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Reversing CD8+ T cell dysfunction is crucial in treating chronic hepatitis B virus (HBV) infection, yet specific molecular targets remain unclear. Our study analyzed co-signaling receptors during hepatocellular priming and traced the trajectory and fate of dysfunctional HBV-specific CD8+ T cells. Early on, these cells upregulate PD-1, CTLA-4, LAG-3, OX40, 4-1BB, and ICOS. While blocking co-inhibitory receptors had minimal effect, activating 4-1BB and OX40 converted them into antiviral effectors. Prolonged stimulation led to a self-renewing, long-lived, heterogeneous population with a unique transcriptional profile. This includes dysfunctional progenitor/stem-like (TSL) cells and two distinct dysfunctional tissue-resident memory (TRM) populations. While 4-1BB expression is ubiquitously maintained, OX40 expression is limited to TSL. In chronic settings, only 4-1BB stimulation conferred antiviral activity. In HBeAg+ chronic patients, 4-1BB activation showed the highest potential to rejuvenate dysfunctional CD8+ T cells. Targeting all dysfunctional T cells, rather than only stem-like precursors, holds promise for treating chronic HBV infection.
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Linfocitos T CD8-positivos , Virus de la Hepatitis B , Hepatitis B Crónica , Humanos , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Hepatitis B Crónica/tratamiento farmacológico , Hepatitis B Crónica/virología , Hepatitis B Crónica/metabolismo , Miembro 9 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/metabolismo , Transducción de Señal , Animales , Receptores OX40/metabolismo , Ratones , Receptor de Muerte Celular Programada 1/metabolismo , Antígenos CD/metabolismoRESUMEN
Background & Aims: Liver diseases resulting from chronic HBV infection are a significant cause of morbidity and mortality. Vaccines that elicit T-cell responses capable of controlling the virus represent a treatment strategy with potential for long-term effects. Here, we evaluated vaccines that induce the activity of type I natural killer T (NKT) cells to limit viral replication and license stimulation of conventional antiviral T-cells. Methods: Vaccines were prepared by conjugating peptide epitopes to an NKT-cell agonist to promote co-delivery to antigen-presenting cells, encouraging NKT-cell licensing and stimulation of T cells. Activity of the conjugate vaccines was assessed in transgenic mice expressing the complete HBV genome, administered intravenously to maximise access to NKT cell-rich tissues. Results: The vaccines induced only limited antiviral activity in unmanipulated transgenic hosts, likely attributable to NKT-cell activation as T-cell tolerance to viral antigens is strong. However, in a model of chronic hepatitis B involving transfer of naive HBcAg-specific CD8+ T cells into the transgenic mice, which typically results in specific T-cell dysfunction without virus control, vaccines containing the targeted HBcAg epitope induced prolonged antiviral activity because of qualitatively improved T-cell stimulation. In a step towards a clinical product, vaccines were prepared using synthetic long peptides covering clusters of known HLA-binding epitopes and shown to be immunogenic in HLA transgenic mice. Predictions based on HLA distribution suggest a product containing three selected SLP-based vaccines could give >90 % worldwide coverage, with an average of 3.38 epitopes targeted per individual. Conclusions: The novel vaccines described show promise for further clinical development as a treatment for chronic hepatitis B. Impact and Implications: Although there are effective prophylactic vaccines for HBV infection, it is estimated that 350-400 million people worldwide have chronic hepatitis B, putting these individuals at significant risk of life-threatening liver diseases. Therapeutic vaccination aimed at activating or boosting HBV-specific T-cell responses holds potential as a strategy for treating chronic infection, but has so far met with limited success. Here, we show that a glycolipid-peptide conjugate vaccine designed to coordinate activity of type I NKT cells alongside conventional antiviral T cells has antiviral activity in a mouse model of chronic infection. It is anticipated that a product based on a combination of three such conjugates, each prepared using long peptides covering clusters of known HLA-binding epitopes, could be developed further as a treatment for chronic hepatitis B with broad global HLA coverage.
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Vaccines have reduced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) morbidity and mortality, yet emerging variants challenge their effectiveness. The prevailing approach to updating vaccines targets the antibody response, operating under the presumption that it is the primary defense mechanism following vaccination or infection. This perspective, however, can overlook the role of T cells, particularly when antibody levels are low or absent. Here we show, through studies in mouse models lacking antibodies but maintaining functional B cells and lymphoid organs, that immunity conferred by prior infection or mRNA vaccination can protect against SARS-CoV-2 challenge independently of antibodies. Our findings, using three distinct models inclusive of a novel human/mouse ACE2 hybrid, highlight that CD8+ T cells are essential for combating severe infections, whereas CD4+ T cells contribute to managing milder cases, with interferon-γ having an important function in this antibody-independent defense. These findings highlight the importance of T cell responses in vaccine development, urging a broader perspective on protective immunity beyond just antibodies.
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COVID-19 , Vacunas , Humanos , Animales , Ratones , SARS-CoV-2 , Linfocitos T CD8-positivos , COVID-19/prevención & control , Anticuerpos , Vacunación , Anticuerpos Antivirales , Anticuerpos NeutralizantesRESUMEN
The vaccination campaign against SARS-CoV-2 relies on the world-wide availability of effective vaccines, with a potential need of 20 billion vaccine doses to fully vaccinate the world population. To reach this goal, the manufacturing and logistic processes should be affordable to all countries, irrespective of economical and climatic conditions. Outer membrane vesicles (OMVs) are bacterial-derived vesicles that can be engineered to incorporate heterologous antigens. Given the inherent adjuvanticity, such modified OMVs can be used as vaccines to induce potent immune responses against the associated proteins. Here, we show that OMVs engineered to incorporate peptides derived from the receptor binding motif (RBM) of the spike protein from SARS-CoV-2 elicit an effective immune response in vaccinated mice, resulting in the production of neutralizing antibodies (nAbs) with a titre higher than 1:300. The immunity induced by the vaccine is sufficient to protect the animals from intranasal challenge with SARS-CoV-2, preventing both virus replication in the lungs and the pathology associated with virus infection. Furthermore, we show that OMVs can be effectively decorated with the RBM of the Omicron BA.1 variant and that such engineered OMVs induce nAbs against Omicron BA.1 and BA.5, as measured using the pseudovirus neutralization infectivity assay. Importantly, we show that the RBM438-509 ancestral-OMVs elicited antibodies which efficiently neutralize in vitro both the homologous ancestral strain, the Omicron BA.1 and BA.5 variants with a neutralization titre ranging from 1:100 to 1:1500, suggesting its potential use as a vaccine targeting diverse SARS-CoV-2 variants. Altogether, given the convenience associated with the ease of engineering, production and distribution, our results demonstrate that OMV-based SARS-CoV-2 vaccines can be a crucial addition to the vaccines currently available.
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The vaccination campaign against SARS-CoV-2 relies on the world-wide availability of effective vaccines, with a potential need of 20 billion vaccine doses to fully vaccinate the world population. To reach this goal, the manufacturing and logistic processes should be affordable to all countries, irrespectively of economical and climatic conditions. Outer membrane vesicles (OMV) are bacterial-derived vesicles that can be engineered to incorporate heterologous antigens. Given the inherent adjuvanticity, such modified OMV can be used as vaccine to induce potent immune responses against the associated protein. Here we show that OMVs engineered to incorporate peptides derived from the receptor binding motif (RBM) of the spike protein from SARS-CoV-2 elicit an effective immune response in vaccinated mice, resulting in the production of neutralizing antibodies (nAbs). The immunity induced by the vaccine is sufficient to protect the animals from intranasal challenge with SARS-CoV-2, preventing both virus replication in the lungs and the pathology associated with virus infection. Furthermore, we show that OMVs can be effectively decorated with the RBM of the Omicron BA.1 variant and that such engineered OMVs induced nAbs against Omicron BA.1 and BA.5, as judged by pseudovirus infectivity assay. Importantly, we show that the RBM438-509 ancestral-OMVs elicited antibodies which efficiently neutralized in vitro both the homologous ancestral strain, the Omicron BA.1 and BA.5 variants, suggesting its potential use as a pan SARS-CoV-2 vaccine. Altogether, given the convenience associated with ease of engineering, production and distribution, our results demonstrate that OMV-based SARS-CoV-2 vaccines can be a crucial addition to the vaccines currently available.
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Alongside vaccines, antiviral drugs are becoming an integral part of our response to the SARS-CoV-2 pandemic. Nirmatrelvir-an orally available inhibitor of the 3-chymotrypsin-like cysteine protease-has been shown to reduce the risk of progression to severe COVID-19. However, the impact of nirmatrelvir treatment on the development of SARS-CoV-2-specific adaptive immune responses is unknown. Here, by using mouse models of SARS-CoV-2 infection, we show that nirmatrelvir administration blunts the development of SARS-CoV-2-specific antibody and T cell responses. Accordingly, upon secondary challenge, nirmatrelvir-treated mice recruited significantly fewer memory T and B cells to the infected lungs and mediastinal lymph nodes, respectively. Together, the data highlight a potential negative impact of nirmatrelvir treatment with important implications for clinical management and might help explain the virological and/or symptomatic relapse after treatment completion reported in some individuals.
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Inmunidad Adaptativa , Antivirales , Tratamiento Farmacológico de COVID-19 , Lactamas , Animales , Ratones , COVID-19/inmunología , SARS-CoV-2 , Antivirales/administración & dosificación , Inmunidad Adaptativa/efectos de los fármacos , Lactamas/administración & dosificación , Células T de Memoria/inmunología , Linfocitos B/inmunología , Ratones Endogámicos C57BLRESUMEN
The COVID-19 pandemic is entering a new era with the approval of many SARS-CoV-2 vaccines. In spite of the restoration of an almost normal way of life thanks to the immune protection elicited by these innovative vaccines, we are still facing high viral circulation, with a significant number of deaths. To further explore alternative vaccination platforms, we developed COVID-eVax-a genetic vaccine based on plasmid DNA encoding the RBD domain of the SARS-CoV-2 spike protein. Here, we describe the correlation between immune responses and the evolution of viral infection in ferrets infected with the live virus. We demonstrate COVID-eVax immunogenicity as means of antibody response and, above all, a significant T-cell response, thus proving the critical role of T-cell immunity, in addition to the neutralizing antibody activity, in controlling viral spread.
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Group 1 innate lymphoid cells (ILCs), which comprise both natural killer (NK) cells and ILC1s, are important innate effectors that can also positively and negatively influence adaptive immune responses. The latter function is generally ascribed to the ability of NK cells to recognize and kill activated T cells. Here, we used multiphoton intravital microscopy in mouse models of hepatitis B to study the intrahepatic behavior of group 1 ILCs and their cross-talk with hepatitis B virus (HBV)-specific CD8+ T cells. We found that hepatocellular antigen recognition by effector CD8+ T cells triggered a prominent increase in the number of hepatic NK cells and ILC1s. Group 1 ILCs colocalized and engaged in prolonged interactions with effector CD8+ T cells undergoing hepatocellular antigen recognition; however, they did not induce T cell apoptosis. Rather, group 1 ILCs constrained CD8+ T cell proliferation by controlling local interleukin-2 (IL-2) availability. Accordingly, group 1 ILC depletion, or genetic removal of their IL-2 receptor a chain, considerably increased the number of intrahepatic HBV-specific effector CD8+ T cells and the attendant immunopathology. Together, these results reveal a role for group 1 ILCs in controlling T cell-mediated liver immunopathology by limiting local IL-2 concentration and have implications for the treatment of chronic HBV infection.
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Linfocitos T CD8-positivos/inmunología , Inmunidad Innata/inmunología , Interleucina-2/inmunología , Linfocitos/inmunología , Animales , Células Asesinas Naturales/inmunología , Ratones , Ratones Congénicos , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones TransgénicosRESUMEN
The development of a tractable small animal model faithfully reproducing human coronavirus disease 2019 pathogenesis would arguably meet a pressing need in biomedical research. Thus far, most investigators have used transgenic mice expressing the human ACE2 in epithelial cells (K18-hACE2 transgenic mice) that are intranasally instilled with a liquid severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) suspension under deep anesthesia. Unfortunately, this experimental approach results in disproportionate high central nervous system infection leading to fatal encephalitis, which is rarely observed in humans and severely limits this model's usefulness. Here, we describe the use of an inhalation tower system that allows exposure of unanesthetized mice to aerosolized virus under controlled conditions. Aerosol exposure of K18-hACE2 transgenic mice to SARS-CoV-2 resulted in robust viral replication in the respiratory tract, anosmia, and airway obstruction but did not lead to fatal viral neuroinvasion. When compared with intranasal inoculation, aerosol infection resulted in a more pronounced lung pathology including increased immune infiltration, fibrin deposition, and a transcriptional signature comparable to that observed in SARS-CoV-2infected patients. This model may prove useful for studies of viral transmission, disease pathogenesis (including long-term consequences of SARS-CoV-2 infection), and therapeutic interventions.
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Enzima Convertidora de Angiotensina 2/genética , COVID-19/fisiopatología , Modelos Animales de Enfermedad , Encefalitis Viral/prevención & control , Queratina-18/genética , Rociadores Nasales , SARS-CoV-2/fisiología , Administración por Inhalación , Enzima Convertidora de Angiotensina 2/metabolismo , Animales , COVID-19/inmunología , COVID-19/virología , Encefalitis Viral/mortalidad , Células Epiteliales/metabolismo , Femenino , Humanos , Queratina-18/metabolismo , Pulmón/inmunología , Pulmón/patología , Pulmón/fisiopatología , Masculino , Ratones , Ratones Transgénicos , Regiones Promotoras Genéticas/genética , Transcriptoma , Replicación ViralRESUMEN
The COVID-19 pandemic caused by SARS-CoV-2 has made the development of safe and effective vaccines a critical priority. To date, four vaccines have been approved by European and American authorities for preventing COVID-19, but the development of additional vaccine platforms with improved supply and logistics profiles remains a pressing need. Here we report the preclinical evaluation of a novel COVID-19 vaccine candidate based on the electroporation of engineered, synthetic cDNA encoding a viral antigen in the skeletal muscle. We constructed a set of prototype DNA vaccines expressing various forms of the SARS-CoV-2 spike (S) protein and assessed their immunogenicity in animal models. Among them, COVID-eVax-a DNA plasmid encoding a secreted monomeric form of SARS-CoV-2 S protein receptor-binding domain (RBD)-induced the most potent anti-SARS-CoV-2 neutralizing antibody responses (including against the current most common variants of concern) and a robust T cell response. Upon challenge with SARS-CoV-2, immunized K18-hACE2 transgenic mice showed reduced weight loss, improved pulmonary function, and lower viral replication in the lungs and brain. COVID-eVax conferred significant protection to ferrets upon SARS-CoV-2 challenge. In summary, this study identifies COVID-eVax as an ideal COVID-19 vaccine candidate suitable for clinical development. Accordingly, a combined phase I-II trial has recently started.
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Vacunas contra la COVID-19/administración & dosificación , COVID-19/prevención & control , Inmunización/métodos , Modelos Animales , SARS-CoV-2/aislamiento & purificación , Glicoproteína de la Espiga del Coronavirus/inmunología , Vacunas de ADN/administración & dosificación , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , COVID-19/genética , COVID-19/virología , Femenino , Hurones , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Transgénicos , Dominios Proteicos , Ratas Sprague-DawleyRESUMEN
Multiple molecular features, such as activation of specific oncogenes (e.g., MYC, BCL2) or a variety of gene expression signatures, have been associated with disease course in diffuse large B-cell lymphoma (DLBCL), although their relationships and implications for targeted therapy remain to be fully unraveled. We report that MYC activity is closely correlated with-and most likely a driver of-gene signatures related to oxidative phosphorylation (OxPhos) in DLBCL, pointing to OxPhos enzymes, in particular mitochondrial electron transport chain (ETC) complexes, as possible therapeutic targets in high-grade MYC-associated lymphomas. In our experiments, indeed, MYC sensitized B cells to the ETC complex I inhibitor IACS-010759. Mechanistically, IACS-010759 triggered the integrated stress response (ISR) pathway, driven by the transcription factors ATF4 and CHOP, which engaged the intrinsic apoptosis pathway and lowered the apoptotic threshold in MYC-overexpressing cells. In line with these findings, the BCL2-inhibitory compound venetoclax synergized with IACS-010759 against double-hit lymphoma (DHL), a high-grade malignancy with concurrent activation of MYC and BCL2. In BCL2-negative lymphoma cells, instead, killing by IACS-010759 was potentiated by the Mcl-1 inhibitor S63845. Thus, combining an OxPhos inhibitor with select BH3-mimetic drugs provides a novel therapeutic principle against aggressive, MYC-associated DLBCL variants.
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Linfoma de Células B Grandes Difuso , Proteínas Proto-Oncogénicas c-myc , Humanos , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Oncogenes , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , RespiraciónRESUMEN
Kupffer cells (KCs) are highly abundant, intravascular, liver-resident macrophages known for their scavenger and phagocytic functions. KCs can also present antigens to CD8+ T cells and promote either tolerance or effector differentiation, but the mechanisms underlying these discrepant outcomes are poorly understood. Here, we used a mouse model of hepatitis B virus (HBV) infection, in which HBV-specific naive CD8+ T cells recognizing hepatocellular antigens are driven into a state of immune dysfunction, to identify a subset of KCs (referred to as KC2) that cross-presents hepatocellular antigens upon interleukin-2 (IL-2) administration, thus improving the antiviral function of T cells. Removing MHC-I from all KCs, including KC2, or selectively depleting KC2 impaired the capacity of IL-2 to revert the T cell dysfunction induced by intrahepatic priming. In summary, by sensing IL-2 and cross-presenting hepatocellular antigens, KC2 overcome the tolerogenic potential of the hepatic microenvironment, suggesting new strategies for boosting hepatic T cell immunity.
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Presentación de Antígeno/inmunología , Linfocitos T CD8-positivos/inmunología , Reactividad Cruzada/inmunología , Interleucina-2/inmunología , Macrófagos del Hígado/inmunología , Animales , Hepatitis B/inmunología , Tolerancia Inmunológica/inmunología , Ratones , Ratones TransgénicosRESUMEN
RATIONALE: Intercellular tight junctions are crucial for correct regulation of the endothelial barrier. Their composition and integrity are affected in pathological contexts, such as inflammation and tumor growth. JAM-A (junctional adhesion molecule A) is a transmembrane component of tight junctions with a role in maintenance of endothelial barrier function, although how this is accomplished remains elusive. OBJECTIVE: We aimed to understand the molecular mechanisms through which JAM-A expression regulates tight junction organization to control endothelial permeability, with potential implications under pathological conditions. METHODS AND RESULTS: Genetic deletion of JAM-A in mice significantly increased vascular permeability. This was associated with significantly decreased expression of claudin-5 in the vasculature of various tissues, including brain and lung. We observed that C/EBP-α (CCAAT/enhancer-binding protein-α) can act as a transcription factor to trigger the expression of claudin-5 downstream of JAM-A, to thus enhance vascular barrier function. Accordingly, gain-of-function for C/EBP-α increased claudin-5 expression and decreased endothelial permeability, as measured by the passage of fluorescein isothiocyanate (FITC)-dextran through endothelial monolayers. Conversely, C/EBP-α loss-of-function showed the opposite effects of decreased claudin-5 levels and increased endothelial permeability. Mechanistically, JAM-A promoted C/EBP-α expression through suppression of ß-catenin transcriptional activity, and also through activation of EPAC (exchange protein directly activated by cAMP). C/EBP-α then directly binds the promoter of claudin-5 to thereby promote its transcription. Finally, JAM-A-C/EBP-α-mediated regulation of claudin-5 was lost in blood vessels from tissue biopsies from patients with glioblastoma and ovarian cancer. CONCLUSIONS: We describe here a novel role for the transcription factor C/EBP-α that is positively modulated by JAM-A, a component of tight junctions that acts through EPAC to up-regulate the expression of claudin-5, to thus decrease endothelial permeability. Overall, these data unravel a regulatory molecular pathway through which tight junctions limit vascular permeability. This will help in the identification of further therapeutic targets for diseases associated with endothelial barrier dysfunction. Graphic Abstract: An graphic abstract is available for this article.
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Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Permeabilidad Capilar , Moléculas de Adhesión Celular/metabolismo , Claudina-5/metabolismo , Células Endoteliales/metabolismo , Receptores de Superficie Celular/metabolismo , Uniones Estrechas/metabolismo , Adulto , Anciano , Animales , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Proteínas Potenciadoras de Unión a CCAAT/genética , Moléculas de Adhesión Celular/genética , Línea Celular , Claudina-5/genética , Femenino , Glioblastoma/metabolismo , Glioblastoma/patología , Humanos , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Persona de Mediana Edad , Neovascularización Patológica , Neoplasias Ováricas/metabolismo , Neoplasias Ováricas/patología , Receptores de Superficie Celular/genética , Transducción de Señal , Uniones Estrechas/genética , Regulación hacia ArribaRESUMEN
The Wnt/ß-catenin pathway regulates T-cell functions, including the repression of effector functions to the advantage of memory development via Tcf1. In a companion study, we demonstrate that, in human cancers, Wnt3a/ß-catenin signaling maintains tumor-infiltrating T cells in a partially exhausted status. Here, we have investigated the effects of Wnt3a neutralization in vivo in a mouse tumor model. Abundant Wnt3a was released, mostly by stromal cells, in the tumor microenvironment. We tested whether Wnt3a neutralization in vivo could rescue the effector capacity of tumor-infiltrating T cells, by administering an antibody to Wnt3a to tumor-bearing mice. This therapy restrained tumor growth and favored the expansion of tumor antigen-specific CD8+ effector memory T cells with increased expression of Tbet and IFNγ and reduced expression of Tcf1. However, the effect was not attributable to the interruption of T-cell-intrinsic ß-catenin signaling, because Wnt3a/ß-catenin activation correlated with enhanced, not reduced, T-cell effector functions both ex vivo and in vitro Adoptively transferred CD8+ T cells, not directly exposed to the anti-Wnt3a antibody but infiltrating previously Wnt3a-neutralized tumors, also showed improved functions. The rescue of T-cell response was thus secondary to T-cell-extrinsic changes that likely involved dendritic cells. Indeed, tumor-derived Wnt3a strongly suppressed dendritic cell maturation in vitro, and anti-Wnt3a treatment rescued dendritic cell activities in vivo Our results clarify the function of the Wnt3a/ß-catenin pathway in antitumor effector T cells and suggest that Wnt3a neutralization might be a promising immunotherapy for rescuing dendritic cell activities. Cancer Immunol Res; 6(8); 953-64. ©2018 AACR.
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Adenocarcinoma/terapia , Neoplasias del Colon/terapia , Linfocitos Infiltrantes de Tumor/inmunología , Vía de Señalización Wnt/inmunología , Proteína Wnt3A/inmunología , Adenocarcinoma/inmunología , Animales , Linfocitos T CD8-positivos/inmunología , Línea Celular Tumoral , Neoplasias del Colon/patología , Células Dendríticas/inmunología , Humanos , Inmunoterapia/métodos , Transfusión de Linfocitos/métodos , Masculino , Ratones Endogámicos C57BL , Células del Estroma/inmunología , Proteína Wnt3A/antagonistas & inhibidores , Proteína Wnt3A/biosíntesisRESUMEN
High-grade B cell lymphomas with concurrent activation of the MYC and BCL2 oncogenes, also known as double-hit lymphomas (DHL), show dismal prognosis with current therapies. MYC activation sensitizes cells to inhibition of mitochondrial translation by the antibiotic tigecycline, and treatment with this compound provides a therapeutic window in a mouse model of MYC-driven lymphoma. We now addressed the utility of this antibiotic for treatment of DHL. BCL2 activation in mouse Eµ-myc lymphomas antagonized tigecycline-induced cell death, which was specifically restored by combined treatment with the BCL2 inhibitor venetoclax. In line with these findings, tigecycline and two related antibiotics, tetracycline and doxycycline, synergized with venetoclax in killing human MYC/BCL2 DHL cells. Treatment of mice engrafted with either DHL cell lines or a patient-derived xenograft revealed strong antitumoral effects of the tigecycline/venetoclax combination, including long-term tumor eradication with one of the cell lines. This drug combination also had the potential to cooperate with rituximab, a component of current front-line regimens. Venetoclax and tigecycline are currently in the clinic with distinct indications: Our preclinical results warrant the repurposing of these drugs for combinatorial treatment of DHL.
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Compuestos Bicíclicos Heterocíclicos con Puentes/uso terapéutico , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , Sulfonamidas/uso terapéutico , Tigeciclina/uso terapéutico , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Femenino , Ratones , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-myc/antagonistas & inhibidoresRESUMEN
The ST18 gene has been proposed to act either as a tumor suppressor or as an oncogene in different human cancers, but direct evidence for its role in tumorigenesis has been lacking thus far. Here, we demonstrate that ST18 is critical for tumor progression and maintenance in a mouse model of liver cancer, based on oncogenic transformation and adoptive transfer of primary precursor cells (hepatoblasts). ST18 messenger RNA (mRNA) and protein were detectable neither in normal liver nor in cultured hepatoblasts, but were readily expressed after subcutaneous engraftment and tumor growth. ST18 expression in liver cells was induced by inflammatory cues, including acute or chronic inflammation in vivo, as well as coculture with macrophages in vitro. Knocking down the ST18 mRNA in transplanted hepatoblasts delayed tumor progression. Induction of ST18 knockdown in pre-established tumors caused rapid tumor involution associated with pervasive morphological changes, proliferative arrest, and apoptosis in tumor cells, as well as depletion of tumor-associated macrophages, vascular ectasia, and hemorrhage. Reciprocally, systemic depletion of macrophages in recipient animals had very similar phenotypic consequences, impairing either tumor development or maintenance, and suppressing ST18 expression in hepatoblasts. Finally, RNA sequencing of ST18-depleted tumors before involution revealed down-regulation of inflammatory response genes, pointing to the suppression of nuclear factor kappa B-dependent transcription. CONCLUSION: ST18 expression in epithelial cells is induced by tumor-associated macrophages, contributing to the reciprocal feed-forward loop between both cell types in liver tumorigenesis. Our findings warrant the exploration of means to interfere with ST18-dependent epithelium-macrophage interactions in a therapeutic setting. (Hepatology 2017;65:1708-1719).
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Carcinoma Hepatocelular/etiología , Neoplasias Hepáticas Experimentales/etiología , Factores de Transcripción/metabolismo , Animales , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas Experimentales/metabolismo , Ratones Endogámicos C57BLRESUMEN
Tumors driven by activation of the transcription factor MYC generally show oncogene addiction. However, the gene expression programs that depend upon sustained MYC activity remain unknown. In this study, we employed a mouse model of liver carcinoma driven by a reversible tet-MYC transgene, combined with chromatin immunoprecipitation and gene expression profiling to identify MYC-dependent regulatory events. As previously reported, MYC-expressing mice exhibited hepatoblastoma- and hepatocellular carcinoma-like tumors, which regressed when MYC expression was suppressed. We further show that cellular transformation, and thus initiation of liver tumorigenesis, were impaired in mice harboring a MYC mutant unable to associate with the corepressor protein MIZ1 (ZBTB17). Notably, switching off the oncogene in advanced carcinomas revealed that MYC was required for the continuous activation and repression of distinct sets of genes, constituting no more than half of all genes deregulated during tumor progression and an even smaller subset of all MYC-bound genes. Altogether, our data provide the first detailed analysis of a MYC-dependent transcriptional program in a fully developed carcinoma and offer a guide to identifying the critical effectors contributing to MYC-driven tumor maintenance. Cancer Res; 76(12); 3463-72. ©2016 AACR.