@article{SturmHessWeibeletal.2012, author = {Sturm, Julia B. and Hess, Michael and Weibel, Stephanie and Chen, Nanhei G. and Yu, Yong A. and Zhang, Quian and Donat, Ulrike and Reiss, Cora and Gambaryan, Stepan and Krohne, Georg and Stritzker, Jochen and Szalay, Aladar A.}, title = {Functional hyper-IL-6 from vaccinia virus-colonized tumors triggers platelet formation and helps to alleviate toxicity of mitomycin C enhanced virus therapy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75224}, year = {2012}, abstract = {Background: Combination of oncolytic vaccinia virus therapy with conventional chemotherapy has shown promise for tumor therapy. However, side effects of chemotherapy including thrombocytopenia, still remain problematic. Methods: Here, we describe a novel approach to optimize combination therapy of oncolytic virus and chemotherapy utilizing virus-encoding hyper-IL-6, GLV-1h90, to reduce chemotherapy-associated side effects. Results: We showed that the hyper-IL-6 cytokine was successfully produced by GLV-1h90 and was functional both in cell culture as well as in tumor-bearing animals, in which the cytokine-producing vaccinia virus strain was well tolerated. When combined with the chemotherapeutic mitomycin C, the anti-tumor effect of the oncolytic virotherapy was significantly enhanced. Moreover, hyper-IL-6 expression greatly reduced the time interval during which the mice suffered from chemotherapy-induced thrombocytopenia. Conclusion: Therefore, future clinical application would benefit from careful investigation of additional cytokine treatment to reduce chemotherapy-induced side effects.}, subject = {Biologie}, language = {en} } @article{PatilGentschevNolteetal.2012, author = {Patil, Sandeep S. and Gentschev, Ivaylo and Nolte, Ingo and Ogilvie, Gregory and Szalay, Aladar A.}, title = {Oncolytic virotherapy in veterinary medicine: current status and future prospects for canine patients}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75128}, year = {2012}, abstract = {Oncolytic viruses refer to those that are able to eliminate malignancies by direct targeting and lysis of cancer cells, leaving non-cancerous tissues unharmed. Several oncolytic viruses including adenovirus strains, canine distemper virus and vaccinia virus strains have been used for canine cancer therapy in preclinical studies. However, in contrast to human studies, clinical trials with oncolytic viruses for canine cancer patients have not been reported. An 'ideal' virus has yet to be identified. This review is focused on the prospective use of oncolytic viruses in the treatment of canine tumors - a knowledge that will undoubtedly contribute to the development of oncolytic viral agents for canine cancer therapy in the future.}, subject = {Medizin}, language = {en} } @article{AdelfingerGentschevdeGuibertetal.2014, author = {Adelfinger, Marion and Gentschev, Ivaylo and de Guibert, Julio Grimm and Weibel, Stephanie and Langbein-Laugwitz, Johanna and H{\"a}rtl, Barbara and Escobar, Hugo Murua and Nolte, Ingo and Chen, Nanhai G. and Aguilar, Richard J. and Yu, Yong A. and Zhang, Qian and Frentzen, Alexa and Szalay, Aladar A.}, title = {Evaluation of a New Recombinant Oncolytic Vaccinia Virus Strain GLV-5b451 for Feline Mammary Carcinoma Therapy}, series = {PLoS ONE}, volume = {9}, journal = {PLoS ONE}, number = {8}, doi = {10.1371/journal.pone.0104337}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119387}, pages = {e104337}, year = {2014}, abstract = {Virotherapy on the basis of oncolytic vaccinia virus (VACV) infection is a promising approach for cancer therapy. In this study we describe the establishment of a new preclinical model of feline mammary carcinoma (FMC) using a recently established cancer cell line, DT09/06. In addition, we evaluated a recombinant vaccinia virus strain, GLV-5b451, expressing the anti-vascular endothelial growth factor (VEGF) single-chain antibody (scAb) GLAF-2 as an oncolytic agent against FMC. Cell culture data demonstrate that GLV-5b451 virus efficiently infected, replicated in and destroyed DT09/06 cancer cells. In the selected xenografts of FMC, a single systemic administration of GLV-5b451 led to significant inhibition of tumor growth in comparison to untreated tumor-bearing mice. Furthermore, tumor-specific virus infection led to overproduction of functional scAb GLAF-2, which caused drastic reduction of intratumoral VEGF levels and inhibition of angiogenesis. In summary, here we have shown, for the first time, that the vaccinia virus strains and especially GLV-5b451 have great potential for effective treatment of FMC in animal model.}, language = {en} } @article{KilincEhrigPessianetal.2016, author = {Kilinc, Mehmet Okyay and Ehrig, Klaas and Pessian, Maysam and Minev, Boris R. and Szalay, Aladar A.}, title = {Colonization of xenograft tumors by oncolytic vaccinia virus (VACV) results in enhanced tumor killing due to the involvement of myeloid cells}, series = {Journal of Translational Medicine}, volume = {14}, journal = {Journal of Translational Medicine}, number = {340}, doi = {10.1186/s12967-016-1096-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168914}, year = {2016}, abstract = {Background The mechanisms by which vaccinia virus (VACV) interacts with the innate immune components are complex and involve different mechanisms. iNOS-mediated NO production by myeloid cells is one of the central antiviral mechanisms and this study aims to investigate specifically whether iNOS-mediated NO production by myeloid cells, is involved in tumor eradication following the virus treatment. Methods Human colon adenocarcinoma (HCT-116) xenograft tumors were infected by VACV. Infiltration of iNOS\(^{+}\) myeloid cell population into the tumor, and virus titer was monitored following the treatment. Single-cell suspensions were stained for qualitative and quantitative flow analysis. The effect of different myeloid cell subsets on tumor growth and colonization were investigated by depletion studies. Finally, in vitro culture experiments were carried out to study NO production and tumor cell killing. Student's t test was used for comparison between groups in all of the experiments. Results Infection of human colon adenocarcinoma (HCT-116) xenograft tumors by VACV has led to recruitment of many CD11b\(^{+}\) ly6G\(^{+}\) myeloid-derived suppressor cells (MDSCs), with enhanced iNOS expression in the tumors, and to an increased intratumoral virus titer between days 7 and 10 post-VACV therapy. In parallel, both single and multiple rounds of iNOS-producing cell depletions caused very rapid tumor growth within the same period after virus injection, indicating that VACV-induced iNOS\(^{+}\) MDSCs could be an important antitumor effector component. A continuous blockade of iNOS by its specific inhibitor, L-NIL, showed similar tumor growth enhancement 7-10 days post-infection. Finally, spleen-derived iNOS+ MDSCs isolated from virus-injected tumor bearing mice produced higher amounts of NO and effectively killed HCT-116 cells in in vitro transwell experiments. Conclusions We initially hypothesized that NO could be one of the factors that limits active spreading of the virus in the cancerous tissue. In contrast to our initial hypothesis, we observed that PMN-MDSCs were the main producer of NO through iNOS and NO provided a beneficial antitumor effect, The results strongly support an important novel role for VACV infection in the tumor microenvironment. VACV convert tumor-promoting MDSCs into tumor-killing cells by inducing higher NO production.}, language = {en} } @article{CecilGentschevAdelfingeretal.2019, author = {Cecil, Alexander and Gentschev, Ivaylo and Adelfinger, Marion and Dandekar, Thomas and Szalay, Aladar A.}, title = {Vaccinia virus injected human tumors: oncolytic virus efficiency predicted by antigen profiling analysis fitted boolean models}, series = {Bioengineered}, volume = {10}, journal = {Bioengineered}, number = {1}, doi = {10.1080/21655979.2019.1622220}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200507}, pages = {190-196}, year = {2019}, abstract = {Virotherapy on the basis of oncolytic vaccinia virus (VACV) strains is a promising approach for cancer therapy. Recently, we showed that the oncolytic vaccinia virus GLV-1h68 has a therapeutic potential in treating human prostate and hepatocellular carcinomas in xenografted mice. In this study, we describe the use of dynamic boolean modeling for tumor growth prediction of vaccinia virus-injected human tumors. Antigen profiling data of vaccinia virus GLV-1h68-injected human xenografted mice were obtained, analyzed and used to calculate differences in the tumor growth signaling network by tumor type and gender. Our model combines networks for apoptosis, MAPK, p53, WNT, Hedgehog, the T-killer cell mediated cell death, Interferon and Interleukin signaling networks. The in silico findings conform very well with in vivo findings of tumor growth. Similar to a previously published analysis of vaccinia virus-injected canine tumors, we were able to confirm the suitability of our boolean modeling for prediction of human tumor growth after virus infection in the current study as well. In summary, these findings indicate that our boolean models could be a useful tool for testing of the efficacy of VACV-mediated cancer therapy already before its use in human patients.}, language = {en} } @article{PetrovGentschevVyalkovaetal.2020, author = {Petrov, Ivan and Gentschev, Ivaylo and Vyalkova, Anna and Elashry, Mohamed I. and Klymiuk, Michele C. and Arnhold, Stefan and Szalay, Aladar A.}, title = {Canine Adipose-Derived Mesenchymal Stem Cells (cAdMSCs) as a "Trojan Horse" in Vaccinia Virus Mediated Oncolytic Therapy against Canine Soft Tissue Sarcomas}, series = {Viruses}, volume = {12}, journal = {Viruses}, number = {7}, doi = {10.3390/v12070750}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236007}, year = {2020}, abstract = {Several oncolytic viruses (OVs) including various human and canine adenoviruses, canine distemper virus, herpes-simplex virus, reovirus, and members of the poxvirus family, such as vaccinia virus and myxoma virus, have been successfully tested for canine cancer therapy in preclinical and clinical settings. The success of the cancer virotherapy is dependent on the ability of oncolytic viruses to overcome the attacks of the host immune system, to preferentially infect and lyse cancer cells, and to initiate tumor-specific immunity. To date, several different strategies have been developed to overcome the antiviral host defense barriers. In our study, we used canine adipose-derived mesenchymal stem cells (cAdMSCs) as a "Trojan horse" for the delivery of oncolytic vaccinia virus Copenhagen strain to achieve maximum oncolysis against canine soft tissue sarcoma (CSTS) tumors. A single systemic administration of vaccinia virus-loaded cAdMSCs was found to be safe and led to the significant reduction and substantial inhibition of tumor growth in a CSTS xenograft mouse model. This is the first example that vaccinia virus-loaded cAdMSCs could serve as a therapeutic agent against CSTS tumors.}, language = {en} } @article{YeKeicherGentschevetal.2021, author = {Ye, Mingyu and Keicher, Markus and Gentschev, Ivaylo and Szalay, Aladar A.}, title = {Efficient selection of recombinant fluorescent vaccinia virus strains and rapid virus titer determination by using a multi-well plate imaging system}, series = {Biomedicines}, volume = {9}, journal = {Biomedicines}, number = {8}, issn = {2227-9059}, doi = {10.3390/biomedicines9081032}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245104}, year = {2021}, abstract = {Engineered vaccinia virus (VACV) strains are used extensively as vectors for the development of novel cancer vaccines and cancer therapeutics. In this study, we describe for the first time a high-throughput approach for both fluorescent rVACV generation and rapid viral titer measurement with the multi-well plate imaging system, IncuCyte\(^®\)S3. The isolation of a single, well-defined plaque is critical for the generation of novel recombinant vaccinia virus (rVACV) strains. Unfortunately, current methods of rVACV engineering via plaque isolation are time-consuming and laborious. Here, we present a modified fluorescent viral plaque screening and selection strategy that allows one to generally obtain novel fluorescent rVACV strains in six days, with a minimum of just four days. The standard plaque assay requires chemicals for fixing and staining cells. Manual plaque counting based on visual inspection of the cell culture plates is time-consuming. Here, we developed a fluorescence-based plaque assay for quantifying the vaccinia virus that does not require a cell staining step. This approach is less toxic to researchers and is reproducible; it is thus an improvement over the traditional assay. Lastly, plaque counting by virtue of a fluorescence-based image is very convenient, as it can be performed directly on the computer.}, language = {en} }