Publications by authors named "Thierry Velu"

Therapeutic cancer vaccines have effectively induced durable regressions of premalignant oncogenic human papilloma virus type 16 (HPV16)-induced anogenital lesions. However, the treatment of HPV16-induced cancers requires appropriate countermeasures to overcome cancer-induced immune suppression. We previously showed that standard-of-care carboplatin/paclitaxel chemotherapy can reduce abnormally high numbers of immunosuppressive myeloid cells in patients, allowing the development of much stronger therapeutic HPV16 vaccine (ISA101)-induced tumor immunity.

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The standard treatment for advanced ovarian cancer consists in complete cytoreductive surgery (CRS) and intravenous combination chemotherapy with a platinum compound and a taxane. Although response rates to initial therapy are high, many patients will recur and die of peritoneal carcinomatosis. The addition of Hyperthermic IntraPEritoneal Chemotherapy (HIPEC) to the standard therapy aims at increasing survival by reducing peritoneal recurrence.

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Vaccination of dendritic cells (DC) combined with GM-CSF secreting tumor cells has shown good therapeutic efficacy in several tumor models. Nevertheless, the engineering of GM-CSF secreting tumor cell line could represent a tedious step limiting its application for treatment in patients. We therefore developed in rats, an "all in vivo" strategy of combined vaccination using an in vivo local irradiation of the tumor as a source of tumor antigens for DC vaccines and an exogenous source of GM-CSF.

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MUC1 over-expression in renal clear-cell carcinoma (RCC) is associated with poor prognosis. This phase II study determined the efficacy and tolerability of TG4010, a cancer vaccine based on a modified vaccinia virus expressing MUC1 and interleukin-2, in combination with cytokines, as first-line therapy in metastatic RCC. Thirty-seven patients with progressive, MUC1-positive RCC received TG4010 10(8) pfu/inj weekly for 6 weeks, then every 3 weeks until progression, when TG4010 was continued in combination with interferon-α2a and interleukin-2.

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Dendritic cell (DC) immunotherapy for cancer certainly holds promises but definitely needs improvements, especially for enhancing tumor-specific responses able to eradicate preexisting tumors. To this end, we investigated here, for the treatment of a preimplanted murine renal cell carcinoma Renca, a new vaccination approach combining injection of DC and granulocyte macrophage colony-stimulating factor (GM-CSF) gene-transduced tumor cells. When treatment by either DC or Renca-mGM-CSF cells alone had no therapeutic effect at all, combined vaccines induced therapeutic response in 50% of the tumor-bearing mice, in a GM-CSF dose-dependent manner.

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Background: TG4010 is a recombinant viral vector expressing both the tumor-associated antigen MUC1 and Interleukine-2. This vector is based on the modified virus of Ankara, a significantly attenuated strain of vaccinia virus. TG4010 has been designed to induce or amplify a cellular immune response directed against tumor cells expressing MUC1.

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The death of dendritic cells (DCs) can potentially influence immune responses by affecting the duration of DC stimulation of lymphocytes. Here, we report that cultured mature monocyte-derived DCs manifest early mitochondrial damage (i.e.

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Numerous preclinical and clinical studies have shown that interleukin-2 (IL-2) induces regression of metastatic tumors. We have conducted a phase I/II, multicenter, open-label, dose-escalating study to evaluate the safety, efficacy, and biological effects of repeated intratumoral injections of adenovirus-IL-2 (TG1024) in patients with advanced solid tumors and melanoma. Thirty five patients (twenty-five with metastatic melanoma and ten with other solid tumors) were treated in eight successive cohorts at dose levels ranging from 3 x 10(8) to 3 x 10(11) viral particles (vp).

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Despite the increasing number of immunotherapeutic strategies for the treatment of cancer, most approaches have failed to correlate the induction of an anti-tumor immune response with therapeutic efficacy. We therefore took advantage of a successful vaccination strategy-combining dendritic cells and irradiated GM-CSF secreting tumor cells-to compare the immune response induced against 9L gliosarcoma tumors in cured rats versus those with progressively growing tumors. At the systemic level, the tumor specific cytotoxic responses were quite heterogeneous in uncured vaccinated rats, and were surprisingly often high in animals with rapidly-growing tumors.

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Mild heat stress can modulate the activities of immune cells, including dendritic cells (DC) and theoretically, would constitute an innovative approach capable of enhancing the antitumor functions of DC. Therefore, we tested the effects of mild heat stress on the physiology and viability of human monocyte-derived DC, the major type of DC used in tumor immunotherapy trials. We first designed a heat-stress protocol consisting of repetitive, sublethal heat shocks throughout the generation of DC.

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Vectors derived from the autonomous parvovirus Minute virus of mice, MVM(p), are promising tools for the gene therapy of cancer. The validation of their in vivo anti-tumour effect is, however, hampered by the difficulty to produce high-titre stocks. In an attempt to increase vector titres, host cells were subjected to low oxygen tension (hypoxia).

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Background: Hybrids obtained by fusion between tumour cells (TC) and dendritic cells (DC) have been proposed as anti-tumour vaccines because of their potential to combine the expression of tumour-associated antigens with efficient antigen presentation. The classical methods used for fusion, polyethylene glycol (PEG) and electrofusion, are cytotoxic and generate cell debris that can be taken up by DC rendering the identification of true hybrids difficult.

Methods: We have established a stable cell line expressing a viral fusogenic membrane glycoprotein (FMG) that is not itself susceptible to fusion.

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The aim of the present phase I/II study was to evaluate the safety, immune responses and clinical activity of a vaccine based on autologous dendritic cells (DC) loaded with an allogeneic tumor cell lysate in advanced melanoma patients. DC derived from monocytes were generated in serum-free medium containing GM-CSF and IL-13 according to Good Manufacturing Practices. Fifteen patients with metastatic melanoma (stage III or IV) received four subcutaneous, intradermal, and intranodal vaccinations of both DC loaded with tumor cell lysate and DC loaded with hepatitis B surface protein (HBs) and/or tetanus toxoid (TT).

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Background: Based on phase II trial results, chemoimmunotherapy combinations have become the preferred treatment for patients with metastatic melanoma in many institutions. This study was performed to determine whether interleukin-2 (IL-2) as a component of chemoimmunotherapy influences survival of patients with metastatic melanoma.

Patients And Methods: Patients with advanced metastatic melanoma were randomly assigned to receive dacarbazine 250 mg/m2 and cisplatin 30 mg/m2 on days 1 to 3 combined with interferon-alfa-2b 10 x 10(6) U/m2 subcutaneously on days 1 through 5 without (arm A) or with (arm B) a high-dose intravenous decrescendo regimen of IL-2 on days 5 through 10 (18 x 10(6) U/m2/6 hours, 18 x 10(6) U/m2/12 hours, 18 x 10(6) U/m2/24 hours, and 4.

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Dendritic cells derived from monocytes cultured in the presence of type I interferon were found to induce efficient T cell responses against tumor antigens in vitro. We vaccinated eight stage III or IV melanoma patients with dendritic cells generated with interferon-beta and interleukin-3, activated by poly I: C, and pulsed with the tumor-specific antigen NA17.A2.

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Gene delivery into dendritic cells (DC) is most efficiently achieved by viral vectors. Recombinant canarypox viruses (ALVAC) were validated safe and efficient in humans. We aimed firstly to evaluate DC transduction by ALVAC vectors, then to investigate if such infection induced or not the maturation of the DC, and finally to assess the efficiency of ALVAC-MAGE-transduced DC to activate specific CTL clones.

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After vaccination of melanoma patients with MAGE antigens, we observed that even in the few patients showing tumor regression, the frequency of anti-vaccine T cells in the blood was often either undetectable or <10(-5) of CD8 T cells. This frequency being arguably too low for these cells to be sole effectors of rejection, we reexamined the contribution of T cells recognizing other tumor antigens. The presence of such antitumor T cells in melanoma patients has been widely reported.

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In an attempt to induce potent immune antitumor activities, we investigated, within the rat 9L gliosarcoma model, distal therapeutic vaccinations associating three therapies: dendritic cell vaccination, intratumoral granulocyte macrophage colony-stimulating factor (GM-CSF) gene transfer, and tumor apoptosis induction. Vaccines of dendritic cells coinjected with processed GM-CSF secreting 9L cells induced systemic responses, resulting in the complete regression of distant preimplanted 9L tumor masses in, with the best strategy, 94% of male rats. All of the cured rats developed a long-term resistance to a rechallenge with parental cells.

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Background: The natural oncotropism and oncotoxicity of vectors derived from the autonomous parvovirus, minute virus of mice (prototype strain) [MVM(p)], combined with the immunotherapeutic properties of cytokine transgenes, make them interesting candidates for cancer gene therapy.

Methods: The in vivo anti-tumour activity of a recombinant parvoviral vector, MVM-IL2, was evaluated in a syngeneic mouse melanoma model that is relatively resistant in vitro to the intrinsic cytotoxicity of wild-type MVM(p).

Results: In vitro infection of the K1735 melanoma cells prior to their injection resulted in loss of tumorigenicity in 70% of mice (7/10).

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Production of DNA damage is the basis of cancer treatments such as chemo- and radiotherapy. Such treatments induce mitotic catastrophe, a form of cell death resulting from abnormal mitosis and leading to the formation of interphase cells with multiple micronuclei. In this study, we compared apoptosis induction and micronuclei formation to assess the DNA damage provoked in vivo by cytotoxic agents in established 9L rat gliosarcoma tumors expressing a mutated p53 gene.

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Memory CD8 T cells mediate rapid and effective immune responses against previously encountered Ags. However, these cells display considerable phenotypic and functional heterogeneity. In an effort to identify parameters that correlate with immune protection, we compared cell surface markers, proliferation, and cytokine production of distinct virus- and tumor-specific human CD8 populations.

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The preferential expression of autonomous parvoviruses in tumour cells and their oncolytic activity has attracted attention to the potential use of these viruses as vectors for cancer gene therapy. Moreover, they are non-pathogenic in adult animals and they seem to be associated with low or no immunogenicity. Other interesting features are their episomal replication and high stability.

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Minocycline has been suggested to be an anti-apoptotic compound and an anti-inflammatory agent in various models of neurodegeneration. In the present study, using a stable cell line expressing green fluorescent protein under the control of a tetracycline-responsive promoter, we demonstrate that minocycline is able to promote tetracycline-controlled gene expression although it needs longer time and higher concentration to reach the effect obtained with the classical inducer doxycycline. Furthermore, the extinction of the system after antibiotics removal is faster when using minocycline.

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We have analyzed the T cell responses of HLA-A1 metastatic melanoma patients with detectable disease, following vaccination with a recombinant ALVAC virus, which bears short MAGE-1 and MAGE-3 sequences coding for antigenic peptides presented by HLA-A1. To evaluate the anti-MAGE CTL responses, we resorted to antigenic stimulation of blood lymphocytes under limiting dilution conditions, followed by tetramer analysis and cloning of the tetramer-positive cells. The clones were tested for their specific lytic ability and their TCR sequences were obtained.

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Due to inhibitory activities on cell-mediated immune responses, interleukin-10 (IL-10) has been proposed as a good candidate to treat inflammatory eye disease and proliferative vitreoretinopathy (PVR). In this study we evaluate the effect of human IL-10 (hIL-10) expression in a cell-induced animal model of PVR. Rabbit dermal fibroblasts were genetically modified by infection with retroviral particles carrying the neomycin resistance gene (neoR) alone or in combination with the hIL-10 gene.

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