Primary-effusion lymphoma and Kaposi's sarcoma in a cardiac-transplant recipient.
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HIV Seronegativity↗
Biomedical subjects
D T Scadden
Publications and source records attributed to D T Scadden.
Expression of extracellular calcium (Ca2+o)-sensing receptor in human peripheral blood monocytes.
The calcium-sensing receptor (CaR) is a G protein-coupled receptor playing key roles in extracellular calcium ion (Ca2+o) homeostasis in parathyroid gland and kidney. Macrophage-like mononuclear cells appear at sites of osteoclastic bone resorption during bone turnover and may play a role in the "reversal" phase of skeletal remodeling that follows osteoclastic resorption and precedes osteoblastic bone formation. Bone resorption produces substantial local increases in Ca2+o that could provide a signal for such mononuclear cells present locally within the bone marrow microenvironment. Indeed, previous studies by other investigators have shown that raising Ca2+o either in vivo or in vitro stimulated the release of interleukin-6 (IL-6) from human peripheral blood monocytes, suggesting that these cells express a Ca2+o-sensing mechanism. In these earlier studies, however, the use of reverse transcription-polymerase chain reaction (RT-PCR) failed to detect transcripts for the CaR previously cloned from parathyroid and kidney in peripheral blood monocytes. Since we recently found that non-specific esterase-positive, putative monocytes isolated from murine bone marrow express the CaR, we reevaluated the expression of this receptor in human peripheral blood monocytes. Immunocytochemistry, flow cytometry, and Western blot analysis, performed using a polyclonal antiserum specific for the CaR, detected CaR protein in human monocytes. In addition, the use of RT-PCR with CaR-specific primers, followed by nucleotide sequencing of the amplified products, identified CaR transcripts in the cells. Therefore, taken together, our data show that human peripheral blood monocytes possess both CaR protein and mRNA very similar if not identical to those expressed in parathyroid and kidney that could mediate the previously described, direct effects of Ca2+o on these cells. Furthermore, since mononuclear cells isolated from bone marrow also express the CaR, the latter might play some role in the "reversal" phase of bone remodeling, sensing local changes in Ca2+o resulting from osteoclastic bone resorption and secreting osteotropic cytokines or performing other Ca2+o-regulated functions that contribute to the control of bone turnover.
Base Sequence↗
Mother knows best.
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Acquired Immunodeficiency Syndrome↗
AIDS-related malignancies.
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AIDS-Related Opportunistic Infections↗
CCAAT/enhancer binding protein alpha is a regulatory switch sufficient for induction of granulocytic development from bipotential myeloid progenitors.
The transcription factor CCAAT/enhancer binding protein alpha (C/EBPalpha) regulates a number of myeloid cell-specific genes. To delineate the role of C/EBPalpha in human granulopoiesis, we studied its expression and function in human primary cells and bipotential (granulocytic/monocytic) myeloid cell lines. We show that the expression of C/EBPalpha initiates with the commitment of multipotential precursors to the myeloid lineage, is specifically upregulated during granulocytic differentiation, and is rapidly downregulated during the alternative monocytic pathway. Conditional expression of C/EBPalpha alone in stably transfected bipotential cells triggers neutrophilic differentiation, concomitant with upregulation of the granulocyte-specific granulocyte colony-stimulating factor receptor and secondary granule protein genes. Moreover, induced expression of C/EBPalpha in bipotential precursors blocks their monocytic differentiation program. These results indicate that C/EBPalpha serves as a myeloid differentiation switch acting on bipotential precursors and directing them to mature to granulocytes.
CCAAT-Enhancer-Binding Proteins↗
Phase II trial of liposomal daunorubicin in the treatment of AIDS-related pulmonary Kaposi's sarcoma.
PURPOSE: Kaposi's sarcoma (KS) is the most common tumor in patients with AIDS and can be fatal in patients with lung involvement. Systemic chemotherapy is the most effective treatment for pulmonary KS. We thus conducted this study to determine the efficacy of liposomal daunorubicin in the treatment of patients with pulmonary KS. METHODS: Patients with biopsy-proven, symptomatic pulmonary KS were accrued. Liposomal daunorubicin was given at a dose of 60 mg/m2 intravenously every 2 weeks. Response was monitored by chest radiographs, pulmonary function tests, arterial blood gases, and grading of pulmonary symptoms. RESULTS: Fifty-three male patients were accrued. The median CD4+ lymphocyte count was 13/microL (range, 0 to 200); 70% reported a prior AIDS-defining opportunistic infection. All patients were symptomatic, with cough reported in all patients, shortness of breath in 94%, and hemoptysis in 55%. The mean study entry diffusing capacity of carbon monoxide (DLCO) was 58.5% (percent of predicted). The median dose of liposomal daunorubicin delivered was 360 mg/m2 (range, 60 to 1,380). More than 75% of patients had complete or partial resolution of baseline pulmonary symptoms. Complete or partial improvement in DLCO was observed in 22%; complete or partial resolution of radiographic abnormalities was reported in 32%. The most common treatment-related toxicity was neutropenia, which occurred in 85%. There were no instances of cardiac toxicity observed, even at high cumulative doses. CONCLUSION: Liposomal daunorubicin at 60 mg/m2 is safe and active in patients with pulmonary KS. Trials combining liposomal daunorubicin with other active agents in KS should be considered.
Acquired Immunodeficiency Syndrome↗
Posttransplant Kaposi's sarcoma treated with paclitaxel.
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Antineoplastic Agents, Phytogenic↗
T-lymphopoietic capacity of cord blood-derived CD34+ progenitor cells.
Umbilical cord blood contains an abundance of CD34+ hematopoietic progenitor cells and has been used in transplantation as an alternative to adult bone marrow or mobilized peripheral blood. Although efficient myelomonocytic, erythroid, and B lymphoid differentiation has been shown in highly purified cord blood CD34+ mononuclear cells lacking expression of lineage-specific antigens, generation of functional T cells has not been previously documented. Exploiting two recently developed, complementary thymic stromal monolayer systems, we show here that immature hematopoietic progenitor cells (CD34+lineage-) from human and rhesus monkey cord blood mononuclear cells undergo T lymphopoiesis in a manner that recapitulates T cell ontogeny in vivo. After 2 weeks of proliferation, cultures contained myeloid [corrected] cells and discrete populations of CD4+CD8+ (double-positive) immature T lymphocytes, followed after an additional 2 weeks by the appearance of single-positive CD4+CD8- and CD4-CD8+ T cells that coexpressed CD3. The T lymphoid phenotype was confirmed at the transcriptional level by the presence of the lymphoid-restricted genes RAG-2 and T cell receptor. T cells generated from cord blood progenitors in these systems exhibited immunofunction as assessed by alloreactive responses in mixed lymphocyte reactions. These findings were comparable between human and rhesus progenitor cells and closely resemble previous data using adult bone marrow CD34+ cells in these models. Together, these observations demonstrate that cord blood contains abundant lymphoid progenitors that undergo T lymphopoiesis in vitro, suggesting the full multipotentiality of this stem cell source and its validity in investigating T lymphoid differentiation.
Animals↗
Robust, but transient expression of adeno-associated virus-transduced genes during human T lymphopoiesis.
Recombinant adeno-associated viruses (rAAV) have been proposed to be gene transfer vehicles for hematopoietic stem cells with advantages over other virus-based systems due to their high titers and relative lack of dependence on cell cycle for target cell integration. We evaluated rAAV vector containing a LacZ reporter gene under the control of a cytomegalovirus (CMV) promoter in the context of primary human CD34+CD2- progenitor cells induced to undergo T-cell differentiation using an in vitro T-lymphopoiesis system. Target cells from either adult bone marrow or umbilical cord blood were efficiently transduced, and 71% to 79% CD2+ cells expressed a LacZ marker gene mRNA and produced LacZ-encoded protein after exposure to rAAV-CMV-LacZ. The impact of transgene expression on the differentiation of T cells was assessed by sequential quantitation of immunophenotypic subsets of virus-exposed cells and no alteration was noted compared with control. The durability of transgene expression was assessed and found to decay by day 35 with kinetics dependent on the multiplicity of infection. In addition, vector DNA was absent from CD4 or CD8 subselected CD3+ cells by DNA-polymerase chain reaction. These data suggest that rAAV vectors may result in robust transgene expression in primitive cells undergoing T-cell lineage commitment without toxicity or alteration in the pattern of T-cell differentiation. However, expression is transient and integration of the transgene unlikely. Recombinant AAV vectors are potentially valuable gene transfer tools for the genetic manipulation of events during T-cell ontogony but their potential in gene therapy strategies for diseases such as acquired immunodeficiency syndrome is limited.
Antigens, CD↗
Cytokine use in the management of HIV disease.
Multilineage hematopoietic defects occur in patients with human immunodeficiency virus (HIV) infection and affect therapy of the disease and of associated opportunistic infections and neoplasms. Anemia and neutropenia are common in HIV patients, and can occur as a result of HIV-related myelosuppression or complications or may be secondary effects of antiretroviral or other agents used in management of the disease. With the advent of combination drug therapy for the treatment of HIV infection and prophylaxis and treatment of infectious complications, myelosuppression is frequently encountered and may be treated with synthetic hematopoietic growth factors. Erythropoietin has been shown to increase mean hematocrit levels and to reduce transfusion requirements in anemic HIV-infected patients receiving zidovudine. Granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor have been shown to increase neutrophil counts in patients with AIDS-related bone marrow failure and those receiving zidovudine, interferon-alpha, or ganciclovir. Although recent research using interleukin-2 (IL-2) has shown that use of this cytokine in AIDS patients can lead to increases in CD4 cell counts that appear to be functional, further study is needed to determine whether cytokines can play a role other than palliation in HIV-infected patients.
Cytokines↗
Mitoguazone therapy in patients with refractory or relapsed AIDS-related lymphoma: results from a multicenter phase II trial.
PURPOSE: Patients with AIDS-related lymphoma usually have extensive lymphomatous disease, with relatively frequent involvement of the CNS. Approximately half may achieve complete remission after chemotherapy. Mitoguazone, an inhibitor of polyamine biosynthesis, has demonstrated efficacy in patients with de novo recurrent lymphoma. The drug is relatively nonmyelotoxic and may cross the blood-brain barrier. The current study was designed to assess the safety and potential efficacy of mitoguazone in patients with relapsed or refractory AIDS-lymphoma. PATIENTS AND METHODS: Thirty-five patients were accrued, all of whom had failed one (51%) or multiple (two to six) prior regimens. Mitoguazone (600 mg/m2) was given intravenously on days 1 and 8, and then every 2 weeks, until best response, progression, or toxicity. RESULTS: The median age was 39 years. High-grade lymphoma was diagnosed in 29 patients (83%). Extranodal disease was present in 30 patients (86%), with multiple extranodal sites (two to seven) in 18 (51%). The median CD4 cell count at study entry was 66/dL (range, zero to 549). Twenty-six patients were assessable for response. The objective response rate was 23% (95% confidence interval [CI], 6.9 to 39.3), with complete remission in three patients (11.5%), and partial remission (PR) in three patients (11.5%). Six patients experienced stable disease. Median survival from study entry was 2.6 months for the group as a whole; 21.5 months (range, 3.8 to 29.1) in complete responders, 5.6 months (range, 3.8 to 34.8) in partial responders. The most common toxicities occurred solely during drug infusion and included vasodilation (63%), paresthesia (86%), and somnolence (17%). Fourteen patients (40%) experienced nausea and 16 (46%) vomiting (grade 3 in one). Ten patients (29%) developed stomatitis, including grade 3 in two and grade 4 in one. Seven patients (20%) developed neutropenia, with grade 4 in one. Thrombocytopenia occurred in nine patients (26%). While on study, three patients developed sepsis, four had pneumonia, and two developed opportunistic infections. CONCLUSION: Mitoguazone is an effective agent in patients with multiply relapsed or refractory AIDS-related lymphoma, with acceptable toxicity. Further study in patients with newly diagnosed disease is warranted.
Adult↗
Temporal mapping of gene expression levels during the differentiation of individual primary hematopoietic cells.
A hierarchical order of gene expression has been proposed to control developmental events in hematopoiesis, but direct demonstration of the temporal relationships between regulatory gene expression and differentiation has been difficult to achieve. We modified a single-cell PCR method to detect 2-fold changes in mRNA copies per cell (dynamic range, 250-250,000 copies/cell) and used it to sequentially quantitate gene expression levels as single primitive (CD34+,CD38-) progenitor cells underwent differentiation to become erythrocytes, granulocytes, or monocyte/macrophages. Markers of differentiation such as CD34 or cytokine receptor mRNAs and transcription factors associated with their regulation were assessed. All transcription factors tested were expressed in multipotent progenitors. During lineage-specific differentiation, however, distinct patterns of expression emerged. SCL, GATA-2, and GATA-1 expression sequentially extinguished during erythroid differentiation. PU.1, AML1B, and C/EBP alpha expression profiles and their relationship to cytokine receptor expression in maturing granulocytes could be distinguished from similar profiles in monocytic cells. These data characterize the dynamics of gene expression accompanying blood cell development and define a signature gene expression pattern for specific stages of hematopoietic differentiation.
Adult↗
Lack of in vivo effect of granulocyte-macrophage colony-stimulating factor on human immunodeficiency virus type 1.
Neutropenia complicates HIV disease or its treatment in a large proportion of patients. Hematopoietic growth factor support has been tested in a number of clinical settings in HIV disease and has been demonstrated to be of benefit for specific parameters. One consideration regarding the use of hematopoietic growth factors in HIV disease is their potential effect on HIV viral burden, since alterations in HIV expression have been documented with certain cytokines in vitro. It has also been reported that some cytokines, notably GM-CSF, potentiate the antiviral properties of thymidine analogs such as zidovudine (AZT) in vitro. We tested these observations in vivo. Twelve HIV-positive patients with a CD4 cell count < or = 200/mm3 or HIV plasma viremia who were receiving a stable dose of zidovudine were enrolled into three dose cohorts of yeast-derived GM-CSF at 50, 125, or 250 micrograms/m2 daily by subcutaneous self-injection for 28 days. Measurements of HIV activity included serum acid-dissociated HIV p24 antigen levels, plasma and peripheral blood mononuclear cell (PBMC) limiting dilution HIV culture, and plasma HIV quantitative competitive polymerase chain reaction (PCR). Serum and intracellular zidovudine levels were measured as well as hematologic, immunologic, and toxicity parameters. Virologic measures showed neither significant upregulation nor downregulation of serum acid-dissociated HIV p24 antigen, plasma and PBMC HIV culture, or PCR in association with GM-CSF administration. A trend toward increased intracellular AZT levels was noted, but this did not achieve statistical significance (p = 0.073). CD4 and CD8 lymphocytes were essentially unaffected while absolute neutrophil counts increased with GM-CSF administration as expected. These data suggest that administration of GM-CSF does not perturb HIV activity or immunologic parameters in patients receiving AZT for advanced HIV disease. No potentiation of AZT antiviral effect was demonstrated.
Adult↗
In vitro T lymphopoiesis of human and rhesus CD34+ progenitor cells.
Differentiation of hematopoietic progenitor cells into T lymphocytes generally occurs in the unique environment of the thymus, a feature that has hindered efforts to model this process in the laboratory. We now report that thymic stromal cultures from rhesus macaques can support T-cell differentiation of human or rhesus CD34+ progenitor cells. Culture of rhesus or human CD34+ bone marrow-derived cells depleted of CD34+ lymphocytes on rhesus thymic stromal monolayers yielded CD3+CD4+CD8+, CD3+CD4+CD8-, and CD3+CD4-CD8+ cells after 10 to 14 days. In addition to classical T lymphocytes, a discrete population of CD3+CD8loCD16+CD56+ cells was detected after 14 days in cultures inoculated with rhesus CD34+ cells. CD3+ T cells arising from these cultures were not derived from contaminating T cells present in the CD34+ cells used to inoculate thymic stromal monolayers or from the thymic monolayers, as shown by labeling of cells with the lipophilic membrane dye PKH26. Expression of the recombinase activation gene RAG-2, which is selectively expressed in developing lymphocytes, was detectable in thymic cultures inoculated with CD34+ cells but not in CD34+ cells before thymic culture or in thymic stromal monolayers alone. Reverse transcriptase-polymerase chain reaction analysis of T cells derived from thymic stromal cultures of rhesus and human CD34+ cells showed a polyclonal T-cell receptor repertoire. T-cell progeny derived from rhesus CD34+ cells cultured on thymic stroma supported vigorous simian immunodeficiency virus replication in the absence of exogenous mitogenic stimuli. Rhesus thymic stromal cultures provide a convenient means to analyze T-cell differentiation in vitro and may be useful as a model of hematopoietic stem cell therapy for diseases of T cells, including acquired immunodeficiency syndrome.
Animals↗
Hematologic disorders and growth factor support in HIV infection.
During the course of HIV disease a broad spectrum of hematologic disorders develop including abnormalities in blood cell generation, survival, and function Alterations in coagulation parameters may evolve associated with disruption of immunoglobulin or factor production. This article reviews the manifestations and pathophysiology of these abnormalities and discusses the role for growth factor support.
Blood Coagulation Disorders↗
Generation of human T lymphocytes from bone marrow CD34+ cells in vitro.
Analysis of the events that regulate development of red blood cells or granulocytes has led to therapies altering clinical conditions associated with anemia or neutropenia. The development of therapeutic approaches to target conditions associated with lymphopenia, such as AIDS, has been thwarted by limited techniques for studying T-lymphocyte development. We describe an in vitro system in which human bone marrow CD34+ cells proliferate, acquire the expression of the lymphoid-specific RAG-2 gene and a broad repertoire of rearranged T-cell receptor genes, develop the ability to produce T cell-specific interleukin-2 and achieve a range of T-cell immunophenotypes. The cells also become susceptible to infection with the T-lymphotropic strain of human immunodeficiency virus-1, HIV-1IIIB. This culture system induces human T lymphopoiesis and may permit further analysis of the events regulating human T-lineage differentiation. It provides a preclinical model for screening stem cell gene therapies directed toward AIDS.
Adult↗
Epstein-Barr virus-driven gene therapy for EBV-related lymphomas.
Genetic alterations in malignant tissues are potential targets for gene-based cancer therapies. Alternatively, aberrant expression of certain specific genes associated with malignant transformation may be envisioned to enhance the expression of chemosensitizing drugs. Epstein-Barr virus (EBV)-related B-cell lymphomas are fatal complications of immunosuppression due to AIDS, organ transplantation or congenital immune abnormalities. The malignant cells latently infected with EBV typically express the transcription factor EBNA2 as one of nine latent viral genes. We tested whether an EBNA2-responsive EBV promoter may selectively target EBV-related lymphoma cells by virus-regulated expression of a suicide gene. Using the BamC promoter driving a hygromycin-thymidine kinase fusion gene or controls, we demonstrated that sensitivity to ganciclovir was selectively enhanced in cells expressing EBNA2. Further, there was complete macroscopic regression of established B-cell lymphomas in mice with severe combined immunodeficiency disease (SCID mice) treated with a single course of ganciclovir. These data provide in vitro and in vivo support for a model of exploiting the molecular basis of tumor development to enhance the specificity of gene therapy.
Animals↗
Randomized phase III trial of liposomal daunorubicin versus doxorubicin, bleomycin, and vincristine in AIDS-related Kaposi's sarcoma.
PURPOSE: To compare the safety and efficacy of liposomal daunorubicin (DaunoXome; NeXstar Pharmaceuticals, Inc, Boulder, CO) with a reference regimen of doxorubicin, bleomycin, and vincristine (ABV) in advanced AIDS-related Kaposi's sarcoma (KS). PATIENTS AND METHODS: In a prospective randomized phase III trial, 232 patients were randomized to receive DaunoXome 40 mg/m2 or a combination regimen of doxorubicin 10 mg/m2, bleomycin 15 U, and vincristine 1 mg, administered intravenously every 2 weeks. Treatment was continued until complete response (CR), disease progression, or unacceptable toxicity. RESULTS: Of 232 patients randomized, 227 were treated: 116 with DaunoXome and 111 with ABV. The overall response rate (CR or partial response [PR]) was 25% (three CRs and 26 PRs) for DaunoXome and 28% (one CR and 30 PRs) for ABV. The difference in response rates was not statistically significant. The median survival time was 369 days for DaunoXome patients and 342 days for ABV patients (P = .19). The median time to treatment failure was 115 days for DaunoXome and 99 days for ABV (P = .13). ABV patients experienced significantly more alopecia and neuropathy (P < .0001). DaunoXome patients experienced more grade 4 neutropenia (P = .021). Cardiac function remained stable, with no instances of congestive heart failure on either treatment arm. CONCLUSION: In this large phase III trial, the efficacy of DaunoXome was comparable to that of ABV. Response rates, time to treatment failure, and overall survival were similar on both treatment arms. DaunoXome is a safe and effective primary therapy for advanced AIDS-related KS.
Acquired Immunodeficiency Syndrome↗