Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Front Immunol ; 13: 1029269, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36405739

RESUMO

Colorectal cancer is the third most diagnosed cancer and the second leading cause of cancer mortality worldwide, highlighting an urgent need for new therapeutic options and combination strategies for patients. The orchestration of potent T cell responses against human cancers is necessary for effective antitumour immunity. However, regression of a limited number of cancers has been induced by immune checkpoint inhibitors, T cell engagers (TCEs) and/or oncolytic viruses. Although one TCE has been FDA-approved for the treatment of hematological malignancies, many challenges exist for the treatment of solid cancers. Here, we show that TCEs targeting CEACAM5 and CD3 stimulate robust activation of CD4 and CD8-positive T cells in in vitro co-culture models with colorectal cancer cells, but in vivo efficacy is hindered by a lack of TCE retention in the tumour microenvironment and short TCE half-life, as demonstrated by HiBiT bioluminescent TCE-tagging technology. To overcome these limitations, we engineered Bispecific Engager Viruses, or BEVirs, a novel tumour-targeted vaccinia virus platform for intra-tumour delivery of these immunomodulatory molecules. We characterized virus-mediated TCE-secretion, TCE specificity and functionality from infected colorectal cancer cells and patient tumour samples, as well as TCE cytotoxicity in spheroid models, in the presence and absence of T cells. Importantly, we show regression of colorectal tumours in both syngeneic and xenograft mouse models. Our data suggest that a different profile of cytokines may contribute to the pro-inflammatory and immune effects driven by T cells in the tumour microenvironment to provide long-lasting immunity and abscopal effects. We establish combination regimens with immune checkpoint inhibitors for aggressive colorectal peritoneal metastases. We also observe a significant reduction in lung metastases of colorectal tumours through intravenous delivery of our oncolytic virus driven T-cell based combination immunotherapy to target colorectal tumours and FAP-positive stromal cells or CTLA4-positive Treg cells in the tumour microenvironment. In summary, we devised a novel combination strategy for the treatment of colorectal cancers using oncolytic vaccinia virus to enhance immune-payload delivery and boost T cell responses within tumours.


Assuntos
Neoplasias Colorretais , Terapia Viral Oncolítica , Vírus Oncolíticos , Humanos , Camundongos , Animais , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Imunoterapia , Vaccinia virus , Modelos Animais de Doenças , Neoplasias Colorretais/terapia , Microambiente Tumoral
2.
Mol Ther Oncolytics ; 22: 85-97, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34514091

RESUMO

Vaccinia virus (VV) has emerged as a promising platform for oncolytic virotherapy. Many clinical VV candidates, such as the double-deleted VV, vvDD, are engineered with deletions that enhance viral tumor selectivity based on cellular proliferation rates. An alternative approach is to exploit the dampened interferon-based innate immune responses of tumor cells by deleting one of the many VV immunomodulatory genes expressed to dismantle the antiviral response. We hypothesized that such a VV mutant would be attenuated in non-tumor cells but retain the ability to effectively propagate in and kill tumor cells, yielding a tumor-selective oncolytic VV with significant anti-tumor potency. In this study, we demonstrated that VVs with a deletion in one of several VV immunomodulatory genes (N1L, K1L, K3L, A46R, or A52R) have similar or improved in vitro replication, spread, and cytotoxicity in colon and ovarian cancer cells compared to vvDD. These deletion mutants are tumor selective, and the best performing candidates (ΔK1L, ΔA46R, and ΔA52R VV) are associated with significant improvement in survival, as well as immunomodulation, within the tumor environment. Overall, we show that exploiting the diminished antiviral responses in tumors serves as an effective strategy for generating tumor-selective and potent oncolytic VVs, with important implications in future oncolytic virus (OV) design.

3.
ACS Omega ; 4(8): 13015-13026, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31460428

RESUMO

Recently, the use of mRNA-based vaccines for cancer immunotherapy has gained growing attention. Several studies have shown that mRNA delivered in a vectorized format can generate a robust and efficient immune response. In this work, a new lipopolyplex vector (multi-LP), incorporating the immune adjuvant α-galactosylceramide (α-GalCer) and a multivalent cationic lipid, was proposed for the in vivo delivery of mRNA into antigen-presenting cells. We demonstrate that dendritic cells (DCs) can be targeted in vivo by intravenous administration of a α-GalCer-/mRNA-loaded multi-LP vector, without the need for its functionalization with cell-specific antibodies or ligands. The multi-LP nanoparticles loaded with a reporter mRNA efficiently led to high expression of the enhanced green fluorescence protein in DCs both in vitro and in vivo, exhibiting an intrinsic selectivity for DCs. Finally, the TRP2-mRNA/α-GalCer-based multi-LP vaccine induced a significant therapeutic effect against a highly malignant B16-F10 melanoma tumor. This study provides the first evidence that a combination of antigen-mRNA and α-GalCer can be used as an effective antitumor vaccine, inducing strong innate and adaptive immune responses.

4.
Int J Mol Sci ; 20(3)2019 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-30700020

RESUMO

The rising demand for powerful oncolytic virotherapy agents has led to the identification of Maraba virus, one of the most potent oncolytic viruses from Rhabdoviridae family which displays high selectivity for killing malignant cells and low cytotoxicity in normal cells. Although the virus is readied to be used for clinical trials, the interactions between the virus and the host cells is still unclear. Using a newly developed interferon-sensitive mutant Maraba virus (MG1), we have identified two key regulators of global translation (4E-BP1 and eIF2α) as being involved in the regulation of protein synthesis in the infected cells. Despite the translational arrest upon viral stress, we showed an up-regulation of anti-apoptotic Bcl-xL protein that provides a survival benefit for the host cell, yet facilitates effective viral propagation. Given the fact that eIF5B canonically regulates 60S ribosome subunit end joining and is able to replace the role of eIF2 in delivering initiator tRNA to the 40S ribosome subunit upon the phosphorylation of eIF2α we have tested whether eIF5B mediates the translation of target mRNAs during MG1 infection. Our results show that the inhibition of eIF5B significantly down-regulates the level of Bcl-xL steady-state mRNA, thus indirectly attenuates viral propagation.


Assuntos
Vírus Oncolíticos/fisiologia , Fator de Iniciação 2 em Eucariotos/metabolismo , Fatores de Iniciação em Eucariotos/metabolismo , Humanos , Terapia Viral Oncolítica , Fosforilação , Biossíntese de Proteínas , RNA Mensageiro/metabolismo , Subunidades Ribossômicas Maiores de Eucariotos/metabolismo , Proteína bcl-X/metabolismo
5.
J Clin Invest ; 129(2): 518-530, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30422820

RESUMO

Despite its success in treating melanoma and hematological malignancies, adoptive cell therapy (ACT) has had only limited effects in solid tumors. This is due in part to a lack of specific antigen targets, poor trafficking and infiltration, and immunosuppression in the tumor microenvironment. In this study, we combined ACT with oncolytic virus vaccines (OVVs) to drive expansion and tumor infiltration of transferred antigen-specific T cells and demonstrated that the combination is highly potent for the eradication of established solid tumors. Consistent with other successful immunotherapies, this approach elicited severe autoimmune consequences when the antigen targeted was a self-protein. However, modulation of IFN-α/-ß signaling, either by functional blockade or rational selection of an OVV backbone, ameliorated autoimmune side effects without compromising antitumor efficacy. Our study uncovers a pathogenic role for IFN-α/-ß in facilitating autoimmune toxicity during cancer immunotherapy and presents a safe and powerful combinatorial regimen with immediate translational applications.


Assuntos
Transferência Adotiva , Interferon-alfa , Interferon beta , Melanoma Experimental , Terapia Viral Oncolítica , Transdução de Sinais , Animais , Linhagem Celular Tumoral , Interferon-alfa/genética , Interferon-alfa/imunologia , Interferon beta/genética , Interferon beta/imunologia , Melanoma Experimental/genética , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Melanoma Experimental/terapia , Camundongos , Camundongos Knockout , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Linfócitos T/imunologia , Linfócitos T/patologia , Linfócitos T/transplante
6.
Oncoimmunology ; 8(1): e1512329, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30546947

RESUMO

Multiple immunotherapeutics have been approved for cancer patients, however advanced solid tumors are frequently refractory to treatment. We evaluated the safety and immunogenicity of a vaccination approach with multimodal oncolytic potential in non-human primates (NHP) (Macaca fascicularis). Primates received a replication-deficient adenoviral prime, boosted by the oncolytic Maraba MG1 rhabdovirus. Both vectors expressed the human MAGE-A3. No severe adverse events were observed. Boosting with MG1-MAGEA3 induced an expansion of hMAGE-A3-specific CD4+ and CD8+ T-cells with the latter peaking at remarkable levels and persisting for several months. T-cells reacting against epitopes fully conserved between simian and human MAGE-A3 were identified. Humoral immunity was demonstrated by the detection of circulating MAGE-A3 antibodies. These preclinical data establish the capacity for the Ad:MG1 vaccination to engage multiple effector immune cell populations without causing significant toxicity in outbred NHPs. Clinical investigations utilizing this program for the treatment of MAGE-A3-positive solid malignancies are underway (NCT02285816, NCT02879760).

7.
Oncolytic Virother ; 7: 117-128, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30538968

RESUMO

Oncolytic activity of the MG1 strain of the Maraba vesiculovirus has proven efficacy in numerous preclinical cancer models, and relied not only on a direct cytotoxicity but also on the induction of both innate and adaptive antitumor immunity. To further expand tumor-specific T-cell effector and long-lasting memory compartments, we introduced the MG1 virus in a prime-boost cancer vaccine strategy. To this aim, a replication-incompetent adenoviral [Ad] vector together with the oncolytic MG1 have each been armed with a transgene expressing a same tumor antigen. Immune priming with the Ad vaccine subsequently boosted with the MG1 vaccine mounted tumor-specific responses of remarkable magnitude, which significantly prolonged survival in various murine cancer models. Based on these promising results, we validated the safety profile of the Ad:MG1 oncolytic vaccination strategy in nonhuman primates and initiated clinical investigations in cancer patients. Two clinical trials are currently under way (NCT02285816; NCT02879760). The present review will recapitulate the discoveries that led to the development of MG1 oncolytic vaccines from bench to bedside.

8.
Oncoimmunology ; 7(7): e1445459, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29900060

RESUMO

Prostate cancer (PCa) was estimated to have the second highest global incidence rate for male non-skin tumors and is the fifth most deadly in men thus mandating the need for novel treatment options. MG1-Maraba is a potent and versatile oncolytic virus capable of lethally infecting a variety of prostatic tumor cell lines alongside primary PCa biopsies and exerts direct oncolytic effects against large TRAMP-C2 tumors in vivo. An oncolytic immunotherapeutic strategy utilizing a priming vaccine and intravenously administered MG1-Maraba both expressing the human six-transmembrane antigen of the prostate (STEAP) protein generated specific CD8+ T-cell responses against multiple STEAP epitopes and resulted in functional breach of tolerance. Treatment of mice with bulky TRAMP-C2 tumors using oncolytic STEAP immunotherapy induced an overt delay in tumor progression, marked intratumoral lymphocytic infiltration with an active transcriptional profile and up-regulation of MHC class I. The preclinical data generated here offers clear rationale for clinically evaluating this approach for men with advanced PCa.

9.
J Vis Exp ; (134)2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29683442

RESUMO

High-throughput genome-wide RNAi (RNA interference) screening technology has been widely used for discovering host factors that impact virus replication. Here we present the application of this technology to uncovering host targets that specifically modulate the replication of Maraba virus, an oncolytic rhabdovirus, and vaccinia virus with the goal of enhancing therapy. While the protocol has been tested for use with oncolytic Maraba virus and oncolytic vaccinia virus, this approach is applicable to other oncolytic viruses and can also be utilized for identifying host targets that modulate virus replication in mammalian cells in general. This protocol describes the development and validation of an assay for high-throughput RNAi screening in mammalian cells, the key considerations and preparation steps important for conducting a primary high-throughput RNAi screen, and a step-by-step guide for conducting a primary high-throughput RNAi screen; in addition, it broadly outlines the methods for conducting secondary screen validation and tertiary validation studies. The benefit of high-throughput RNAi screening is that it allows one to catalogue, in an extensive and unbiased fashion, host factors that modulate any aspect of virus replication for which one can develop an in vitro assay such as infectivity, burst size, and cytotoxicity. It has the power to uncover biotherapeutic targets unforeseen based on current knowledge.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Neoplasias/genética , Neoplasias/virologia , Terapia Viral Oncolítica/métodos , Vírus Oncolíticos/fisiologia , Interferência de RNA , Linhagem Celular Tumoral , Técnicas de Silenciamento de Genes , Humanos , Neoplasias/terapia , Vírus Oncolíticos/genética , RNA Interferente Pequeno/genética , Transfecção , Vaccinia virus/genética , Vaccinia virus/fisiologia , Vesiculovirus/genética , Vesiculovirus/fisiologia , Replicação Viral
10.
Sci Transl Med ; 10(422)2018 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-29298865

RESUMO

Triple-negative breast cancer (TNBC) is an aggressive disease for which treatment options are limited and associated with severe toxicities. Immunotherapeutic approaches like immune checkpoint inhibitors (ICIs) are a potential strategy, but clinical trials have demonstrated limited success in this patient cohort. Clinical studies using ICIs have revealed that patients with preexisting anticancer immunity are the most responsive. Given that oncolytic viruses (OVs) induce antitumor immunity, we investigated their use as an ICI-sensitizing approach. Using a therapeutic model that mimics the course of treatment for women with newly diagnosed TNBC, we demonstrate that early OV treatment coupled with surgical resection provides long-term benefits. OV therapy sensitizes otherwise refractory TNBC to immune checkpoint blockade, preventing relapse in most of the treated animals. We suggest that OV therapy in combination with immune checkpoint blockade warrants testing as a neoadjuvant treatment option in the window of opportunity between TNBC diagnosis and surgical resection.


Assuntos
Terapia Viral Oncolítica/métodos , Neoplasias de Mama Triplo Negativas/terapia , Feminino , Humanos , Terapia Neoadjuvante/métodos , Vírus Oncolíticos/fisiologia
11.
Mol Ther Oncolytics ; 7: 45-56, 2017 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-29062886

RESUMO

The oncolytic mutant vesicular stomatitis virus VSVΔ51 achieves robust efficacy in multiple extracranial tumor models. Yet for malignancies of the brain, direct intratumoral infusion of VSVΔ51 causes lethal virus-induced neuropathology. Here, we have developed a novel therapeutic regime that uses peripheral immunization with a single sub-lethal dose of VSVΔ51 to establish an acute anti-viral state that enables the safe intracranial (IC) infusion of an otherwise lethal dose of VSVΔ51 within just 6 hr. Although type I interferons alone appeared insufficient to explain this protective phenotype, serum isolated at early time points from primed animals conferred protection against an IC dose of virus. Adaptive immune populations had minimal contributions. Finally, the therapeutic utility of this novel strategy was demonstrated by peripherally priming and intracranially treating mice bearing aggressive CT2A syngeneic astrocytomas with VSVΔ51. Approximately 25% of animals achieved complete regression of established tumors, with no signs of virus-induced neurological impairment. This approach may harness an early warning system in the brain that has evolved to protect the host against otherwise lethal neurotropic viral infections. We have exploited this protective mechanism to safely and efficaciously treat brain tumors with an otherwise neurotoxic virus, potentially widening the available treatment options for oncolytic virotherapy in the brain.

12.
BMC Cancer ; 17(1): 594, 2017 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-28854921

RESUMO

BACKGROUND: Epithelial ovarian cancer exhibits extensive interpatient and intratumoral heterogeneity, which can hinder successful treatment strategies. Herein, we investigated the efficacy of an emerging oncolytic, Maraba virus (MRBV), in an in vitro model of ovarian tumour heterogeneity. METHODS: Four ovarian high-grade serous cancer (HGSC) cell lines were isolated and established from a single patient at four points during disease progression. Limiting-dilution subcloning generated seven additional subclone lines to assess intratumoral heterogeneity. MRBV entry and oncolytic efficacy were assessed among all 11 cell lines. Low-density receptor (LDLR) expression, conditioned media treatments and co-cultures were performed to determine factors impacting MRBV oncolysis. RESULTS: Temporal and intratumoral heterogeneity identified two subpopulations of cells: one that was highly sensitive to MRBV, and another set which exhibited 1000-fold reduced susceptibility to MRBV-mediated oncolysis. We explored both intracellular and extracellular mechanisms influencing sensitivity to MRBV and identified that LDLR can partially mediate MRBV infection. LDLR expression, however, was not the singular determinant of sensitivity to MRBV among the HGSC cell lines and subclones. We verified that there were no apparent extracellular factors, such as type I interferon responses, contributing to MRBV resistance. However, direct cell-cell contact by co-culture of MRBV-resistant subclones with sensitive cells restored virus infection and oncolytic killing of mixed population. CONCLUSIONS: Our data is the first to demonstrate differential efficacy of an oncolytic virus in the context of both spatial and temporal heterogeneity of HGSC cells and to evaluate whether it will constitute a barrier to effective viral oncolytic therapy.


Assuntos
Neoplasias Epiteliais e Glandulares/patologia , Vírus Oncolíticos/fisiologia , Neoplasias Ovarianas/patologia , Carcinoma Epitelial do Ovário , Linhagem Celular Tumoral , Técnicas de Cocultura/métodos , Heterogeneidade Genética , Humanos , Neoplasias Epiteliais e Glandulares/virologia , Terapia Viral Oncolítica/métodos , Neoplasias Ovarianas/virologia
13.
Cancer Immunol Res ; 5(10): 847-859, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28912369

RESUMO

The viral-transforming proteins E6 and E7 make human papillomavirus-positive (HPV+) malignancies an attractive target for cancer immunotherapy. However, therapeutic vaccination exerts limited efficacy in the setting of advanced disease. We designed a strategy to induce substantial specific immune responses against multiple epitopes of E6 and E7 proteins based on an attenuated transgene from HPV serotypes 16 and 18 that is incorporated into MG1-Maraba virotherapy (MG1-E6E7). Mutations introduced to the transgene abrogate the ability of E6 and E7 to perturb p53 and retinoblastoma, respectively, while maintaining the ability to invoke tumor-specific, multifunctional CD8+ T-cell responses. Boosting with MG1-E6E7 significantly increased the magnitude of T-cell responses compared with mice treated with a priming vaccine alone (greater than 50 × 106 E7-specific CD8+ T cells per mouse was observed, representing a 39-fold mean increase in boosted animals). MG1-E6E7 vaccination in the HPV+ murine model TC1 clears large tumors in a CD8+-dependent manner and results in durable immunologic memory. MG1-Maraba can acutely alter the tumor microenvironment in vivo and exploit molecular hallmarks of HPV+ cancer, as demonstrated by marked infection of HPV+ patient tumor biopsies and is, therefore, ideally suited as an oncolytic treatment against clinical HPV+ cancer. This approach has the potential to be directly translatable to human clinical oncology to tackle a variety of HPV-associated neoplasms that cause significant morbidity and mortality globally. Cancer Immunol Res; 5(10); 847-59. ©2017 AACR.


Assuntos
Imunoterapia , Neoplasias/etiologia , Neoplasias/patologia , Papillomaviridae , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/virologia , Adenovírus Humanos/genética , Animais , Vacinas Anticâncer/imunologia , Linhagem Celular Tumoral , Citocinas/metabolismo , Citotoxicidade Imunológica , Modelos Animais de Doenças , Epitopos de Linfócito T/imunologia , Feminino , Vetores Genéticos/genética , Humanos , Imunoterapia/métodos , Camundongos , Mutação , Neoplasias/metabolismo , Neoplasias/terapia , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/imunologia , Terapia Viral Oncolítica , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/imunologia , Proteólise , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Repressoras/genética , Proteínas Repressoras/imunologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Transgenes , Carga Tumoral/imunologia , Proteína Supressora de Tumor p53/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Cancer Immunol Res ; 5(3): 211-221, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28159747

RESUMO

Despite improvements in chemotherapy and radical surgical debulking, peritoneal carcinomatosis (PC) remains among the most common causes of death from abdominal cancers. Immunotherapies have been effective for selected solid malignancies, but their potential in PC has been little explored. Here, we report that intraperitoneal injection of an infected cell vaccine (ICV), consisting of autologous tumor cells infected ex vivo with an oncolytic Maraba MG1 virus expressing IL12, promotes the migration of activated natural killer (NK) cells to the peritoneal cavity in response to the secretion of IFNγ-induced protein-10 (IP-10) from dendritic cells. The recruitment of cytotoxic, IFNγ-secreting NK cells was associated with reduced tumor burden and improved survival in a colon cancer model of PC. Even in mice with bulky PC (tumors > 8 mm), a complete radiologic response was demonstrated within 8 to14 weeks, associated with 100% long-term survival. The impact of MG1-IL12-ICV upon NK-cell recruitment and function observed in the murine system was recapitulated in human lymphocytes exposed to human tumor cell lines infected with MG1-IL12. These findings suggest that an MG1-IL12-ICV is a promising therapy that could provide benefit to the thousands of patients diagnosed with PC each year. Cancer Immunol Res; 5(3); 211-21. ©2017 AACR.


Assuntos
Vacinas Anticâncer/imunologia , Quimiotaxia/imunologia , Interleucina-12/genética , Células Matadoras Naturais/imunologia , Neoplasias Peritoneais/genética , Neoplasias Peritoneais/imunologia , Animais , Vacinas Anticâncer/administração & dosagem , Vacinas Anticâncer/genética , Linhagem Celular Tumoral , Citocinas/metabolismo , Citotoxicidade Imunológica , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Feminino , Vetores Genéticos/genética , Humanos , Interleucina-12/metabolismo , Células Matadoras Naturais/metabolismo , Ativação Linfocitária/imunologia , Melanoma Experimental , Camundongos , Vírus Oncolíticos/genética , Neoplasias Peritoneais/patologia , Neoplasias Peritoneais/terapia , Transdução Genética
15.
Oncotarget ; 8(2): 3495-3508, 2017 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-27966453

RESUMO

Rhabdomyosarcoma (RMS), a neoplasm characterized by undifferentiated myoblasts, is the most common soft tissue tumour in children. Therapeutic resistance is common in RMS and is often caused by acquired defects in the cellular apoptotic program. Smac mimetic compounds (SMCs) are a novel class of inhibitor of apoptosis (IAP) antagonists that are currently under clinical development as cancer therapeutics. We previously reported that cIAP1 is overexpressed in human primary RMS tumours and in patient-derived RMS cell lines where it drives resistance to apoptosis. In this study, we investigated whether inflammatory cytokine production triggered by activators of innate immunity synergizes with LCL161 to induce bystander killing of RMS cells in vitro and in vivo. Indeed, we show that innate immune stimuli (oncolytic virus (VSVΔ51-GFP), interferon γ (IFNγ), and tumour necrosis factor-like weak inducer of apoptosis (TWEAK)) combine with SMCs in vitro to reduce cell viability in the Kym-1 RMS cancer cell line. Other human RMS cell lines (RH36, RH41, RD, RH18, RH28, and RH30) and the murine RMS cell line 76-9 are resistant to treatment with LCL161 alone or in combination with immune stimulants in in vitro cell viability assays. In contrast, we report that the combination of LCL161 and VSVΔ51-GFP reduces tumour volume and prolongs survival in a 76-9 syngeneic murine model. Our results support further exploration of the combined use of IAP antagonists and innate immune stimuli as a therapeutic approach for RMS cancers.


Assuntos
Mimetismo Molecular , Terapia Viral Oncolítica , Vírus Oncolíticos , Rabdomiossarcoma/imunologia , Rabdomiossarcoma/patologia , Tiazóis/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/imunologia , Terapia Combinada , Modelos Animais de Doenças , Feminino , Humanos , Imunidade Inata/efeitos dos fármacos , Fator Regulador 1 de Interferon/genética , Fator Regulador 1 de Interferon/metabolismo , Camundongos , Vírus Oncolíticos/genética , Rabdomiossarcoma/genética , Rabdomiossarcoma/terapia , Carga Tumoral , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Mol Ther Oncolytics ; 3: 16027, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27909702

RESUMO

The systemic delivery of therapeutic viruses, such as oncolytic viruses or vaccines, is limited by the generation of neutralizing antibodies. While pseudotyping of rhabdoviruses with the lymphocytic choriomeningitis virus glycoprotein has previously allowed for multiple rounds of delivery in mice, this strategy has not translated to other animal models. For the first time, we provide experimental evidence that antibodies generated against the lymphocytic choriomeningitis virus glycoprotein mediate robust complement-dependent viral neutralization via activation of the classical pathway. We show that this phenotype can be capitalized upon to deliver maraba virus pseudotyped with the lymphocytic choriomeningitis virus glycoprotein in a Fischer rat model in the face of neutralizing antibody through the use of complement modulators. This finding changes the understanding of the humoral immune response to arenaviruses, and also describes methodology to deliver viral vectors to their therapeutic sites of action without the interference of neutralizing antibody.

17.
Oncolytic Virother ; 5: 15-25, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27579293

RESUMO

High-throughput screens can rapidly scan and capture large amounts of information across multiple biological parameters. Although many screens have been designed to uncover potential new therapeutic targets capable of crippling viruses that cause disease, there have been relatively few directed at improving the efficacy of viruses that are used to treat disease. Oncolytic viruses (OVs) are biotherapeutic agents with an inherent specificity for treating malignant disease. Certain OV platforms - including those based on herpes simplex virus, reovirus, and vaccinia virus - have shown success against solid tumors in advanced clinical trials. Yet, many of these OVs have only undergone minimal engineering to solidify tumor specificity, with few extra modifications to manipulate additional factors. Several aspects of the interaction between an OV and a tumor-bearing host have clear value as targets to improve therapeutic outcomes. At the virus level, these include delivery to the tumor, infectivity, productivity, oncolysis, bystander killing, spread, and persistence. At the host level, these include engaging the immune system and manipulating the tumor microenvironment. Here, we review the chemical- and genome-based high-throughput screens that have been performed to manipulate such parameters during OV infection and analyze their impact on therapeutic efficacy. We further explore emerging themes that represent key areas of focus for future research.

18.
Viruses ; 8(2)2016 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-26861383

RESUMO

Large-scale assays, such as microarrays, next-generation sequencing and various "omics" technologies, have explored multiple aspects of the immune response following virus infection, often from a public health perspective. Yet a lack of similar data exists for monitoring immune engagement during oncolytic virus immunotherapy (OVIT) in the cancer setting. Tracking immune signatures at the tumour site can create a snapshot or longitudinally analyse immune cell activation, infiltration and functionality within global populations or individual cells. Mapping immune changes over the course of oncolytic biotherapy-from initial infection to tumour stabilisation/regression through to long-term cure or escape/relapse-has the potential to generate important therapeutic insights around virus-host interactions. Further, correlating such immune signatures with specific tumour outcomes has significant value for guiding the development of novel oncolytic virus immunotherapy strategies. Here, we provide insights for OVIT from large-scale analyses of immune populations in the infection, vaccination and immunotherapy setting. We analyse several approaches to manipulating immune engagement during OVIT. We further explore immunocentric changes in the tumour tissue following immunotherapy, and compile several immune signatures of therapeutic success. Ultimately, we highlight clinically relevant large-scale approaches with the potential to strengthen future oncolytic strategies to optimally engage the immune system.


Assuntos
Imunoterapia , Neoplasias/terapia , Terapia Viral Oncolítica , Vírus Oncolíticos/fisiologia , Animais , Humanos , Imunoterapia/tendências , Neoplasias/imunologia , Terapia Viral Oncolítica/tendências , Vírus Oncolíticos/genética
19.
Nat Med ; 21(5): 530-6, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25894825

RESUMO

Tumors are complex ecosystems composed of networks of interacting 'normal' and malignant cells. It is well recognized that cytokine-mediated cross-talk between normal stromal cells, including cancer-associated fibroblasts (CAFs), vascular endothelial cells, immune cells, and cancer cells, influences all aspects of tumor biology. Here we demonstrate that the cross-talk between CAFs and cancer cells leads to enhanced growth of oncolytic virus (OV)-based therapeutics. Transforming growth factor-ß (TGF-ß) produced by tumor cells reprogrammed CAFs, dampened their steady-state level of antiviral transcripts and rendered them sensitive to virus infection. In turn, CAFs produced high levels of fibroblast growth factor 2 (FGF2), initiating a signaling cascade in cancer cells that reduced retinoic acid-inducible gene I (RIG-I) expression and impeded the ability of malignant cells to detect and respond to virus. In xenografts derived from individuals with pancreatic cancer, the expression of FGF2 correlated with the susceptibility of the cancer cells to OV infection, and local application of FGF2 to resistant tumor samples sensitized them to virotherapy both in vitro and in vivo. An OV engineered to express FGF2 was safe in tumor-bearing mice, showed improved therapeutic efficacy compared to parental virus and merits consideration for clinical testing.


Assuntos
Fibroblastos/metabolismo , Vírus Oncolíticos/metabolismo , Microambiente Tumoral , Idoso , Animais , Antivirais/química , Linhagem Celular Tumoral , Chlorocebus aethiops , Técnicas de Cocultura , Feminino , Fator 2 de Crescimento de Fibroblastos/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Humanos , Neoplasias Pulmonares/metabolismo , Masculino , Camundongos , Microscopia de Fluorescência , Pessoa de Meia-Idade , Transplante de Neoplasias , Terapia Viral Oncolítica/métodos , Neoplasias Ovarianas/metabolismo , Transdução de Sinais , Células Estromais/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Células Vero
20.
Mol Ther Oncolytics ; 2: 15013, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27119108

RESUMO

Epithelial ovarian cancer is unique among most carcinomas in that metastasis occurs by direct dissemination of malignant cells traversing throughout the intraperitoneal fluid. Accordingly, we test new therapeutic strategies using an in vitro three-dimensional spheroid suspension culture model that mimics key steps of this metastatic process. In the present study, we sought to uncover the differential oncolytic efficacy among three different viruses-Myxoma virus, double-deleted vaccinia virus, and Maraba virus-using three ovarian cancer cell lines in our metastasis model system. Herein, we demonstrate that Maraba virus effectively infects, replicates, and kills epithelial ovarian cancer (EOC) cells in proliferating adherent cells and with slightly slower kinetics in tumor spheroids. Myxoma virus and vaccinia viruses infect and kill adherent cells to a much lesser extent than Maraba virus, and their oncolytic potential is almost completely attenuated in spheroids. Myxoma virus and vaccinia are able to infect and spread throughout spheroids, but are blocked in the final stages of the lytic cycle, and oncolytic-mediated cell killing is reactivated upon spheroid reattachment. Alternatively, Maraba virus has a remarkably reduced ability to initially enter spheroid cells, yet rapidly infects and spreads throughout spheroids generating significant cell killing effects. We show that low-density lipoprotein receptor expression in ovarian cancer spheroids is reduced and this controls efficient Maraba virus binding and entry into infected cells. Taken together, these results are the first to implicate the potential impact of differential viral oncolytic properties at key steps of ovarian cancer metastasis.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...