RESUMO
Tumor-associated macrophages are composed of distinct populations arising from monocytes or tissue macrophages, with a poorly understood link to disease pathogenesis. Here, we demonstrate that mouse monocyte migration was supported by glutaminyl-peptide cyclotransferase-like (QPCTL), an intracellular enzyme that mediates N-terminal modification of several substrates, including the monocyte chemoattractants CCL2 and CCL7, protecting them from proteolytic inactivation. Knockout of Qpctl disrupted monocyte homeostasis, attenuated tumor growth and reshaped myeloid cell infiltration, with loss of monocyte-derived populations with immunosuppressive and pro-angiogenic profiles. Antibody targeting of the receptor CSF1R, which more broadly eliminates tumor-associated macrophages, reversed tumor growth inhibition in Qpctl-/- mice and prevented lymphocyte infiltration. Modulation of QPCTL synergized with anti-PD-L1 to expand CD8+ T cells and limit tumor growth. QPCTL inhibition constitutes an effective approach for myeloid cell-targeted cancer immunotherapy.
Assuntos
Aminoaciltransferases , Linfócitos T CD8-Positivos , Quimiocinas , Neoplasias , Aminoaciltransferases/genética , Aminoaciltransferases/metabolismo , Animais , Linfócitos T CD8-Positivos/patologia , Quimiocinas/metabolismo , Imunoterapia , Infiltração Leucêmica , Camundongos , Camundongos Knockout , Monócitos , Neoplasias/imunologiaRESUMO
RNA viruses present an extraordinary threat to human health, given their sudden and unpredictable appearance, the potential for rapid spread among the human population, and their ability to evolve resistance to antiviral therapies. The recent emergence of chikungunya virus, Zika virus, and Ebola virus highlights the struggles to contain outbreaks. A significant hurdle is the availability of antivirals to treat the infected or protect at-risk populations. While several compounds show promise in vitro and in vivo, these outbreaks underscore the need to accelerate drug discovery. The replication of several viruses has been described to rely on host polyamines, small and abundant positively charged molecules found in the cell. Here, we describe the antiviral effects of two molecules that alter polyamine levels: difluoromethylornithine (DFMO; also called eflornithine), which is a suicide inhibitor of ornithine decarboxylase 1 (ODC1), and diethylnorspermine (DENSpm), an activator of spermidine/spermine N1-acetyltransferase (SAT1). We show that reducing polyamine levels has a negative effect on diverse RNA viruses, including several viruses involved in recent outbreaks, in vitro and in vivo These findings highlight the importance of the polyamine biosynthetic pathway to viral replication, as well as its potential as a target in the development of further antivirals or currently available molecules, such as DFMO. IMPORTANCE: RNA viruses present a significant hazard to human health, and combatting these viruses requires the exploration of new avenues for targeting viral replication. Polyamines, small positively charged molecules within the cell, have been demonstrated to facilitate infection for a few different viruses. Our study demonstrates that diverse RNA viruses rely on the polyamine pathway for replication and highlights polyamine biosynthesis as a promising drug target.
Assuntos
Antivirais/farmacologia , Poliaminas/metabolismo , Vírus de RNA/efeitos dos fármacos , Acetiltransferases/metabolismo , Animais , Linhagem Celular , Febre de Chikungunya/tratamento farmacológico , Febre de Chikungunya/virologia , Vírus Chikungunya/efeitos dos fármacos , Vírus Chikungunya/metabolismo , Surtos de Doenças , Ebolavirus/efeitos dos fármacos , Ebolavirus/metabolismo , Eflornitina/farmacologia , Doença pelo Vírus Ebola/tratamento farmacológico , Doença pelo Vírus Ebola/virologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Espermina/análogos & derivados , Espermina/farmacologia , Replicação Viral/efeitos dos fármacos , Zika virus/efeitos dos fármacos , Infecção por Zika virus/tratamento farmacológico , Infecção por Zika virus/virologiaRESUMO
Chikungunya virus (CHIKV) is a re-emerging alphavirus that has caused significant disease in the Indian Ocean region since 2005. During this outbreak, in addition to fever, rash and arthritis, severe cases of CHIKV infection have been observed in infants. Challenging the notion that the innate immune response in infants is immature or defective, we demonstrate that both human infants and neonatal mice generate a robust type I interferon (IFN) response during CHIKV infection that contributes to, but is insufficient for, the complete control of infection. To characterize the mechanism by which type I IFNs control CHIKV infection, we evaluated the role of ISG15 and defined it as a central player in the host response, as neonatal mice lacking ISG15 were profoundly susceptible to CHIKV infection. Surprisingly, UbE1Lâ»/â» mice, which lack the ISG15 E1 enzyme and therefore are unable to form ISG15 conjugates, displayed no increase in lethality following CHIKV infection, thus pointing to a non-classical role for ISG15. No differences in viral loads were observed between wild-type (WT) and ISG15â»/â» mice, however, a dramatic increase in proinflammatory cytokines and chemokines was observed in ISG15â»/â» mice, suggesting that the innate immune response to CHIKV contributes to their lethality. This study provides new insight into the control of CHIKV infection, and establishes a new model for how ISG15 functions as an immunomodulatory molecule in the blunting of potentially pathologic levels of innate effector molecules during the host response to viral infection.
Assuntos
Infecções por Alphavirus/imunologia , Vírus Chikungunya/fisiologia , Citocinas/imunologia , Interferon Tipo I/imunologia , Enzimas Ativadoras de Ubiquitina/imunologia , Ubiquitinas/imunologia , Infecções por Alphavirus/diagnóstico , Infecções por Alphavirus/metabolismo , Animais , Animais Recém-Nascidos , Febre de Chikungunya , Vírus Chikungunya/patogenicidade , Citocinas/metabolismo , Modelos Animais de Doenças , Humanos , Interferon Tipo I/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Ligação Proteica , Recombinação Genética , Estudos Retrospectivos , Enzimas Ativadoras de Ubiquitina/metabolismo , Ubiquitinas/metabolismoRESUMO
PURPOSE: COSMIC-021 is evaluating cabozantinib plus atezolizumab in patients with solid tumors. We report results from patients with advanced clear cell (cc) and non-clear cell (ncc) renal cell carcinoma (RCC). METHODS: This phase Ib study (NCT03170960) enrolled patients age ≥ 18 years with advanced RCC. A dose-escalation stage was followed by expansion cohorts. For cohort expansion, prior systemic therapy was not permitted for ccRCC but allowed for nccRCC. Patients received oral cabozantinib 40 mg once a day (ccRCC and nccRCC) or 60 mg once a day (ccRCC only) plus atezolizumab (1,200 mg intravenously, once every 3 weeks). The primary end point was investigator-assessed objective response rate (ORR) per RECIST v1.1; the secondary end point was safety. RESULTS: A total of 102 patients were enrolled. Median follow-up was 25.8, 15.3, and 13.3 months for the 40-mg ccRCC, 60-mg ccRCC, and nccRCC groups, respectively. ORR was 53% (80% CI, 41 to 65) in the 40-mg ccRCC group (n = 34) and 58% (80% CI, 46 to 70) in the 60-mg ccRCC group (n = 36), 3% and 11%, respectively, with complete response; median progression-free survival (exploratory end point) was 19.5 and 15.1 months, respectively. In nccRCC (n = 32), ORR was 31% (80% CI, 20 to 44), all partial responses; median progression-free survival was 9.5 months. Grade 3 or 4 treatment-related adverse events (TRAEs) were reported by 71% of patients in the 40-mg ccRCC group, 67% in the 60-mg ccRCC group, and 38% in the nccRCC group; TRAEs leading to discontinuation of both agents occurred in 15%, 6%, and 3% of patients, respectively. There were no grade 5 TRAEs. CONCLUSION: The novel combination of cabozantinib plus atezolizumab demonstrated encouraging clinical activity and acceptable tolerability in patients with advanced ccRCC and nccRCC. Disease control was observed across dose levels and histologic subtypes.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Neoplasias Renais/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anilidas/administração & dosagem , Anticorpos Monoclonais Humanizados/administração & dosagem , Carcinoma de Células Renais/patologia , Feminino , Seguimentos , Humanos , Neoplasias Renais/patologia , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Prognóstico , Piridinas/administração & dosagemRESUMO
Type I interferon (IFN-I) responses are critical for the control of RNA virus infections, however, many viruses, including Dengue (DENV) and Chikungunya (CHIKV) virus, do not directly activate plasmacytoid dendritic cells (pDCs), robust IFN-I producing cells. Herein, we demonstrated that DENV and CHIKV infected cells are sensed by pDCs, indirectly, resulting in selective IRF7 activation and IFN-I production, in the absence of other inflammatory cytokine responses. To elucidate pDC immunomodulatory functions, we developed a mouse model in which IRF7 signaling is restricted to pDC. Despite undetectable levels of IFN-I protein, pDC-restricted IRF7 signaling controlled both viruses and was sufficient to protect mice from lethal CHIKV infection. Early pDC IRF7-signaling resulted in amplification of downstream antiviral responses, including an accelerated natural killer (NK) cell-mediated type II IFN response. These studies revealed the dominant, yet indirect role of pDC IRF7-signaling in directing both type I and II IFN responses during arbovirus infections.
Assuntos
Febre de Chikungunya/imunologia , Dengue/imunologia , Interações Hospedeiro-Patógeno/imunologia , Fator Regulador 3 de Interferon/imunologia , Fator Regulador 7 de Interferon/imunologia , Interferon Tipo I/imunologia , Animais , Febre de Chikungunya/genética , Febre de Chikungunya/mortalidade , Febre de Chikungunya/patologia , Vírus Chikungunya/crescimento & desenvolvimento , Vírus Chikungunya/imunologia , Vírus Chikungunya/patogenicidade , Células Dendríticas/imunologia , Células Dendríticas/virologia , Dengue/genética , Dengue/mortalidade , Dengue/patologia , Vírus da Dengue/crescimento & desenvolvimento , Vírus da Dengue/imunologia , Vírus da Dengue/patogenicidade , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Humanos , Fator Regulador 3 de Interferon/deficiência , Fator Regulador 3 de Interferon/genética , Fator Regulador 7 de Interferon/deficiência , Fator Regulador 7 de Interferon/genética , Interferon Tipo I/genética , Interferon gama/genética , Interferon gama/imunologia , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/virologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Viral/antagonistas & inibidores , RNA Viral/genética , RNA Viral/imunologia , Transdução de Sinais , Baço/imunologia , Baço/virologia , Análise de SobrevidaRESUMO
Type I interferons (IFNs) are essential mediators of antiviral responses. These cytokines have been implicated in the pathogenesis of autoimmunity, most notably systemic lupus erythematosus (SLE), diabetes mellitus, and dermatomyositis, as well as monogenic type I interferonopathies. Despite a fundamental role in health and disease, the direct quantification of type I IFNs has been challenging. Using single-molecule array (Simoa) digital ELISA technology, we recorded attomolar concentrations of IFNα in healthy donors, viral infection, and complex and monogenic interferonopathies. IFNα protein correlated well with functional activity and IFN-stimulated gene expression. High circulating IFNα levels were associated with increased clinical severity in SLE patients, and a study of the cellular source of IFNα protein indicated disease-specific mechanisms. Measurement of IFNα attomolar concentrations by digital ELISA will enhance our understanding of IFN biology and potentially improve the diagnosis and stratification of pathologies associated with IFN dysregulation.
Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Interferon-alfa/sangue , Humanos , Fatores Reguladores de Interferon/sangue , Fatores Reguladores de Interferon/líquido cefalorraquidiano , Interferon-alfa/líquido cefalorraquidiano , Lúpus Eritematoso Sistêmico/sangue , Sensibilidade e Especificidade , Índice de Gravidade de Doença , Linfócitos T/metabolismo , Estomatite Vesicular/imunologiaRESUMO
Experimental cancer models must consider the role of the immune system.
Assuntos
Hipoglicemiantes , Fator 2 Relacionado a NF-E2 , Antioxidantes , Humanos , Neoplasias , Estresse OxidativoRESUMO
Autophagy is an important survival pathway and can participate in the host response to infection. Studying Chikungunya virus (CHIKV), the causative agent of a major epidemic in India, Southeast Asia, and southern Europe, we reveal a novel mechanism by which autophagy limits cell death and mortality after infection. We use biochemical studies and single cell multispectral assays to demonstrate that direct infection triggers both apoptosis and autophagy. CHIKV-induced autophagy is mediated by the independent induction of endoplasmic reticulum and oxidative stress pathways. These cellular responses delay apoptotic cell death by inducing the IRE1α-XBP-1 pathway in conjunction with ROS-mediated mTOR inhibition. Silencing of autophagy genes resulted in enhanced intrinsic and extrinsic apoptosis, favoring viral propagation in cultured cells. Providing in vivo evidence for the relevance of our findings, Atg16L(HM) mice, which display reduced levels of autophagy, exhibited increased lethality and showed a higher sensitivity to CHIKV-induced apoptosis. Based on kinetic studies and the observation that features of apoptosis and autophagy were mutually exclusive, we conclude that autophagy inhibits caspase-dependent cell death but is ultimately overwhelmed by viral replication. Our study suggests that inducers of autophagy may limit the pathogenesis of acute Chikungunya disease.
Assuntos
Infecções por Alphavirus/fisiopatologia , Apoptose/fisiologia , Autofagia/fisiologia , Retículo Endoplasmático/fisiologia , Estresse Oxidativo/fisiologia , Transdução de Sinais/fisiologia , Animais , Proteínas Relacionadas à Autofagia , Western Blotting , Proteínas de Transporte/genética , Caspases/metabolismo , Linhagem Celular , Febre de Chikungunya , Proteínas de Ligação a DNA/metabolismo , Endorribonucleases/metabolismo , Citometria de Fluxo , Imunofluorescência , Processamento de Imagem Assistida por Computador , Camundongos , Camundongos Mutantes , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Fatores de Transcrição de Fator Regulador X , Fatores de Transcrição/metabolismo , Proteína 1 de Ligação a X-BoxRESUMO
It has been recognized that macroautophagy constitutes an important survival mechanism that allows both the maintenance of cellular homeostasis and the regulation of programmed cell death pathways (e.g., apoptosis). Although several pathogens have been described to induce autophagy, the prosurvival function of this process in infectious models remains poorly characterized. Our recent studies on chikungunya virus (CHIKV), the causative agent of major epidemics in India, Southeast Asia and southern Europe, reveal a novel mechanism by which autophagy limits the cytopathic effects of CHIKV by impinging upon virus-induced cell death pathways.