@article{TsonevaMinevFrentzenetal.2017, author = {Tsoneva, Desislava and Minev, Boris and Frentzen, Alexa and Zhang, Qian and Wege, Anja K. and Szalay, Aladar A.}, title = {Humanized Mice with Subcutaneous Human Solid Tumors for Immune Response Analysis of Vaccinia Virus-Mediated Oncolysis}, series = {Molecular Therapy Oncolytics}, volume = {5}, journal = {Molecular Therapy Oncolytics}, doi = {10.1016/j.omto.2017.03.001}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170786}, pages = {41-61}, year = {2017}, abstract = {Oncolytic vaccinia virus (VACV) therapy is an alternative cancer treatment modality that mediates targeted tumor destruction through a tumor-selective replication and an induction of anti-tumor immunity. We developed a humanized tumor mouse model with subcutaneous human tumors to analyze the interactions of VACV with the developing tumors and human immune system. A successful systemic reconstitution with human immune cells including functional T cells as well as development of tumors infiltrated with human T and natural killer (NK) cells was observed. We also demonstrated successful in vivo colonization of such tumors with systemically administered VACVs. Further, a new recombinant GLV-1h376 VACV encoding for a secreted human CTLA4-blocking single-chain antibody (CTLA4 scAb) was tested. Surprisingly, although proving CTLA4 scAb's in vitro binding ability and functionality in cell culture, beside the significant increase of CD56\(^{bright}\) NK cell subset, GLV-1h376 was not able to increase cytotoxic T or overall NK cell levels at the tumor site. Importantly, the virus-encoded β-glucuronidase as a measure of viral titer and CTLA4 scAb amount was demonstrated. Therefore, studies in our "patient-like" humanized tumor mouse model allow the exploration of newly designed therapy strategies considering the complex relationships between the developing tumor, the oncolytic virus, and the human immune system.}, 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} } @article{SzalayWeibelHofmannetal.2013, author = {Szalay, Aladar A and Weibel, Stephanie and Hofmann, Elisabeth and Basse-Luesebrink, Thomas Christian and Donat, Ulrike and Seubert, Carolin and Adelfinger, Marion and Gnamlin, Prisca and Kober, Christina and Frentzen, Alexa and Gentschev, Ivaylo and Jakob, Peter Michael}, title = {Treatment of malignant effusion by oncolytic virotherapy in an experimental subcutaneous xenograft model of lung cancer}, series = {Journal of Translational Medicine}, journal = {Journal of Translational Medicine}, doi = {doi:10.1186/1479-5876-11-106}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96016}, year = {2013}, abstract = {Background Malignant pleural effusion (MPE) is associated with advanced stages of lung cancer and is mainly dependent on invasion of the pleura and expression of vascular endothelial growth factor (VEGF) by cancer cells. As MPE indicates an incurable disease with limited palliative treatment options and poor outcome, there is an urgent need for new and efficient treatment options. Methods In this study, we used subcutaneously generated PC14PE6 lung adenocarcinoma xenografts in athymic mice that developed subcutaneous malignant effusions (ME) which mimic pleural effusions of the orthotopic model. Using this approach monitoring of therapeutic intervention was facilitated by direct observation of subcutaneous ME formation without the need of sacrificing mice or special imaging equipment as in case of MPE. Further, we tested oncolytic virotherapy using Vaccinia virus as a novel treatment modality against ME in this subcutaneous PC14PE6 xenograft model of advanced lung adenocarcinoma. Results We demonstrated significant therapeutic efficacy of Vaccinia virus treatment of both advanced lung adenocarcinoma and tumor-associated ME. We attribute the efficacy to the virus-mediated reduction of tumor cell-derived VEGF levels in tumors, decreased invasion of tumor cells into the peritumoral tissue, and to viral infection of the blood vessel-invading tumor cells. Moreover, we showed that the use of oncolytic Vaccinia virus encoding for a single-chain antibody (scAb) against VEGF (GLAF-1) significantly enhanced mono-therapy of oncolytic treatment. Conclusions Here, we demonstrate for the first time that oncolytic virotherapy using tumor-specific Vaccinia virus represents a novel and promising treatment modality for therapy of ME associated with advanced lung cancer.}, subject = {Lungenkrebs}, language = {en} } @article{HaddadSocciChenetal.2016, author = {Haddad, Dana and Socci, Nicholas and Chen, Chun-Hao and Chen, Nanhai G and Zhang, Qian and Carpenter, Susanne G and Mittra, Arjun and Szalay, Aladar A and Fong, Yuman}, title = {Molecular network, pathway, and functional analysis of-time dependent gene changes associated with pancreatic cancer susceptibility to oncolytic vaccinia virotherapy}, series = {Molecular Therapy — Oncolytics}, volume = {3}, journal = {Molecular Therapy — Oncolytics}, doi = {10.1038/mto.2016.8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165855}, pages = {16008}, year = {2016}, abstract = {Background: Pancreatic cancer is a fatal disease associated with resistance to conventional therapies. This study aimed to determine changes in gene expression patterns associated with infection and susceptibility of pancreatic cancer cells to an oncolyticvaccinia virus, GLV-1h153, carrying the human sodium iodide symporter for deep tissue imaging of virotherapy. Methods: Replication and susceptibility of pancreatic adenocarcinoma PANC-1 cells to GLV-1h153 was confirmed with replication and cytotoxicity assays. PANC-1 cells were then infected with GLV-1h153 and near-synchronous infection confirmed via flow cytometry of viral-induced green fluorescent protein (GFP) expression. Six and 24 hours after infection, three samples of each time point were harvested, and gene expression patterns assessed using HG-U133A cDNA microarray chips as compared to uninfected control. Differentially expressed genes were identified using Bioconductor LIMMA statistical analysis package. A fold change of 2.0 or above was used as a cutoff, with a P value of 0.01. The gene list was then analyzed using Ingenuity Pathways Analysis software. Results: Differential gene analysis revealed a total of 12,412 up- and 11,065 downregulated genes at 6 and 24 hours postinfection with GLV-1h153 as compared to control. At 6 hours postinfection. A total of 139 genes were either up or downregulated >twofold (false discovery rate < 0.05), of which 124 were mapped by Ingenuity Pathway Analysis (IPA). By 24 hours postinfection, a total of 5,698 genes were identified and 5,563 mapped by IPA. Microarray revealed gene expression changes, with gene networks demonstrating downregulation of processes such as cell death, cell cycle, and DNA repair, and upregulation of infection mechanisms (P < 0.01). Six hours after infection, gene changes involved pathways such as HMGB-1, interleukin (IL)-2, IL-6, IL-8, janus kinase/signal tranducer and activator of transcription (JAK/STAT), interferon, and ERK 5 signaling (P < 0.01). By 24 hours, prominent pathways included P53- and Myc-induced apoptotic processes, pancreatic adenocarcinoma signaling, and phosphoinositide 3-kinase/v-akt murine thymoma vial oncogene homolog 1 (PI3/AKT) pathways. Conclusions: Our study reveals the ability to assess time-dependent changes in gene expression patterns in pancreatic cancer cells associated with infection and susceptibility to vaccinia viruses. This suggests that molecular assays may be useful to develop safer and more efficacious oncolyticvirotherapies and support the idea that these treatments may target pathways implicated in pancreatic cancer resistance to conventional therapies.}, language = {en} }