Browsing by Subject "gene therapy"

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  • Albert, Katrina; Voutilainen, Merja H.; Domanskyi, Andrii; Airavaara, Mikko (2017)
    Gene delivery using adeno-associated virus (AAV) vectors is a widely used method to transduce neurons in the brain, especially due to its safety, efficacy, and long-lasting expression. In addition, by varying AAV serotype, promotor, and titer, it is possible to affect the cell specificity of expression or the expression levels of the protein of interest. Dopamine neurons in the substantia nigra projecting to the striatum, comprising the nigrostriatal pathway, are involved in movement control and degenerate in Parkinson's disease. AAV-based gene targeting to the projection area of these neurons in the striatum has been studied extensively to induce the production of neurotrophic factors for disease-modifying therapies for Parkinson's disease. Much less emphasis has been put on AAV-based gene therapy targeting dopamine neurons in substantia nigra. We will review the literature related to targeting striatum and/or substantia nigra dopamine neurons using AAVs in order to express neuroprotective and neurorestorative molecules, as well as produce animal disease models of Parkinson's disease. We discuss difficulties in targeting substantia nigra dopamine neurons and their vulnerability to stress in general. Therefore, choosing a proper control for experimental work is not trivial. Since the axons along the nigrostriatal tract are the first to degenerate in Parkinson's disease, the location to deliver the therapy must be carefully considered. We also review studies using AAV--synuclein (-syn) to target substantia nigra dopamine neurons to produce an -syn overexpression disease model in rats. Though these studies are able to produce mild dopamine system degeneration in the striatum and substantia nigra and some behavioural effects, there are studies pointing to the toxicity of AAV-carrying green fluorescent protein (GFP), which is often used as a control. Therefore, we discuss the potential difficulties in overexpressing proteins in general in the substantia nigra.
  • Juntunen, Valtteri (Helsingin yliopisto, 2021)
    Adeno-Associated Viruses (AAVs) are quickly becoming one of the most applied vectors for gene therapy applications. In the recent years three new AAV-based gene therapies have been approved by U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA). The regulatory bodies require accurate and reliable characterisation of the clinical grade viral vectors during and after production. Analytic methods measuring the purity, potency and safety of the product support the up-stream and down-stream processes during the production and are used for final-drug substance characterisation. Median Tissue Culture Infectious Dose (TCID50) is a well-established method for measuring the infectious titer of a virus. Here, an assay for determining the infectious titer of AAVs, which has previously been used to characterise the existing AAV2 Reference Standard Material (AAV2RSM) was set up and optimised for research use at Kuopio Center for Gene and Cell Therapy (KCT). The assay utilizes the HeRC32-cell line, a HeLa clone, that stably expresses AAV Rep and Cap -proteins and in presence of adenovirus, enables the replication of recombinant AAV-vectors. The cells were grown in 96-well plates and infected with 10-fold dilution series of AAV vectors (AAV2 and AAV6) using human adenovirus type 5 as the co-infector. 72 hours post infection the vector genome replication of AAV was detected with quantitative PCR (qPCR). Thresholds for qPCR determined copy number and cycle threshold (Ct) were set and used for the determination of infection-positive wells. The 50-percent endpoint was observed and used to calculate the infectious titer according to the Spearman-Kärber method. The assay was set up and optimised with the AAV2 Reference standard material (AAV2RSM) using two different primer-probe sets (targeted sequences were; SV40 polyadenylation signal and AAV inverted terminal repeats (ITRs)). Plates infected with AAV2RSM were analysed separately with both primers resulting in mean infectious titers of 8.07 ± 3.13 x 108 TCID50 Infectious Units (IU) / mL (n = 9) and 1.27 ± 0.464 x 109 TCID50 IU/mL (n = 9) for SV40 and ITR, respectively. After the assay was set up with the AAV2RSM, an in-house AAV6 product was analysed with the ITR primers yielding 6.09 ± 3.94 x 109 TCID50 (IU) / mL (n = 5). The assay protocol was successfully set up for research use at the KCT laboratory. Improvements were added to the original protocol to increase assay robustness, accuracy and precision as well as to minimize the possibility of over-estimation of the infectious titer. The assay can be further optimised for a particular therapeutic AAV product in the research laboratory or technology transferred to a production facility for optimisation and validation for the analytics needs of a production pipeline.
  • Cerullo, Vincenzo; Capasso, Cristian; Vähä-Koskela, Markus; Hemminki, Otto; Hemminki, Akseli (2018)
    Adenovirus is one of the most commonly used vectors for gene therapy and it is the first approved virus-derived drug for treatment of cancer. As an oncolytic agent, it can induce lysis of infected cells, but it can also engage the immune system, promoting activation and maturation of antigen-presenting cells (APCs). In essence, oncolysis combined with the associated immunostimulatory actions result in a "personalized in situ vaccine" for each patient. In order to take full advantage of these features, we should try to understand how adenovirus interacts with the immune system, what are the receptors involved in triggering subsequent signals and which kind of responses they elicit. Tackling these questions will give us further insight in how to manipulate adenovirus-mediated immune responses for enhancement of anti-tumor efficacy. In this review, we first highlight how oncolytic adenovirus interacts with the innate immune system and its receptors such as Toll-like receptors, nucleotide-binding and oligomerization domain (NOD)-like receptors and other immune sensors. Then we describe the effect of these interactions on the adaptive immune system and its cells, especially B and T lymphocytes. Finally, we summarize the most significant preclinical and clinical results in the field of gene therapy where researchers have engineered adenovirus to manipulate the host immune system by expressing cytokines and signal-ingmediators.
  • Yu, Jennifer; Mietzsch, Mario; Singh, Amriti; Ybargollin, Alberto Jimenez; Grimm, Dirk; Kapoor, Amit; Kučinskaitė-Kodzė, Indrė; Žvirblienė, Aurelija; Söderlund-Venermo, Maria; McKenna, Robert; Agbandje-McKenna, Mavis (2021)
    Human bocavirus 1 (HBoV1) has gained attention as a gene delivery vector with its ability to infect polarized human airway epithelia and 5.5 kb genome packaging capacity. Gorilla bocavirus 1 (GBoV1) VP3 shares 86% amino acid sequence identity with HBoV1 but has better transduction efficiency in several human cell types. Here, we report the capsid structure of GBoV1 determined to 2.76 angstrom resolution using cryo-electron microscopy (cryo-EM) and its interaction with mouse monoclonal antibodies (mAbs) and human sera. GBoV1 shares capsid surface morphologies with other parvoviruses, with a channel at the 5-fold symmetry axis, protrusions surrounding the 3-fold axis and a depression at the 2-fold axis. A 2/5-fold wall separates the 2-fold and 5-fold axes. Compared to HBoV1, differences are localized to the 3-fold protrusions. Consistently, native dot immunoblots and cryo-EM showed cross-reactivity and binding, respectively, by a 5-fold targeted HBoV1 mAb, 15C6. Surprisingly, recognition was observed for one out of three 3-fold targeted mAbs, 12C1, indicating some structural similarity at this region. In addition, GBoV1, tested against 40 human sera, showed the similar rates of seropositivity as HBoV1. Immunogenic reactivity against parvoviral vectors is a significant barrier to efficient gene delivery. This study is a step towards optimizing bocaparvovirus vectors with antibody escape properties.
  • Terracciano, Monica; Fontana, Flavia; Falanga, Andrea Patrizia; D'Errico, Stefano; Torrieri, Giulia; Greco, Francesca; Tramontano, Chiara; Rea, Ilaria; Piccialli, Gennaro; De Stefano, Luca; Oliviero, Giorgia; Santos, Helder A.; Borbone, Nicola (2022)
    Redox-responsive silica drug delivery systems are synthesized by aeco-friendly diatomite source to achieve on-demand release of peptide nucleic acid (PNA) in tumor reducing microenvironment, aiming to inhibit the immune check-point programmed cell death 1 receptor/programmed cell death receptor ligand 1 (PD-1/PD-L1) in cancer cells. The nanoparticles (NPs) are coated with polyethylene glycol chains as gatekeepers to improve their physicochemical properties and control drug release through the cleavable disulfide bonds (S-S) in a reductive environment. This study describes different chemical conditions to achieve the highest NPs' surface functionalization yield, exploring both multistep and one-pot chemical functionalization strategies. The best formulation is used for covalent PNA conjugation via the S-S bond reaching a loading degree of 306 +/- 25 mu g (PNA) mg(DNPs)(-1). These systems are used for in vitro studies to evaluate the kinetic release, biocompatibility, cellular uptake, and activity on different cancer cells expressing high levels of PD-L1. The obtained results prove the safety of the NPs up to 200 mu g mL(-1) and their advantage for controlling and enhancing the PNA intracellular release as well as antitumor activity. Moreover, the downregulation of PD-L1 observed only with MDA-MB-231 cancer cells paves the way for targeted immunotherapy.
  • 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.
  • Hannila, Teija (Helsingfors universitet, 2013)
    Gene therapy is an experimental technique that involves inserting therapeutic genes into the target cells to treat diseases. Gene transfer can be performed by ex vivo or in vivo method. Ex vivo method means transferring the therapeutic gene in laboratory to the cells that are removed from the patient, after which the cells are returned to the patient. In the in vivo method the gene transfer is performed directly to the target tissue inside the patient's body. Gene therapy clinical trials have been carried out to treat many diseases. The majority of the clinical trials have so far been cancer trials. Nevertheless, the most promising results have been established in treating diseases that arise from mutations in a single gene, i.e. monogenic diseases. Monogenic diseases include e.g. hemophilia and heritable immunodeficiencies. The biggest challenges in the clinical trials so far have been the limited gene transfer efficiency of the currently used gene vectors, the short duration of the transgene expression and the side-effects in viral-mediated gene transfer. Nonviral gene transfer agents have so far been less efficient in vivo than the viral vectors. This is partly due to the interaction between serum components and nonviral vectors. The main purpose of this study was to investigate the effect of serum to the gene transfer efficiency of a nonviral vector polyethyleneimine PEI22K and the combination of PEI22K and cationic liposome Dosper in vitro in the SMC-cells. The potential synergistic increase in the transfection efficiency of PEI22K/Dosper combination was also studied. The secondary goal in this study was to develop an in vitro model which could be used to predict the gene transfer efficiency of gene vectors in vivo. The combination of PEI22K and Dosper resulted in a synergistic increase in the transfection efficiency in serum-free transfection. In the presence of serum the efficiency of PEI22K was higher than the efficiency of PEI22K/Dosper combination. 1-10% serum concentrations did not significantly affect PEI22K`s transfection efficiency, but dramatically decreased the efficiency of PEI22K/Dosper combination. The results suggest that PEI22K is more suitable than PEI22K/Dosper combination for in vivo gene transfer.
  • Chen, Wei; Chen, Hao; Zheng, Dandan; Zhang, Hongbo; Deng, Lianfu; Cui, Wenguo; Zhang, Yuhui; Santos, Hélder A.; Shen, Hongxing (2020)
    Gene therapy provides an ideal potential treatment for intervertebral disk degeneration by delivering synthetic microRNAs (miRNAs) to regulate the gene expression levels. However, it is very challenging to deliver miRNAs directly, which leads to inactivation, low transfection efficiency, and short half‐life. Here, Agomir is loaded in hydrogel to construct a gene‐hydrogel microenvironment for regulating the synthesis/catabolism balance of the tissue extracellular matrix (ECM) to treat degenerative diseases. Agomir is a cholesterol‐, methylation‐, and phosphorothioate‐modified miRNA, which can mimic the function of miRNA to regulate the expression of the target gene. Agomir874 that mimics miRNA874 is synthesized to down regulate the expression of matrix metalloproteinases (MMPs) in nucleus pulposus (NP). At the same time, a polyethylene glycol (PEG) hydrogel is synthesized through Ag‐S coordination of 4‐arm PEG‐SH and silver ion solution, which has injectable, self‐healing, antimicrobial, degradable, and superabsorbent properties and matches perfectly with the mechanism of intervertebral disk. By delivering Agomir‐loaded PEG‐hydrogel to a degenerative intervertebral disk, a gene‐hydrogel microenvironment is constructed in situ, which reduces the expression of MMPs, regulates the synthesis/catabolism balance of ECM in the NP of the intervertebral disk, and improves the tissue microenvironment regeneration.
  • Sarkar, Aira; Junnuthula, Vijayabhaskarreddy; Dyawanapelly, Sathish (2021)
    Age-related macular degeneration (AMD) is the leading cause of vision loss in geriatric population. Intravitreal (IVT) injections are popular clinical option. Biologics and small molecules offer efficacy but relatively shorter half-life after intravitreal injections. To address these challenges, numerous technologies and therapies are under development. Most of these strategies aim to reduce the frequency of injections, thereby increasing patient compliance and reducing patient-associated burden. Unlike IVT frequent injections, molecular therapies such as cell therapy and gene therapy offer restoration ability hence gained a lot of traction. The recent approval of ocular gene therapy for inherited disease offers new hope in this direction. However, until such breakthrough therapies are available to the majority of patients, antibody therapeutics will be on the shelf, continuing to provide therapeutic benefits. The present review aims to highlight the status of pre-clinical and clinical studies of neovascular AMD treatment modalities including Anti-VEGF therapy, upcoming bispecific antibodies, small molecules, port delivery systems, photodynamic therapy, radiation therapy, gene therapy, cell therapy, and combination therapies.
  • Tonttila, Kialiina (Helsingin yliopisto, 2021)
    Respirometry is a polarographic method that provides insights into mitochondrial respiratory capacity – specifically to electron transport chain (ETC) complexes I to V –, mitochondrial integrity and energy metabolism. The limitation of the respiratory measurements has been that it requires freshly isolated mitochondria or tissue sample. Long-term preservation of mitochondrial function in frozen samples has been a considerable challenge, since the membrane integrity of the mitochondria is lost during the freezing process. Thus, samples do not display coupled respiration. However, previous studies have found that despite coupled respiration is impaired the individual ETC complexes and the ability of ETC supercomplexes to consume oxygen are not destroyed due to freezing and thawing. On the basis of this knowledge, recently published article presented a novel protocol that overcomes the damages caused by freeze-thaw cycles. The protocol also enables respiration measurement of ETC complexes I-IV by using Seahorse XF96 Extracellular flux analyzer. In this MSc thesis I modified and optimized the aforementioned protocol for Oroboros O2k high- resolution respirometry using frozen skeletal muscle samples. In addition, this study provides an optimized sample preparation protocol for frozen muscle samples and respiration measurement. The new method broadens the possibilities within mitochondrial respiration studies since Oroboros O2k high-resolution respirometry records results with high sensitivity without limiting the number of substrates used. The possibility to use frozen samples reduces research costs, simplifies logistics and enables retrospective studies with previously stored frozen tissue samples. I also utilized the optimized respiration measurement protocol to study metabolic effects of combined gene therapy in skeletal muscle. This gene therapy mimics the positive effects of exercise by inducing skeletal muscle growth and angiogenesis. The mimicking effect was induced by systemic delivery of adeno-associated viral vectors encoding pro-myostatin and VEGF-B. In previous studies inhibition of myostatin has been connected to compromised oxidative capacity and vascular rarefaction. In contrast, VEGF-B has demonstrated to induce angiogenesis in several tissues. Thus, my hypothesis was that combination gene therapy would result in better mitochondrial function than pro-myostatin alone. Results from this study indicate that moderate inhibition of myostatin signaling by pro-myostatin using rAAV vectors could provide enhancements in ETC function when it is induced independently or combined with rAAV-VEGF-B. This result lays a solid foundation for future research and could provide a new therapeutic option against muscle loss and related metabolic diseases.
  • Mansnérus, Juli; Lahti, Raimo; Blick, Amanda (University of Helsinki, Faculty of Law, 2020)
    Forum iuris
    The paradigm of personalized medicine is an emerging topic, triggering some specific legal and ethical challenges as regards data collection, sharing and use, informed consent, privacy and public trust, and the changing status of patients and social equality. These legislative developments and challenges have been discussed in light of the Finnish and the common-European experiences. During recent years, the Finnish legislative processes aiming at generating ‘innovation-friendly’ legislation for scientific research purposes as well as integrating genomic research results into the clinical setting have been heavily challenged by rapid developments in technology and medicine. In particular, there is a need to pursue the right balance between scientific and commercial interests, public health, and individual rights. We aim at providing insights into the legislative processes surrounding personalized medicine with a special focus on how the freedom of science, equitable access to healthcare, public health, and commercial issues that must be balanced with individual rights as expressed in the EU Charter and the Council of Europe’s Oviedo Convention on Human Rights and Biomedicine. A wide spectrum of different types of challenges arises; among other things, there is a need to discuss the Finnish and international legislation of genome testing in terms of consent on behalf of a young child. Also the legal and ethical aspects of disruptive gene-editing technologies need to be analysed: How should we interpret the concept of human dignity in the bioethical discussion surrounding germline editing? Furthermore, an overview of ongoing initiatives to accelerate the market-entry of advanced therapy medicinal products will be provided. The European regulators are now taking measures to create a facilitative regulatory environment that encourages innovation, protects public health, and enables timely patient access to innovative, new therapies whilst ensuring patient safety. The role of risk-proportionate adaptations to clinical trials and GMP manufacture along with the European Medicines Agency’s early-access incentives and initiatives are presented as potential facilitators of market entry. Furthermore, in this context, the role of conditional reimbursement schemes and risk sharing-agreements is also discussed in light of the newest Finnish experiences. Furthermore, in terms of patent law, some specific challenges arise; in this anthology, attention is paid to the recent transatlantic legal dispute over a patent concerning the use of the CRISPR/Cas9 system in eukaryotic cells. Finally, some considerations beyond legal or ethical aspects of personalised medicine are presented. How can machine learning be used to support personalized care that addresses the patient’s needs?
  • Sairanen, Viljami; Tokola, Anna; Tikkanen, Ritva; Laine, Minna; Autti, Taina (2020)
    Aspartylglucosaminuria (AGU) is a rare lysosomal storage disorder causing developmental delay, intellectual disability, and eventual death. A distinct feature in AGU is iron accumulation within the thalamus. Our aim is to demonstrate that susceptibility-weighted images (SWI) could be used as an MRI biomarker to evaluate the response within the AGU population to newly evolving treatments. SWI from 16 patients with AGU and 16 age-matched controls were used in the analysis. Thalamic volume with an iron accumulation was identified using a permutation test. Group differences were investigated for both the complete thalamus and the iron accumulation regions. Group-wise age correlation within these volumes were assessed with analysis of variance and multivariate regression. We found a statistically significant and large difference (p-value = 0.01, Cohen's D = 0.97) for the whole thalamus comparison and an even greater difference in the iron accumulation regions (p-value <0.01, Cohen's D = 3.52). Furthermore, we found strong evidence for iron accumulation as a linear function of age with R-2 = 0.65 only for AGU. The statistical analysis of SWI provides tools for assessing the degree of iron accumulation. This method could be used to study the response to treatments, in that a successful treatment would be expected to result in a decline in iron accumulation.
  • Lähteenvuo, Johanna; Hätinen, Olli-Pekka; Kuivanen, Antti; Huusko, Jenni; Paananen, Jussi; Lähteenvuo, Markku; Nurro, Jussi; Hedman, Marja; Hartikainen, Juha; Laham-Karam, Nihay; Mäkinen, Petri; Räsänen, Markus; Alitalo, Kari; Rosenzweig, Anthony; Ylä-Herttuala, Seppo (2020)
    VEGF-B gene therapy is a promising proangiogenic treatment for ischemic heart disease, but unexpectedly, we found that high doses of VEGF-B promote ventricular arrhythmias (VA).VEGF-B knockout, αMHC-VEGF-B transgenic mice, and pigs transduced intramyocardially with adenoviral (Ad)VEGF- B186 were studied.Immunostaining showed a 2-fold increase in the number of nerves (76 vs.39 in controls, nerves/field,p
  • Capasso, Cristian; Garofalo, Mariangela; Hirvinen, Mari; Cerullo, Vincenzo (2014)