Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Biol Chem ; 299(6): 104749, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37100284

RESUMO

The recent SARS-CoV-2 and mpox outbreaks have highlighted the need to expand our arsenal of broad-spectrum antiviral agents for future pandemic preparedness. Host-directed antivirals are an important tool to accomplish this as they typically offer protection against a broader range of viruses than direct-acting antivirals and have a lower susceptibility to viral mutations that cause drug resistance. In this study, we investigate the exchange protein activated by cAMP (EPAC) as a target for broad-spectrum antiviral therapy. We find that the EPAC-selective inhibitor, ESI-09, provides robust protection against a variety of viruses, including SARS-CoV-2 and Vaccinia (VACV)-an orthopox virus from the same family as mpox. We show, using a series of immunofluorescence experiments, that ESI-09 remodels the actin cytoskeleton through Rac1/Cdc42 GTPases and the Arp2/3 complex, impairing internalization of viruses that use clathrin-mediated endocytosis (e.g. VSV) or micropinocytosis (e.g. VACV). Additionally, we find that ESI-09 disrupts syncytia formation and inhibits cell-to-cell transmission of viruses such as measles and VACV. When administered to immune-deficient mice in an intranasal challenge model, ESI-09 protects mice from lethal doses of VACV and prevents formation of pox lesions. Altogether, our finding shows that EPAC antagonists such as ESI-09 are promising candidates for broad-spectrum antiviral therapy that can aid in the fight against ongoing and future viral outbreaks.


Assuntos
Antivirais , COVID-19 , Mpox , Vacínia , Animais , Camundongos , Antivirais/farmacologia , Mpox/tratamento farmacológico , SARS-CoV-2/efeitos dos fármacos , Vacínia/tratamento farmacológico , Vaccinia virus/efeitos dos fármacos
2.
Front Immunol ; 14: 1099459, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36969187

RESUMO

Introduction: Adipocytes in the tumour microenvironment are highly dynamic cells that have an established role in tumour progression, but their impact on anti-cancer therapy resistance is becoming increasingly difficult to overlook. Methods: We investigated the role of adipose tissue and adipocytes in response to oncolytic virus (OV) therapy in adipose-rich tumours such as breast and ovarian neoplasms. Results: We show that secreted products in adipocyte-conditioned medium significantly impairs productive virus infection and OV-driven cell death. This effect was not due to the direct neutralization of virions or inhibition of OV entry into host cells. Instead, further investigation of adipocyte secreted factors demonstrated that adipocyte-mediated OV resistance is primarily a lipid-driven phenomenon. When lipid moieties are depleted from the adipocyte-conditioned medium, cancer cells are re-sensitized to OV-mediated destruction. We further demonstrated that blocking fatty acid uptake by cancer cells, in a combinatorial strategy with virotherapy, has clinical translational potential to overcome adipocyte-mediated OV resistance. Discussion: Our findings indicate that while adipocyte secreted factors can impede OV infection, the impairment of OV treatment efficacy can be overcome by modulating lipid flux in the tumour milieu.


Assuntos
Terapia Viral Oncolítica , Vírus Oncolíticos , Neoplasias Ovarianas , Humanos , Feminino , Microambiente Tumoral , Meios de Cultivo Condicionados , Vírus Oncolíticos/fisiologia , Neoplasias Ovarianas/terapia , Lipídeos
3.
Mol Ther ; 30(5): 1885-1896, 2022 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-34687845

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic requires the continued development of safe, long-lasting, and efficacious vaccines for preventive responses to major outbreaks around the world, and especially in isolated and developing countries. To combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we characterize a temperature-stable vaccine candidate (TOH-Vac1) that uses a replication-competent, attenuated vaccinia virus as a vector to express a membrane-tethered spike receptor binding domain (RBD) antigen. We evaluate the effects of dose escalation and administration routes on vaccine safety, efficacy, and immunogenicity in animal models. Our vaccine induces high levels of SARS-CoV-2 neutralizing antibodies and favorable T cell responses, while maintaining an optimal safety profile in mice and cynomolgus macaques. We demonstrate robust immune responses and protective immunity against SARS-CoV-2 variants after only a single dose. Together, these findings support further development of our novel and versatile vaccine platform as an alternative or complementary approach to current vaccines.


Assuntos
COVID-19 , Vacinas , Animais , Camundongos , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Imunidade , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus , Linfócitos T
4.
Int J Mol Sci ; 22(5)2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33668756

RESUMO

Despite sequence similarity to SARS-CoV-1, SARS-CoV-2 has demonstrated greater widespread virulence and unique challenges to researchers aiming to study its pathogenicity in humans. The interaction of the viral receptor binding domain (RBD) with its main host cell receptor, angiotensin-converting enzyme 2 (ACE2), has emerged as a critical focal point for the development of anti-viral therapeutics and vaccines. In this study, we selectively identify and characterize the impact of mutating certain amino acid residues in the RBD of SARS-CoV-2 and in ACE2, by utilizing our recently developed NanoBiT technology-based biosensor as well as pseudotyped-virus infectivity assays. Specifically, we examine the mutational effects on RBD-ACE2 binding ability, efficacy of competitive inhibitors, as well as neutralizing antibody activity. We also look at the implications the mutations may have on virus transmissibility, host susceptibility, and the virus transmission path to humans. These critical determinants of virus-host interactions may provide more effective targets for ongoing vaccines, drug development, and potentially pave the way for determining the genetic variation underlying disease severity.


Assuntos
Enzima de Conversão de Angiotensina 2/química , Enzima de Conversão de Angiotensina 2/metabolismo , COVID-19/metabolismo , COVID-19/virologia , SARS-CoV-2/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Sequência de Aminoácidos , Enzima de Conversão de Angiotensina 2/genética , Anticorpos Neutralizantes/imunologia , Antivirais/farmacologia , Sítios de Ligação , COVID-19/imunologia , Células HEK293 , Interações entre Hospedeiro e Microrganismos , Humanos , Modelos Moleculares , Mutação , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Receptores Virais/química , Receptores Virais/metabolismo , SARS-CoV-2/efeitos dos fármacos , Alinhamento de Sequência , Tratamento Farmacológico da COVID-19
5.
Membranes (Basel) ; 10(9)2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32872641

RESUMO

The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic presents an urgent need for an effective vaccine. Molecular characterization of SARS-CoV-2 is critical to the development of effective vaccine and therapeutic strategies. In the present study, we show that the fusion of the SARS-CoV-2 spike protein receptor-binding domain to its transmembrane domain is sufficient to mediate trimerization. Our findings may have implications for vaccine development and therapeutic drug design strategies targeting spike trimerization. As global efforts for developing SARS-CoV-2 vaccines are rapidly underway, we believe this observation is an important consideration for identifying crucial epitopes of SARS-CoV-2.

6.
Cancers (Basel) ; 12(8)2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32722184

RESUMO

The Hippo pathway plays a critical role in tissue and organ growth under normal physiological conditions, and its dysregulation in malignant growth has made it an attractive target for therapeutic intervention in the fight against cancer. To date, its complex signaling mechanisms have made it difficult to identify strong therapeutic candidates. Hippo signaling is largely carried out by two main activated signaling pathways involving receptor tyrosine kinases (RTKs)-the RTK/RAS/PI3K and the RTK-RAS-MAPK pathways. However, several RTKs have also been shown to regulate this pathway to engage downstream Hippo effectors and ultimately influence cell proliferation. In this text, we attempt to review the diverse RTK signaling pathways that influence Hippo signaling in the context of oncogenesis.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...