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Blood 02/2013; 99:3072-3074. · 9.90 Impact Factor
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02/2013;
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Ross Brown,
Karieshma Kabani,
James Favaloro,
Shihong Yang, P Joy Ho,
John Gibson,
Phillip Fromm,
Hayley Suen,
Narelle Woodland,
Najah Nassif,
Derek Hart,
Douglas Joshua
Blood 02/2013; 120:2055-2063. · 9.90 Impact Factor
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Oncoimmunology. 02/2013; 1(9):1-3.
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ABSTRACT: Trogocytosis, which results in the acquisition of myeloma cell-derived membrane proteins by T cells, and hence generates novel regulatory T cells, adds to the growing list of immune defects of multiple myeloma patients. The increasing complexity of the cancer-associated immune defects must be attentively considered for attempting to improve the so-far unsatisfactory rates of clinical responses to immunotherapy in patients affected by multiple myeloma and other malignancies.
Oncoimmunology. 12/2012; 1(9):1658-1660.
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Ross Brown,
Karieshma Kabani,
James Favaloro,
Shihong Yang, P Joy Ho,
John Gibson,
Phillip Fromm,
Hayley Suen,
Narelle Woodland,
Najah Nassif,
Derek Hart,
Douglas Joshua
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ABSTRACT: The transfer of membrane proteins between cells during contact, known as trogocytosis, can create novel cells with a unique phenotype and altered function. We demonstrate that trogocytosis is more common in multiple myeloma (MM) than chronic lymphocytic leukemia and Waldenstrom macroglobulinaemia; that T cells are more probable to be recipients than B or natural killer cells; that trogocytosis occurs independently of either the T-cell receptor or HLA compatibility; and that after trogocytosis, T cells with acquired antigens can become novel regulators of T-cell proliferation. We screened 168 patients with MM and found that CD86 and human leukocyte antigen G (HLA-G) were antigens commonly acquired by T cells from malignant plasma cells. CD3(+)CD86(acq+) and CD3(+) HLA-G(acq+) cells were more prevalent in bone marrow than peripheral blood samples. The presence of either CD86 or HLA-G on malignant plasma cells was associated with a poor prognosis. CD38(++) side population cells expressed HLA-G, suggesting that these putative myeloma stem cells could generate immune tolerance. HLA-G(+) T cells had a regulatory potency similar to natural Tregs, thus providing another novel mechanism for MM to avoid effective immune surveillance.
Blood 06/2012; 120(10):2055-63. · 9.90 Impact Factor
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Silvia C W Ling,
Edwin K K Lau,
Ammira Al-Shabeeb,
Angela Nikolic,
Albert Catalano,
Harry Iland,
Noemi Horvath, P Joy Ho,
Simon Harrison,
Shaun Fleming,
Douglas E Joshua,
John D Allen
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ABSTRACT: Multiple myeloma, a malignancy of the antibody-secreting plasma cells, remains incurable by current therapy. However, the proteasome inhibitor bortezomib and other new drugs are revolutionizing its treatment. It remains unclear why myelomas are peculiarly sensitive to bortezomib, or what causes primary or acquired resistance. The 'unfolded protein response' is necessary for folding and assembly of immunoglobulin chains in both normal and malignant plasma cells, as well as for the disposal of incorrectly folded or unpaired chains via the ubiquitin-proteasome pathway. We tested the hypothesis that levels of transcription factor XBP-1, a major regulator of the unfolded protein response, predict response to bortezomib.
Expression of XBP-1 and other regulators of the unfolded protein response were measured in myeloma and other cancer cell lines and two cohorts of patients with refractory myeloma and correlated with sensitivity/response to bortezomib. Bortezomib-resistant myeloma cell lines were derived and the effects on expression of unfolded protein response regulators, immunoglobulin secretion, proteasome activity and cross-resistance to cytotoxic drugs and tunicamycin determined. The consequences of manipulation of XBP-1 levels for sensitivity to bortezomib were tested.
Low XBP-1 levels predicted poor response to bortezomib, both in vitro and in myeloma patients. Moreover, myeloma cell lines selected for resistance to bortezomib had down-regulated XBP-1 and immunoglobulin secretion. Expression of ATF6, another regulator of the unfolded protein response, also correlated with bortezomib sensitivity. Direct manipulation of XBP-1 levels had only modest effects on sensitivity to bortezomib, suggesting it is a surrogate marker of response to bortezomib rather than a target itself.
The unfolded protein response may be a relevant target pathway for proteasome inhibitors in the treatment of myeloma and its regulator XBP-1 is a potential response marker. (The BIR study was registered with Australian Clinical Trial Registry Number 12605000770662).
Haematologica 01/2012; 97(1):64-72. · 6.42 Impact Factor
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Jia Li,
Daniel M-Y Sze,
Ross D Brown,
Mark J Cowley,
Warren Kaplan,
Sui-Lin Mo,
Shihong Yang,
Esther Aklilu,
Karieshma Kabani,
Yen S Loh,
Tetsuo Yamagishi,
Yuling Chen, P Joy Ho,
Douglas E Joshua
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ABSTRACT: T cells contribute to host-tumor interactions in patients with monoclonal gammopathies. Expansions of CD8(+)CD57(+) T-cell receptor Vbeta-positive (TCRVbeta(+))-restricted cytotoxic T-cell (CTL) clones are found in 48% of patients with multiple myeloma and confer a favorable prognosis. We now report that CTL clones with varying TCRVbeta repertoire are present in 70% of patients with Waldenström macroglobulinemia (WM; n = 20). Previous nucleoside analog (NA) therapy, associated with increased incidence of transformation to aggressive lymphoma, significantly influenced the presence of TCRVbeta expansions (chi(2) = 11.6; P < .001), as 83% of patients without (n = 6) and only 7% with (n = 14) TCRVbeta expansions had received NA. Clonality of CD3(+)CD8(+)CD57(+)TCRVbeta(+)-restricted CTLs was confirmed by TCRVbeta CDR3 size analysis and direct sequencing. The differential expression of CD3(+)CD8(+)CD57(+)TCRVbeta(+) cells was profiled using DNA microarrays and validated at mRNA and protein level. By gene set enrichment analysis, CTL clones expressed not only genes from cytotoxic pathways (GZMB, PRF1, FGFBP2) but also genes that suppress apoptosis, inhibit proliferation, arrest cell-cycle G1/S transition, and activate T cells (RAS, CSK, and TOB pathways). Proliferation tracking after stimulation confirmed their anergic state. Our studies demonstrate the incidence, NA sensitivity, and nature of clonal CTLs in WM and highlight mechanisms that cause anergy in these cells.
Blood 02/2010; 115(17):3580-8. · 9.90 Impact Factor
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ABSTRACT: Many clinical observations point to active immunologic phenomena in patients with myeloma. These consist of active suppression of the host's immune system and partially successful attempts by the host's immune system to suppress the malignant B-cell population. Clinical conditions such as asymptomatic myeloma, which represents clinical presentation in the plateau phase of the disease, plateau establishment after conventional induction therapy without the ongoing need for therapy, and the positive prognostic importance of the presence of clones of cytotoxic T cells in the peripheral blood of some patients, suggest that host-tumor interaction is an active dynamic state. Regulatory T (Treg) cells comprise 5%-10% of peripheral CD4 T cells and are responsible for the control of autoimmune phenomena. Deficiency of the FoxP3 transcription factor, which normally characterizes Treg cells, leads to multiorgan autoimmune disorders in humans and mice. The role of Treg cells in the protection from malignancy is unclear, but their depletion can lead to the induction of tumor rejection in murine models, and their demonstration as tumorinfiltrating lymphocytes in malignancy point to a significant immunomodulator role. In myeloma, host-tumor immune interactions are complex. However, patients can clearly exhibit control of their B-cell malignancy for many years with stability of paraprotein levels, demonstrating a homeostasis between tumor and host. Whether Treg cells are playing a role in this homeostasis is unclear. At present, there is considerable debate in the literature regarding observations such as whether Treg cells are increased or decreased, functional or dysfunctional. In this review, we will discuss the potential importance of Treg cells and their role in myeloma, a disease characterized by a unique set of host-tumor interactions.
Clinical Lymphoma & Myeloma 11/2008; 8(5):283-6. · 1.13 Impact Factor
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ABSTRACT: Multiple myeloma is a hematological malignancy characterized by an increased number of bone marrow plasma cells and the presence
of high levels of a serum monoclonal immunoglobulin that is coded by a unique genetic sequence in the variable region of the
immunoglobulin heavy chain gene. Morphological examination of bone marrow biopsy samples prior to therapy and serum immunofixation
studies of the monoclonal immunoglobulin are usually sufficient to clearly diagnose this disease. However, after therapy when
the number of malignant cells is reduced, it is not possible to differentiate between the small number of malignant and normal
(polyclonal) plasma cells using traditional microscopy. In addition, while the malignant cells are generally found predominantly
in the bone marrow, in many patients with progressive disease the malignant cells may spill over into the peripheral blood.
03/2008: pages 85-91;
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ABSTRACT: Thalidomide and its immunomodulatory derivatives have provided the most significant advance in the therapy of myeloma since the introduction of high dose chemotherapy followed by stem cell transplantation nearly 20 years ago. The mechanism of action of thalidomide is complex and involves many aspects of malignant plasma cell growth and bone marrow stromal cell microenvironment interaction. Thalidomide was first used because of its anti-angiogenic properties, however it is the immunomodulatory actions that involve increasing host tumour-specific immunosurveillance by both T cell and natural killer cells which may be the most important mode of action.
Current Cancer Drug Targets 07/2006; 6(4):325-31. · 4.33 Impact Factor
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ABSTRACT: We report two cases of Waldenström's macroglobulinemia with an unusual aggressive transformation following treatment with cladribine (2-chlorodeoxyadenosine, 2-CdA), a purine analogue. The first patient developed transformation to a diffuse large-cell non-Hodgkin lymphoma, while the second developed extensive extramedullary involvement. Both patients displayed rapid progression following transformation and were refractory to chemotherapy. Both patients were pretreated with multiple courses of prednisone and chlorambucil, and transformation occurred shortly after therapy with cladribine. We propose that immune suppression from alkylating agents and purine analogues may have contributed to the unusual progression, resulting in a dismal outcome.
American Journal of Hematology 03/2006; 81(2):110-4. · 4.67 Impact Factor
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Methods in molecular medicine 02/2005; 113:1-4.
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ABSTRACT: Patients with multiple myeloma have a clonal proliferation of malignant plasma cells, each with an identical rearrangement of immunoglobulin heavy and light chain genes. When these unique sequences are determined, a valuable molecular tool is available that can been used to detect the presence of the malignant population. Previous methods have employed oligonucleotides derived from these sequences and allele-specific polymerase chain reaction to detect clonality. The method described in this chapter uses mRNA in situ hybridization (ISH) to demonstrate the presence of individual malignant cells. Single-cell analysis using mRNA ISH provides opportunities that when combined with immunophenotyping offer a valuable new investigative tool.
Methods in molecular medicine 02/2005; 113:175-81.
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ABSTRACT: The poor response to immunotherapy in patients with multiple myeloma (MM) indicates that a better understanding of any defects in the immune response in these patients is required before effective therapeutic strategies can be developed. Recently we reported that high potency (CMRF44(+)) dendritic cells (DC) in the peripheral blood of patients with MM failed to significantly up-regulate the expression of the B7 co-stimulatory molecules, CD80 and CD86, in response to an appropriate signal from soluble trimeric human CD40 ligand. This defect was caused by transforming growth factor beta(1) (TGFbeta(1)) and interleukin (IL)-10, produced by malignant plasma cells, and the defect was neutralized in vitro with anti-TGFbeta(1). As this defect could impact on immunotherapeutic strategies and may be a major cause of the failure of recent trials, it was important to identify a more clinically useful agent that could correct the defect in vivo. In this study of 59 MM patients, the relative and absolute numbers of blood DC were only significantly decreased in patients with stage III disease and CD80 up-regulation was reduced in both stage I and stage III. It was demonstrated that both IL-12 and interferon-gamma neutralized the failure to stimulate CD80 up-regulation by huCD40LT in vitro. IL-12 did not cause a change in the distribution of DC subsets that were predominantly myeloid (CD11c+ and CDw123-) suggesting that there would be a predominantly T-helper cell type response. The addition of IL-12 or interferon-gamma to future immunotherapy trials involving these patients should be considered.
British Journal of Haematology 07/2004; 125(6):743-8. · 4.94 Impact Factor
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ABSTRACT: Murine T cells do not endogenously upregulate CD80 expression but rather acquire CD80 from antigen presenting cells (APC) during CD28 ligation. Murine CD80+ memory T cells undergo apoptosis in the presence of high levels of antigen while naive CD80+ T cells are capable of acting as APC and T cell:T cell ligation induces anergy and unresponsiveness to antigen rechallenge. Reversing T cell unresponsiveness may be a key factor in the development of immunotherapy strategies for patients with myeloma. We have determined that B7+ T cells (CD80+ or CD86+) are common in patients with myeloma (n = 45), can be either CD4 or CD8, tend to be associated with stable disease and are polyclonal memory T cells (CD45RO). CD80 mRNA expression was present in CD80+ monocytes but not in CD3+ cells with a similar level of CD80 antigen expression. CD80 and CD86 antigen expression was upregulated on B cells but not T cells during incubation with trimeric human CD40 ligand (huCD40LT) + IL-2. Although there was a gradual loss of expression during in vitro culture, CD80+ T cells could be purified for further study. We conclude that B7 expression is common on T cells of patients with myeloma but that this is acquired rather than endogenously produced. B7+ CD45RO+ T cells constitute a population of memory T cells chronically exposed to antigen and warrant further study.
Leukemia and Lymphoma 03/2004; 45(2):363-71. · 2.58 Impact Factor
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P Joy Ho
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ABSTRACT: Chromosomal translocations are a hallmark of lymphoid tumours. Multiple myeloma (MM) is a tumour of the plasma cell, the terminally differentiated B lymphoid cell. In recent years, a large number of chromosomal and genetic abnormalities have been detected in myeloma, the most prominent being chromosome 13q deletions and translocations affecting the immunoglobulin heavy chain (IgH) locus on chromosome 14q32. The latter involve a large array of chromosomal partners, from which multiple oncogenes have been proposed as candidates for dysregulation. In addition, a wide variety of changes including numerical aberrations, translocations involving loci other than the immunoglobulin genes, and aberrations of known oncogenes such as N-ras mutations, have been found. With the refinement of molecular cytogenetic techniques, the sensitivity of detecting these molecular abnormalities is continuing to increase. However, with the exception of 13q deletions which have been consistently associated with an adverse prognosis, the role of the other changes in the pathogenesis of MM, and their effect on disease behaviour and prognosis are still being clarified. In this review, we will discuss the most common molecular abnormalities found in primary MM and cell lines, and consider the available evidence for a pathogenic role in MM.
Clinical & Laboratory Haematology 11/2002; 24(5):259-69. · 1.11 Impact Factor
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ABSTRACT: Despite the advances in our knowledge of myeloma cell biology, our understanding of myeloma pathogenesis is still incomplete. In this review, we present a summary of the cellular and molecular aspects of B-cell development and immunoglobulin (Ig) gene rearrangement which have been important in defining the characteristics of the myeloma plasma cell (MPC). The PMC has undergone variable gene recombination, somatic hypermutation and isotype switching, and is therefore at a postgerminal center stage of development. The finding of preswitch clonal cells and isotype variants have raised interesting questions about the cell of origin of myeloma, for which no conclusive data is as yet available. However much information has been obtained about the chromosomal and genetic aberrations in myeloma, including monosomy 13, Ig heavy chain (IgH) switch region translocations, numerical abnormalities and a multitude of heterogeneous changes. A variety of techniques have been developed to overcome the insensitivity of conventional karyotyping, utilizing molecular cytogenetic strategies ranging from the delineation of precise loci by fluorescent in situ hybridization, a more “global” assessment of the genome by multicolor spectral karyotyping, to the quantitation of chromosomal material of specific origin by comparative genomic hybridization. Whether the abnormalities detected represent oncogenic insults, are involved in disease progression or are simply “by-products” of genetic instability is still unclear. For IgH translocations, the role of candidate genes such as Cyclin D1 and FGFR3 has been studied extensively by quantitating their expression and assessment of their oncogenicity (e.g. for FGFR3) in animal models. The significance of other aberrations such as c-myc, ras and p53 has also been investigated. With the advent of oligonucleotide microarrays, the expression of thousands of genes can be efficiently examined. So far, this approach seems promising in defining subgroups of different disease behavior, and may highlight specific genes and molecular mechanisms which are important in myeloma pathogenesis.
Reviews in Clinical and Experimental Hematology 10/2002; 6(3):276 - 300.
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[show abstract]
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ABSTRACT: Despite the advances in our knowledge of myeloma cell biology, our understanding of myeloma pathogenesis is still incomplete. In this review, we present a summary of the cellular and molecular aspects of B-cell development and immunoglobulin (lg) gene rearrangement which have been important in defining the characteristics of the myeloma plasma cell (MPC). The PMC has undergone variable gene recombination, somatic hypermutation and isotype switching, and is therefore at a postgerminal center stage of development. The finding of preswitch clonal cells and isotype variants have raised interesting questions about the cell of origin of myeloma, for which no conclusive data is as yet available. However much information has been obtained about the chromosomal and genetic aberrations in myeloma, including monosomy 13, Ig heavy chain (IgH) switch region translocations, numerical abnormalities and a multitude of heterogeneous changes. A variety of techniques have been developed to overcome the insensitivity of conventional karyotyping, utilizing molecular cytogenetic strategies ranging from the delineation of precise loci by fluorescent in situ hybridization, a more "global" assessment of the genome by multicolor spectral karyotyping, to the quantitation of chromosomal material of specific origin by comparative genomic hybridization. Whether the abnormalities detected represent oncogenic insults, are involved in disease progression or are simply "by-products" of genetic instability is still unclear. For IgH translocations, the role of candidate genes such as Cyclin D1 and FGFR3 has been studied extensively by quantitating their expression and assessment of their oncogenicity (e.g. for FGFR3) in animal models. The significance of other aberrations such as c-myc, ras and p53 has also been investigated. With the advent of oligonucleotide microarrays, the expression of thousands of genes can be efficiently examined. So far, this approach seems promising in defining subgroups of different disease behavior, and may highlight specific genes and molecular mechanisms which are important in myeloma pathogenesis.
Reviews in Clinical and Experimental Hematology 10/2002; 6(3):276-300.
