Browsing by Subject "oncolytic virus"

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  • Cervera-Carrascon, Victor; Quixabeira, Dafne C. A.; Santos, Joao M.; Havunen, Riikka; Milenova, Ioanna; Verhoeff, Jan; Heinio, Camilla; Zafar, Sadia; Garcia-Vallejo, Juan J.; van Beusechem, Victor W.; de Gruijl, Tanja D.; Kalervo, Aino; Sorsa, Suvi; Kanerva, Anna; Hemminki, Akseli (2021)
    Immune checkpoint inhibitors such as anti-PD-1 have revolutionized the field of oncology over the past decade. Nevertheless, the majority of patients do not benefit from them. Virotherapy is a flexible tool that can be used to stimulate and/or recruit different immune populations. T-cell enabling virotherapy could enhance the efficacy of immune checkpoint inhibitors, even in tumors resistant to these inhibitors. The T-cell potentiating virotherapy used here consisted of adenoviruses engineered to express tumor necrosis factor alpha and interleukin-2 in the tumor microenvironment. To study virus efficacy in checkpoint-inhibitor resistant tumors, we developed an anti-PD-1 resistant melanoma model in vivo. In resistant tumors, adding virotherapy to an anti-PD-1 regimen resulted in increased survival (p=0.0009), when compared to anti-PD-1 monotherapy. Some of the animals receiving virotherapy displayed complete responses, which did not occur in the immune checkpoint-inhibitor monotherapy group. When adenoviruses were delivered into resistant tumors, there were signs of increased CD8 T-cell infiltration and activation, which - together with a reduced presence of M2 macrophages and myeloid-derived suppressor cells - could explain those results. T-cell enabling virotherapy appeared as a valuable tool to counter resistance to immune checkpoint inhibitors. The clinical translation of this approach could increase the number of cancer patients benefiting from immunotherapies.
  • Fusciello, Manlio; Fontana, Flavia; Tähtinen, Siri; Capasso, Cristian; Feola, Sara; da Silva Lopes Martins, Beatriz; Chiaro, Jacopo; Peltonen, Karita; Ylösmäki, Leena; Ylösmäki, Erkko; Hamdan Hissaoui, Firas; Kari, Otto K.; Ndika, Joseph; Alenius, Harri; Urtti, Arto; Hirvonen, Jouni T.; Santos, Hélder A.; Cerullo, Vincenzo (2019)
    Virus-based cancer vaccines are nowadays considered an interesting approach in the field of cancer immunotherapy, despite the observation that the majority of the immune responses they elicit are against the virus and not against the tumor. In contrast, targeting tumor associated antigens is effective, however the identification of these antigens remains challenging. Here, we describe ExtraCRAd, a multi-vaccination strategy focused on an oncolytic virus artificially wrapped with tumor cancer membranes carrying tumor antigens. We demonstrate that ExtraCRAd displays increased infectivity and oncolytic effect in vitro and in vivo. We show that this nanoparticle platform controls the growth of aggressive melanoma and lung tumors in vivo both in preventive and therapeutic setting, creating a highly specific anti-cancer immune response. In conclusion, ExtraCRAd might serve as the next generation of personalized cancer vaccines with enhanced features over standard vaccination regimens, representing an alternative way to target cancer.
  • Havunen, Riikka; Kalliokoski, Riikka; Siurala, Mikko; Sorsa, Suvi; Santos, Joao M.; Cervera-Carrascon, Victor; Anttila, Marjukka; Hemminki, Akseli (2021)
    Oncolytic viruses provide a biologically multi-faceted treatment option for patients who cannot be cured with currently available treatment options. We constructed an oncolytic adenovirus, TILT-123, to support T-cell therapies and immune checkpoint inhibitors in solid tumors. Adenoviruses are immunogenic by nature, are easy to produce in large quantities, and can carry relatively large transgenes. They are the most commonly used gene therapy vectors and are well tolerated in patients. TILT-123 expresses two potent cytokines, tumor necrosis factor alpha and interleukin-2, to stimulate especially the T-cell compartment in the tumor microenvironment. Before entering clinical studies, the safety and biodistribution of TILT-123 was studied in Syrian hamsters and in mice. The results show that TILT-123 is safe in animals as monotherapy and in combination with an immune checkpoint inhibitor anti-PD-1. The virus treatment induces acute changes in circulating immune cell compartments, but the levels return to normal by the middle of the treatment period. The virus is rapidly cleared from healthy tissues, and it does not cause damage to vital organs. The results support the initiation of a phase 1 dose-escalation trial, where melanoma patients receiving a tumor-infiltrating lymphocyte therapy are treated with TILT-123 (NCT04217473).
  • Juntunen, Maiju (Helsingin yliopisto, 2020)
    Cancer immunotherapy refers to therapy strategies that utilise the mechanisms of the immune system to treat cancer patients. The benefits of the approach include the possibility for specific targeting and utilisation of the host immune system. The treatment methods include cancer vaccines, oncolytic viruses (OVs), cell-based immunotherapies and antibodies. The interplay between the cancer and the immune system has been observed crucial for the progress of the cancer and the success of immunotherapies. An immune inflamed tumour microenvironment has been observed beneficial for the success of several therapy methods. Many immunotherapy methods rely on detecting tumour specific antigens that are used to guide the therapy agent to the target site. This strategy poses challenges when considering tumour immune evasion mechanisms, which can cause downregulation of target antigens, and heterogeneity of tumour cells and patients. OVs have the advantage of not requiring predetermined target structures to exert their effect to the tumour cells. They cause direct tumour cell lysis and induce immune responses, and may be modified to express additional genes, including immunostimulatory agents. However, virus-related immunosuppressive mechanisms and a rapid viral clearance may limit their effects. A Western Reserve (WR) Vaccinia virus (VACV) is a highly oncolytic virus strain but the virus has been observed to suppress the function of the cyclic guanosine monophosphate adenosine monophosphate synthase – stimulator of interferon genes (cGAS STING) innate immune pathway which has been shown to have a significant role in anti-tumour immune responses. The aim of this study was to create a WR VACV encoding a dominantly active (D A) STING and to determine whether the virus is capable of activating the cGAS STING pathway. The effects were compared to a corresponding virus vvdd tdTomato that does not have the STING encoding gene. The pathogenicity of viruses was controlled by a double deletion of the thymidine kinase and vaccinia growth factor genes which restricts the virus replication to tumour cells. Transgene fragments were cloned from template plasmids by polymerase chain reactions (PCRs) and joined together in a Gibson Assembly (GA) reaction to form a STING-P2A-eGFP gene insert. The insert was attached to a shuttle vector pSC65-tdTomato by restriction enzyme digestion, ligation and transformation in Escherichia coli. The correct transgene plasmid construct was verified by Sanger sequencing and PCRs. The transgene was inserted to a modified WR VACV vvdd-tdTomato-hDAI by a homologous recombination. The newly created VVdd STING-P2A-eGFP virus was purified by plaque purification. The STING protein expression was studied by an immunocytochemistry (ICC) assay. The immune signalling pathway activation was examined by testing nuclear factor kappa-light chain-enhancer of activated B cells (NF-κB) activation in RAW-Blue cells and dendritic cell activation and maturation in JAWS II cells. The cell viability after iinfection was studied with four cell lines; A549, B16-F10, HEK293 and MB49. The D-A STING expressing virus was produced successfully. The ICC experiment verified the capability of the VVdd STING-P2A eGFP to produce the STING protein in the infected cells. The preliminary findings indicate that the VVdd STING-P2A-eGFP virus activates the NF-κB signalling in the RAW-Blue cells and that the activation is dependent on the STING expression. The activation level is relative to the infection concentration at MOI range 0,001 to 0,1. The findings suggest that the VVdd-STING-eGFP virus can induce innate immune signalling via the STING pathway. The reference virus did not activate the signalling. The in vitro experiments also indicated that the STING virus may induce DC activation and maturation. We observed a trend of CD86 and CD40 expression upregulation on the JAWS II DCs. The effects to the cell viability were inconclusive. More studies should be conducted to verify the results. The effects of the virus should be studied in more advanced cancer models that take into account the complexity of the immune system. These preliminary results indicate the that the VVdd-STING-P2A-eGFP virus could stimulate the immune signalling through the STING pathway.
  • Heiniö, Camilla; Sorsa, Suvi; Siurala, Mikko; Grönberg-Vähä-Koskela, Susanna; Havunen, Riikka; Haavisto, Elina; Koski, Anniina; Hemminki, Otto; Zafar, Sadia; Cervera-Carrascon, Victor; Munaro, Eleonora; Kanerva, Anna; Hemminki, Akseli (2019)
    After the discovery and characterization of the adenovirus in the 1950s, this prevalent cause of the common cold and other usually mild diseases has been modified and utilized in biomedicine in several ways. To date, adenoviruses are the most frequently used vectors and therapeutic (e.g., oncolytic) agents with a number of beneficial features. They infect both dividing and nondividing cells, enable high-level, transient protein expression, and are easy to amplify to high concentrations. As an important and versatile research tool, it is of essence to understand the limits and advantages that genetic modification of adenovirus vectors may entail. Therefore, a retrospective analysis was performed of adenoviral gene therapy constructs produced in the same laboratory with similar methods. The aim was to assess the impact of various modifications on the physical and functional titer of the virus. It was found that genome size (designed within "the 105% golden rule") did not significantly affect the physical titer of the adenovirus preparations, regardless of the type of transgene (e.g., immunostimulatory vs. other), number of engineered changes, and size of the mutated virus genome. One statistically significant exception was noted, however. Chimeric adenoviruses (5/3) had a slightly lower physical titer compared to Ad5-based viruses, although a trend for the opposite was true for functional titers. Thus, 5/3 chimeric viruses may in fact be appealing from a safety versus efficacy viewpoint. Armed viruses had lower functional and physical titers than unarmed viruses, while five genomic modifications started to decrease functional titer. Importantly, even highly modified armed viruses generally had good titers compatible with clinical testing. In summary, this paper shows the plasticity of adenovirus for various vector, oncolytic, and armed oncolytic uses. These results inform future generations of adenovirus-based drugs for human use. This information is directly transferable to academic laboratories and the biomedical industry involved in vector design and production optimization.
  • Quixabeira, Dafne C.A.; Zafar, Sadia; Santos, Joao M.; Cervera-Carrascon, Victor; Havunen, Riikka; Kudling, Tatiana V.; Basnet, Saru; Anttila, Marjukka; Kanerva, Anna; Hemminki, A. (2021)
  • Santos, João Manuel; Heiniö, Camilla; Cervera-Carrascon, Victor; Quixabeira, Dafne C A; Siurala, Mikko; Havunen, Riikka; Butzow, Ralf; Zafar, Sadia; de Gruijl, Tanja; Lassus, Heini; Kanerva, Anna; Hemminki, Akseli (2020)
    BACKGROUND: Ovarian cancers often contain significant numbers of tumor-infiltrating lymphocytes (TILs) that can be readily harnessed for adoptive T-cell therapy (ACT). However, the immunosuppressive ovarian tumor microenvironment and lack of tumor reactivity in TILs can limit the effectiveness of the therapy. We hypothesized that by using an oncolytic adenovirus (Ad5/3-E2F-D24-hTNFa-IRES-hIL2; TILT-123) to deliver tumor necrosis factor alpha (TNFa) and interleukin-2 (IL-2), we could counteract immunosuppression, and enhance antitumor TIL responses in ovarian cancer (OVCA). METHODS: We established ex vivo tumor cultures freshly derived from patients with advanced OVCA and evaluated the effects of Ad5/3-E2F-D24-hTNFa-IRES-hIL2 or Ad5/3-E2F-D24 (the control virus without TNFa and IL-2) on TILs, cytokine response and tumor viability. Tumor reactivity was assessed by determining interferon gamma (IFNg) response of clinically relevant TILs towards autologous T-cell-depleted ex vivo tumor cultures pretreated with or without the aforementioned oncolytic adenoviruses. RESULTS: Treatment of ex vivo tumor cultures with Ad5/3-E2F-D24-hTNFa-IRES-hIL2 caused a substantial rise in proinflammatory signals: increased secretion of IFNg, CXCL10, TNFa and IL-2, and concomitant activation of CD4+ and CD8+ TILs. Potent tumor reactivity was seen, as clinically relevant TIL secreted high levels of IFNg in response to autologous T-cell-depleted ovarian ex vivo tumor cultures treated with Ad5/3-E2F-D24-hTNFa-IRES-hIL2. This phenomenon was independent of PD-L1 expression in tumor cells, a factor that determined the variability of IFNg responses seen in different patient samples. CONCLUSIONS: Overall, oncolytic adenovirus Ad5/3-E2F-D24-hTNFa-IRES-hIL2 was able to rewire the ovarian tumor microenvironment to accommodate heightened antitumor TIL reactivity. Such effects may improve the clinical effectiveness of ACT with TILs in patients with advanced OVCA.
  • Honkasalo, Oona (Helsingfors universitet, 2018)
    Cancer immunotherapies aim to target the immune defence mechanisms of the body specifically and efficiently against the tumour tissue. Cancer vaccines and oncolytic viruses are forms of active immunotherapies, which require patients having a properly functioning immune system. The vaccines are based on the administration of tumour antigens into the body to which the immune system reacts. However, often the response is not robust enough. The oncolytic viruses in turn kill the cancer cells which causes the release of antigens from the tumour tissue. Viruses usually elicit a strong immune response but sometimes it is targeted too much against the virus instead of the tumour. Oncolytic vaccine is a composition of an oncolytic virus and a cancer vaccine. Tumour antigens can be coded to the genome of the virus therefore, when the virus invades tumour cells they start to produce the antigens. Eventually the cancer cells are also destroyed due to viral replication. The antigens can be tumour-associated that is, they are expressed in healthy tissues too. Their usage is not always efficient which is why an interest towards utilizing tumour-specific antigens has been increased. Considering the expression of antigens, tumour tissue is very heterogenous and distinctive between patients. Hence, utilizing mutated patient unique neoantigens would enable the development of personalized tumour-specific oncolytic vaccines. Genetic modification of viruses is complicated thus, an easier way to insert the neoantigens to the virus has been invented. The developed oncolytic vaccine platform is called PeptiENV, and it is designed to use with enveloped viruses. The idea is to fuse tumour-specific antigens onto the envelope of the virus and eliminate the need of gene insertion. The aim of this study is to investigate in vivo the efficacy of PeptiENV in preventing tumour growth and eliciting a tumour-specific immune response. An object is also to observe survival times of the treated animals. Furthermore, the preservation of infectivity is studied in vitro. The research was executed with two potential oncolytic viruses, vaccinia virus (VACV) and herpes simplex virus type 1 (HSV-1). The PeptiENV complex was formed by using an artificial tumour antigen, ovalbumin epitope SIINFEKL, which was attached to the viral envelope with cell penetrating peptide (CPP) or cholesterol anchor. The preservation of infectivity was examined by measuring cell viability of PeptiENV infected cells. Animal experiments instead were performed with a mouse melanoma model created with B16-OVA cells, which express ovalbumin and therefore the antigen epitope SIINFEKL. PeptiENV was compared to control treatments which were virus, SIINFEKL peptide and complexation medium only. Treatments were administered as intratumoural injections. Tumour growth was followed by measuring the size of implanted tumours every other day. With flow cytometry, tumour-specific immune response was assessed by acquiring the relative amount of SIINFEKL-specific CD8+ T cells in the tumour tissue. Euthanizing dates were registered in order to observe the survival of the mice. According to the in vitro results, conjugation of peptides to the virus does not affect infectivity. In addition, the in vivo studies show that PeptiENV VACV CPP prevents tumour growth the most. Difference in tumour growth between PeptiENV VACV CPP and control treatments is significant. Mice injected with the same treatment also lived considerably longer than mice injected with virus, peptide or medium only. Also, PeptiENV HSV-1 hinders tumour growth distinctly more than virus only and slightly more than SIINFEKL only, but unfortunately it did not have an evident impact on the survival time. In both experiments, the PeptiENV treatment elicits the largest proportional amount of SIINFEKL-specific CD8+ T cells. In other words, PeptiENV engenders a tumour-specific immune response. In the PeptiENV VACV study the difference to control treatments is clearer than in the PeptiENV HSV-1 study. At present, the PeptiENV platforms performs better with VACV than HSV-1. With further investigations however, the results can be verified and improved. All in all, the results are encouraging. The PeptiENV platform shows great promise for being a part of personalized cancer immunotherapy developments in the future.
  • Santos, Joao; Heiniö, Camilla; Quixabeira, Dafne; Zafar, Sadia; Clubb, James; Pakola, Santeri; Cervera-Carrascon, Victor; Havunen, Riikka; Kanerva, Anna; Hemminki, Akseli (2021)
    Immunotherapy with tumor-infiltrating lymphocytes (TIL) or oncolytic adenoviruses, have shown promising results in cancer treatment, when used as separate therapies. When used in combination, the antitumor effect is synergistically potentiated due oncolytic adenovirus infection and its immune stimulating effects on T cells. Indeed, studies in hamsters have shown a 100% complete response rate when animals were treated with oncolytic adenovirus coding for TNFa and IL-2 (Ad5/3-E2F-D24-hTNFa-IRES-hIL2; TILT-123) and TIL therapy. In humans, one caveat with oncolytic virus therapy is that intratumoral injection has been traditionally preferred over systemic administration, for achieving sufficient virus concentrations in tumors, especially when neutralizing antibodies emerge. We have previously shown that 5/3 chimeric oncolytic adenovirus can bind to human lymphocytes for avoidance of neutralization. In this study, we hypothesized that incubation of oncolytic adenovirus (TILT-123) with TILs prior to systemic injection would allow delivery of virus to tumors. This approach would deliver both components in one self-amplifying product. TILs would help deliver TILT-123, whose replication will recruit more TILs and increase their cytotoxicity. In vitro, TILT-123 was seen binding efficiently to lymphocytes, supporting the idea of dual administration. We show in vivo in different models that virus could be delivered to tumors with TILs as carriers.
  • Heiniö, Camilla; Havunen, Riikka; Santos, Joao; de Lint, Klaas; Cervera-Carrascon, Victor; Kanerva, Anna; Hemminki, Akseli (2020)
    In order to break tumor resistance towards traditional treatments, we investigate the response of tumor and immune cells to a novel, cytokine-armed oncolytic adenovirus: Ad5/3-d24-E2F-hTNFa-IRES-hIL2 (also known as TILT-123 and OAd.TNFa-IL2). There are several pattern recognition receptors (PRR) that might mediate adenovirus-infection recognition. However, the role and specific effects of each PRR on the tumor microenvironment and treatment outcome remain unclear. Hence, the aim of this study was to investigate the effects of OAd.TNFa-IL2 infection on PRR-mediated danger- and pathogen-associated molecular pattern (DAMP and PAMP, respectively) signaling. In addition, we wanted to see which PRRs mediate an antitumor response and are therefore relevant for optimizing this virotherapy. We determined that OAd.TNFa-IL2 induced DAMP and PAMP release and consequent tumor microenvironment modulation. We show that the AIM2 inflammasome is activated during OAd.TNFa-IL2 virotherapy, thus creating an immunostimulatory antitumor microenvironment.