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Blood Sep 2013Denileukin diftitox (DD), a diphtheria toxin fragment IL-2 fusion protein, is thought to target and kill CD25(+) cells. It is approved for the treatment of cutaneous... (Clinical Trial)
Clinical Trial
Denileukin diftitox (DD), a diphtheria toxin fragment IL-2 fusion protein, is thought to target and kill CD25(+) cells. It is approved for the treatment of cutaneous T-cell lymphoma and is used experimentally for the depletion of regulatory T cells (Treg) in cancer trials. Curiously enough, clinical effects of DD did not strictly correlate with CD25 expression, and Treg depletion was not confirmed unambiguously. Here, we report that patients with melanoma receiving DD immediately before a dendritic cell (DC) vaccine failed to develop a tumor-antigen-specific CD4 and CD8 T-cell immune response even after repeated vaccinations. Analyzing the underlying mechanism, so far we found unknown effects of DD. First, DD modulated DCs toward tolerance by downregulating costimulatory receptors such as CD83 and CD25 while upregulating tolerance-associated proteins/pathways including Stat-3, β-catenin, and class II transactivator-dependent antigen presentation. Second, DD blocked Stat3 phosphorylation in maturing DCs. Third, only activated, but not resting, Treg internalized DD and were killed. Conversely, resting Treg showed increased survival because of DD-mediated antiapoptotic IL-2 signaling. We conclude that DD exerts functions beyond CD25(+) cell killing that may affect their clinical use and could be tested for novel indications.
Topics: Antineoplastic Agents; Cancer Vaccines; Cell Survival; Combined Modality Therapy; Dendritic Cells; Diphtheria Toxin; Flow Cytometry; Humans; Immune Tolerance; Interleukin-2; Lymphocyte Culture Test, Mixed; Melanoma; Microscopy, Confocal; Oligonucleotide Array Sequence Analysis; Phenotype; Recombinant Fusion Proteins; Skin Neoplasms; T-Lymphocytes, Regulatory
PubMed: 23958949
DOI: 10.1182/blood-2012-09-456988 -
Acta Dermato-venereologica Jan 2014
Topics: Aged; Aged, 80 and over; Antineoplastic Agents; Chemoradiotherapy; Diphtheria Toxin; Electrons; Female; Humans; Interleukin-2; Male; Mycosis Fungoides; Recombinant Fusion Proteins; Skin Neoplasms
PubMed: 23756575
DOI: 10.2340/00015555-1627 -
The Journal of Investigative Dermatology Jul 2013Merkel cell carcinomas (MCCs) are rare but highly malignant skin cancers associated with a recently described polyomavirus. MCC tumors were infiltrated by T cells,... (Comparative Study)
Comparative Study
Merkel cell carcinomas (MCCs) are rare but highly malignant skin cancers associated with a recently described polyomavirus. MCC tumors were infiltrated by T cells, including effector, central memory, and regulatory T cells. Infiltrating T cells showed markedly reduced activation as evidenced by reduced expression of CD69 and CD25. Treatment of MCC tumors in vitro with IL-2 and IL-15 led to T-cell activation, proliferation, enhanced cytokine production, and loss of viable tumor cells from cultures. Expanded tumor-infiltrating lymphocytes showed TCR repertoire skewing and upregulation of CD137. MCC tumors implanted into immunodeficient mice failed to grow unless human T cells in the tumor grafts were depleted with denileukin diftitox, suggesting that tumor-specific T cells capable of controlling tumor growth were present in MCC. Both CD4(+) and CD8(+) FOXP3(+) regulatory T cells were frequent in MCC. Fifty percent of nonactivated T cells in MCC-expressed PD-1, a marker of T-cell exhaustion, and PD-L1 and PD-L2 were expressed by a subset of tumor dendritic cells and macrophages. In summary, we observed tumor-specific T cells with suppressed activity in MCC tumors. Agents that stimulate T-cell activity, block regulatory T cell function, or inhibit PD-1 signaling may be effective in the treatment of this highly malignant skin cancer.
Topics: Animals; Antigens, CD; Antigens, Differentiation, T-Lymphocyte; CD8 Antigens; Carcinoma, Merkel Cell; Carcinoma, Squamous Cell; Cell Proliferation; Cells, Cultured; Cytokines; Forkhead Transcription Factors; Humans; In Vitro Techniques; Interleukin-15; Interleukin-2; Interleukin-2 Receptor alpha Subunit; Lectins, C-Type; Mice; Mice, Inbred NOD; Mice, SCID; Programmed Cell Death 1 Receptor; Signal Transduction; Skin; Skin Neoplasms; T-Lymphocytes; T-Lymphocytes, Regulatory; Transplantation, Heterologous
PubMed: 23419694
DOI: 10.1038/jid.2013.75 -
Journal For Immunotherapy of Cancer 2013An effective anti-tumor immune response requires the coordinated action of the innate and adaptive phases of the immune system. Critical processes include the activation... (Review)
Review
An effective anti-tumor immune response requires the coordinated action of the innate and adaptive phases of the immune system. Critical processes include the activation of dendritic cells to present antigens, produce cytokines including type I interferons, and express multiple costimulatory ligands; induction of a productive T cell response within lymph nodes; migration of activated T cells to the tumor microenvironment in response to chemokines and homing receptor expression; and having effector T cells gain access to antigen-expressing tumor cells and maintain sufficient functionality to destroy them. However, tumors can become adept at escaping the immune response, developing multiple mechanisms to disrupt key processes. In general, tumors can be assigned into two different, major groups depending on whether the tumor there is an 'inflamed' or 'non-inflamed' tumor microenvironment. Improvements in our understanding of the interactions between the immune system and cancer have resulted in the development of various strategies to improve the immune-mediated control of tumors in both sub-groups. Categories of major immunotherapeutic intervention include methods to increase the frequency of tumor antigen-specific effector T cells in the circulation, strategies to block or uncouple a range of immune suppressive mechanisms within the tumor microenvironment, and tactics to induce de novo immune inflammation within the tumor microenvironment. The latter may be particularly important for eliciting immune recognition of non-inflamed tumor phenotypes. The premise put forth in this review is that synergistic therapeutic effects in vivo may be derived from combination therapies taken from distinct "bins" based on these mechanisms of action. Early data in both preclinical and some clinical studies provide support for this model. We also suggest that optimal application of these combinations may be aided by appropriate patient selection based on predictive biomarkers.
PubMed: 24829752
DOI: 10.1186/2051-1426-1-16 -
Biology of Blood and Marrow... Mar 2013Although significant strides have been made in understanding the biology of graft-versus-host disease (GVHD) and its prevention over the last 4 decades, little is known... (Randomized Controlled Trial)
Randomized Controlled Trial
Although significant strides have been made in understanding the biology of graft-versus-host disease (GVHD) and its prevention over the last 4 decades, little is known about the different populations of lymphocytes and the changes in response to treatment for this condition. BMT-CTN 0302 was a randomized phase II clinical trial in the Blood and Marrow Transplant Clinical Trials Network that assessed the efficacy of combination therapy with steroids plus pentostatin, mycophenolate mofetil, etanercept, or denileukin diftitox in patients with acute GVHD. Patients enrolled in the study underwent blood analysis by flow cytometry on days 0, 14, and 28 of therapy to enumerate the number of total lymphocytes, T cells, B cells, and lymphocytes expressing activation markers. Baseline total lymphocyte counts and subpopulations were similar in the 4 treatment arms. Responding patients had a smaller decrease in total CD45(+) cell count (P = .005) compared with nonresponding patients at day 28. On univariate analysis, those who developed chronic GVHD had significantly higher CD8(+) cell counts at day 14 compared with those without it (P = .005). There was no significant association between baseline lymphocyte count and survival. On univariate analysis, among the patients with higher lymphocyte counts at days 14 and 28, there was a trend toward better survival at day 180, although this trend did not reach the predetermined threshold for significance. We found no significant differences in lymphocyte total or subpopulation counts among the 4 treatment arms, and no notable influence on outcomes.
Topics: Acute Disease; Adult; Antigens, CD; Antineoplastic Agents; B-Lymphocyte Subsets; Bone Marrow Transplantation; Diphtheria Toxin; Etanercept; Female; Graft vs Host Disease; Humans; Immunoglobulin G; Immunophenotyping; Immunosuppressive Agents; Interleukin-2; Lymphocyte Count; Male; Middle Aged; Mycophenolic Acid; Pentostatin; Receptors, Tumor Necrosis Factor; Recombinant Fusion Proteins; Survival Analysis; T-Lymphocyte Subsets; Transplantation, Homologous
PubMed: 23247045
DOI: 10.1016/j.bbmt.2012.12.003 -
Neurology Nov 2012A 38-year-old woman was diagnosed with cutaneous anaplastic T-cell lymphoma that proved refractory to methotrexate, bexarotene, denileukin diftitox, interferon γ-1b,...
A 38-year-old woman was diagnosed with cutaneous anaplastic T-cell lymphoma that proved refractory to methotrexate, bexarotene, denileukin diftitox, interferon γ-1b, interferon α-2b, vorinostat, and pralatrexate. She was therefore started on the newly approved monoclonal anti-CD30 antibody brentuximab vedotin. Treatment with brentuximab 1.8 mg/kg IV every 3 weeks quickly led to disappearance of her cutaneous tumors. The day after her second brentuximab infusion she developed word-finding difficulties and unsteady gait. Due to further neurologic deterioration, she was admitted to an outside hospital. Brain MRI revealed multifocal enhancing white matter lesions throughout bilateral cerebral hemispheres and posterior fossa (figure, A-C). Brain biopsy was performed 15 days after her last brentuximab dose to rule out metastases and she was diagnosed with progressive multifocal leukoencephalopathy (PML) (figure, J). The patient was discharged home with hospice care. Upon discharge, she was started on prednisone 50 mg daily to help treat her eczema. Her family brought her to our clinic for a second opinion.
Topics: Adult; Antibodies; Brentuximab Vedotin; Female; Humans; Immune Reconstitution Inflammatory Syndrome; Immunoconjugates; Immunologic Factors; Leukoencephalopathies; Lymphoma, T-Cell, Cutaneous; Magnetic Resonance Imaging; Platelet Endothelial Cell Adhesion Molecule-1; Treatment Outcome
PubMed: 23115213
DOI: 10.1212/WNL.0b013e3182749f17 -
Blood Jan 2013Natural regulatory T cells (Tregs) participate in responses to various chronic infections including HIV. HIV infection is associated with a progressive CD4 lymphopenia... (Review)
Review
Natural regulatory T cells (Tregs) participate in responses to various chronic infections including HIV. HIV infection is associated with a progressive CD4 lymphopenia and defective HIV-specific CD8 responses known to play a key role in the control of viral replication. Persistent immune activation is a hallmark of HIV infection and is involved in disease progression independent of viral load. The consequences of Treg expansion, observed in HIV infection, could be either beneficial, by suppressing generalized T-cell activation, or detrimental, by weakening HIV-specific responses and thus contributing to viral persistence. The resulting balance between Tregs contrasting outcomes might have critical implications in pathogenesis. Topics covered in this review include HIV-induced alterations of Tregs, Treg cell dynamics in blood and tissues, Treg-suppressive function, and the relationship between Tregs and immune activation. This review also provides a focus on the role of CD39(+) Tregs and other regulatory cell subsets. All these issues will be explored in different situations including acute and chronic infection, antiretroviral treatment-mediated viral control, and spontaneous viral control. Results must be interpreted with regard to both the Treg definition used in context and to the setting of the disease in an attempt to draw clearer conclusions from the apparently conflicting results.
Topics: Animals; Anti-HIV Agents; Antigens, CD; Apyrase; CD4-Positive T-Lymphocytes; Chlorocebus aethiops; Diphtheria Toxin; Disease Progression; Forkhead Transcription Factors; HIV Infections; HIV Seronegativity; HIV-1; Humans; Immune Reconstitution Inflammatory Syndrome; Immune Tolerance; Immunity, Cellular; Immunity, Mucosal; Interleukin-2; Lymphocyte Activation; Lymphocyte Count; Lymphoid Tissue; Recombinant Fusion Proteins; Recombinant Proteins; Simian Acquired Immunodeficiency Syndrome; T-Lymphocytes, Regulatory; Virus Replication
PubMed: 23043072
DOI: 10.1182/blood-2012-07-409755 -
Leukemia & Lymphoma Jan 2013In a placebo-controlled study, denileukin diftitox (DD) was effective against cutaneous T-cell lymphoma (CTCL) expressing CD25. An open-label companion study examined... (Clinical Trial)
Clinical Trial
In a placebo-controlled study, denileukin diftitox (DD) was effective against cutaneous T-cell lymphoma (CTCL) expressing CD25. An open-label companion study examined the efficacy and safety of DD in 36 patients with skin biopsies containing < 20% CD25 cells by immunohistochemistry staining (CD25 low expression). Patients received DD 18 μg/kg/day for 5 consecutive days every 3 weeks for up to eight courses. The primary endpoint, overall response rate, was 30.6% (95% confidence interval: 16.3, 48.1), 33.3% for stage IIA or lower disease, and 26.7% for stage IIB or greater disease. Median progression-free survival (PFS) was > 487 days, and median time to treatment failure was 68.5 days. No difference in PFS by disease stage was observed. The safety profile of DD in CD25 low-expression disease was similar to that in CD25+ disease. These findings suggest that CD25 low expression does not preclude a meaningful clinical response to DD in patients with CTCL.
Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Diphtheria Toxin; Female; Humans; Interleukin-2; Interleukin-2 Receptor alpha Subunit; Male; Middle Aged; Mycosis Fungoides; Neoplasm Staging; Recombinant Fusion Proteins; Sezary Syndrome; Treatment Outcome
PubMed: 22738414
DOI: 10.3109/10428194.2012.706286 -
Journal of Immunology (Baltimore, Md. :... Jun 2012Denileukin diftitox (DD), a fusion protein comprising IL-2 and diphtheria toxin, was initially expected to enhance antitumor immunity by selectively eliminating...
Denileukin diftitox (DD), a fusion protein comprising IL-2 and diphtheria toxin, was initially expected to enhance antitumor immunity by selectively eliminating regulatory T cells (Tregs) displaying the high-affinity IL-2R (α-β-γ trimers). Although DD was shown to deplete some Tregs in primates, its effects on NK cells (CD16(+)CD8(+)NKG2A(+)CD3(-)), which constitutively express the intermediate-affinity IL-2R (β-γ dimers) and play a critical role in antitumor immunity, are still unknown. To address this question, cynomolgus monkeys were injected i.v. with two doses of DD (8 or 18 μg/kg). This treatment resulted in a rapid, but short-term, reduction in detectable peripheral blood resting Tregs (CD4(+)CD45RA(+)Foxp3(+)) and a transient increase in the number of activated Tregs (CD4(+)CD45RA(-)Foxp3(high)), followed by their partial depletion (50-60%). In contrast, all NK cells were deleted immediately and durably after DD administration. This difference was not due to a higher binding or internalization of DD by NK cells compared with Tregs. Coadministration of DD with IL-15, which binds to IL-2Rβ-γ, abrogated DD-induced NK cell deletion in vitro and in vivo, whereas it did not affect Treg elimination. Taken together, these results show that DD exerts a potent cytotoxic effect on NK cells, a phenomenon that might impair its antitumoral properties. However, coadministration of IL-15 with DD could alleviate this problem by selectively protecting potentially oncolytic NK cells, while allowing the depletion of immunosuppressive Tregs in cancer patients.
Topics: Animals; Antineoplastic Agents; Diphtheria Toxin; Flow Cytometry; Immunotoxins; Interleukin-15; Interleukin-2; Killer Cells, Natural; Macaca fascicularis; Male; Recombinant Fusion Proteins; T-Lymphocytes, Regulatory
PubMed: 22586034
DOI: 10.4049/jimmunol.1200656 -
Cancer Research Apr 2012Although cancer tends to affect the elderly, most preclinical studies are carried out in young subjects. In this study, we developed a melanoma-specific cancer...
Although cancer tends to affect the elderly, most preclinical studies are carried out in young subjects. In this study, we developed a melanoma-specific cancer immunotherapy that shows efficacy in aged but not young hosts by mitigating age-specific tumor-associated immune dysfunction. Both young and aged CD4(+)CD25(hi) regulatory T cells (Treg) exhibited equivalent in vitro T-cell suppression and tumor-associated augmentation in numbers. However, denileukin diftitox (DT)-mediated Treg depletion improved tumor-specific immunity and was clinically effective only in young mice. DT-mediated Treg depletion significantly increased myeloid-derived suppressor cell (MDSC) numbers in aged but not young mice, and MDSC depletion improved tumor-specific immunity and reduced tumor growth in aged mice. Combining Treg depletion with anti-Gr-1 antibody was immunologically and clinically more efficacious than anti-Gr-1 antibody alone in aged B16-bearing mice, similar to Treg depletion alone in young mice. In contrast, DT increased MDSCs in young and aged mice following MC-38 tumor challenge, although effects were greater in aged mice. Anti-Gr-1 boosted DT effects in young but not aged mice. Aged antitumor immune effector cells are therefore competent to combat tumor when underlying tumor-associated immune dysfunction is appropriately mitigated, but this dysfunction varies with tumor, thus also varying responses to immunotherapy. By tailoring immunotherapy to account for age-related tumor-associated immune dysfunctions, cancer immunotherapy for aged patients with specific tumors can be remarkably improved.
Topics: Aging; Animals; Antibodies, Monoclonal; Antineoplastic Agents; Diphtheria Toxin; Disease Models, Animal; Flow Cytometry; Immunotherapy; Interleukin-2; Lymphocyte Depletion; Mice; Mice, Inbred C57BL; Neoplasms, Experimental; Receptors, Cell Surface; Recombinant Fusion Proteins; T-Lymphocytes, Regulatory
PubMed: 22496463
DOI: 10.1158/0008-5472.CAN-11-3019