Biomedical subjects

Michael A Caligiuri

Publications and source records attributed to Michael A Caligiuri.

At least 19 recordsLinked to original sources

PubMed2006

A phase 2 study of rituximab in combination with recombinant interleukin-2 for rituximab-refractory indolent non-Hodgkin's lymphoma.

PURPOSE: The incidence of non-Hodgkin's lymphoma (NHL), the fifth most common malignancy in the United States, has increased over 70% in the last 30 years. Fifty percent to 75% of patients with low-grade or follicular NHL respond to rituximab therapy. However, responses are generally of limited duration, and complete responses are rare. Preclinical work suggests that human recombinant interleukin-2 (rIL-2; aldesleukin, Proleukin) enhances rituximab efficacy. Antibody-dependent cellular cytotoxicity (ADCC) is an important mechanism of action of rituximab. rIL-2 induces expansion and activation of Fc receptor (FcR)-bearing cells, thereby enhancing ADCC. Therefore, a large, multicenter phase 2 trial to assess the effects of rIL-2 on rituximab therapy in patients with rituxumab-refractory low-grade NHL was conducted. EXPERIMENTAL DESIGN: The combination of rituximab and rIL-2 was studied in 57 patients with rituximab-refractory low-grade NHL (i.e., patients must have received a single-agent course of rituximab and showed no tumor response, or had a response lasting <6 months). I.V. rituximab was given at 375 mg/m(2) (weeks 1-4). S.C. rIL-2 was given thrice a week at 14 MIU (weeks 2-5) and at 10 MIU (weeks 6-9). RESULTS: Rituximab plus rIL-2 combination therapy was safe and generally well tolerated, but responses were low. Fifty-seven patients were enrolled with 54 evaluable for response; however, only five responses (one complete and four partial) were observed. Correlative data indicate that rIL-2 expanded FcR-bearing cells and enhanced ADCC. However, other factors, such as FcgammaR polymorphisms in patients refractory to single-agent rituxumab and heterogeneous tumor biology, may have influenced the lack of clinical efficacy seen with this combination therapy. CONCLUSIONS: rIL-2 expands FcR-bearing cellular subsets in vivo and enhances in vitro ADCC of rituxumab. However, these findings do not directly translate into meaningful clinical benefit for patients with rituxumab-refractory NHL.

Adult↗

PubMed2006

Hlx homeobox transcription factor negatively regulates interferon-gamma production in monokine-activated natural killer cells.

Natural killer (NK) cells contribute to host immunity, including tumor surveillance, through the production of interferon gamma (IFN-gamma). Although there is some knowledge about molecular mechanisms that induce IFN-gamma in NK cells, considerably less is known about the mechanisms that reduce its expression. Here, we investigate the role of the Hlx transcription factor in IFN-gamma production by NK cells. Hlx expression is induced in monokine-activated NK cells, but with delayed kinetics compared to IFN-gamma. Ectopic Hlx expression decreases IFN-gamma synthesis in primary human NK cells and IFN-gamma promoter activity in an NK-like cell line. Hlx protein levels inversely correlate with those of STAT4, a requisite factor for optimal IFN-gamma transcription. Mechanistically, we provide evidence indicating that Hlx overexpression accelerates dephosphorylation and proteasome-dependent degradation of the active Y693-phosphorylated form of STAT4. Thus, Hlx expression in activated NK cells temporally controls and limits the monokine-induced production of IFN-gamma, in part through the targeted depletion of STAT4.

Animals↗

PubMed2006

Mll partial tandem duplication induces aberrant Hox expression in vivo via specific epigenetic alterations.

We previously identified a rearrangement of mixed-lineage leukemia (MLL) gene (also known as ALL-1, HRX, and HTRX1), consisting of an in-frame partial tandem duplication (PTD) of exons 5 through 11 in the absence of a partner gene, occurring in approximately 4%-7% of patients with acute myeloid leukemia (AML) and normal cytogenetics, and associated with a poor prognosis. The mechanism by which the MLL PTD contributes to aberrant hematopoiesis and/or leukemia is unknown. To examine this, we generated a mouse knockin model in which exons 5 through 11 of the murine Mll gene were targeted to intron 4 of the endogenous Mll locus. Mll(PTD/WT) mice exhibit an alteration in the boundaries of normal homeobox (Hox) gene expression during embryogenesis, resulting in axial skeletal defects and increased numbers of hematopoietic progenitor cells. Mll(PTD/WT) mice overexpress Hoxa7, Hoxa9, and Hoxa10 in spleen, BM, and blood. An increase in histone H3/H4 acetylation and histone H3 lysine 4 (Lys4) methylation within the Hoxa7 and Hoxa9 promoters provides an epigenetic mechanism by which this overexpression occurs in vivo and an etiologic role for MLL PTD gain of function in the genesis of AML.

Animals↗

PubMed2006

Cyclophosphamide enhances glioma virotherapy by inhibiting innate immune responses.

Clinical trials are testing oncolytic viruses (OVs) as therapies for cancer. We have shown that animals that have brain tumors and are treated with a herpes simplex virus (HSV)-derived OV live significantly longer when cyclophosphamide (CPA) is preadministered. Here, we explore the mechanisms behind this finding. In a syngeneic rat glioma model, intratumoral HSV administration is associated with rapid increase of natural killer cells, microglia/macrophages (CD68+ and CD163+), and IFN-gamma. Pretreatment with CPA enhances HSV replication and oncolysis and reduces an HSV-mediated increase in CD68+ and CD163+ cells and intratumoral IFN-gamma. Molecular imaging shows CPA pretreatment to inhibit HSV-induced infiltration of tumor-associated phagocytic cells. Our results reveal molecular and cellular mechanisms that inhibit intratumoral spread of HSV and suggest a therapeutic path for improving the efficacy of virotherapy as a treatment for cancer.

Animals↗

PubMed2006

Phase 1 clinical results with tandutinib (MLN518), a novel FLT3 antagonist, in patients with acute myelogenous leukemia or high-risk myelodysplastic syndrome: safety, pharmacokinetics, and pharmacodynamics.

Tandutinib (MLN518/CT53518) is a novel quinazoline-based inhibitor of the type III receptor tyrosine kinases: FMS-like tyrosine kinase 3 (FLT3), platelet-derived growth factor receptor (PDGFR), and KIT. Because of the correlation between FLT3 internal tandem duplication (ITD) mutations and poor prognosis in acute myelogenous leukemia (AML), we conducted a phase 1 trial of tandutinib in 40 patients with either AML or high-risk myelodysplastic syndrome (MDS). Tandutinib was given orally in doses ranging from 50 mg to 700 mg twice daily The principal dose-limiting toxicity (DLT) of tandutinib was reversible generalized muscular weakness, fatigue, or both, occurring at doses of 525 mg and 700 mg twice daily. Tandutinib's pharmacokinetics were characterized by slow elimination, with achievement of steady-state plasma concentrations requiring greater than 1 week of dosing. Western blotting showed that tandutinib inhibited phosphorylation of FLT3 in circulating leukemic blasts. Eight patients had FLT3-ITD mutations; 5 of these were evaluable for assessment of tandutinib's antileukemic effect. Two of the 5 patients, treated at 525 mg and 700 mg twice daily, showed evidence of antileukemic activity, with decreases in both peripheral and bone marrow blasts. Tandutinib at the MTD (525 mg twice daily) should be evaluated more extensively in patients with AML with FLT3-ITD mutations to better define its antileukemic activity.

Administration, Oral↗

PubMed2006

A phase I study of ultra low dose interleukin-2 and stem cell factor in patients with HIV infection or HIV and cancer.

PURPOSE: Ultra low doses of interleukin-2 (IL-2) can activate the high-affinity IL-2 receptor constitutively expressed on CD56(bright) natural killer (NK) cells, the CD34+ NK cell precursor, and CD4+ CD25+ regulatory T cells (Tregs) in vivo. We have previously shown synergy between IL-2 and stem cell factor (SCF) in the generation of CD56(bright) NK cells from CD34+ hemopoietic progenitor cells in vitro and showed synergistic NK cell expansion in an in vivo preclinical model. To determine the safety, toxicity, and immune modulation of this combination of cytokines in vivo, we conducted a first-in-man phase I study. EXPERIMENTAL DESIGN: A phase I dose escalation study was conducted using IL-2 at 900,000 or 650,000 IU/m2/d for 8 weeks with 5 or 10 microg/kg/d of SCF given thrice a week for 8 weeks in patients with HIV infection and/or cancer. RESULTS: Ten of 13 patients completed therapy; four experienced the dose-limiting toxicities of grade 3 fatigue or urticaria. The maximum tolerated doses of IL-2 and SCF in combination is 650,000 IU/m2/d of IL-2 and 5 microg/kg/d thrice a week of SCF. NK cells were expanded over 2-fold on therapy; Tregs were expanded nearly 6-fold from baseline. CONCLUSIONS: Administration of IL-2 with SCF is safe and well tolerated and leads to expansion of lymphocyte subsets in patients with HIV or HIV and cancer; however, the changes in NK cell and Treg expansion seen with this cytokine combination were no different than those seen with a similar dose of IL-2 alone.

Adult↗

PubMed2006

Trans-presentation of donor-derived interleukin 15 is necessary for the rapid onset of acute graft-versus-host disease but not for graft-versus-tumor activity.

The "holy grail" of allogeneic stem cell transplantation is to preserve the graft-versus-tumor (GVT) effect while eliminating graft-versus-host disease (GVHD). Endogenous donor-derived interleukin 15 (IL-15) has been implicated in the pathogenesis of acute GVHD, yet the mechanism by which it impacts this lethal process remains unclear. Using the well-described and clinically relevant C57BL/6 --> B6D2F1 murine model of acute GVHD, we demonstrate that in trans presentation of IL-15 by donor bone marrow-derived cells is required for the rapid onset of acute GVHD. Recipients of IL-15-/- C57BL/6 bone marrow cells show diminished type 1 polarization of T cells, yet there is no decrease in donor T-cell reconstitution. A molecular basis for these findings is provided with the observation that expression of T-bet, the master control gene for type 1 T-cell functions, is necessary for IL-15-mediated acute GVHD lethality. Finally, we demonstrate that in the absence of donor-derived IL-15, the GVT effect is maintained. These findings thus establish a mechanism by which endogenous donor-derived IL-15 impacts the pathobiology of acute GVHD and GVT activity.

Animals↗

PubMed2006

Preclinical assessment of FHIT gene replacement therapy in human leukemia using a chimeric adenovirus, Ad5/F35.

PURPOSE: Expression of the FHIT protein is lost or reduced in most solid tumors and a significant fraction of hematopoietic malignancies. Adenovirus 5 (Ad5) virus or adeno-associated viral vectors have been used to study the tumor suppressor function of FHIT in solid tumors, but these tools have not been effective in leukemias. We have generated a chimeric FHIT-containing adenovirus composed of Ad5 and the group B adenovirus called F35 with which we have been able to efficiently infect hematopoietic cells. EXPERIMENTAL DESIGN: Infection efficiency of Ad5/F35-FHIT and Ad5/F35-GFP viruses was tested in leukemia cell lines that lacked FHIT expression, and biological effects of successful infection were assessed. An acute myelogenous leukemia, a chronic myelogenous leukemia, and four acute lymphoblastic leukemia human cell lines were examined as well as two EBV-transformed B lymphoblastoid cell lines that expressed endogenous FHIT. RESULTS: Two of four acute lymphoblastic leukemia cell lines, Jurkat and MV4;11, which were efficiently infected with Ad5/F35-FHIT, underwent growth suppression and massive induction of apoptosis without apparent activation of caspase-8 or caspase-2 and late activation of caspase-3. Treatment of infected cells with caspase-9 and caspase-3 inhibitors partially blocked FHIT-induced apoptosis. The two remaining infected acute lymphoblastic leukemia cell lines, Molt-3 and RS4;11, were apparently unaffected. Restoration of FHIT expression in the chronic myelogenous leukemia K562 cell line and the acute myelogenous leukemia KG1a cell line also induced apoptosis but at later time points than seen in the acute lymphoblastic leukemia Jurkat and MV4;11 cell lines. I.v. injection of Ad5/F35-FHIT-infected Jurkat cells resulted in abrogation of tumorigenicity in the NOD/SCID xenogeneic engraftment model. CONCLUSION: FHIT restoration in some FHIT-deficient leukemia cells induces both antiproliferative and proapoptotic effects involving the intrinsic caspase apoptotic pathway.

Acid Anhydride Hydrolases↗

PubMed2006

Cancer and leukemia group B leukemia correlative science committee: major accomplishments and future directions.

The Cancer and Leukemia Group B (CALGB) Leukemia Correlative Science Committee (LCSC) has a remarkable history of outstanding productivity and has been at the cutting edge of correlative science for adult leukemia for almost 25 years. Its work, initially focused on the use of immunophenotyping for diagnosis and prognosis of acute lymphoblastic leukemia and acute myeloid leukemia, has, for the last 15 years, focused on the clinical use of cytogenetic and molecular genetic markers in acute myeloid leukemia and acute lymphoblastic leukemia as well as in chronic lymphocytic leukemia. Numerous CALGB LCSC studies have had a major effect on the way we currently diagnose, predict outcome, select appropriate treatment, document complete remission, and monitor residual disease in adults with acute leukemia. In part as a result of the work of the CALGB LCSC, we are increasingly moving toward molecularly targeted therapy in acute and chronic leukemias. In this report, we briefly review those contributions from the CALGB LCSC that have had, or are likely to have in the future, a major effect on how we currently manage leukemia and outline directions of ongoing and future research conducted by the CALGB LCSC.

Adult↗

PubMed2006

Independent confirmation of a prognostic gene-expression signature in adult acute myeloid leukemia with a normal karyotype: a Cancer and Leukemia Group B study.

Patients with acute myeloid leukemia (AML) and normal karyotype are classified in an intermediate-risk group, albeit this subset is heterogeneous for clinical outcome. A recent complementary DNA microarray study identified a gene-expression signature that--when used to cluster normal karyotype patients--separated them into 2 prognostically relevant subgroups. We sought the first independent validation of the prognostic value of this signature. Using oligonucleotide microarrays to measure gene expression in samples from uniformly treated adults with karyotypically normal AML, we performed cluster analysis based on the previously identified signature. We also developed a well-defined classification rule using the signature to predict outcome for individual patients. Cluster analysis confirmed the prognostic utility of the signature: patient clusters differed in overall (P = .001) and disease-free (P = .001) survival. The signature-based classifier identified groups with differences in overall (P = .02) and disease-free (P = .05) survival. A strong association of the outcome classifier with the prognostically adverse FLT3 internal tandem duplication (FLT3 ITD) potentially explained the prognostic significance of the signature. However, in the subgroup of patients without FLT3 ITD there was a moderate difference in survival for the classifier-derived groups. Our analysis confirms the applicability of the gene-expression profiling strategy for outcome prediction in cytogenetically normal AML.

Acute Disease↗

PubMed2006

Assessment of tumor necrosis factor alpha blockade as an intervention to improve tolerability of dose-intensive chemotherapy in cancer patients.

PURPOSE: Maintaining dose-intensity with chemotherapeutic agents is hindered by a number of adverse effects including asthenia/fatigue. Tumor necrosis factor (TNF) is one of the cytokines responsible for the fatigue and cachexia associated with malignancies. We used etanercept (TNF-decoy receptor) to maintain dose-intensity of weekly docetaxel. PATIENTS AND METHODS: Initially, 12 patients with advanced malignancies were randomly assigned to either docetaxel 43 mg/m2 weekly alone (cohort A) or the same docetaxel dose plus etanercept 25 mg subcutaneously twice weekly (cohort B). Subsequently, higher doses of docetaxel in combination with etanercept were evaluated. Pharmacokinetics (PKs), nuclear factor-kappa B (NF-kappaB) activation, and intracellular cytokines levels were measured. Patients completed weekly questionnaires quantifying asthenia/fatigue. RESULTS: Twenty-nine of 36 intended docetaxel doses during the first cycle were delivered in cohort A, and 35 of 36 doses were delivered in cohort B (P = .055). Three cohort B patients received additional cycles in the absence of disease progression or severe toxicity, whereas no patients from cohort A received additional cycles. Escalation to docetaxel 52 mg/m2 weekly with etanercept resulted in neutropenia, not fatigue, as the limiting adverse effect, and the addition of filgrastim permitted the maintenance of dose-intensity in additional patients. Patients randomly selected to receive etanercept/docetaxel self-reported less fatigue (P < .001), and docetaxel PKs show no relevant influence of etanercept. NF-kappaB activation and increased expression of TNF-alpha were associated with increments in docetaxel dose. Antitumor activity was noticed exclusively in patients receiving etanercept. CONCLUSION: The addition of etanercept is safe and had no impact on docetaxel concentrations. The significant improvement in tolerability and the trend toward preservation of dose-intensity suggests further exploration of TNF blockade as an adjunct to cancer therapies.

Adult↗

PubMed2006

Evidence for discrete stages of human natural killer cell differentiation in vivo.

Human natural killer (NK) cells originate from CD34(+) hematopoietic progenitor cells, but the discrete stages of NK cell differentiation in vivo have not been elucidated. We identify and functionally characterize, from human lymph nodes and tonsils, four NK cell developmental intermediates spanning the continuum of differentiation from a CD34(+) NK cell progenitor to a functionally mature NK cell. Analyses of each intermediate stage for CD34, CD117, and CD94 cell surface expression, lineage differentiation potentials, capacity for cytokine production and natural cytotoxicity, and ETS-1, GATA-3, and T-BET expression provide evidence for a new model of human NK cell differentiation in secondary lymphoid tissues.

Biomarkers↗

PubMed2006

Tumor growth impedes natural-killer-cell maturation in the bone marrow.

Natural-killer (NK)-cell dysfunction and IFN-gamma deficiencies have been associated with increased incidence of both malignancy and infection. The immunologic basis of NK-cell defects in cancer-bearing hosts has not been extensively studied. Here, we demonstrate that multiple lineages of tumors, including thymoma, breast cancer, colon cancer, and melanoma cell lines, interrupt functional maturation during NK-cell development in the bone marrow. The immature NK cells in the periphery of tumor-bearing mice had impaired IFN-gamma production but seemingly normal cytotoxicity. T cells are not involved in this NK maturation arrest, because T-cell depletion did not restore NK-cell development. Moreover, the extent of tumor-cell infiltration into the bone marrow does not correlate with defective NK maturation. Interestingly, the defect was associated with a significant reduction in the IL-15Ralpha+ cells in the non-T, non-NK compartment of bone marrow cells and restored by overexpression of IL-15. Our data demonstrate that tumor growth can impede functional maturation of NK cells, most likely by interrupting the requisite IL-15 signaling pathway.

Animals↗

PubMed2006

FcgammaR-induced production of superoxide and inflammatory cytokines is differentially regulated by SHIP through its influence on PI3K and/or Ras/Erk pathways.

Phagocytosis of IgG-coated particles via FcgammaR is accompanied by the generation of superoxide and inflammatory cytokines, which can cause collateral tissue damage in the absence of regulation. Molecular mechanisms regulating these phagocytosis-associated events are not known. SHIP is an inositol phosphatase that downregulates PI3K-mediated activation events. Here, we have examined the role of SHIP in FcgammaR-induced production of superoxide and inflammatory cytokines. We report that primary SHIP-deficient bone marrow macrophages produce elevated levels of superoxide upon FcgammaR clustering. Analysis of the molecular mechanism revealed that SHIP regulates upstream Rac-GTP binding, an obligatory event for superoxide production. Likewise, SHIP-deficient macrophages displayed enhanced IL-1beta and IL-6 production in response to FcgammaR clustering. Interestingly, whereas IL-6 production required activation of both PI3K and Ras/Erk pathways, IL-1beta production was dependent only on Ras/Erk activation, suggesting that SHIP may also regulate the Ras/Erk pathway in macrophages. Consistently, SHIP-deficient macrophages displayed enhanced activation of Erk upon FcgammaR clustering. Inhibition of Ras/Erk or PI3K suppressed the enhanced production of IL-6 in SHIP-deficient macrophages. In contrast, inhibition of Ras/Erk, but not PI3K, suppressed IL-1beta production in these cells. Together, these data demonstrate that SHIP regulates phagocytosis-associated events through the inhibition of PI3K and Ras/Erk pathways.

Animals↗

PubMed2006

EBV-encoded dUTPase induces immune dysregulation: Implications for the pathophysiology of EBV-associated disease.

Epstein-Barr virus (EBV) encodes for several enzymes that are involved in viral DNA replication. There is evidence that some viral proteins, by themselves, can induce immune dysregulation that may contribute to the pathophysiology of the virus infection. In this study, we focused on the EBV-encoded deoxyuridine triphosphate nucleotidohydrolase (dUTPase) and present the first evidence that the dUTPase is able to induce immune dysregulation in vitro as demonstrated by the inhibition of the replication of stimulated peripheral blood mononuclear cells (PBMCs) and the upregulation of several proinflammatory cytokines including TNF-alpha, IL-1beta, IL-8, IL-6, and IL-10 produced by unstimulated PBMCs treated with purified EBV-encoded dUTPase. Depletion of CD14-positive cells (monocytes) eliminated the cytokine profile induced by EBV dUTPase treatment. The data support the hypothesis that at least one protein of the EBV early antigen complex can induce immune dysregulation and may be involved in the pathophysiology of EBV-associated disease.

Amino Acid Sequence↗

PubMed2006

Responsiveness of naive CD4 T cells to polarizing cytokine determines the ratio of Th1 and Th2 cell differentiation.

The intrinsic features of naive CD4 T cells that affect their ability to respond to polarizing signals for Th cell differentiation are not well understood. In this study, we show that naive CD4 T cells from mice transgenic for the Hlx gene expressed lower levels of IL-4Ralpha. The down-regulation of IL-4Ralpha diminished IL-4 signaling and the Th2 response and enhanced the Th1 response under suboptimal polarizing conditions. In nontransgenic CD4 T cells, blocking IL-4Ralpha with Abs had the same effect in an Ab dose-dependent manner. Conversely, Hlx haploinsufficiency caused higher expression of IL-4Ralpha to favor Th2 cell differentiation. Thus, the IL-4Ralpha level on naive CD4 T cells is genetically controlled by Hlx and determines the ratio of Th1 and Th2 cell differentiation.

Animals↗

PubMed2006

STAT-1-mediated repression of monocyte interleukin-10 gene expression in vivo.

There have been substantial advances in understanding the events that regulate gene expression at the cellular and molecular level; however, there has been limited progress integrating this information to understand how biological systems function in vivo. For example, the anti-inflammatory cytokine IL-10 is thought to down-regulate the effects of the pro-inflammatory cytokine IFN-gamma on monocyte activation following LPS stimulation. However, the often-postulated reciprocal regulation of IL-10 gene expression by IFN-gamma has not been studied in vivo. Here we demonstrate that the regulation of IL-10 gene expression has at least two phases following challenge with LPS or a gram-negative organism. In C57BL/6 mice, early IL-10 induction occurs independently of STAT-1, while a delayed active repression of IL-10 gene expression is critically dependent on STAT-1, but only partially dependent upon IFN-alpha/beta and IFN-gamma. This in vivo IL-10 production comes from blood monocytes, but not tissue macrophages, and cannot be reproduced in vitro. This study provides new insights into the regulation of IL-10 following challenge with a gram-negative organism, and highlights the importance of studying these cytokine regulatory pathways in vivo.

Animals↗

PubMed2006

The effect of KIR ligand incompatibility on the outcome of unrelated donor transplantation: a report from the center for international blood and marrow transplant research, the European blood and marrow transplant registry, and the Dutch registry.

Matching for HLA class I alleles, including HLA-C, is an important criterion for outcome of unrelated donor transplantation. However, haplotype-mismatched transplantations for myeloid malignancies, mismatched for killer immunoglobulin-like receptor (KIR) ligands in the graft-versus-host (GVH) direction, is associated with lower rates of graft-versus-host disease (GVHD), relapse, and mortality. This study investigated the effect of KIR ligand mismatching on the outcome of unrelated donor transplantation. The outcomes after 1571 unrelated donor transplantations for myeloid malignancies where donor-recipient pairs were HLA-A, -B, -C, and -DRB1 matched (n = 1004), GVH KIR ligand-mismatched (n = 137), host-versus-graft (HVG) KIR ligand-mismatched (n = 170), and HLA-B and/or -C-mismatched but KIR ligand-matched (n = 260) were compared using Cox regression models. Treatment-related mortality (TRM), treatment failure, and overall mortality were lowest after matched transplantations. Patients who received grafts from donors mismatched at the KIR ligand in the GVH or HVG direction and mismatched at HLA-B and/or C but matched at the KIR ligand had similar rates of TRM, treatment failure, and overall mortality. There were no differences in leukemia recurrence between the 4 groups. These results do not support the choice of an unrelated donor on the basis of KIR ligand mismatch determined from HLA typing.

Adolescent↗