Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085110 (SCID)
 11,041 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

AML1-ETO is generated by the t(8;21) translocation found in approximately 12% of acute myelogenous leukemia. Studies to delineate the mechanism by which AML1-ETO induces leukemia have primarily relied on transformed human cell lines or murine model systems. The goal of this study was to determine the effect of AML1-ETO expression on primary human hematopoietic cells in vitro and in a xenograft model. We used a FMEV retroviral vector for the transfer of AML1/ETO into human CD34 + cells. The repopulation, self-renewal, and differentiation potential of infected cells were assessed in serum-free liquid culture, colony assays, and in transplanted NOD-SCID mice. High transcription levels were confirmed by real-time PCR. AML1-ETO expressing cells were expandable for up to 12 weeks and retained an immature morphology. The capacity for prolonged survival, however, did not abrogate maturation, as AML1-ETO cells gave rise to normal colonies in a CFU-assay. AML1/ETO-expressing cells also contributed to myeloid (CD15, CD33), B-lymphoid (CD20), NK-cell (CD56) and erythroid (GPA) lineages in xenografted NOD/SCID mice. Although able to engraft all major lineages, AML1/ETO transplanted cells were primarily found in less differentiated fractions as measured by cell surface markers CD34 and CD38. In spite of a good engraftment and prolonged observation period none of the NOD/SCID-mice developed an acute myelogenous leukemia. Our findings demonstrate that AML1/ETO promotes the maintenance of early human hematopoietic progenitors, but does not abrogate their physiologic differentiation. Furthermore, the leukemogenic potential of AML1/ETO expressed in human progenitors is low, despite transcription levels equivalent to those found in AMLs.
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PMID:AML1/ETO promotes the maintenance of early hematopoietic progenitors in NOD/SCID mice but does not abrogate their lineage specific differentiation. 1562 11

Antibodies (Abs) conjugated to 177Lu, a relatively low-energy beta-particle emitter, were evaluated in vitro for their cytotoxic activity and in vivo for their therapeutic activity against disseminated B-cell lymphoma xenografts in SCID mice. 177Lu was compared with other beta-particle emitters ((131)I and 90Y), and also with emitters of low-energy electrons (LEEs, meaning Auger and conversion electrons of < 50 keV). The Abs used reacted with CD20, CD74 or HLA-DR, and the target cell was the Raji B lymphoma. Like the other beta-particle emitters, 177Lu was a potent and specific toxic agent in vitro, when conjugated to Abs recognizing high-density antigens. It appeared to be slightly less potent than (131)I per decay, but this difference was relatively small, and would not be a major factor in the selection of the optimal radionuclide for clinical use. The nonspecific toxicity from 177Lu was less than from 90Y, but 177Lu still produced greater nonspecific toxicity in vitro than LEE emitters. The maximum tolerated dose (MTD) of 177Lu-anti-CD74 in SCID mice was 1.81 MBq (49 microCi)/mouse. When this dose was administered on day 5 after tumor inoculation, significant protection was obtained, but considerably less than the protection obtained in previous experiments with LEE emitters (111)In and 67Ga. In conclusion, 177Lu has advantages over other available beta-particle emitters as a therapeutic agent, but its efficacy in the treatment of micrometastases seems to be less than that of LEE emitters, due to greater nonspecific toxicity. This conclusion, however, may not apply to therapy of macroscopic tumors.
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PMID:177Lu-antibody conjugates for single-cell kill of B-lymphoma cells in vitro and for therapy of micrometastases in vivo. 1582 Jul 62

Lymphoproliferative disease (LPD) is a complication of congenital and acquired immunodeficiency states. There are a number of treatment options for LPD arising after haematopoietic stem cell or solid organ transplantation including reduction of immunosuppression, targeted therapies, such as the anti-CD20 monoclonal antibody, rituximab, and EBV specific cytotoxic lymphocytes. Treatment of LPD in children with congenital immunodeficiency syndromes remains unsatisfactory and is associated with a high mortality rate. We recently managed an infant found to have polymorphic LPD concurrent with X-linked severe combined immunodeficiency (SCID). Haematopoietic stem cell transplantation (HSCT) had to be deferred because of progressive LPD. Treatment with rituximab resulted in regression of the LPD following which the patient received a 5/6 HLA matched umbilical cord blood (UCB) transplant. The patient remains well 20 months following transplantation. Rituximab treatment may have a useful role in the control of LPD associated with congenital immunodeficiency prior to HSCT.
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PMID:Rituximab for lymphoproliferative disease prior to haematopoietic stem cell transplantation for X-linked severe combined immunodeficiency. 1673 83

A novel canine lymphoma cell line, OSW, was established from the malignant pleural effusion of a dog with peripheral T-cell lymphoma. The immunoprofile as determined by flow cytometry was as follows: positive for CD45, CD49d, CD18, CD11a; weakly positive for CD11b, CD11c, CD11d; and negative for CD45RA, CD1a, CD1c, CD3, TCRalphabeta, TCRgammadelta, CD4, CD5, CD8a, CD8b, CD90(Thy1), CD21, MHCII, CD14(TUK4), CD34, and MPO. Immunocytochemistry of cytospin preparations was negative for cytoplasmic CD3, CD79a, and MPO, but was positive for CD20. The cell line had an oligoclonal T-cell receptor gamma (TCRgamma) gene rearrangement. Array comparative genomic hybridization (aCGH) and single locus probe (SLP) analysis showed that there were copy number increases of loci on dog chromosome 13 (CFA 13), and copy number decreases were evident for regions of CFA 11, 22, 26, 30 and 32, which include several of the more common chromosomal aberrations reported previously in canine lymphoma. The OSW cell line grows rapidly in vitro and is tumorigenic as a xenograft in SCID/NOD mice. OSW represents one of only a few reported canine lymphoma cell lines and is the most thoroughly characterized. This cell line and xenograft represent significant in vitro and in vivo models, respectively, for comparative and translational lymphoma research.
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PMID:A novel canine lymphoma cell line: a translational and comparative model for lymphoma research. 1753 64

Infusion of standard-dose rituximab (RTX) in chronic lymphocytic leukemia (CLL) patients promotes rapid complement activation and deposition of C3 fragments on CLL B cells. However, immediately after RTX infusions, there is substantial loss (shaving) of CD20 from circulating malignant cells. Because shaving can compromise efficacies of anticancer immunotherapeutic mAbs, we investigated whether shaving occurs in SCID mouse models. Z138 cells, a B cell line derived from human mantle cell lymphoma, were infused i.v. or s.c. The i.v. model recapitulates findings we previously reported for therapeutic RTX in CLL: i.v. infused RTX rapidly binds to Z138 cells in lungs, and binding is accompanied by deposition of C3 fragments. However, within 1 h targeted cells lose bound RTX and CD20, and these shaved cells are still demonstrable 40 h after RTX infusion. Z138 cells grow in tumors at s.c. injection sites, and infusion of large amounts of RTX (0.50 mg on each of 4 days) leads to considerable loss of CD20 from these cells. Human i.v. Ig blocked shaving, suggesting that FcgammaRI on cells of the mononuclear phagocytic system promote shaving. Examination of frozen tumor sections from treated mice by immunofluorescence revealed large areas of B cells devoid of CD20, with CD20 intact in adjacent areas; it is likely that RTX had opsonized Z138 cells closest to capillaries, and these cells were shaved by monocyte/macrophages. The shaving reaction occurs in neoplastic B cells in tissue and in peripheral blood, and strategies to enhance therapeutic targeting and block shaving are under development.
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PMID:Rituximab-CD20 complexes are shaved from Z138 mantle cell lymphoma cells in intravenous and subcutaneous SCID mouse models. 1778 67

Mantle cell lymphoma (MCL) is an aggressive B-cell lymphoma with poor clinical outcome. Although front therapy induces a high rate of complete remission (CR), relapse is inevitable and new regimens are much needed for relapsed MCL. The proteasome inhibitor bortezomib (BTZ) induces apoptosis and sensitizes MCL cells to chemotherapy in relapsed MCL, but CR rates are low, with a short duration of response and severe toxicity. Here we evaluated whether BTZ is additive or synergistic with cyclophosphamide (CTX) and rituximab (RTX). Increasing doses of BTZ with a fixed dose of RTX and CTX (BRC regimen) resulted in markedly synergistic growth inhibition of MCL cells. BRC significantly enhanced apoptosis in MCL cell lines and primary tumor cells compared with single-agent treatment. Furthermore, western blotting analysis indicated that BRC induces apoptosis earlier via activation and cleavage of caspases-8, -9 and -3, and poly (ADP-ribose) polymerase, than single-agent treatment. The pan-caspase inhibitor completely blocked apoptosis induced by BRC. In vivo studies showed that BRC eradicated subcutaneous tumors in MCL-bearing SCID mice and significantly prolonged the long-term event-free survival in 70% of the mice. Hence, our study demonstrates that cytoreductive chemotherapy with both BTZ and anti-CD20 antibody may offer a better therapeutic modality for relapsed MCL.
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PMID:Bortezomib is synergistic with rituximab and cyclophosphamide in inducing apoptosis of mantle cell lymphoma cells in vitro and in vivo. 1789 87

B cells have been implicated in the pathogenesis of rheumatoid arthritis (RA) since the discovery of RA as an autoimmune disease. There is renewed interest in B cells in RA based on the clinical efficacy of B cell depletion therapy in RA patients. Although, reduced titers of rheumatoid factor and anti-cyclic citrullinated peptide Abs are recorded, the mechanisms that convey clinical improvement are incompletely understood. In the proteoglycan-induced arthritis (PGIA) mouse model of RA, we reported that Ag-specific B cells have two important functions in the development of arthritis. PG-specific B cells are required as autoantibody-producing cells as well as Ag-specific APCs. Herein we report on the effects of anti-CD20 mAb B cell depletion therapy in PGIA. Mice were sensitized to PG and treated with anti-CD20 Ab at a time when PG-specific autoantibodies and T cell activation were evident but before acute arthritis. In mice treated with anti-CD20 mAb, development of arthritis was significantly reduced in comparison to control mAb-treated mice. B cell depletion reduced the PG-specific autoantibody response. Furthermore, there was a significant reduction in the PG-specific CD4(+) T cell recall response as well as significantly fewer PG-specific CD4(+) T cells producing IFN-gamma and IL-17, but not IL-4. The reduction in PG-specific T cells was confirmed by the inability of CD4(+) T cells from B cell-depleted mice to adoptively transfer disease into SCID mice. Overall, B cell depletion during PGIA significantly reduced disease and inhibited both autoreactive B cell and T cell function.
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PMID:Suppression of proteoglycan-induced arthritis by anti-CD20 B Cell depletion therapy is mediated by reduction in autoantibodies and CD4+ T cell reactivity. 1835 25

The objective of this study was to generate new P-glycoprotein (P-gp)-expressing multidrug resistant (MDR) cell lines by drug selection. Since our previous studies have been carried out with cells infected with a P-gp-containing vector, it was important to confirm our findings in cells generated by drug selection. In this report, we describe three B-lymphoma cell lines which became drug-resistant by stepwise exposure to vincristine (VCR): Raji cells resistant to 18 nM VCR (R18V), Namalwa cells resistant to 21 nM VCR (N21V) and DHL-4 cells resistant to 12 nM VCR (DHL-4/12V). Cells overexpressed P-gp and continued to express CD19, CD20 and CD22, all of which are targets for monoclonal antibody (MAb) therapy. The P-gp pump in these new cells was functional as determined by the efflux of Rhodamine 123 and DIOC2, and the three cell lines were resistant to several chemotherapeutic drugs. We further determined that their P-gp phenotype was stable in xenografted SCID mice and that the tumors were also resistant to chemotherapy. We will now use these new MDR cells to determine whether monoclonal antibodies against CD19 and -20 can reverse P-gp, as we previously demonstrated using Namalwa cells infected with a human mdr1 gene-containing retrovirus.
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PMID:Generation of multidrug resistant lymphoma cell lines stably expressing P-glycoprotein. 1835 72

Rituximab (RTX), a chimeric anti-CD20 antibody, is associated with direct induction of apoptosis and antibody-dependent cell-mediated cytotoxicity (ADCC) with clinical efficacy in mantle cell lymphoma (MCL). Lenalidomide (LEN), a novel immunomodulatory agent, sensitizes tumor cells and enhances ADCC. Our study attempted to elucidate the mechanism of LEN-enhanced RTX-mediated cytotoxicity of MCL cells. We found that LEN and RTX induced growth inhibition of both cultured and fresh primary MCL cells. LEN enhanced RTX-induced apoptosis via upregulating phosphorylation of c-Jun N-terminal protein kinases (JNK), Bcl-2, Bad; increasing release of cytochrome-c; enhancing activation of caspase-3, -8, -9 and cleavage of PARP. Meanwhile, LEN activated NK cells and increased CD16 expression on CD56(low)CD16(+) NK cells. Whole PBMCs but not NK cell-depleted PBMCs treated with LEN augmented 30% of RTX-dependent cytotoxicity. Daily treatment with LEN increased NK cells by 10-folds in SCID mice, and combination of LEN and RTX decreased tumor burden and prolonged survival of MCL-bearing SCID mice. Taken together, our study demonstrates that LEN plus RTX provides a synergistically therapeutic effect on MCL cells by enhancing apoptosis and RTX-dependent NK cell-mediated cytotoxicity and may be an optimal combination in the clinical trial of relapsed or refractory MCL.
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PMID:Synergistic antitumor effects of lenalidomide and rituximab on mantle cell lymphoma in vitro and in vivo. 1956 49

A humanized IgG4 anti-HLA-DR monoclonal antibody (IMMU-114), engineered to avoid side effects associated with complement activation, was examined for binding and cytotoxicity on leukemia, lymphoma, and multiple myeloma cell lines and chronic lymphocytic leukemia (CLL) patient specimens, followed by evaluation of the effects of IMMU-114 on extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) signaling pathways. HLA-DR was expressed on the majority of these cells at markedly higher levels than CD20, CD22, and CD74. IMMU-114 was toxic to mantle cell lymphoma, CLL, acute lymphoblastic leukemia, hairy cell leukemia, non-Hodgkin lymphoma (including rituximab-resistant), and multiple myeloma cell lines, and also patient CLL cells. IMMU-114 induced disease-free survival in tumor-bearing SCID mice with early-stage disease and in models that are relatively resistant to anti-CD20 monoclonal antibodies. Despite positive staining, acute myelogenous leukemic cells were not killed by IMMU-114. The ability of IMMU-114 to induce activation of ERK and JNK signaling correlated with cytotoxicity and differentiates the mechanism of action of IMMU-114 from monoclonal antibodies against CD20 and CD74. Thus, antigen expression is not sufficient for cytotoxicity; antibody-induced hyperactivation of ERK and JNK mitogen activated protein kinase signaling pathways are also required.
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PMID:Therapy of B-cell malignancies by anti-HLA-DR humanized monoclonal antibody, IMMU-114, is mediated through hyperactivation of ERK and JNK MAP kinase signaling pathways. 2057 16


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