimp-1 expression, which is crucial for plasma cell differentiation. Further, Wnt pathway activation and cellular survival were impaired in differentiated CLL cells compared to undifferentiated CLL cells. These data support the notion that CLL can differentiate into ISC and that this triggers decreased leukemic cell survival secondary to the down regulation of LEF-1 and decreased Wnt pathway activation.

  1. huJCAR014 CAR-T Cells in Treating Adult Patients With Relapsed or Refractory B-Cell Non-Hodgkin Lymphoma or Acute Lymphoblastic Leukemia

    Science.gov (United States)

    2018-03-26

    Adult B Acute Lymphoblastic Leukemia; BCL2 Gene Rearrangement; BCL6 Gene Rearrangement; CD19 Positive; Diffuse Large B-Cell Lymphoma, Not Otherwise Specified; MYC Gene Rearrangement; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory Adult Acute Lymphoblastic Leukemia; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Transformed Recurrent Non-Hodgkin Lymphoma

  2. Suppression of Glut1 and Glucose Metabolism by Decreased Akt/mTORC1 Signaling Drives T Cell Impairment in B Cell Leukemia

    NARCIS (Netherlands)

    Siska, Peter J.; van der Windt, Gerritje J. W.; Kishton, Rigel J.; Cohen, Sivan; Eisner, William; MacIver, Nancie J.; Kater, Arnon P.; Weinberg, J. Brice; Rathmell, Jeffrey C.

    2016-01-01

    Leukemia can promote T cell dysfunction and exhaustion that contributes to increased susceptibility to infection and mortality. The treatment-independent mechanisms that mediate leukemia-associated T cell impairments are poorly understood, but metabolism tightly regulates T cell function and may

  3. KIR2DS5 is associated with leukemia free survival after HLA identical stem cell transplantation in chronic myeloid leukemia patients.

    NARCIS (Netherlands)

    Meer, A. van der; Schaap, N.P.M.; Schattenberg, A.V.M.B.; Cranenbroek, B. van; Tijssen, H.J.; Joosten, I.

    2008-01-01

    BACKGROUND: Alloreactive NK cells play a role in tumor eradication after allogeneic HLA mismatched stem cell transplantation (SCT). The effect of NK alloreactivity in HLA identical SCT is still under debate and in particular in transplantation for chronic myeloid leukemia (CML) the data are very

  4. Radioinduced leukemia. An introduction to the study of experimental leukemia in mice

    International Nuclear Information System (INIS)

    Baudon, P.P.

    1974-01-01

    This thesis attempts to gain insight into any mechanisms involved in the onset of irradiation-induced leukemia in mice, then to show up the presence of a virus in the same animals. Concerning the mechanisms of radio-induced leukemias the pathogenic factors according to Kaplan are analysed: role of the thymus and cell mutation theory; lymphoid leukemias of extra-thymic origin; leukemogenesis co-factor; inhibiting action of the bone narrow. Evidence of the virus in mice was obtained by the use of electron microscopy, by inoculation. The contribution of experimental leukemia research is analysed, especially as it affects the therapeutic aspect. It is shown that in spite of setbacks in the most recent research on man, therapeutic trials on animals should be viewed from the angle of imminent human applications [fr

  5. Hepatitis C virus host cell interactions uncovered

    DEFF Research Database (Denmark)

    Gottwein, Judith; Bukh, Jens

    2007-01-01

      Insights into virus-host cell interactions as uncovered by Randall et al. (1) in a recent issue of PNAS further our understanding of the hepatitis C virus (HCV) life cycle, persistence, and pathogenesis and might lead to the identification of new therapeutic targets. HCV persistently infects 180...

  6. Migration of acute lymphoblastic leukemia cells into human bone marrow stroma.

    Science.gov (United States)

    Makrynikola, V; Bianchi, A; Bradstock, K; Gottlieb, D; Hewson, J

    1994-10-01

    Most cases of acute lymphoblastic leukemia (ALL) arise from malignant transformation of B-cell precursors in the bone marrow. Recent studies have shown that normal and leukemic B-cell precursors bind to bone marrow stromal cells through the beta-1 integrins VLA-4 and VLA-5, thereby exposing early lymphoid cells to regulatory cytokines. It has been recently reported that the pre-B cell line NALM-6 is capable of migrating under layers of murine stromal cells in vitro (Miyake et al. J Cell Biol 1992;119:653-662). We have further analyzed leukemic cell motility using human bone marrow fibroblasts (BMF) as a stromal layer. The precursor-B ALL cell line NALM-6 rapidly adhered to BMF, and underwent migration or tunneling into BMF layers within 5 h, as demonstrated by light and electron microscopy, and confirmed by a chromium-labeling assay. Migration was also observed with the precursor-B ALL lines Reh and KM-3, with a T leukemia line RPMI-8402, the monocytic line U937, and the mature B line Daudi. In contrast, mature B (Raji), myeloid (K562, HL-60), and T lines (CCRF-CEM, MOLT-4) did not migrate. When cases of leukemia were analyzed, BMF migration was largely confined to precursor-B ALL, occurring in eight of 13 cases tested. Of other types of leukemia, migration was observed in one of four cases of T-ALL, but no evidence was seen in six acute myeloid leukemias and two patients with chronic lymphocytic leukemia. Only minimal migration into BMF was observed with purified sorted CD10+ CD19+ early B cells from normal adult marrow, while normal mature B lymphocytes from peripheral blood did not migrate. ALL migration was inhibited by monoclonal antibodies to the beta sub-unit of the VLA integrin family, and by a combination of antibodies to VLA-4 and VLA-5. Partial inhibition was also observed when leukemic cells were incubated with antibodies to VLA-4, VLA-5, or VLA-6 alone. In contrast, treatment of stromal cells with antibodies to vascular cell adhesion molecule or

  7. Alloreactive natural killer cells for the treatment of acute myeloid leukemia: from stem cell transplantation to adoptive immunotherapy

    Directory of Open Access Journals (Sweden)

    Loredana eRuggeri

    2015-10-01

    Full Text Available Natural killer cells express activating and inhibitory receptors which recognize MHC class I alleles, termed Killer cell Immunoglobulin-like Receptors (KIRs. Preclinical and clinical data from haploidentical T-cell depleted stem cell transplantation have demonstrated that alloreactive KIR-L mismatched natural killer cells play a major role as effectors against acute myeloid leukemia. Outside the transplantation setting, several reports have proven the safety and feasibility of natural killer cell infusion in acute myeloid leukemia patients and, in some cases, provided evidence that transferred NK cells are functionally alloreactive and may have a role in disease control. Aim of the present work is to briefly summarize the most recent advances in the field by moving from the first preclinical and clinical demonstration of donor NK alloreactivity in the transplantation setting to the most recent attempts of exploiting the use of alloreactive NK cell infusion as a means of adoptive immunotherapy against acute myeloid leukemia. Altogether, these data highlight the pivotal role of NK cells for the development of novel immunological approaches in the clinical management of acute myeloid leukemia.

  8. T cells in chronic lymphocytic leukemia display dysregulated expression of immune checkpoints and activation markers.

    Science.gov (United States)

    Palma, Marzia; Gentilcore, Giusy; Heimersson, Kia; Mozaffari, Fariba; Näsman-Glaser, Barbro; Young, Emma; Rosenquist, Richard; Hansson, Lotta; Österborg, Anders; Mellstedt, Håkan

    2017-03-01

    Chronic lymphocytic leukemia is characterized by impaired immune functions largely due to profound T-cell defects. T-cell functions also depend on co-signaling receptors, inhibitory or stimulatory, known as immune checkpoints, including cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and programmed death-1 (PD-1). Here we analyzed the T-cell phenotype focusing on immune checkpoints and activation markers in chronic lymphocytic leukemia patients (n=80) with different clinical characteristics and compared them to healthy controls. In general, patients had higher absolute numbers of CD3 + cells and the CD8 + subset was particularly expanded in previously treated patients. Progressive patients had higher numbers of CD4 + and CD8 + cells expressing PD-1 compared to healthy controls, which was more pronounced in previously treated patients ( P =0.0003 and P =0.001, respectively). A significant increase in antigen-experienced T cells was observed in patients within both the CD4 + and CD8 + subsets, with a significantly higher PD-1 expression. Higher numbers of CD4 + and CD8 + cells with intracellular CTLA-4 were observed in patients, as well as high numbers of proliferating (Ki67 + ) and activated (CD69 + ) CD4 + and CD8 + cells, more pronounced in patients with active disease. The numbers of Th1, Th2, Th17 and regulatory T cells were substantially increased in patients compared to controls ( P leukemia T cells display increased expression of immune checkpoints, abnormal subset distribution, and a higher proportion of proliferating cells compared to healthy T cells. Disease activity and previous treatment shape the T-cell profile of chronic lymphocytic leukemia patients in different ways. Copyright© Ferrata Storti Foundation.

  9. Brief communication: evidence that B lymphocytes carry the nuclear pocket abnormality associated with bovine leukemia virus infection

    Energy Technology Data Exchange (ETDEWEB)

    Pomeroy, K.A.; Paul, P.S.; Weber, A.F.; Sorensen, D.K.; Johnson, D.W.

    1976-01-01

    Peripheral blood lymphocytes from three cows with persistent lymphocytosis were separated on nylon wool columns into nylon wool adherent and nonadherent populations. The percentage of cells coated with surface immunoglobulin and the frequency of lymphocytic nuclear pockets in each subpopulation were then determined. In each case the adherent population consisted predominantly of B cells with an increased nuclear pocket frequency while the non-adherent cells were 98 to 99 percent surface immunoglobulin negative and contained essentially no nuclear pockets. These findings provide additional evidence that the B subpopulation of cells is highly involved in bovine leukemia oncogenesis.

  10. In vitro cellular uptake and cytotoxic effect of functionalized nickel nanoparticles on leukemia cancer cells.

    Science.gov (United States)

    Guo, Dadong; Wu, Chunhui; Li, Xiaomao; Jiang, Hui; Wang, Xuemei; Chen, Baoan

    2008-05-01

    Nickel nanoparticles (Ni NPs) have been applied in a wide range of areas because of their unique structure and properties such as catalysts, high-density magnetic recording media and others. However, little effort has been paid to their biological application and the concrete effect of Ni NPs on biological systems is still unknown. In this study, the possibility of the utilization of the magnetic Ni NPs in cancer cell studies was explored and the effects of the Ni NPs capped with positively charged tetraheptylammonium on leukemia K562 cells in vitro were investigated. Our observations of optical microscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM) studies indicate that the morphological changes of cancer cells induced by Ni NPs could be apparently observed. The results of 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) assay, DNA fragmentation and flow cytometry studies demonstrate that the Ni NPs could exert cytotoxicity to leukemia K562 cells at high concentration, and subsequently induce both apoptosis and necrosis of target cancer cells, whilst it had little impact on target cells when at low concentration. Meanwhile, functionalized Ni NPs with positively charged groups could enhance the permeability of cell membrane and facilitate the cellular uptake of outer target molecules into cancer cells. These findings reveal the potential mechanism of Ni NPs to target cancer cells which could induce the cytotoxicity to leukemia cancer cells and suggest the possibility for applications of the Ni NPs in related clinical and biomedical areas.

  11. Role of NOXA and its ubiquitination in proteasome inhibitor-induced apoptosis in chronic lymphocytic leukemia cells

    NARCIS (Netherlands)

    Baou, Maria; Kohlhaas, Susan L.; Butterworth, Michael; Vogler, Meike; Dinsdale, David; Walewska, Renata; Majid, Aneela; Eldering, Eric; Dyer, Martin J. S.; Cohen, Gerald M.

    2010-01-01

    Bortezomib has been successfully used in the treatment of multiple myeloma and has been proposed as a potential treatment for chronic lymphocytic leukemia. In this study we investigated the mechanism by which bortezomib induces apoptosis in chronic lymphocytic leukemia cells. Using western blot

  12. Role of NOXA and its ubiquitination in proteasome inhibitor-induced apoptosis in chronic lymphocytic leukemia cells

    NARCIS (Netherlands)

    Baou, M.; Kohlhaas, S.L.; Butterworth, M.; Vogler, M.; Dinsdale, D.; Walewska, R.; Majid, A.; Eldering, E.; Dyer, M.J.S.; Cohen, G.M.

    2010-01-01

    Background Bortezomib has been successfully used in the treatment of multiple myeloma and has been proposed as a potential treatment for chronic lymphocytic leukemia. In this study we investigated the mechanism by which bortezomib induces apoptosis in chronic lymphocytic leukemia cells. Design and

  13. Effects of the antitumoural dequalinium on NB4 and K562 human leukemia cell lines. Mitochondrial implication in cell death.

    Science.gov (United States)

    Galeano, Eva; Nieto, Elena; García-Pérez, Ana Isabel; Delgado, M Dolores; Pinilla, Montserrat; Sancho, Pilar

    2005-10-01

    Dequalinium (DQA) is a delocalized lipophylic cation that selectively targets the mitochondria of carcinoma cells. However, the underlying mechanisms of DQA action are not yet well understood. We have studied the effects of DQA on two different leukemia cell lines: NB4, derived from acute promyelocytic leukemia, and K562, derived from chronic myeloid leukemia. We found that DQA displays differential cytotoxic activity in these cell lines. In NB4 cells, a low DQA concentration (2microM) induces a mixture of apoptosis and necrosis, whereas a high DQA concentration (20microM) induces mainly necrosis. However, K562 cell death was always by necrosis as the cells showed a resistance to apoptosis at all time-periods and DQA concentrations assayed. In both cell lines, the cell death seems to be mediated by alterations of mitochondrial function as evidenced by loss of mitochondrial transmembrane potential, O2*- accumulation and ATP depletion. The current study improves the knowledge on DQA as a novel anticancer agent with a potential application in human acute promyelocytic leukemia chemotherapy.

  14. Epigenetic heterochromatin markers distinguish terminally differentiated leukocytes from incompletely differentiated leukemia cells in human blood

    Czech Academy of Sciences Publication Activity Database

    Popova, Evgenya Y.; Claxton, David F.; Lukášová, Emilie; Bird, Philip I.; Grigoryev, Sergei A.

    2006-01-01

    Roč. 34, č. 4 (2006), s. 453-462 ISSN 0301-472X R&D Projects: GA AV ČR(CZ) 1QS500040508 Institutional research plan: CEZ:AV0Z50040507 Keywords : terminal cell differentiation * chromatin structure * chronic myeloid leukemia Subject RIV: BO - Biophysics Impact factor: 3.408, year: 2006

  15. A recurrent germline PAX5 mutation confers susceptibility to pre-B cell acute lymphoblastic leukemia

    NARCIS (Netherlands)

    Shah, S.; Schrader, K.A.; Waanders, E.; Timms, A.E.; Vijai, J.; Miething, C.; Wechsler, J.; Yang, J.; Hayes, J.; Klein, R.J.; Zhang, J.; Wei, L.; Wu, G.; Rusch, M.; Nagahawatte, P.; Ma, J; Chen, S.C.; Song, G.; Cheng, J.; Meyers, P.; Bhojwani, D.; Jhanwar, S.; Maslak, P.; Fleisher, M.; Littman, J.; Offit, L.; Rau-Murthy, R.; Fleischut, M.H.; Corines, M.; Murali, R.; Gao, X.; Manschreck, C.; Kitzing, T.; Murty, V.V.; Raimondi, S.C.; Kuiper, R.P.; Simons, A.; Schiffman, J.D.; Onel, K.; Plon, S.E.; Wheeler, D.A.; Ritter, D.; Ziegler, D.S.; Tucker, K.; Sutton, R.; Chenevix-Trench, G.; Li, J.; Huntsman, D.G.; Hansford, S.; Senz, J.; Walsh, T.; Lee (Helen Dowling Instituut), M. van der; Hahn, C.N.; Roberts, K.G.; King, M.C.; Lo, S.M.; Levine, R.L.; Viale, A.; Socci, N.D.; Nathanson, K.L.; Scott, H.S.; Daly, M.; Lipkin, S.M.; Lowe, S.W.; Downing, J.R.; Altshuler, D.; Sandlund, J.T.; Horwitz, M.S.; Mullighan, C.G.; Offit, K.

    2013-01-01

    Somatic alterations of the lymphoid transcription factor gene PAX5 (also known as BSAP) are a hallmark of B cell precursor acute lymphoblastic leukemia (B-ALL), but inherited mutations of PAX5 have not previously been described. Here we report a new heterozygous germline variant, c.547G>A

  16. The significance of PTEN and AKT aberrations in pediatric T-cell acute lymphoblastic leukemia

    NARCIS (Netherlands)

    L.C. Zuurbier (Linda); E.F. Petricoin (Emanuel F.); M.J. Vuerhard (Maartje); V. Calvert (V.); C. Kooi (Clarissa); J.G.C.A.M. Buijs-Gladdines (Jessica); W.K. Smits; E. Sonneveld (Edwin); A.J.P. Veerman (Anjo); W.A. Kamps (Willem); M.A. Horstmann (Martin); R. Pieters (Rob); J.P.P. Meijerink (Jules)

    2012-01-01

    textabstractBackground PI3K/AKT pathway mutations are found in T-cell acute lymphoblastic leukemia, but their overall impact and associations with other genetic aberrations is unknown. PTEN mutations have been proposed as secondary mutations that follow NOTCH1-activating mutations and cause cellular

  17. The significance of PTEN and AKT aberrations in pediatric T-cell acute lymphoblastic leukemia

    NARCIS (Netherlands)

    Zuurbier, Linda; Petricoin, Emanuel F.; Vuerhard, Maartje J.; Calvert, Valerie; Kooi, Clarissa; Buijs-Gladdines, Jessica G. C. A. M.; Smits, Willem K.; Sonneveld, Edwin; Veerman, Anjo J. P.; Kamps, Willem A.; Horstmann, Martin; Pieters, Rob; Meijerink, Jules P. P.

    Background PI3K/AKT pathway mutations are found in T-cell acute lymphoblastic leukemia, but their overall impact and associations with other genetic aberrations is unknown. PTEN mutations have been proposed as secondary mutations that follow NOTCH1-activating mutations and cause cellular resistance

  18. Modulation of monocytic leukemia cell function and survival by highgradient magnetic fields and mathematical modeling studies

    Czech Academy of Sciences Publication Activity Database

    Zablotskyy, Vitaliy A.; Syrovets, T.; Schmidt, Z.W.; Dejneka, Alexandr; Simmet, T.

    2014-01-01

    Roč. 35, č. 10 (2014), s. 3164-3171 ISSN 0142-9612 Grant - others:AV ČR(CZ) M100101219 Institutional support: RVO:68378271 Keywords : magnetic field * cell proliferation * leukemia * apoptosis * modeling Subject RIV: BO - Biophysics Impact factor: 8.557, year: 2014

  19. 75 FR 53202 - Diseases Associated With Exposure to Certain Herbicide Agents (Hairy Cell Leukemia and Other...

    Science.gov (United States)

    2010-08-31

    ... association between exposure to certain herbicides and the subsequent development of hairy cell leukemia and... address only one tier of possible association between exposure to herbicides and the development of long... relationship between PTSD or stress and cardiovascular disease. Another commenter wanted VA to give greater...

  20. Successful Treatment of Fanconi Anemia and T-Cell Acute Lymphoblastic Leukemia

    Directory of Open Access Journals (Sweden)

    Terrie Flatt

    2012-01-01

    Full Text Available Fanconi anemia is associated with an increased risk of malignancy. Patients are sensitive to the toxic effects of chemotherapy. We report the case of a patient with Fanconi anemia who developed T-cell acute lymphoblastic leukemia. He experienced chemotherapy-related complications including prolonged neutropenia, grade IV vincristine neuropathy, and disseminated aspergillosis. He was successfully treated with modified dosing of cytarabine and intrathecal methotrexate followed by allogeneic bone marrow transplant. The aspergillosis was treated with systemic antifungal treatment and surgical resection. Now 30 months after bone marrow transplant the patient is without evidence of aspergillosis or leukemia.

  1. Analysis of cerebrospinal fluid from chronic fatigue syndrome patients for multiple human ubiquitous viruses and xenotropic murine leukemia-related virus.

    Science.gov (United States)

    Schutzer, Steven E; Rounds, Megan A; Natelson, Benjamin H; Ecker, David J; Eshoo, Mark W

    2011-04-01

    Recent reports showed many patients with chronic fatigue syndrome (CFS) harbor a retrovirus, xenotropic murine leukemia-related virus (XMRV), in blood; other studies could not replicate this finding. A useful next step would be to examine cerebrospinal fluid, because in some patients CFS is thought to be a brain disorder. Finding a microbe in the central nervous system would have greater significance than in blood because of the integrity of the blood-brain barrier. We examined cerebrospinal fluid from 43 CFS patients using polymerase chain reaction techniques, but did not find XMRV or multiple other common viruses, suggesting that exploration of other causes or pathogenetic mechanisms is warranted. Copyright © 2011 American Neurological Association.

  2. [1 alpha(OH) D3 (Alfarol) is effective for the treatment of chronic B cell leukemia: a case report].

    Science.gov (United States)

    Hashimoto, E; Takeuchi, H; Saitou, M; Hirashima, K

    1989-10-01

    We reported a case of chronic B-cell leukemia reacted to the administration of 1 alpha (OH)D3 (Alfarol-CHUGAI Pharm. Co.), The patient showed pancytopenia with IgM-kappa type monoclonal protein in the serum. The bone marrow aspiration was failed due to a dry tap, but the biopsied specimen showed a marked infiltration of small sized lymphoid cells with wide cytoplasm. The leukemic cells from peripheral blood showed a morphology of atypical hairy cells, Surface markers of the leukemic cells were IgM, D(kappa)+, CD 19+, CD 20+, CD 21- and HLADR+, The leukemic cells showed no L-tartrate resistant acid phosphatase sensitivity. This case was diagnosed as a chronic B-cell leukemia closely related to a hairy cell leukemia. The treatment with estrogen-chlorambucil compound (Bestrabucil-KUREHA Chem, Co.) or splenic irradiation was not effective. However, after two months' administration of Alfarol the regular blood transfusion was not needed because of increment of the Hb concentration. After eight months of its administration, the bone marrow aspirate showed a marked decrease in the number of the leukemic cells and a restoration of normal hematopoietic cells. This experience suggested that Alfarol in usefull for the treatment of chronic B cell leukemia including hairy cell leukemia and chronic lymphocytic leukemia.

  3. Concise Review: Chronic Myeloid Leukemia: Stem Cell Niche and Response to Pharmacologic Treatment

    Science.gov (United States)

    Arrigoni, Elena; Del Re, Marzia; Galimberti, Sara; Restante, Giuliana; Rofi, Eleonora; Crucitta, Stefania; Baratè, Claudia; Petrini, Mario; Di Paolo, Antonello

    2018-01-01

    Abstract Nowadays, more than 90% of patients affected by chronic myeloid leukemia (CML) survive with a good quality of life, thanks to the clinical efficacy of tyrosine kinase inhibitors (TKIs). Nevertheless, point mutations of the ABL1 pocket occurring during treatment may reduce binding of TKIs, being responsible of about 20% of cases of resistance among CML patients. In addition, the presence of leukemic stem cells (LSCs) represents the most important event in leukemia progression related to TKI resistance. LSCs express stem cell markers, including active efflux pumps and genetic and epigenetic alterations together with deregulated cell signaling pathways involved in self‐renewal, such as Wnt/β‐catenin, Notch, and Hedgehog. Moreover, the interaction with the bone marrow microenvironment, also known as hematopoietic niche, may influence the phenotype of surrounding cells, which evade mechanisms controlling cell proliferation and are less sensitive or frankly resistant to TKIs. This Review focuses on the role of LSCs and stem cell niche in relation to response to pharmacological treatments. A literature search from PubMed database was performed until April 30, 2017, and it has been analyzed according to keywords such as chronic myeloid leukemia, stem cell, leukemic stem cells, hematopoietic niche, tyrosine kinase inhibitors, and drug resistance. Stem Cells Translational Medicine 2018;7:305–314 PMID:29418079

  4. Interferon-γ affects leukemia cell apoptosis through regulating Fas/FasL signaling pathway.

    Science.gov (United States)

    Xia, H-L; Li, C-J; Hou, X-F; Zhang, H; Wu, Z-H; Wang, J

    2017-05-01

    Imbalance of hematopoietic cell proliferation and apoptosis is one of the major causes of leukemia. Enhanced cell proliferation and reduced apoptosis lead to hemocytes accumulation. Fas/FasL signaling pathway promotes cell apoptosis. This study investigated the impact of interferon γ (IFN-γ) on chronic myelogenous leukemia cell proliferation and apoptosis to elucidate its interaction with Fas/FasL signaling pathway. Leukemia K562 cells were routinely cultivated and treated with 10 U/ml, 100 U/ml, and 1000 U/ml interferon for 12 h, 24 h, and 48 h, respectively. MTT assay was applied to test cell proliferation. TUNEL assay was adopted to determine cell apoptosis. Western blot was selected to detect Fas/FasL expression. Different concentrations of IFN-γ inhibited cell proliferation at various time points. IFN-γ at 1000 U/ml treatment for 48 h exhibited the strongest suppressive effect on cell proliferation (p facilitating Fas and FasL proteins expressions.

  5. Epidemiology of acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Pendergrass, T.W.

    1985-01-01

    Although the etiology of acute leukemia is largely unknown, some facets of the puzzle are becoming clarified. Recognition of important patterns in age-specific mortality rates has suggested that events early in life, perhaps even prenatally, may have an influence on developing leukemia in childhood. The racial differences evident in mortality, incidence, and immunologic subtype of ALL suggest either differences in exposures to certain factors or differences in responses to those factors by white children. Hereditary factors appear to play a role. Familial and hereditary conditions exist that have high incidences of acute leukemia. Chromosomal anomalies are common in these conditions. Viral infections may play a role by contributing to alteration in genetic material through incorporation of the viral genome. How that virus is dealt with after primary infection seems important. The presence of immunodeficiency may allow wider dissemination or enhanced replication of such viruses, thereby increasing the likelihood of cellular transformation to an abnormal cell. Proliferation of that malignant cell to a clone may depend on other cofactors. Perhaps prolonged exposure to substances like benzene or alkylating agents may enhance these interactions between virus and genetic material. Does this change DNA repair mechanisms. Are viral infections handled differently. Is viral genomic information more easily integrated into host cells. Ionizing radiation has multiple effects. Alteration in genetic material occurs both at the molecular and chromosomal levels. DNA may be altered, lost, or added in the cell's attempt to recover from the injury

  6. Kelainan Hemostasis pada Leukemia

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    Zelly Dia Rofinda

    2012-09-01

    Full Text Available AbstrakLatar belakang: Leukemia adalah penyakit keganasan pada jaringan hematopoietik yang ditandai denganpenggantian elemen sumsum tulang normal oleh sel darah abnormal atau sel leukemik. Salah satu manifestasi klinisdari leukemia adalah perdarahan yang disebabkan oleh berbagai kelainan hemostasis.Kelainan hemostasis yang dapat terjadi pada leukemia berupa trombositopenia, disfungsi trombosit,koagulasi intravaskuler diseminata, defek protein koagulasi, fibrinolisis primer dan trombosis. Patogenesis danpatofosiologi kelainan hemostasis pada leukemia tersebut terjadi dengan berbagai mekanisme.Kata kunci: leukemia, kelainan hemostasisAbstractBackground: AbstractLeukemia is a malignancy of hematopoietic tissue which is characterized bysubstituted of bone marrow element with abnormal blood cell or leukemic cell. One of clinical manifestation ofleukemia is bleeding that is caused by several hemostasis disorders.Hemostasis disorders in leukemia such asthrombocytopenia, platelet dysfunction, disseminated intravascular coagulation, coagulation protein defect, primaryfibrinolysis and thrombosis. Pathogenesis and pathophysiology of thus hemostasis disorders in leukemia occur withdifferent mechanism.Keywords: leukemia, hemostasis disorder

  7. Radiogenic leukemia revisited

    International Nuclear Information System (INIS)

    Moloney, W.C.

    1987-01-01

    Radiation-induced leukemia is considered to be similar to the de novo disease. However, following an analysis of clinical and hematological findings in leukemia occurring in irradiated cervical cancer patients, adult Japanese atomic-bomb survivors, and spondylitics treated with x-ray, striking differences were noted. Acute leukemias in cervical cancer patients and Japanese survivors were similar in type to acute de novo leukemias in adults. Cell types among spondylitics were very dissimilar; rare forms, eg, acute erythromyelocytic leukemia (AEL) and acute megakaryocytic leukemia, were increased. Pancytopenia occurred in 25 of 35 cases and erythromyelodysplastic disorders were noted in seven of 35 acute cases. The leukemias and myelodysplastic disorders closely resembled those occurring in patients treated with alkylating agents. This similarity suggests a common pathogenesis involving marrow stem cell injury and extra-medullary mediators of hematopoiesis. Investigation of early acute leukemias and myelodysplastic disorders with newer techniques may provide valuable insights into the pathogenesis of leukemia in humans

  8. Epigenetic inactivation of Notch-Hes pathway in human B-cell acute lymphoblastic leukemia.

    Directory of Open Access Journals (Sweden)

    Shao-Qing Kuang

    Full Text Available The Notch pathway can have both oncogenic and tumor suppressor roles, depending on cell context. For example, Notch signaling promotes T cell differentiation and is leukemogenic in T cells, whereas it inhibits early B cell differentiation and acts as a tumor suppressor in B cell leukemia where it induces growth arrest and apoptosis. The regulatory mechanisms that contribute to these opposing roles are not understood. Aberrant promoter DNA methylation and histone modifications are associated with silencing of tumor suppressor genes and have been implicated in leukemogenesis. Using methylated CpG island amplification (MCA/DNA promoter microarray, we identified Notch3 and Hes5 as hypermethylated in human B cell acute lymphoblastic leukemia (ALL. We investigated the methylation status of other Notch pathway genes by bisulfite pyrosequencing. Notch3, JAG1, Hes2, Hes4 and Hes5 were frequently hypermethylated in B leukemia cell lines and primary B-ALL, in contrast to T-ALL cell lines and patient samples. Aberrant methylation of Notch3 and Hes5 in B-ALL was associated with gene silencing and was accompanied by decrease of H3K4 trimethylation and H3K9 acetylation and gain of H3K9 trimethylation and H3K27 trimethylation. 5-aza-2'-deoxycytidine treatment restored Hes5 expression and decreased promoter hypermethylation in most leukemia cell lines and primary B-ALL samples. Restoration of Hes5 expression by lentiviral transduction resulted in growth arrest and apoptosis in Hes5 negative B-ALL cells but not in Hes5 expressing T-ALL cells. These data suggest that epigenetic modifications are implicated in silencing of tumor suppressor of Notch/Hes pathway in B-ALL.

  9. Epigenetic inactivation of Notch-Hes pathway in human B-cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Kuang, Shao-Qing; Fang, Zhihong; Zweidler-McKay, Patrick A; Yang, Hui; Wei, Yue; Gonzalez-Cervantes, Emilio A; Boumber, Yanis; Garcia-Manero, Guillermo

    2013-01-01

    The Notch pathway can have both oncogenic and tumor suppressor roles, depending on cell context. For example, Notch signaling promotes T cell differentiation and is leukemogenic in T cells, whereas it inhibits early B cell differentiation and acts as a tumor suppressor in B cell leukemia where it induces growth arrest and apoptosis. The regulatory mechanisms that contribute to these opposing roles are not understood. Aberrant promoter DNA methylation and histone modifications are associated with silencing of tumor suppressor genes and have been implicated in leukemogenesis. Using methylated CpG island amplification (MCA)/DNA promoter microarray, we identified Notch3 and Hes5 as hypermethylated in human B cell acute lymphoblastic leukemia (ALL). We investigated the methylation status of other Notch pathway genes by bisulfite pyrosequencing. Notch3, JAG1, Hes2, Hes4 and Hes5 were frequently hypermethylated in B leukemia cell lines and primary B-ALL, in contrast to T-ALL cell lines and patient samples. Aberrant methylation of Notch3 and Hes5 in B-ALL was associated with gene silencing and was accompanied by decrease of H3K4 trimethylation and H3K9 acetylation and gain of H3K9 trimethylation and H3K27 trimethylation. 5-aza-2'-deoxycytidine treatment restored Hes5 expression and decreased promoter hypermethylation in most leukemia cell lines and primary B-ALL samples. Restoration of Hes5 expression by lentiviral transduction resulted in growth arrest and apoptosis in Hes5 negative B-ALL cells but not in Hes5 expressing T-ALL cells. These data suggest that epigenetic modifications are implicated in silencing of tumor suppressor of Notch/Hes pathway in B-ALL.

  10. Escin sodium induces apoptosis of human acute leukemia Jurkat T cells.

    Science.gov (United States)

    Zhang, Zhenzhen; Gao, Jian; Cai, Xueting; Zhao, Youlong; Wang, Yafei; Lu, Wuguang; Gu, Zhenhua; Zhang, Shuangquan; Cao, Peng

    2011-12-01

    Escin sodium has been used in the clinic as an antioedematous, antiexudative and vasoprotective agent for many years and has shown excellent tolerability. However, little is known about its anticancer activity. This is a report for the first time that escin sodium exerts a cytotoxic effect on human acute leukemia Jurkat T cells via the induction of apoptosis rather than cell cycle arrest. Escin sodium activated the initiator caspase-8, -9, and the effector caspase-3, degraded poly (ADP-ribose) polymerase (PARP) and attenuated the expression of Bcl-2. In addition, escin sodium inhibited the growth of cancer cells in a selective manner with Jurkat cells most sensitive to it. Taken together, the data show that escin sodium possesses potent apoptogenic activity toward human acute leukemia Jurkat T cells. Copyright © 2011 John Wiley & Sons, Ltd.

  11. Distinct protein signatures of acute myeloid leukemia bone marrow-derived stromal cells are prognostic for patient survival.

    Science.gov (United States)

    Kornblau, Steven M; Ruvolo, Peter P; Wang, Rui-Yu; Battula, V Lokesh; Shpall, Elisabeth J; Ruvolo, Vivian R; McQueen, Teresa; Qui, YiHua; Zeng, Zhihong; Pierce, Sherry; Jacamo, Rodrigo; Yoo, Suk-Young; Le, Phuong M; Sun, Jeffery; Hail, Numsen; Konopleva, Marina; Andreeff, Michael

    2018-03-15

    Mesenchymal stromal cells support acute myeloid leukemia cell survival in the bone marrow microenvironment. Protein expression profiles of acute myeloid leukemia-derived mesenchymal stromal cells are unknown. Reverse phase protein array analysis was performed to compare expression of 151 proteins from acute myeloid leukemia mesenchymal stromal cells (n = 106) with mesenchymal stromal cells from healthy donors (n = 71). Protein expression differed significantly between the two groups with nineteen proteins overexpressed in leukemia stromal cells and nine overexpressed in normal stromal cells. Unbiased hierarchical clustering analysis of the samples using these twenty-eight proteins revealed three protein constellations whose variation in expression defined four mesenchymal stromal cells protein expression signatures: Class 1, Class 2, Class 3, and Class 4. These cells populations appear to have clinical relevance. Specifically, patients with Class 3 cells have longer survival and remission duration compared to other groups. Comparison of leukemia mesenchymal stromal cells at first diagnosis with those obtained at salvage (i.e., relapse/refractory) showed differential expression of nine proteins reflecting a shift toward osteogenic differentiation. Leukemia mesenchymal stromal cells are more senescent compared to their normal counterparts, possibly due to the over expressed p53/p21 axis as confirmed by high β-galactosidase staining. In addition, over expression of BCL-XL in leukemia mesenchymal stromal cells might accord survival advantage under conditions of senescence or stress and over-expressed galectin-3 exerts profound immunosuppression. Together, our findings suggest that the identification of specific populations of mesenchymal stromal cells in acute myeloid leukemia patients may be an important determinant of therapeutic response. Copyright © 2018, Ferrata Storti Foundation.

  12. Effects of exogenous agmatine in human leukemia HMC-1 and HL-60 cells on proliferation, polyamine metabolism and cell cycle.

    Science.gov (United States)

    Haenisch, Britta; Bönisch, Heinz; Cichon, Sven; Allam, Jean-Pierre; Novak, Natalija; Molderings, Gerhard J

    2011-09-01

    Impairment of agmatine homeostasis is involved in the regulation of cell proliferation in malignant solid tumors. The present study aimed at analyzing the relevance of agmatine homeostasis in pathophysiology of human leukemia. Proliferation of the human leukemia cells HMC-1 and HL-60 was determined in the absence or presence of agmatine. Apoptosis and cell cycle distribution was investigated by determination of caspase-3 activity and/or flow cytometry after staining with propidium iodide. Expression analysis was performed by qPCR and by a microarray genechip. Exogenous agmatine inhibited proliferation of both HMC-1 and HL-60 cells. The antiproliferative effect was due to interference of agmatine with the cell cycle with no evident signs of apoptosis. Comparative analysis of expression of mRNA in untreated HMC-1 cells and in non-leukemic human mast cells revealed a much lower expression of agmatinase and diamine oxidase in HMC-1 cells indicating a significantly reduced agmatine catabolism in the leukemic cells. At the mRNA level, inhibition of proliferation of both cell lines by agmatine was associated with cell type-specific alterations of the expression of enzymes of the polyamine pathway. The present results point to a significant role of agmatine homeostasis in the (patho)physiology of cell proliferation of leukemic cells, at least in HMC-1 and HL-60 cells, that may serve as a potential target for an adjuvant therapy in the treatment of human leukemia. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. B-chronic lymphocytic leukemia cells and other B cells can produce granzyme B and gain cytotoxic potential after interleukin-21-based activation

    Science.gov (United States)

    Jahrsdörfer, Bernd; Blackwell, Sue E.; Wooldridge, James E.; Huang, Jian; Andreski, Melinda W.; Jacobus, Laura S.; Taylor, Christiana M.; Weiner, George J.

    2006-01-01

    B cells currently are not viewed as being capable of producing granzyme B or being cytotoxic. We found that B-chronic lymphocytic leukemia (B-CLL) cells treated with interleukin-21 (IL-21) produce low levels of granzyme B. The addition of either CpG oligodeoxynucleotide (ODN) or anti-B-cell-receptor antibody (anti-BCR) to IL-21 results in enhanced production of functional granzyme B by B-CLL cells. B-CLL cells treated with IL-21 and CpG ODN undergo apoptosis and are able to induce apoptosis of untreated bystander B-CLL cells. This effect can be inhibited by anti-granzyme B antibody. Benign human B cells, Epstein-Barr virus (EBV)-transformed lymphoblasts, and many standard lymphoma cell lines produce high levels of granzyme B in response to IL-21 and anti-BCR. Our results suggest that the ability to induce production of functional granzyme B by B cells could open new approaches to the therapy of B-CLL and other B-cell malignancies. Our findings also have significant implications for our understanding of the role of B cells for immune regulation and for a variety of immune phenomena, including cancer immunity, autoimmunity, and infectious immunity. PMID:16809616

  14. EBI2 overexpression in mice leads to B1 B-cell expansion and chronic lymphocytic leukemia-like B-cell malignancies.

    Science.gov (United States)

    Niss Arfelt, Kristine; Barington, Line; Benned-Jensen, Tau; Kubale, Valentina; Kovalchuk, Alexander L; Daugvilaite, Viktorija; Christensen, Jan Pravsgaard; Thomsen, Allan Randrup; Egerod, Kristoffer L; Bassi, Maria R; Spiess, Katja; Schwartz, Thue W; Wang, Hongsheng; Morse, Herbert C; Holst, Peter J; Rosenkilde, Mette M

    2017-02-16

    Human and mouse chronic lymphocytic leukemia (CLL) develops from CD5 + B cells that in mice and macaques are known to define the distinct B1a B-cell lineage. B1a cells are characterized by lack of germinal center (GC) development, and the B1a cell population is increased in mice with reduced GC formation. As a major mediator of follicular B-cell migration, the G protein-coupled receptor Epstein-Barr virus-induced gene 2 ( EBI2 or GPR183 ) directs B-cell migration in the lymphoid follicles in response to its endogenous ligands, oxysterols. Thus, upregulation of EBI2 drives the B cells toward the extrafollicular area, whereas downregulation is essential for GC formation. We therefore speculated whether increased expression of EBI2 would lead to an expanded B1 cell subset and, ultimately, progression to CLL. Here, we demonstrate that B-cell-targeted expression of human EBI2 (hEBI2) in mice reduces GC-dependent immune responses, reduces total immunoglobulin M (IgM) and IgG levels, and leads to increased proliferation and upregulation of cellular oncogenes. Furthermore, hEBI2 overexpression leads to an abnormally expanded CD5 + B1a B-cell subset (present as early as 4 days after birth), late-onset lymphoid cancer development, and premature death. These findings are highly similar to those observed in CLL patients and identify EBI2 as a promoter of B-cell malignancies.

  15. Leukemia cutis

    Directory of Open Access Journals (Sweden)

    Angoori G Rao

    2012-01-01

    Full Text Available Leukemia cutis is the infiltration of neoplastic leukocytes or their precursors into the epidermis, the dermis, or the subcutis, resulting in clinically identifiable cutaneous lesions. Leukemia cutis may follow, precede or occur concomitantly with the diagnosis of systemic leukemia. A 50-year-old woman presented with asymptomatic multiple cutaneous nodules all over the body of 4 months duration. Cutaneous examination showed multiple hyperpigmented nodules and plaques involving face, trunk, and extremities. Peripheral smear showed abnormally elevated leucocyte count (TLC-70,000 with abnormal cells: myeloblasts 40%, promyelocytes 8% and myelocytes 39%. Auer rods were present in few myeloblasts. Bone marrow aspiration showed increased cellularity, erythroid hyperplasia with megaloblastic change, increased myeloblasts with maturation arrest. Immunohistochemistry showed strongly positive myeloperoxidase infiltrating cells and negative for CD20 and CD3 consistent with the diagnosis of AML-M 2 with leukemia cutis. This case is reported for its rarity.

  16. The roles of reactive oxygen species (ROS) and autophagy in the survival and death of leukemia cells.

    Science.gov (United States)

    Chen, Yong-Feng; Liu, Hao; Luo, Xin-Jing; Zhao, Zhiqiang; Zou, Zhen-You; Li, Jing; Lin, Xiao-Jing; Liang, Yong

    2017-04-01

    As a clonal disease of hematopoietic stem cells (HSCs), the etiology and pathogenesis of leukemia is not fully understood. Recent studies suggest that cellular homeostasis plays an essential role in maintaining the function of HSCs because dysregulation of cellular homeostasis is one of the major factors underlying the malignant transformation of HSCs. Reactive oxygen species (ROS) and autophagy, key factors regulating cellular homeostasis, are commonly observed in the human body. Autophagy can be induced by ROS through a variety of signaling pathways, and conversely inhibits ROS-induced damage to cells and tissues. ROS and autophagy coordinate to maintain cellular homeostasis. Previous studies have demonstrated that both of ROS and autophagy play important roles in the development of leukemia and are closely involved in drug resistance in leukemia. Interference with cellular homeostasis by promoting programmed leukemia cell death via ROS and autophagy has been verified to be an efficient technique in the treatment of leukemia. However, the critical roles of ROS and autophagy in the development of leukemia are largely unknown. In this review, we summarize the roles of ROS and autophagy in the pathogenesis of leukemia, which may allow the identification of novel targets and drugs for the treatment of leukemia based on the regulation of HSCs homeostasis through ROS and autophagy. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Microvesicles released from human embryonic stem cell derived-mesenchymal stem cells inhibit proliferation of leukemia cells.

    Science.gov (United States)

    Ji, Yuan; Ma, Yongbin; Chen, Xiang; Ji, Xianyan; Gao, Jianyi; Zhang, Lei; Ye, Kai; Qiao, Fuhao; Dai, Yao; Wang, Hui; Wen, Xiangmei; Lin, Jiang; Hu, Jiabo

    2017-08-01

    Human embryonic stem cell derived-mesenchymal stem cells (hESC‑MSCs) are able to inhibit proliferation of leukemia cells. Microvesicles released from human embryonic stem cell derived-mesenchymal stem cells (hESC‑MSC‑MVs) might play an important part in antitumor activity. Microvesicles were isolated by ultracentrifugation and identified under a scanning electron microscopy and transmission electron microscope separately. After 48-h cocultured with hESC‑MSCs and hESC‑MSC‑MVs, the number of K562 and HL60 was counted and tumor cell viability was measured by CCK8 assay. The expression of proteins Bcl-2 and Bax were estimated by western blotting. Transmission electron microscope and western blot analysis were adopted to evaluate the autophagy level. Results showed that both hESC‑MSCs and hESC‑MSC‑MVs inhibited proliferation of leukemia cells in a concentration-dependent manner. hESC‑MSC‑MVs reduced the ratio of Bcl/Bax, enhanced the protein level of Beclin-1 and LC3-II conversion, thus upregulating autophagy and apoptosis. In conclusion, microvesicles released from human embryonic stem cell derived-mesenchymal stem cells inhibited tumor growth and stimulated autophagy and excessive autophagy might induce apoptosis.

  18. Autologous stem cell transplantation versus alternative allogeneic donor transplants in adult acute leukemias.

    Science.gov (United States)

    Claude Gorin, Norbert

    2016-04-01

    The availability of alternative sources of stem cells including most recently T-replete haploidentical marrow or peripheral blood, and the increasing use of reduced-intensity conditioning (RIC), renders feasible an allogeneic transplant to almost all patients with acute leukemia up to 70 years of age. Autologous stem cell transplantation (ASCT) for consolidation of complete remission (CR), however, offers in some circumstances an alternative option. Although associated with a higher relapse rate, autologous transplant benefits from a lower non-relapse mortality, the absence of graft-versus-host disease (GVHD), and a better quality of life for long-term survivors. The recent use of intravenous busulfan (IVBU) with high-dose melphalan, better monitoring of minimal residual disease (MRD), and maintenance therapy post autografting bring new interest. Few retrospective studies compared the outcome following alternative donor versus autologous transplants for remission consolidation. Genoidentical and phenoidentical allogeneic stem cell transplantations are undisputed gold standards, but there are no data showing the superiority of alternative allogeneic donor over autologous transplantation, at the time of undetectable MRD, in patients with good- and intermediate-1 risk acute myelocytic leukemia (AML) in first complete remission (CR1), acute promyelocytic leukemia in second complete remission (CR2), and Philadelphia chromosome-positive (Ph(+)) acute lymphocytic leukemia (ALL). Copyright © 2016. Published by Elsevier Inc.

  19. RNA Viruses: ROS-Mediated Cell Death

    Science.gov (United States)

    Reshi, Mohammad Latif; Su, Yi-Che; Hong, Jiann-Ruey

    2014-01-01

    Reactive oxygen species (ROS) are well known for being both beneficial and deleterious. The main thrust of this review is to investigate the role of ROS in ribonucleic acid (RNA) virus pathogenesis. Much evidences has accumulated over the past decade, suggesting that patients infected with RNA viruses are under chronic oxidative stress. Changes to the body's antioxidant defense system, in relation to SOD, ascorbic acid, selenium, carotenoids, and glutathione, have been reported in various tissues of RNA-virus infected patients. This review focuses on RNA viruses and retroviruses, giving particular attention to the human influenza virus, Hepatitis c virus (HCV), human immunodeficiency virus (HIV), and the aquatic Betanodavirus. Oxidative stress via RNA virus infections can contribute to several aspects of viral disease pathogenesis including apoptosis, loss of immune function, viral replication, inflammatory response, and loss of body weight. We focus on how ROS production is correlated with host cell death. Moreover, ROS may play an important role as a signal molecule in the regulation of viral replication and organelle function, potentially providing new insights in the prevention and treatment of RNA viruses and retrovirus infections. PMID:24899897

  20. Deregulated expression of Cdc6 as BCR/ABL-dependent survival factor in chronic myeloid leukemia cells.

    Science.gov (United States)

    Zhang, Jia-Hua; He, Yan-Li; Zhu, Rui; Du, Wen; Xiao, Jun-Hua

    2017-06-01

    Chronic myeloid leukemia is characterized by the presence of the reciprocal translocation t(9;22) and the BCR/ABL oncogene. The BCR/ABL oncogene activates multiple signaling pathways and involves the dysregulation of oncogenes during the progression of chronic myeloid leukemia. The cell division cycle protein 6, an essential regulator of DNA replication, is elevated in some human cancer cells. However, the expression of cell division cycle protein 6 in chronic myeloid leukemia and the underlying regulatory mechanism remain to be elucidated. In this study, our data showed that cell division cycle protein 6 expression was significantly upregulated in primary chronic myeloid leukemia cells and the chronic myeloid leukemia cell line K562 cells, as compared to the normal bone marrow mononuclear cells. BCR/ABL kinase inhibitor STI571 or BCR/ABL small interfering RNA could significantly downregulate cell division cycle protein 6 messenger RNA expression in K562 cells. Moreover, phosphoinositide 3-kinase/AKT pathway inhibitor LY294002 and Janus kinase/signal transducer and activator of transcription pathway inhibitor AG490 could downregulate cell division cycle protein 6 expression in K562 cells, but not RAS/mitogen-activated protein kinase pathway inhibitor PD98059 had such effect. Cell division cycle protein 6 gene silencing by small interfering RNA effectively resulted in decrease of proliferation, increase of apoptosis, and arrest of cell cycle in K562 cells. These findings have demonstrated that cell division cycle protein 6 overexpression may contribute to the high proliferation and low apoptosis in chronic myeloid leukemia cells and can be regulated by BCR/ABL signal transduction through downstream phosphoinositide 3-kinase/Akt and Janus kinase/signal transducer and activator of transcription pathways, suggesting cell division cycle protein 6 as a potential therapeutic target in chronic myeloid leukemia.

  1. Differential expression of the ufo/axl oncogene in human leukemia-lymphoma cell lines.

    Science.gov (United States)

    Challier, C; Uphoff, C C; Janssen, J W; Drexler, H G

    1996-05-01

    The ufo protein (also termed axl) is a member of a new family of receptor tyrosine kinases and is encoded by a transforming gene that was initially isolated from primary human myeloid leukemia cells by DNA-mediated transformation of NIH/3T3 cells. The ligand, Gas6, a protein S-related molecule lacking any known function yet, has recently been identified. We report the expression pattern of ufo mRNA in a panel of 76 human continuous leukemia-lymphoma cell lines. The gene was not expressed in cell lines derived from lymphoid malignancies (n=28), but transcription was seen in 3/11 myeloid, 0/6 monocytic, 9/13 erythroid and 11/18 megakaryocytic cell lines. Several cell lines were treated with phorbol ester leading to significant upregulation of the ufo message in constitutively positive cells. An apparent ufo mRNA overexpression was not found in any of the positive leukemia cell lines, but was identified in the drug-resistant subclones of the cervix carcinoma cell line HeLa. Southern blot analysis of restriction enzyme-digested genomic DNA did not provide evidence for gene amplification, but the HeLa subclones showed banding patterns suggestive of gene rearrangement. Two main ufo mRNA bands of 3.2 and 5.0 kb were identified; no differences in the half-lives (t1/2 = 2.5 h) of these two mRNA species could be identified. In summary, ufo, representing a novel type of receptor tyrosine kinase, is expressed solely in myeloid and erythro-megakaryocytic leukemias but not in lymphoid malignancies. These and previous data suggest an involvement of the ufo receptor tyrosine kinase in normal and malignant myelopoiesis; however, its exact role, if any, and mode of operation in leukemogenesis remains to be determined.

  2. CAR-T cells and allogeneic hematopoietic stem cell transplantation for relapsed/refractory B-cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Liu, Jun; Zhang, Xi; Zhong, Jiang F; Zhang, Cheng

    2017-10-01

    Relapsed/refractory acute lymphoblastic leukemia (ALL) has a low remission rate after chemotherapy, a high relapse rate and poor long-term survival even when allogeneic hematopoietic stem cell transplantation (allo-HSCT) is performed. Chimeric antigen receptors redirected T cells (CAR-T cells) can enhance disease remission with a favorable outcome for relapsed/refractory ALL, though some cases quickly relapsed after CAR-T cell treatment. Thus, treatment with CAR-T cells followed by allo-HSCT may be the best way to treat relapsed/refractory ALL. In this review, we first discuss the different types of CAR-T cells. We then discuss the treatment of relapsed/refractory ALL using only CAR-T cells. Finally, we discuss the use of CAR-T cells, followed by allo-HSCT, for the treatment of relapsed/refractory ALL.

  3. Construction of doxycyline-dependent mini-HIV-1 variants for the development of a virotherapy against leukemias

    NARCIS (Netherlands)

    Jeeninga, Rienk E.; Jan, Barbara; van den Berg, Henk; Berkhout, Ben

    2006-01-01

    T-cell acute lymphoblastic leukemia (T-ALL) is a high-risk type of blood-cell cancer. We describe the improvement of a candidate therapeutic virus for virotherapy of leukemic cells. Virotherapy is based on the exclusive replication of a virus in leukemic cells, leading to the selective removal of

  4. Ileum perforation due to cytomegalovirus infection in a patient with adult T-cell leukemia.

    Science.gov (United States)

    Nishimura, Takeshi; Nakao, Atsunori; Okamoto, Ayana; Kihara, Takako; Hirota, Seiichi; Fujisaki, Noritomo; Kotani, Joji

    2016-04-01

    A 73-year-old woman was transferred to our department due to severe abdominal pain with peritonitis. Her laboratory data showed that her white blood cell count was elevated to more than 50,000/mm 3 . Antibodies to HTLV-I were positive and we made the diagnosis of adult T-cell leukemia (ATL). Emergency laparotomy was performed and revealed two separate small perforations of the ileum, requiring bowel resection. Immunohistochemistry for cytomegalovirus (CMV) antigen revealed positive staining in the intestinal stromal cells. Despite surgery and antiviral therapy with ganciclovir, she died after 28 days. Adult T-cell leukemia patients may present acute abdominal pain due to intestinal perforation caused by CMV infection. We should be aware of CMV infection as one of the pathogens causing acute abdominal crises such as massive hemorrhage or visceral perforation.

  5. T-type calcium channel antagonists, mibefradil and NNC-55-0396 inhibit cell proliferation and induce cell apoptosis in leukemia cell lines.

    Science.gov (United States)

    Huang, Weifeng; Lu, Chunjing; Wu, Yong; Ouyang, Shou; Chen, Yuanzhong

    2015-05-21

    T-type Ca(2+) channels are often aberrantly expressed in different human cancers and participate in the regulation of cell cycle progression, proliferation and death. RT-PCR, Q-PCR, western blotting and whole-cell patch-clamp recording were employed to assess the expression of T-type Ca(2+) channels in leukemia cell lines. The function of T-type Ca(2+) channels in leukemia cell growth and the possible mechanism of the effect of T-type Ca(2+) channel antagonists on cell proliferation and apoptosis were examined in T-lymphoma cell lines. We show that leukemia cell lines exhibited reduced cell growth when treated with T-type Ca(2+) channel inhibitors, mibefradil and NNC-55-0396 in a concentration-dependent manner. Mechanistically, these inhibitors played a dual role on cell viability: (i) blunting proliferation, through a halt in the progression to the G1-S phase; and (ii) promoting cell apoptosis, partially dependent on the endoplasmic reticulum Ca(2+) release. In addition, we observed a reduced phosphorylation of ERK1/2 in MOLT-4 cells in response to mibefradil and NNC-55-0396 treatment. These results indicate that mibefradil and NNC-55-0396 regulate proliferation and apoptosis in T-type Ca(2+) channel expressing leukemia cell lines and suggest a potential therapeutic target for leukemia.

  6. Inhibition of MerTK increases chemosensitivity and decreases oncogenic potential in T-cell acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Brandao, L N; Winges, A; Christoph, S; Sather, S; Migdall-Wilson, J; Schlegel, J; McGranahan, A; Gao, D; Liang, X; DeRyckere, D; Graham, D K

    2013-01-01

    Pediatric leukemia survival rates have improved dramatically over the past decades. However, current treatment protocols are still largely ineffective in cases of relapsed leukemia and are associated with a significant rate of chronic health conditions. Thus, there is a continued need for new therapeutic options. Here, we show that mer receptor tyrosine kinase (MerTK) was abnormally expressed in approximately one half of pediatric T-cell leukemia patient samples and T-cell acute lymphoblastic leukemia (T-ALL) cell lines. Stimulation of MerTK by the ligand Gas6 led to activation of the prosurvival proteins Erk 1/2 and Stat5, and MerTK-dependent activation of the STAT pathway in leukemia represents a novel finding. Furthermore, inhibition of MerTK expression increased the sensitivity of T-ALL cells to treatment with chemotherapeutic agents and decreased the oncogenic potential of the Jurkat T-ALL cell line in a methylcellulose colony-forming assay. Lastly, inhibition of MerTK expression significantly increased median survival in a xenograft mouse model of leukemia (30.5 days vs 60 days, P<0.0001). These results suggest that inhibition of MerTK is a promising therapeutic strategy for the treatment of leukemia and may allow for dose reduction of currently used chemotherapeutics resulting in decreased rates of therapy-associated toxicities

  7. Utilization of two different T cell receptors by T cell acute lymphoblastic lymphoma and leukemia.

    Science.gov (United States)

    Gouttefangeas, C; Bensussan, A; Boumsell, L

    1990-01-01

    We show further differences between two clinically related entities, T cell acute lymphoblastic leukemia (T-ALL) and lymphoblastic lymphoma (T-LL), by using several monoclonal antibodies (mAb) reacting either with constant or variable regions of T cell receptors (TcR) alpha beta and gamma delta or with various CD molecules. We analysed a panel of 15 T-ALL and 15 T-LL selected for their cell surface expression of the CD3 molecules. The results indicate that TcR gamma delta is more frequently used than TcR alpha beta in T-ALL (10 out of the 15 patients tested). This is in contrast to the results obtained with T-LL where the vast majority expressed TcR alpha beta (13 out of the 15 patients). These findings suggest that the leukemic cells could have a different origin in these two diseases. In addition analysis of TcR variable regions expressed by the leukemic blasts showed that in most cases they had rearranged functional V delta 1 gene segments (8 out of 11 patients) whereas in a unique case V delta 2 gene segment was used. Taken together these results and those indicating that T-ALL cell coexpress the CD1a,b and c molecules strengthen the possibility that even though these leukemic cells express the CD3-TcR complex at their cell surface their normal counterparts are not found in peripheral blood.

  8. Nucleosome repositioning during differentiation of a human myeloid leukemia cell line

    OpenAIRE

    Teif, Vladimir B.; Mallm, Jan-Philipp; Sharma, Tanvi; Mark Welch, David B.; Rippe, Karsten; Eils, Roland; Langowski, J?rg; Olins, Ada L.; Olins, Donald E.

    2017-01-01

    ABSTRACT Cell differentiation is associated with changes in chromatin organization and gene expression. In this study, we examine chromatin structure following differentiation of the human myeloid leukemia cell line (HL-60/S4) into granulocytes with retinoic acid (RA) or into macrophage with phorbol ester (TPA). We performed ChIP-seq of histone H3 and its modifications, analyzing changes in nucleosome occupancy, nucleosome repeat length, eu-/heterochromatin redistribution and properties of ep...

  9. Tumor suppressors BTG1 and IKZF1 cooperate during mouse leukemia development and increase relapse risk in B-cell precursor acute lymphoblastic leukemia patients

    NARCIS (Netherlands)

    Scheijen, B.; Boer, J.M.A.; Marke, R.; Tijchon, E.J.; Ingen Schenau, D.S. van; Waanders, E.; Emst, L. van; Meer, L.T. van der; Pieters, R.; Escherich, G.; Horstmann, M.A.; Sonneveld, E.; Venn, N.; Sutton, R.; Dalla-Pozza, L.; Kuiper, R.P.; Hoogerbrugge, P.M.; Boer, M.L. Den; Leeuwen, F.N. van

    2017-01-01

    Deletions and mutations affecting lymphoid transcription factor IKZF1 (IKAROS) are associated with an increased relapse risk and poor outcome in B-cell precursor acute lymphoblastic leukemia. However, additional genetic events may either enhance or negate the effects of IKZF1 deletions on prognosis.

  10. Donor T cells primed on leukemia lysate-pulsed recipient APCs mediate strong graft-versus-leukemia effects across MHC barriers in full chimeras.

    Science.gov (United States)

    Ghosh, Arnab; Koestner, Wolfgang; Hapke, Martin; Schlaphoff, Verena; Länger, Florian; Baumann, Rolf; Koenecke, Christian; Cornberg, Markus; Welte, Karl; Blazar, Bruce R; Sauer, Martin G

    2009-04-30

    Antigen-presenting cells (APCs) of host origin drive graft-versus-leukemia (GVL) effects but can also trigger life-threatening graft-versus-host disease (GVHD) after hematopoietic cell transplantation (HCT) across major histocompatibility complex (MHC) barriers. We show that in vitro priming of donor lymphocytes can circumvent the need of recipient-derived APCs in vivo for mediating robust GVL effects and significantly diminishes the risk of severe GVHD. In vitro, generated and expanded T cells (ETCs) mediate anti-leukemia effects only when primed on recipient-derived APCs. Loading of APCs in vitro with leukemia cell lysate, chimerism status of the recipient, and timing of adoptive transfer after HCT are important factors determining the outcome. Delayed transfer of ETCs resulted in strong GVL effects in leukemia-bearing full chimera (FC) and mixed chimera (MC) recipients, which were comparable with the GVL/GVHD rates observed after the transfer of naive donor lymphocyte infusion (DLI). Upon early transfer, GVL effects were more pronounced with ETCs but at the expense of significant GVHD. The degree of GVHD was most severe in MCs after transfer of ETCs that had been in vitro primed either on nonpulsed recipient-derived APCs or with donor-derived APCs.

  11. Sorafenib promotes graft-versus-leukemia activity in mice and humans through IL-15 production in FLT3-ITD-mutant leukemia cells

    NARCIS (Netherlands)

    Mathew, N.R.; Baumgartner, F.; Braun, L.; O'Sullivan, D.; Thomas, S.; Waterhouse, M.; Muller, T.A.; Hanke, K.; Taromi, S.; Apostolova, P.; Illert, A.L.; Melchinger, W.; Duquesne, S.; Schmitt-Graeff, A.; Osswald, L.; Yan, K.L.; Weber, A; Tugues, S.; Spath, S.; Pfeifer, D.; Follo, M.; Claus, R.; Lubbert, M.; Rummelt, C.; Bertz, H.; Wasch, R.; Haag, J.; Schmidts, A.; Schultheiss, M.; Bettinger, D.; Thimme, R.; Ullrich, E.; Tanriver, Y.; Vuong, G.L.; Arnold, R.; Hemmati, P.; Wolf, D.; Ditschkowski, M.; Jilg, C.; Wilhelm, K.; Leiber, C.; Gerull, S.; Halter, J.; Lengerke, C.; Pabst, T.; Schroeder, T.; Kobbe, G.; Rosler, W.; Doostkam, S.; Meckel, S.; Stabla, K.; Metzelder, S.K.; Halbach, S.; Brummer, T.; Hu, Z; Dengjel, J.; Hackanson, B.; Schmid, C.; Holtick, U.; Scheid, C.; Spyridonidis, A.; Stolzel, F.; Ordemann, R.; Muller, L.P.; Sicre-de-Fontbrune, F.; Ihorst, G.; Kuball, J.; Ehlert, J.E.; Feger, D.; Wagner, E.M.; Cahn, J.Y.; Schnell, J.; Kuchenbauer, F.; Bunjes, D.; Chakraverty, R.; Richardson, S.; Gill, S.; Kroger, N.; Ayuk, F.; Vago, L.; Ciceri, F.; Muller, A.M.; Kondo, T.; Teshima, T.; Klaeger, S.; Kuster, B.; Kim, D.D.H.; Weisdorf, D.; Velden, W.J. van der; Dorfel, D.; Bethge, W.; Hilgendorf, I.; Hochhaus, A.; Andrieux, G.; Borries, M.; Busch, H.; Magenau, J.; Reddy, P.; Labopin, M.; Antin, J.H., et al.

    2018-01-01

    Individuals with acute myeloid leukemia (AML) harboring an internal tandem duplication (ITD) in the gene encoding Fms-related tyrosine kinase 3 (FLT3) who relapse after allogeneic hematopoietic cell transplantation (allo-HCT) have a 1-year survival rate below 20%. We observed that sorafenib, a

  12. Modeling of C/EBPalpha mutant acute myeloid leukemia reveals a common expression signature of committed myeloid leukemia-initiating cells

    DEFF Research Database (Denmark)

    Kirstetter, Peggy; Schuster, Mikkel B; Bereshchenko, Oksana

    2008-01-01

    Mutations in the CEBPA gene are present in 7%-10% of human patients with acute myeloid leukemia (AML). However, no genetic models exist that demonstrate their etiological relevance. To mimic the most common mutations affecting CEBPA-that is, those leading to loss of the 42 kDa C/EBPalpha isoform (p...... penetrance. p42-deficient leukemia could be transferred by a Mac1+c-Kit+ population that gave rise only to myeloid cells in recipient mice. Expression profiling of this population against normal Mac1+c-Kit+ progenitors revealed a signature shared with MLL-AF9-transformed AML....

  13. Segmentation and Classification of Bone Marrow Cells Images Using Contextual Information for Medical Diagnosis of Acute Leukemias.

    Directory of Open Access Journals (Sweden)

    Carolina Reta

    Full Text Available Morphological identification of acute leukemia is a powerful tool used by hematologists to determine the family of such a disease. In some cases, experienced physicians are even able to determine the leukemia subtype of the sample. However, the identification process may have error rates up to 40% (when classifying acute leukemia subtypes depending on the physician's experience and the sample quality. This problem raises the need to create automatic tools that provide hematologists with a second opinion during the classification process. Our research presents a contextual analysis methodology for the detection of acute leukemia subtypes from