300 research outputs found
Oncolytic Immunotherapy: Can't Start a Fire Without a Spark
No full textRecent advances in cancer immunotherapy have renewed interest in oncolytic viruses (OVs) as a synergistic platform for the development of novel antitumor strategies. Cancer cells adopt multiple mechanisms to evade and suppress antitumor immune responses, essentially establishing a non-immunogenic ('cold') tumor microenvironment (TME), with poor T-cell infiltration and low mutational burden. Limitations to the efficacy of immunotherapy still exist, especially for a variety of solid tumors, where new approaches are necessary to overcome physical barriers in the TME and to mitigate adverse effects associated with current immunotherapeutics. OVs offer an attractive alternative by inducing direct oncolysis, immunogenic cell death, and immune stimulation. These multimodal mechanisms make OVs well suited to reprogram non-immunogenic tumors and TME into inflamed, immunogenic ('hot') tumors; enhanced release of tumor antigens by dying cancer cells is expected to augment T-cell infiltration, thereby eliciting potent antitumor immunity. Advances in virus engineering and understanding of tumor biology have allowed the optimization of OV-tumor selectivity, oncolytic potency, and immune stimulation. However, OV antitumor activity is likely to achieve its greatest potential as part of combinatorial strategies with other immune or cancer therapeutics
A Genome-Wide CRISPR-Cas9 Loss-of-Function Screening to Identify Host Restriction Factors Modulating Oncolytic Virotherapy
No full textOncolytic virotherapy represents an efficient immunotherapeutic approach for cancer treatment. Oncolytic viruses (OVs) promote antitumor responses through tumor-selective cell lysis and immune system activation. However, some tumor cell lines and primary tumors display resistance to therapy. Here we describe a protocol to identify novel host factors responsible for tumor resistance to oncolysis using an unbiased genome-wide CRISPR-Cas9 loss-of-function screening. Cas9-expressing tumor cells are transduced with a library of pooled single-guide RNA (sgRNA)-expressing lentiviruses that target all human genes to obtain a cell population where each cell is knocked out for a single gene. Upon OV infection, resistant cells survive, while sensitive cells die. The relative abundance of each genome-integrated sgRNA is measured by next-generation sequencing (NGS) in resistant and control cells. This protocol is amenable to uncover host factors involved in the resistance to different OVs in multiple tumor models
The Coronavirus pandemic - 2022: Viruses, variants & vaccines
No full textSince the beginning of the COVID-19 pandemic in 2019-2020, Cytokine & Growth Factor Reviews has published several Special Issues focused on the biology, pathogenesis and therapeutic options in the treatment of COVID-19 infection, including articles on the involvement of the chemokine system in the cytokine storm in COVID-19, intervention in the early stages of COVID-19 pneumonia, the therapeutic value of corticosteroid treatment, early clinical intervention with type 1 in-terferons, progress in vaccine development, and organ specific complications of COVID-19. By 2022, multiple highly efficacious vaccines are available and are being administered in countries around the world, therapeutic options have been clinically evaluated and approved, and SARS-CoV-2 has arguably become the most thoroughly studied virus in history. But, with progress has also come unanticipated problems - misinformation, anti-vaxxers, opposition to protective masks, and politically motivated interference disguised as knowledge. With this issue of CGFR, we continue to document the global coronavirus pandemic and provide an update on the emergence of viral variants, the global effort to administer vaccines and the impediments to progress posed by misinformation and anti-vaccine sentiment
Oncolytic virotherapy for pancreatic ductal adenocarcinoma: A glimmer of hope after years of disappointment?
No full textPancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and highly lethal malignancies. Existing therapeutic interventions have so far been unsuccessful in improving prognosis, and survival remains very poor. Oncolytic virotherapy represents a promising, yet not fully explored, alternative strategy for the treatment of PDAC. Oncolytic viruses (OVs) infect, replicate within and lyse tumor cells specifically and stimulate antitumor immune responses. Multiple challenges have hampered the efficacy of oncolytic virotherapy for PDAC, the most significant being the desmoplastic and immunosuppressive pancreatic tumor microenvironment (TME). The TME limits the access of therapeutic drugs and the infiltration of effector T cells and natural killer (NK) cells into the tumor mass. Additionally, cancer cells promote the secretion of immunosuppressive factors and develop mechanisms to evade the host immune system. Because of their oncolytic and immune-stimulating properties, OVs are the ideal candidates for counteracting the pancreatic immunosuppressive TME and for designing combination therapies that can be clinically exploited in clinical trials that seek to improve the prognosis of PDAC.Cellular mechanisms in basic and clinical gastroenterology and hepatolog
Virus-like particle – mediated delivery of the RIG-I agonist M8 induces a type I interferon response and protects cells against viral infection
No full textVirus-Like Particles (VLPs) are nanostructures that share conformation and self-assembly properties with viruses, but lack a viral genome and therefore the infectious capacity. In this study, we produced VLPs by co-expression of VSV glycoprotein (VSV-G) and HIV structural proteins (Gag, Pol) that incorporated a strong sequence-optimized 5’ppp-RNA RIG-I agonist, termed M8. Treatment of target cells with VLPs-M8 generated an antiviral state that conferred resistance against multiple viruses. Interestingly, treatment with VLPs-M8 also elicited a therapeutic effect by inhibiting ongoing viral replication in previously infected cells. Finally, the expression of SARS-CoV-2 Spike glycoprotein on the VLP surface retargeted VLPs to ACE2 expressing cells, thus selectively blocking viral infection in permissive cells. These results highlight the potential of VLPs-M8 as a therapeutic and prophylactic vaccine platform. Overall, these observations indicate that the modification of VLP surface glycoproteins and the incorporation of nucleic acids or therapeutic drugs, will permit modulation of particle tropism, direct specific innate and adaptive immune responses in target tissues, and boost immunogenicity while minimizing off-target effects
The global impact of the coronavirus pandemic
No full textThe coronavirus pandemic has engulfed the nations of the world for the first five months of 2020 and altered the pace, fabric and nature of our lives. In this overview accompanying the Special Issue of Cytokine & Growth Factor Reviews, we examine some of the many social and scientific issues impacted by SARS-CoV2 - personal lives, economy, scientific communication, the environment. International members of Istituto Pasteur in Rome and INITIATE, the Marie Curie Training Network reflect on the lasting global impact of the coronavirus pandemic.Medical Microbiolog
Phorbol ester-mediated NF-Kappa-B transactivation is selectively inhibited by taxol
No full textRecently, NF-kappaB activation has been shown to be directly influenced by the cytoskeletal environment. In an attempt to better understand and characterize cytoskeletal regulation of NF-kappaB a series of experiments were designed to determine whether the microtubule (MT) stabilizing agent taxol could affect NF-kappaB activation in the presence of different NF-kappaB inducers. Pretreatment of murine NIH 3T3 and human 293 cells with 5 muM taxol resulted in complete abolition of phorbol, 12 myristate, 13-acetate (PMA) mediated NF-kappaB activation including loss of DNA binding potential and reduced CAT reporter activity. Phosphorylation and turnover of IkappaBalpha was effectively abrogated in taxol pretreated COS-7 cells. However, taxol was not capable of preventing TNF-alpha induced NF-kappaB activation nor could taxol suppress IkappaBalpha inducible phosphorylation in TNF-alpha treated cells, suggesting TNF-alpha may function through a microtubule-independent pathway. In vitro kinase assays of PMA stimulated cells established that taxol could reduce activation of protein kinase C by 30%, establishing loss of PKC activity as a possible regulatory step in taxol-mediated suppression of NF-kappaB transactivation. Indirect immunofluorescence analysis revealed that PMA treated COS-7 cells underwent dramatic changes in cell morphology as well as depolymerization of MTs. These observations were similar to that seen for nocodazole treated cells, a known MT depolymerizing agent. In contrast, taxol blocked both nocodazole induced effects as well as PMA induced morphological changes. These findings establish a potential mechanism for taxol-mediated stability of MTs and inhibition of NF-kappaB activity, suggesting a link between the state of microtubule integrity and gene regulation
The permissibility of the practice of inscribing graffiti in Beverley Minster, with specific reference to the eastern side of the reredos
No full textThis thesis provides an understanding of the nature of the practice of inscribing graffiti on the eastern side of the reredos in Beverley Minster in the medieval and early modern periods. It focuses on the types of graffiti that were inscribed when the upper platform of the reredos supported the shrine of Saint John of Beverley from c.1330 to 1540. This study shows that in order to interpret the meaning and significance of the graffiti for the individuals who inscribed them, it needs to be placed in a context where writing on walls was accepted and acceptable to both the clergy and the laity. The different categories of graffiti on the eastern side of the reredos are described and examined in detail.A wide range of evidence are employed to provide a holistic interpretation of the rationale behind their inscription. Comparisons with the graffiti surviving in the nave at Beverley Minster; in parish churches situated within the Humber region; and in ecclesiastical buildings from other counties across England are drawn upon to facilitate a synthesis of the graffiti on the eastern side of the reredos. Literary evidence, numismatics and objects recorded by the Portable Antiquities Scheme (PAS) are sources of evidence drawn upon throughout to supplement the lack of contextual information, and to place the practice of inscribing graffiti into a wider religious, social and cultural context. Among the types of graffiti studied are textual inscriptions, crosses, religious symbols, ships, merchants' marks and figures. The different types of graffiti are contextualised in thematic discussions based upon two aspects of religious culture, which show how graffiti can be simultaneously devotional and superstitious. In the process, this study enhances our knowledge of the ways in which individuals interacted with the fabric of church buildings on a physical level
The permissibility of the practice of inscribing graffiti in Beverley Minster, with specific reference to the eastern side of the reredos
No full textThis thesis provides an understanding of the nature of the practice of inscribing graffiti on the eastern side of the reredos in Beverley Minster in the medieval and early modern periods. It focuses on the types of graffiti that were inscribed when the upper platform of the reredos supported the shrine of Saint John of Beverley from c.1330 to 1540. This study shows that in order to interpret the meaning and significance of the graffiti for the individuals who inscribed them, it needs to be placed in a context where writing on walls was accepted and acceptable to both the clergy and the laity. The different categories of graffiti on the eastern side of the reredos are described and examined in detail.A wide range of evidence are employed to provide a holistic interpretation of the rationale behind their inscription. Comparisons with the graffiti surviving in the nave at Beverley Minster; in parish churches situated within the Humber region; and in ecclesiastical buildings from other counties across England are drawn upon to facilitate a synthesis of the graffiti on the eastern side of the reredos. Literary evidence, numismatics and objects recorded by the Portable Antiquities Scheme (PAS) are sources of evidence drawn upon throughout to supplement the lack of contextual information, and to place the practice of inscribing graffiti into a wider religious, social and cultural context. Among the types of graffiti studied are textual inscriptions, crosses, religious symbols, ships, merchants' marks and figures. The different types of graffiti are contextualised in thematic discussions based upon two aspects of religious culture, which show how graffiti can be simultaneously devotional and superstitious. In the process, this study enhances our knowledge of the ways in which individuals interacted with the fabric of church buildings on a physical level
Inhibition of Dengue virus by novel inhibitors of RNA-dependent RNA polymerase and protease activities
No full textDengue virus (DENV) is the leading mosquito-transmitted viral infection in the world. With more than 390 million new infections annually, and up to 1 million clinical cases with severe disease manifestations, there is an urgent need to develop new antiviral agents that inhibit DENV infectivity.[1] Currently, no licensed antiviral drugs are available to block DENV infection and vector control efforts remain the only means to stop the spread of the infection.
In the present study, we focused our attention on the identification of potential anti-DENV inhibitors by targeting the enzymatic activities of the NS5 RdRp polymerase and NS3 protease, in vitro and in vivo. As part of a continuation of our studies,[2,3] we developed new pyrazole derivatives 1-3 as inhibitors of NS5 RdRp polymerase (Chart 1). Furthermore, virtual screening studies on the NS2B/NS3 protease led us to identify indole derivatives 4-5 as inhibitors of NS3 protease. New compounds exhibited anti-DENV replication activity without cytotoxicity; two compounds exhibited anti-DENV activity in ICR suckling mouse model of DENV infection. Interestingly, combination treatment with several compounds demonstrated a synergistic inhibitory effect on DENV replication.
References
[1] Wilder-Smith, A.; Ooi, E. E.; Vasudevan, S. G. et al. Curr. Infect. Dis. Rep. 2010, 12, 157-164. [2] Silvestri, R.; Cascio, M. G.; La Regina, G. et al. J. Med. Chem. 2008, 51, 1560-1576. [3] La Pietra, V.; La Regina, G.; Coluccia, A. et al. J. Med. Chem. 2013, 56, 10066-10078
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