RESUMO
Over the last decade, various new therapies have been developed to promote anti-tumor immunity. Despite interesting clinical results in hematological malignancies, the development of bispecific killer-cell-engager antibody formats directed against tumor cells and stimulating anti-tumor T cell immunity has proved challenging, mostly due to toxicity problems. We report here the generation of trifunctional natural killer (NK) cell engagers (NKCEs), targeting two activating receptors, NKp46 and CD16, on NK cells and a tumor antigen on cancer cells. Trifunctional NKCEs were more potent in vitro than clinical therapeutic antibodies targeting the same tumor antigen. They had similar in vivo pharmacokinetics to full IgG antibodies and no off-target effects and efficiently controlled tumor growth in mouse models of solid and invasive tumors. Trifunctional NKCEs thus constitute a new generation of molecules for fighting cancer. VIDEO ABSTRACT.
Assuntos
Anticorpos Biespecíficos , Antígenos Ly/imunologia , Antineoplásicos Imunológicos , Citotoxicidade Imunológica/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Receptor 1 Desencadeador da Citotoxicidade Natural/imunologia , Neoplasias Experimentais , Animais , Anticorpos Biespecíficos/imunologia , Anticorpos Biespecíficos/uso terapêutico , Antineoplásicos Imunológicos/imunologia , Antineoplásicos Imunológicos/farmacologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina G/farmacologia , Células Matadoras Naturais/patologia , Camundongos , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/patologia , Neoplasias Experimentais/terapiaRESUMO
Checkpoint inhibitors have revolutionized cancer treatment. However, only a minority of patients respond to these immunotherapies. Here, we report that blocking the inhibitory NKG2A receptor enhances tumor immunity by promoting both natural killer (NK) and CD8+ T cell effector functions in mice and humans. Monalizumab, a humanized anti-NKG2A antibody, enhanced NK cell activity against various tumor cells and rescued CD8+ T cell function in combination with PD-x axis blockade. Monalizumab also stimulated NK cell activity against antibody-coated target cells. Interim results of a phase II trial of monalizumab plus cetuximab in previously treated squamous cell carcinoma of the head and neck showed a 31% objective response rate. Most common adverse events were fatigue (17%), pyrexia (13%), and headache (10%). NKG2A targeting with monalizumab is thus a novel checkpoint inhibitory mechanism promoting anti-tumor immunity by enhancing the activity of both T and NK cells, which may complement first-generation immunotherapies against cancer.
Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Carcinoma de Células Escamosas , Cetuximab/uso terapêutico , Imunidade Celular/efeitos dos fármacos , Imunoterapia , Células Matadoras Naturais/imunologia , Subfamília C de Receptores Semelhantes a Lectina de Células NK , Animais , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Ensaios Clínicos Fase II como Assunto , Humanos , Células Matadoras Naturais/patologia , Camundongos , Subfamília C de Receptores Semelhantes a Lectina de Células NK/antagonistas & inibidores , Subfamília C de Receptores Semelhantes a Lectina de Células NK/imunologiaRESUMO
Coronavirus disease 2019 (COVID-19) is a disease caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has resulted in a pandemic1. The C5a complement factor and its receptor C5aR1 (also known as CD88) have a key role in the initiation and maintenance of several inflammatory responses by recruiting and activating neutrophils and monocytes1. Here we provide a longitudinal analysis of immune responses, including phenotypic analyses of immune cells and assessments of the soluble factors that are present in the blood and bronchoalveolar lavage fluid of patients at various stages of COVID-19 severity, including those who were paucisymptomatic or had pneumonia or acute respiratory distress syndrome. The levels of soluble C5a were increased in proportion to the severity of COVID-19 and high expression levels of C5aR1 receptors were found in blood and pulmonary myeloid cells, which supports a role for the C5a-C5aR1 axis in the pathophysiology of acute respiratory distress syndrome. Anti-C5aR1 therapeutic monoclonal antibodies prevented the C5a-mediated recruitment and activation of human myeloid cells, and inhibited acute lung injury in human C5aR1 knock-in mice. These results suggest that blockade of the C5a-C5aR1 axis could be used to limit the infiltration of myeloid cells in damaged organs and prevent the excessive lung inflammation and endothelialitis that are associated with acute respiratory distress syndrome in patients with COVID-19.
Assuntos
COVID-19/complicações , COVID-19/imunologia , Complemento C5a/imunologia , Inflamação/complicações , Inflamação/imunologia , Receptor da Anafilatoxina C5a/imunologia , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/imunologia , Lesão Pulmonar Aguda/prevenção & controle , Animais , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/imunologia , Antígeno CD11b/imunologia , Antígeno CD11b/metabolismo , COVID-19/sangue , COVID-19/patologia , Complemento C5a/antagonistas & inibidores , Complemento C5a/biossíntese , Síndrome da Liberação de Citocina/tratamento farmacológico , Síndrome da Liberação de Citocina/imunologia , Síndrome da Liberação de Citocina/prevenção & controle , Modelos Animais de Doenças , Feminino , Humanos , Inflamação/tratamento farmacológico , Inflamação/patologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Células Mieloides/efeitos dos fármacos , Células Mieloides/imunologia , Células Mieloides/patologia , Receptor da Anafilatoxina C5a/antagonistas & inibidores , Receptor da Anafilatoxina C5a/sangue , Síndrome do Desconforto Respiratório/tratamento farmacológico , Síndrome do Desconforto Respiratório/imunologia , Síndrome do Desconforto Respiratório/prevenção & controle , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidadeRESUMO
New therapies that promote antitumour immunity have been recently developed. Most of these immunomodulatory approaches have focused on enhancing T-cell responses, either by targeting inhibitory pathways with immune checkpoint inhibitors, or by targeting activating pathways, as with chimeric antigen receptor T cells or bispecific antibodies. Although these therapies have led to unprecedented successes, only a minority of patients with cancer benefit from these treatments, highlighting the need to identify new cells and molecules that could be exploited in the next generation of immunotherapy. Given the crucial role of innate immune responses in immunity, harnessing these responses opens up new possibilities for long-lasting, multilayered tumour control.
Assuntos
Imunidade Inata/efeitos dos fármacos , Imunidade Inata/imunologia , Imunoterapia/métodos , Imunoterapia/tendências , Neoplasias/imunologia , Neoplasias/terapia , Animais , Humanos , Neoplasias/tratamento farmacológico , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologiaRESUMO
An Amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
Despite recent treatment improvements, multiple myeloma remains an incurable disease. Since antibody-dependent cell-mediated cytotoxicity is an important effector mechanism of daratumumab, we explored the possibility of improving daratumumab-mediated cell-mediated cytotoxicity by blocking natural killer cell inhibitory receptors with the human monoclonal anti-KIR antibody IPH2102, next to activation of natural killer cells with the immune modulatory drug lenalidomide. In 4-hour antibody-dependent cell-mediated cytotoxicity assays, IPH2102 did not induce lysis of multiple myeloma cell lines, but it did significantly augment daratumumab-induced myeloma cell lysis. Also in an ex vivo setting, IPH2102 synergistically improved daratumumab-dependent lysis of primary myeloma cells in bone marrow mononuclear cells (n=21), especially in patients carrying the FcγRIIIa-158F allele or the FcγRIIa-131R allele, who bind IgG1 with lower affinity than patients carrying the FcγRIIIa-158V allele or the FcγRIIa-131H allele. Finally, a further synergistically improved myeloma cell lysis with the daratumumab-IPH2102 combination was observed by adding lenalidomide, which suggests that more effective treatment strategies can be designed for multiple myeloma by combining daratumumab with agents that independently modulate natural killer cell function.
Assuntos
Anticorpos Monoclonais/administração & dosagem , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Citotoxicidade Imunológica/imunologia , Mieloma Múltiplo/patologia , Mieloma Múltiplo/terapia , Receptores KIR/imunologia , Western Blotting , Proliferação de Células , Células Cultivadas , Sinergismo Farmacológico , Citometria de Fluxo , Humanos , Imunoglobulina G/imunologia , Imunofenotipagem , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Lenalidomida , Mieloma Múltiplo/imunologia , Polimorfismo Genético/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptores de IgG/genética , Receptores KIR/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Talidomida/administração & dosagem , Talidomida/análogos & derivadosRESUMO
CD123, the alpha chain of the IL-3 receptor, is an attractive target for acute myeloid leukemia (AML) treatment. However, cytotoxic antibodies or T cell engagers targeting CD123 had insufficient efficacy or safety in clinical trials. We show that expression of CD64, the high-affinity receptor for human IgG, on AML blasts confers resistance to anti-CD123 antibody-dependent cell cytotoxicity (ADCC) in vitro. We engineer a trifunctional natural killer cell engager (NKCE) that targets CD123 on AML blasts and NKp46 and CD16a on NK cells (CD123-NKCE). CD123-NKCE has potent antitumor activity against primary AML blasts regardless of CD64 expression and induces NK cell activation and cytokine secretion only in the presence of AML cells. Its antitumor activity in a mouse CD123+ tumor model exceeds that of the benchmark ADCC-enhanced antibody. In nonhuman primates, it had prolonged pharmacodynamic effects, depleting CD123+ cells for more than 10 days with no signs of toxicity and very low inflammatory cytokine induction over a large dose range. These results support clinical development of CD123-NKCE.
Assuntos
Leucemia Mieloide Aguda , Humanos , Animais , Camundongos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , Células Matadoras Naturais , Citotoxicidade Celular Dependente de Anticorpos , Linfócitos T , Citocinas/metabolismo , Subunidade alfa de Receptor de Interleucina-3RESUMO
There is a high demand for the development of adjuvants that induce cytotoxic T lymphocytes, which are crucial for the elimination of intracellular pathogens and tumor cells. Toll-like receptor (TLR) agonists are prime candidates to fulfill this role because they induce innate immune activation and promote adaptive immune responses. The successful application of the TLR7 agonist R837 for treatment of basal cell carcinoma shows the potential for exploiting this pathway in tumor immunotherapy. Imidazoquinolines like R837 and stimulatory ssRNA oligonucleotides both trigger TLR7-mediated immune activation, but little is known about their comparative ability to promote immunity induction. We investigated differences in innate immune activation and adjuvant activity between the imidazoquinoline R848 and the ssRNA TLR7 agonist polyUs21. In contrast to R848, polyUs21 induced detectable levels of intracellular interferon-alpha (IFN-alpha) in plasmacytoid dendritic cells (PDCs). In immunization studies, only polyUs21 led to robust priming of type 1 T helper cells and cytotoxic T lymphocytes, and it was more efficient in inducing antitumor immunity than R848. Notably, exogenous IFN-alpha augmented the adjuvant activity of R848, whereas depletion of PDC abrogated the adjuvanticity of polyUs21. This study, therefore, identifies sufficient IFN-alpha production by PDC as an important determinant of vaccine efficacy.
Assuntos
Adjuvantes Imunológicos/farmacologia , Células Dendríticas/metabolismo , Interferon Tipo I/fisiologia , Glicoproteínas de Membrana/agonistas , Receptor 7 Toll-Like/agonistas , Aminoquinolinas/farmacologia , Aminoquinolinas/uso terapêutico , Animais , Antineoplásicos/farmacologia , Vacinas Anticâncer/farmacologia , Células Dendríticas/imunologia , Relação Dose-Resposta a Droga , Imidazóis/farmacologia , Imidazóis/uso terapêutico , Imiquimode , Interferon Tipo I/metabolismo , Melanoma Experimental/imunologia , Melanoma Experimental/metabolismo , Melanoma Experimental/terapia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Quinolinas/farmacologia , RNA/farmacologia , Receptor de Interferon alfa e beta/genética , Células Tumorais CultivadasRESUMO
Cross-talk between NK cells and dendritic cells (DCs) is critical for the potent therapeutic response to dsRNA, but the receptors involved remained controversial. We show in this paper that two dsRNAs, polyadenylic-polyuridylic acid and polyinosinic-polycytidylic acid [poly(I:C)], similarly engaged human TLR3, whereas only poly(I:C) triggered human RIG-I and MDA5. Both dsRNA enhanced NK cell activation within PBMCs but only poly(I:C) induced IFN-gamma. Although myeloid DCs (mDCs) were required for NK cell activation, induction of cytolytic potential and IFN-gamma production did not require contact with mDCs but was dependent on type I IFN and IL-12, respectively. Poly(I:C) but not polyadenylic-polyuridylic acid synergized with mDC-derived IL-12 for IFN-gamma production by acting directly on NK cells. Finally, the requirement of both TLR3 and Rig-like receptor (RLR) on mDCs and RLRs but not TLR3 on NK cells for IFN-gamma production was demonstrated using TLR3- and Cardif-deficient mice and human RIG-I-specific activator. Thus, we report the requirement of cotriggering TLR3 and RLR on mDCs and RLRs on NK cells for a pathogen product to induce potent innate cell activation.
Assuntos
RNA Helicases DEAD-box/metabolismo , Células Dendríticas/efeitos dos fármacos , Interferon gama/metabolismo , Células Matadoras Naturais/efeitos dos fármacos , Receptor 3 Toll-Like/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Proteína DEAD-box 58 , RNA Helicases DEAD-box/genética , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Relação Dose-Resposta a Droga , Humanos , Helicase IFIH1 Induzida por Interferon , Células Matadoras Naturais/citologia , Células Matadoras Naturais/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Mieloides/citologia , Células Mieloides/efeitos dos fármacos , Células Mieloides/metabolismo , Poli A-U/farmacologia , Poli I-C/farmacologia , RNA de Cadeia Dupla/farmacologia , Receptores Imunológicos , Receptor 3 Toll-Like/genética , TransfecçãoRESUMO
Harnessing innate immunity is emerging as a promising therapeutic approach in cancer. We report here the design of tetraspecific molecules engaging natural killer (NK) cell-activating receptors NKp46 and CD16a, the ß-chain of the interleukin-2 receptor (IL-2R), and a tumor-associated antigen (TAA). In vitro, these tetraspecific antibody-based natural killer cell engager therapeutics (ANKETs) induce a preferential activation and proliferation of NK cells, and the binding to the targeted TAA triggers NK cell cytotoxicity and cytokine and chemokine production. In vivo, tetraspecific ANKETs induce NK cell proliferation and their accumulation at the tumor bed, as well as the control of local and disseminated tumors. Treatment of non-human primates with CD20-directed tetraspecific ANKET leads to CD20+ circulating B cell depletion, with minimal systemic cytokine release and no sign of toxicity. Tetraspecific ANKETs, thus, constitute a technological platform for harnessing NK cells as next-generation cancer immunotherapies.
Assuntos
Interleucina-2 , Neoplasias , Animais , Interleucina-2/genética , Células Matadoras Naturais , Receptores de Interleucina-2/metabolismo , Citocinas , Neoplasias/genética , Quimiocinas/metabolismoRESUMO
Background: MICA and MICB are tightly regulated stress-induced proteins that trigger the immune system by binding to the activating receptor NKG2D on cytotoxic lymphocytes. MICA and MICB are highly polymorphic molecules with prevalent expression on several types of solid tumors and limited expression in normal/healthy tissues, making them attractive targets for therapeutic intervention. Methods: We have generated a series of anti-MICA and MICB cross-reactive antibodies with the unique feature of binding to the most prevalent isoforms of both these molecules. Results: The anti-MICA and MICB antibody MICAB1, a human IgG1 Fc-engineered monoclonal antibody (mAb), displayed potent antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) of MICA/B-expressing tumor cells in vitro. However, it showed insufficient efficiency against solid tumors in vivo, which prompted the development of antibody-drug conjugates (ADC). Indeed, optimal tumor control was achieved with MICAB1-ADC format in several solid tumor models, including patient-derived xenografts (PDX) and carcinogen-induced tumors in immunocompetent MICAgen transgenic mice. Conclusions: These data indicate that MICA and MICB are promising targets for cytotoxic immunotherapy.
RESUMO
BACKGROUND: There is increasing evidence that the toll-like receptor 3 (TLR3) is an interesting target for anti-cancer therapy. Unfortunately, most laboratory investigations about the impact of TLR3 stimulation on human malignant cells have been performed with very high concentrations--5 to 100 microg/ml--of the prototype TLR3 ligand, poly(I:C). In a previous study focused on a specific type of human carcinoma - nasopharyngeal carcinoma - we have shown that concentrations of poly(I:C) as low as 100 ng/ml are sufficient to induce apoptosis of malignant cells when combined to a pharmacological antagonist of the IAP family based on Smac mimicry. METHODS: This observation prompted us to investigate the contribution of the IAP family in cell response to poly(I:C) in a variety of human malignant cell types. RESULTS: We report a rapid, intense and selective increase in c-IAP2 protein expression observed under stimulation by poly(I:C)(500 ng/ml) in all types of human malignant cells. In most cell types, this change in protein expression is underlain by an increase in c-IAP2 transcripts and dependent on the TLR3/TRIF pathway. When poly(I:C) is combined to the IAP inhibitor RMT 5265, a cooperative effect in apoptosis induction and/or inhibition of clonogenic growth is obtained in a large fraction of carcinoma and melanoma cell lines. CONCLUSIONS: Currently, IAP inhibitors like RMT 5265 and poly(I:C) are the subject of separate therapeutic trials. In light of our observations, combined use of both types of compounds should be considered for treatment of human malignancies including carcinomas and melanomas.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Neoplasias/patologia , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Adulto , Proteína 3 com Repetições IAP de Baculovírus , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Inibidoras de Apoptose/genética , Proteínas Inibidoras de Apoptose/metabolismo , Masculino , Pessoa de Meia-Idade , Neoplasias/genética , Neoplasias/metabolismo , Poli I-C/farmacologia , Interferência de RNA , RNA Mensageiro/metabolismo , Fatores de Tempo , Receptor 3 Toll-Like/agonistas , Receptor 3 Toll-Like/metabolismo , Células Tumorais Cultivadas , Ubiquitina-Proteína Ligases , Regulação para CimaRESUMO
Immune checkpoint inhibitors have revolutionized cancer treatment. However, many cancers are resistant to ICIs, and the targeting of additional inhibitory signals is crucial for limiting tumor evasion. The production of adenosine via the sequential activity of CD39 and CD73 ectoenzymes participates to the generation of an immunosuppressive tumor microenvironment. In order to disrupt the adenosine pathway, we generated two antibodies, IPH5201 and IPH5301, targeting human membrane-associated and soluble forms of CD39 and CD73, respectively, and efficiently blocking the hydrolysis of immunogenic ATP into immunosuppressive adenosine. These antibodies promoted antitumor immunity by stimulating dendritic cells and macrophages and by restoring the activation of T cells isolated from cancer patients. In a human CD39 knockin mouse preclinical model, IPH5201 increased the anti-tumor activity of the ATP-inducing chemotherapeutic drug oxaliplatin. These results support the use of anti-CD39 and anti-CD73 monoclonal antibodies and their combination with immune checkpoint inhibitors and chemotherapies in cancer.
Assuntos
5'-Nucleotidase/imunologia , Anticorpos Bloqueadores/imunologia , Antígenos CD/imunologia , Apirase/imunologia , 5'-Nucleotidase/genética , 5'-Nucleotidase/metabolismo , Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Anticorpos Bloqueadores/uso terapêutico , Antígenos CD/genética , Antineoplásicos/uso terapêutico , Apirase/deficiência , Apirase/genética , Linhagem Celular Tumoral , Modelos Animais de Doenças , Técnicas de Introdução de Genes , Humanos , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/metabolismo , Melanoma/tratamento farmacológico , Melanoma/imunologia , Melanoma/mortalidade , Melanoma/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oxaliplatina/uso terapêutico , Taxa de Sobrevida , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Microambiente TumoralAssuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/imunologia , Terapia de Alvo Molecular/métodos , Pneumonia Viral/imunologia , Pneumonia/imunologia , Síndrome Respiratória Aguda Grave/imunologia , Antivirais/uso terapêutico , Apirase/antagonistas & inibidores , Apirase/genética , Apirase/imunologia , Linfócitos B/imunologia , Linfócitos B/patologia , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/genética , Antígeno B7-H1/imunologia , Betacoronavirus/imunologia , COVID-19 , Estudos de Casos e Controles , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/genética , Infecções por Coronavirus/virologia , Expressão Gênica/efeitos dos fármacos , Humanos , Fatores Imunológicos/uso terapêutico , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/patologia , Subfamília C de Receptores Semelhantes a Lectina de Células NK/antagonistas & inibidores , Subfamília C de Receptores Semelhantes a Lectina de Células NK/genética , Subfamília C de Receptores Semelhantes a Lectina de Células NK/imunologia , Pandemias , Pneumonia/tratamento farmacológico , Pneumonia/genética , Pneumonia/virologia , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/genética , Pneumonia Viral/virologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/genética , Receptor de Morte Celular Programada 1/imunologia , SARS-CoV-2 , Síndrome Respiratória Aguda Grave/tratamento farmacológico , Síndrome Respiratória Aguda Grave/genética , Síndrome Respiratória Aguda Grave/virologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/patologiaRESUMO
TITLE: Les cellules natural killer : des cibles prometteuses dans la thérapie contre le cancer. ABSTRACT: L'immuno-oncologie est une approche d'immunothérapie novatrice qui change le traitement des cancers en stimulant la capacité du système immunitaire à reconnaître et éliminer les cellules tumorales. Cette approche a pour but de mettre en place une immuno-surveillance anti-tumorale durable chez des patients pour lesquels les thérapies conventionnelles ont échoué.
Assuntos
Citotoxicidade Imunológica/fisiologia , Células Matadoras Naturais/fisiologia , Oncologia/tendências , Terapia de Alvo Molecular/tendências , Neoplasias/terapia , Animais , Humanos , Vigilância Imunológica/fisiologia , Oncologia/métodos , Terapia de Alvo Molecular/métodos , Neoplasias/imunologia , Neoplasias/patologiaRESUMO
Using a yeast-based assay, a previously unsuspected antiprion activity was found for imiquimod (IQ), a potent Toll-like receptor 7 (TLR7) agonist already used for clinical applications. The antiprion activity of IQ was first detected against yeast prions [PSI (+) ] and [URE3], and then against mammalian prion both ex vivo in a cell-based assay and in vivo in a transgenic mouse model for prion diseases. In order to facilitate structure-activity relationship studies, we conducted a new synthetic pathway which provides a more efficient means of producing new IQ chemical derivatives, the activity of which was tested against both yeast and mammalian prions. The comparable antiprion activity of IQ and its chemical derivatives in the above life forms further emphasizes the conservation of prion controlling mechanisms throughout evolution. Interestingly, this study also demonstrated that the antiprion activity of IQ and IQ-derived compounds is independent from their ability to stimulate TLRs. Furthermore, we found that IQ and its active chemical derivatives inhibit the protein folding activity of the ribosome (PFAR) in vitro.
Assuntos
Aminoquinolinas/farmacologia , Glutationa Peroxidase/metabolismo , Fatores de Terminação de Peptídeos/metabolismo , Doenças Priônicas/tratamento farmacológico , Príons/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Aminoquinolinas/síntese química , Animais , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Guanosina/análogos & derivados , Guanosina/farmacologia , Humanos , Imidazóis/farmacologia , Imiquimode , Glicoproteínas de Membrana/agonistas , Glicoproteínas de Membrana/metabolismo , Camundongos , Proteínas PrPSc/metabolismo , Doenças Priônicas/metabolismo , Dobramento de Proteína , Saccharomyces cerevisiae/efeitos dos fármacos , Relação Estrutura-Atividade , Receptor 7 Toll-Like/agonistas , Receptor 7 Toll-Like/metabolismo , Receptor 8 Toll-Like/agonistas , Receptor 8 Toll-Like/metabolismoRESUMO
BACKGROUND: Nasopharyngeal carcinomas (NPC) are consistently associated with the Epstein-Barr virus (EBV). Though NPCs are more radiosensitive and chemosensitive than other tumors of the upper aero-digestive tract, many therapeutic challenges remain. In a previous report, we have presented data supporting a possible therapeutic strategy based on artificial TLR3 stimulation combined to the inhibition of the IAP protein family (Inhibitor of Apoptosis Proteins). The present study was designed to progress towards practical applications of this strategy pursuing 2 main objectives: 1) to formally demonstrate expression of the TLR3 protein by malignant NPC cells; 2) to investigate the effect of poly(A:U) as a novel TLR3-agonist more specific than poly(I:C) which was used in our previous study. METHODS: TLR3 expression was investigated in a series of NPC cell lines and clinical specimens by Western blot analysis and immunohistochemistry, respectively. The effects on NPC cells growth of the TLR3 ligand poly(A:U) used either alone or in combination with RMT5265, an IAP inhibitor based on Smac-mimicry, were assessed using MTT assays and clonogenic assays. RESULTS: TLR3 was detected at a high level in all NPC cell lines and clinical specimens. Low concentrations of poly(A:U) were applied to several types of NPC cells including cells from the C17 xenograft which for the first time have been adapted to permanent propagation in vitro. As a single agent, poly(A:U) had no significant effects on cell growth and cell survival. In contrast, dramatic effects were obtained when it was combined with the IAP inhibitor RMT5265. These effects were obtained using concentrations as low as 0.5 µg/ml (poly(A:U)) and 50 nM (RMT5265). CONCLUSION: These data confirm that TLR3 expression is a factor of vulnerability for NPC cells. They suggest that in some specific pathological and pharmacological contexts, it might be worth to use Smac-mimetics at very low doses, allowing a better management of secondary effects. In light of our observations, combined use of both types of compounds should be considered for treatment of nasopharyngeal carcinomas.
RESUMO
The discovery of a targeted therapeutic compound along with its companion predictive biomarker is a major goal of clinical development for a personalized anticancer therapy to date. Here we present evidence of the predictive value of TLR3 expression by tumor cells for the efficacy of Poly (A:U) dsRNA in 194 breast cancer patients enrolled in a randomized clinical trial. Adjuvant treatment with double-stranded RNA (dsRNA) was associated with a significant decrease in the risk of metastatic relapse in TLR3 positive but not in TLR3-negative breast cancers. Moreover, we show the functional relevance of TLR3 expression by human tumor cells for the antitumor effects mediated by dsRNA in several preclinical mouse models carried out in immunocompromised animals. These 2 independent lines of evidence relied upon the generation of a novel tool, an anti-TLR3 antibody (40F9.6) validated for routine detection of TLR3 expression on paraffin-embedded tissues. Altogether, these data suggest that dsRNA mediates its therapeutic effect through TLR3 expressed on tumor cells, and could therefore represent an effective targeted treatment in patients with TLR3-positive cancers.
Assuntos
Anticorpos Monoclonais , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais/análise , Neoplasias da Mama/tratamento farmacológico , RNA de Cadeia Dupla/uso terapêutico , Receptor 3 Toll-Like/biossíntese , Animais , Especificidade de Anticorpos , Neoplasias da Mama/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos BALB C , Estudos Multicêntricos como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Receptor 3 Toll-Like/análiseRESUMO
Many cancer cells express Toll-like receptors (TLR) that offer possible therapeutic targets. Polyadenylic-polyuridylic acid [poly(A:U)] is an agonist of the Toll-like receptor TLR3 that displays anticancer properties. In this study, we illustrate how the immunostimulatory and immunosuppressive effects of this agent can be uncoupled to therapeutic advantage. We took advantage of two TLR3-expressing tumor models that produced large amounts of CCL5 (a CCR5 ligand) and CXCL10 (a CXCR3 ligand) in response to type I IFN and poly(A:U), both in vitro and in vivo. Conventional chemotherapy or in vivo injection of poly(A:U), alone or in combination, failed to reduce tumor growth unless an immunochemotherapeutic regimen of vaccination against tumor antigens was included. CCL5 blockade improved the efficacy of immunochemotherapy, whereas CXCR3 blockade abolished its beneficial effects. These findings show how poly(A:U) can elicit production of a range of chemokines by tumor cells that reinforce immunostimulatory or immunosuppressive effects. Optimizing the anticancer effects of TLR3 agonists may require manipulating these chemokines or their receptors.
Assuntos
Vacinas Anticâncer/farmacologia , Melanoma Experimental/imunologia , Melanoma Experimental/terapia , Poli A-U/farmacologia , Receptor 3 Toll-Like/antagonistas & inibidores , Animais , Neoplasias da Mama/imunologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Vacinas Anticâncer/imunologia , Linhagem Celular Tumoral , Quimiocina CCL5/biossíntese , Quimiocina CCL5/metabolismo , Sinergismo Farmacológico , Humanos , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Camundongos Transgênicos , Receptores CCR5/biossíntese , Receptores CCR5/metabolismo , Receptores CXCR3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Receptor 3 Toll-Like/imunologia , Receptor 3 Toll-Like/metabolismoRESUMO
The concept of immunogenic chemotherapy that has recently emerged relies upon the capacity of a cytotoxic compound to trigger a cell-death modality. This modality elicits cross-priming by dendritic cells of tumor antigen-specific T cells that will contribute to the tumoricidal activity of the compound and protect the host against relapse. In contrast, most anticancer drugs elicit nonimmunogenic apoptosis that is not accompanied with an immunizing property. This review will discuss some molecular and metabolic changes required at the level of the tumor that must engage key pathways at the level of the host for the induction of Tc1 polarized-protective T cell responses during chemotherapy. We will summarize the immune adjuvants that can boost the immunogenicity of cell death to augment the efficacy of chemotherapy.