scholarly journals Designer nanocarriers for navigating the systemic delivery of oncolytic viruses

Nanomedicine ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 93-110 ◽  
Author(s):  
Faith Howard ◽  
Munitta Muthana

Nanotechnology is paving the way for new carrier systems designed to overcome the greatest challenges of oncolytic virotherapy; systemic administration and subsequent implications of immune responses and specific cell binding and entry. Systemic administration of oncolytic agents is vital for disseminated neoplasms, however transition of nanoparticles (NP) to virotherapy has yielded modest results. Their success relies on how they navigate the merry-go-round of often-contradictory phases of NP delivery: circulatory longevity, tissue permeation and cellular interaction, with many studies postulating design features optimal for each phase. This review discusses the optimal design of NPs for the transport of oncolytic viruses within these phases, to determine whether improved virotherapeutic efficacy lies in the pharmacokinetic/pharmacodynamics characteristics of the NP–oncolytic viruses complexes rather than manipulation of the virus and targeting ligands.

Cancers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 5452
Author(s):  
Masmudur M. Rahman ◽  
Grant McFadden

Cancer remains a leading cause of death worldwide. Despite many signs of progress, currently available cancer treatments often do not provide desired outcomes for too many cancers. Therefore, newer and more effective therapeutic approaches are needed. Oncolytic viruses (OVs) have emerged as a novel cancer treatment modality, which selectively targets and kills cancer cells while sparing normal ones. In the past several decades, many different OV candidates have been developed and tested in both laboratory settings as well as in cancer patient clinical trials. Many approaches have been taken to overcome the limitations of OVs, including engineering OVs to selectively activate anti-tumor immune responses. However, newer approaches like the combination of OVs with current immunotherapies to convert “immune-cold” tumors to “immune-hot” will almost certainly improve the potency of OVs. Here, we discuss strategies that are explored to further improve oncolytic virotherapy.


2021 ◽  
Author(s):  
Nasser Hashemi Goradel ◽  
Arezoo Alizadeh ◽  
Shahnaz Hosseinzadeh ◽  
Mitra Taghipour ◽  
Zeinab Ghesmati ◽  
...  

Oncolytic virotherapy has currently emerged as a powerful therapeutic approach in cancer treatment. Although the history of using viruses goes back to the early 20th century, the approval of talimogene laherparepvec (T-VEC) in 2015 increased interest in oncolytic viruses (OVs). OVs are multifaceted biotherapeutic agents because they replicate in and kill tumor cells and augment immune responses by releasing immunostimulatory molecules from lysed cells. Despite promising results, some limitations hinder the efficacy of oncolytic virotherapy. The delivery challenges and the upregulation of checkpoints following oncolytic virotherapy also mediate resistance to OVs by diminishing immune responses. Furthermore, the localization of receptors of viruses in the tight junctions, interferon responses, and the aberrant expression of genes involved in the cell cycle of the virus, including their infection and replication, reduce the efficacy of OVs. In this review, we present different mechanisms of resistance to OVs and strategies to overcome them.


Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 588
Author(s):  
Ke-Tao Jin ◽  
Wen-Lin Du ◽  
Yu-Yao Liu ◽  
Huan-Rong Lan ◽  
Jing-Xing Si ◽  
...  

Oncolytic virotherapy (OVT) is a promising approach in cancer immunotherapy. Oncolytic viruses (OVs) could be applied in cancer immunotherapy without in-depth knowledge of tumor antigens. The capability of genetic modification makes OVs exciting therapeutic tools with a high potential for manipulation. Improving efficacy, employing immunostimulatory elements, changing the immunosuppressive tumor microenvironment (TME) to inflammatory TME, optimizing their delivery system, and increasing the safety are the main areas of OVs manipulations. Recently, the reciprocal interaction of OVs and TME has become a hot topic for investigators to enhance the efficacy of OVT with less off-target adverse events. Current investigations suggest that the main application of OVT is to provoke the antitumor immune response in the TME, which synergize the effects of other immunotherapies such as immune-checkpoint blockers and adoptive cell therapy. In this review, we focused on the effects of OVs on the TME and antitumor immune responses. Furthermore, OVT challenges, including its moderate efficiency, safety concerns, and delivery strategies, along with recent achievements to overcome challenges, are thoroughly discussed.


Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3386
Author(s):  
Bart Spiesschaert ◽  
Katharina Angerer ◽  
John Park ◽  
Guido Wollmann

The focus of treating cancer with oncolytic viruses (OVs) has increasingly shifted towards achieving efficacy through the induction and augmentation of an antitumor immune response. However, innate antiviral responses can limit the activity of many OVs within the tumor and several immunosuppressive factors can hamper any subsequent antitumor immune responses. In recent decades, numerous small molecule compounds that either inhibit the immunosuppressive features of tumor cells or antagonize antiviral immunity have been developed and tested for. Here we comprehensively review small molecule compounds that can achieve therapeutic synergy with OVs. We also elaborate on the mechanisms by which these treatments elicit anti-tumor effects as monotherapies and how these complement OV treatment.


Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1294
Author(s):  
Yogesh R. Suryawanshi ◽  
Autumn J. Schulze

Glioblastoma is one of the most difficult tumor types to treat with conventional therapy options like tumor debulking and chemo- and radiotherapy. Immunotherapeutic agents like oncolytic viruses, immune checkpoint inhibitors, and chimeric antigen receptor T cells have revolutionized cancer therapy, but their success in glioblastoma remains limited and further optimization of immunotherapies is needed. Several oncolytic viruses have demonstrated the ability to infect tumors and trigger anti-tumor immune responses in malignant glioma patients. Leading the pack, oncolytic herpesvirus, first in its class, awaits an approval for treating malignant glioma from MHLW, the federal authority of Japan. Nevertheless, some major hurdles like the blood–brain barrier, the immunosuppressive tumor microenvironment, and tumor heterogeneity can engender suboptimal efficacy in malignant glioma. In this review, we discuss the current status of malignant glioma therapies with a focus on oncolytic viruses in clinical trials. Furthermore, we discuss the obstacles faced by oncolytic viruses in malignant glioma patients and strategies that are being used to overcome these limitations to (1) optimize delivery of oncolytic viruses beyond the blood–brain barrier; (2) trigger inflammatory immune responses in and around tumors; and (3) use multimodal therapies in combination to tackle tumor heterogeneity, with an end goal of optimizing the therapeutic outcome of oncolytic virotherapy.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amanda W. K. AuYeung ◽  
Robert C. Mould ◽  
Ashley A. Stegelmeier ◽  
Jacob P. van Vloten ◽  
Khalil Karimi ◽  
...  

AbstractVaccination can prevent viral infections via virus-specific T cells, among other mechanisms. A goal of oncolytic virotherapy is replication of oncolytic viruses (OVs) in tumors, so pre-existing T cell immunity against an OV-encoded transgene would seem counterproductive. We developed a treatment for melanomas by pre-vaccinating against an oncolytic vesicular stomatitis virus (VSV)-encoded tumor antigen. Surprisingly, when the VSV-vectored booster vaccine was administered at the peak of the primary effector T cell response, oncolysis was not abrogated. We sought to determine how oncolysis was retained during a robust T cell response against the VSV-encoded transgene product. A murine melanoma model was used to identify two mechanisms that enable this phenomenon. First, tumor-infiltrating T cells had reduced cytopathic potential due to immunosuppression. Second, virus-induced lymphopenia acutely removed virus-specific T cells from tumors. These mechanisms provide a window of opportunity for replication of oncolytic VSV and rationale for a paradigm change in oncolytic virotherapy, whereby immune responses could be intentionally induced against a VSV-encoded melanoma-associated antigen to improve safety without abrogating oncolysis.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A758-A758
Author(s):  
Duong Nguyen ◽  
Alberto Gomez ◽  
Forrest Neuharth ◽  
Ashley Alamillo ◽  
Thomas Herrmann ◽  
...  

BackgroundOncolytic virotherapy has been recognized as a promising new therapy for cancer for decades but only few viruses have been approved worldwide. The therapeutic potential of oncolytic viruses can be severely restricted by innate and adaptive immune barriers making oncolytic virus clinically inefficient. To overcome this obstacle, we utilized adipose-derived stem cells (AD-MSC) loaded with tumor selective CAL1 oncolytic vaccinia virus to generate a new therapeutic agent called SNV1 (SuperNova-1).MethodsCAL1 vaccinia virus was tested for its ability to replicate and selectively kill various human cancer cell lines in vitro and in vivo. Additionally, CAL1 was loaded into adipose-derived mesenchymal stem cells to generate SuperNova1 (SNV1). Both CAL1 and SNV1 were tested for their ability to kill cancer cells in the presence of active complement and neutralizing antibodies in cell culture as well as in mice. Immune cell infiltration of the treated and untreated tumors was analyzed by flow cytometry.ResultsCAL1 showed preferential amplification and killed various tested human (PC3, FaDu, MDA-MB-231, RPMI) and mouse cancer cells (CT26, EMT6, TRAMP-C2, RM1). In animals, CAL1 caused tumor regression in PC3 and CT26 mouse models without signs of toxicity. SNV1 significantly enhanced protection of CAL1 virus from clearance by the immune system as compared to naked CAL1 virus, leading to higher therapeutic efficacy in animals. Five days after SNV1 administration, tumor infiltrating lymphocytes (TILs) from both treated and untreated tumors showed increased CD4 and CD8 T-cell infiltrations. Importantly, we documented a decreased frequency of Tregs, and improved effector to Treg ratios, which was associated with inhibition of tumor growth at the treated tumor site and also at distant untreated sites.ConclusionsCAL1 is potentially used as an oncolytic agent. In addition, SNV1 cell-based platform protects and potentiates oncolytic vaccinia virus by circumventing humoral innate and adaptive immune barriers, resulting in enhanced oncolytic virotherapy. Particularly, SNV1 provided instantly active viral particles for immediate infection and simultaneous release of therapeutic proteins in the injected tumors.


Blood ◽  
2003 ◽  
Vol 101 (3) ◽  
pp. 807-814 ◽  
Author(s):  
James W. Lillard ◽  
Udai P. Singh ◽  
Prosper N. Boyaka ◽  
Shailesh Singh ◽  
Dennis D. Taub ◽  
...  

AbstractMacrophage inflammatory protein-1α (MIP-1α) and MIP-1β are distinct but highly homologous CC chemokines produced by a variety of host cells in response to various external stimuli and share affinity for CCR5. To better elucidate the role of these CC chemokines in adaptive immunity, we have characterized the affects of MIP-1α and MIP-1β on cellular and humoral immune responses. MIP-1α stimulated strong antigen (Ag)–specific serum immunoglobulin G (IgG) and IgM responses, while MIP-1β promoted lower IgG and IgM but higher serum IgA and IgE antibody (Ab) responses. MIP-1α elevated Ag-specific IgG1 and IgG2b followed by IgG2a and IgG3 subclass responses, while MIP-1β only stimulated IgG1 and IgG2b subclasses. Correspondingly, MIP-1β produced higher titers of Ag-specific mucosal secretory IgA Ab levels when compared with MIP-1α. Splenic T cells from MIP-1α– or MIP-1β–treated mice displayed higher Ag-specific Th1 (interferon-γ [IFN-γ]) as well as selective Th2 (interleukin-5 [IL-5] and IL-6) cytokine responses than did T cells from control groups. Interestingly, mucosally derived T cells from MIP-1β–treated mice displayed higher levels of IL-4 and IL-6 compared with MIP-1α–treated mice. However, MIP-1α effectively enhanced Ag-specific cell-mediated immune responses. In correlation with their selective effects on humoral and cellular immune responses, these chemokines also differentially attract CD4+ versus CD8+ T cells and modulate CD40, CD80, and CD86 expressed by B220+ cells as well as CD28, 4-1BB, and gp39 expression by CD4+ and CD8+ T cells in a dose-dependent fashion. Taken together, these studies suggest that these CC chemokines differentially enhance mucosal and serum humoral as well as cellular immune responses.


Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 228 ◽  
Author(s):  
Tereza Brachtlova ◽  
Victor van Beusechem

Oncolytic virus therapy of cancer is an actively pursued field of research. Viruses that were once considered as pathogens threatening the wellbeing of humans and animals alike are with every passing decade more prominently regarded as vehicles for genetic and oncolytic therapies. Oncolytic viruses kill cancer cells, sparing healthy tissues, and provoke an anticancer immune response. Among these viruses, recombinant adenoviruses are particularly attractive agents for oncolytic immunotherapy of cancer. Different approaches are currently examined to maximize their therapeutic effect. Here, knowledge of virus–host interactions may lead the way. In this regard, viral and host microRNAs are of particular interest. In addition, cellular factors inhibiting viral replication or dampening immune responses are being discovered. Therefore, applying RNA interference is an attractive approach to strengthen the anticancer efficacy of oncolytic viruses gaining attention in recent years. RNA interference can be used to fortify the virus’ cancer cell-killing and immune-stimulating properties and to suppress cellular pathways to cripple the tumor. In this review, we discuss different ways of how RNA interference may be utilized to increase the efficacy of oncolytic adenoviruses, to reveal their full potential.


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