Researchers from Japan develop a nanosensing platform that can assess the quality of individual viral vector particles
Viral vectors hold much potential for gene editing and gene therapy, but there is a pressing need to develop quality control methods to minimize potential side effects on patients. Addressing this, researchers from Japan developed a nanosensing-based approach that can differentiate between functional and faulty viral vectors at the single-particle level. This convenient and inexpensive technique will hopefully get us one step closer to advancing treatments for genetic disorders.
Over the past few decades, there has been remarkable progress in genetic manipulation technologies, bringing us closer to the point where genes can be modified in vivo. Such tools would open up the way to gene therapy, ushering in a new era in medicine. Thus far, the most promising strategies for gene therapy involve leveraging the existing molecular machinery found in viruses.
In particular, adeno-associated virus (AAV) vectors have recently garnered significant attention from the scientific community, given their potential to serve as nucleic acid vaccines for diseases like COVID-19. However, during AAV vector manufacturing, some particles may carry only a partial copy of the intended genome, while others may be empty. These defective vectors can lead to unexpected side effects, underscoring the urgent need for robust quality control methods in their production.
Addressing this challenge, a team of researchers from Japan recently reported a novel nanosensing technique to measure viral vector characteristics. Their findings were presented in their latest paper, published online on 5 June, 2024 in ACS Nano. The team includes Associate Professor Makusu Tsutsui from the Institute of Scientific and Industrial Research at Osaka University; Professor Tomoji Kawai, also from the same institute; Lecturer Akihide Arima from the Institute of Nano-Life-Systems at Nagoya University; Specially Appointed Professor Yoshinobu Baba from the Institute of Nano-Life-Systems Institutes of Innovation for Future Society, Nagoya University; Project Researcher Mikako Wada and Assistant Professor Yuji Tsunekawa, both from the Institute of Medical Science at The University of Tokyo; and Professor Takashi Okada, also from the Institute of Medical Science at The University of Tokyo.
The proposed approach involves measuring the ionic current that flows through a nanopore opening when a voltage differential is applied to a solution containing AAVs. When the nanopore is unobstructed, the measured ionic current is relatively constant. But when a viral particle passes through the nanopore, the flow of ions is partially blocked for a brief moment, producing a spike or pulse in the ionic current readout.
Interestingly, because AAV vectors with full genomes are heavier and slightly bulkier than empty or partially filled vectors, it’s possible to discriminate between them as they pass through the nanopore—faulty vectors produce a ‘signature’ in the measured ionic current that is noticeably different from that of full-genome vectors. The team verified this through experiments, finite-element simulations, and theoretical analyses. “By designing a sensor with an optimal structure, we identified for the first time the gene-derived sub-nanometer-scale differences in the size of the viral vectors,” explains Tsutsui.
This technique allows for the convenient and inexpensive quality control of AAV vectors, which thus far has relied on complex methods such as mass photometry, transmission electron microscopy, and analytical ultracentrifugation. “The present work may revolutionize medicine by providing a tool for preparing AAV vectors with ultra-high quality for safe and effective gene therapy,” highlights Tsunekawa. “It may be key in the development of production and purification systems for AAV vectors,” he further adds.
Moreover, beyond AAV vectors, this approach holds promise for studying other types of viral vectors, potentially opening new avenues for effective gene therapies and advancing our understanding of viral biology. Moreover, ensuring the high quality of clinically used AAV vectors could allow for lower patient doses, thereby minimizing side effects.
Let us hope these efforts serve as a stepping stone towards effective treatments for hereditary disorders, as well as challenging diseases like cancer.
When manufactured, some viral vectors are non-functional because they contain a partial copy of the desired genome or are outright empty. In this study, researchers developed a convenient and inexpensive nanosensing method to assess the quality of viral vectors. These efforts could lead to gene therapy with less side effects at a more affordable price.
Reference
Journal：
ACS Nano
Title of original paper：Identifying Viral Vector Characteristics by Nanopore Sensing
ACS Nano
Title of original paper：Identifying Viral Vector Characteristics by Nanopore Sensing
DOI：
10.1021/acsnano.4c01888
Authors：
Makusu Tsutsui1, Mikako Wada2, Akihide Arima3, Yuji Tsunekawa2, Takako Sasaki2, Kenji Sakamoto2, Kazumichi Yokota4, Yoshinobu Baba3,5,6, Tomoji Kawai7, and Takashi Okada2
Affiliations：
1 The Institute of Scientific and Industrial Research, Osaka University, Japan
2 Division of Molecular and Medical Genetics, Center for Gene and Cell Therapy, The Institute of Medical Science, The University of Tokyo, Japan
3 Institute of Nano-Life-Systems Institutes of Innovation for Future Society, Nagoya University, Japan
4 National Institute of Advanced Industrial Science and Technology, Japan
5 Department of Biomolecular Engineering Graduate School of Engineering, Nagoya University, Japan
6 Institute of Quantum Life Science, National Institutes for Quantum and Radiological Science and Technology, Japan
7 The Institute of Scientific and Industrial Research, Osaka University, Japan
About Associate Professor Makusu Tsutsui from The Institute of Scientific and Industrial Research, Osaka University
Dr. Makusu Tsutsui earned his PhD from Kyoto University and currently holds the position of Associate Professor at the Institute of Scientific and Industrial Research, Osaka University. His research expertise lies in micro- and nanotechnology, focusing on nanofluidic devices, nanopore-based techniques, and nanocontacts. Tsutsui has contributed significantly to these fields with over 150 publications.UTokyo PEOPLE
Dr. TSUTSUI Makusu
About Project Researcher Mikako Wada from The Institute of Medical Science, The University of Tokyo, Japan
Mikako Wada is currently a Project Researcher at the Division of Molecular and Medical Genetics of The Institute of Medical Science, The University of Tokyo. Her research focuses on genetics and viral vectors, and she has published over 5 papers in these fields. She is also a member of the Japan Society for Gene and Cell Therapy.UTokyo PEOPLE
Dr. WADA Mikako
About Lecturer Akihide Arima from Nagoya University
Dr. Akihide Arima earned his PhD from Osaka University in 2016, where he subsequently served as Assistant Professor until March 2019. Transitioning to Nagoya University in April 2019, he currently holds the position of Specially Appointed Lecturer at the Institute of Nano-Life-Systems within the Institutes of Innovation for Future Society. Dr. Arima's research focuses on single-bioparticle analysis using nanobiodevices, reflecting his keen interest in advancing this area of study. He has contributed over 25 research papers to the field, showcasing his expertise and dedication to nanotechnology and bioparticle analysis.UNagoya PEOPLE
Dr. ARIMA Akihide
About Assistant Professor Yuji Tsunekawa from The Institute of Medical Science, The University of Tokyo
Yuji Tsunekawa, Assistant Professor at the Institute of Medical Science, The University of Tokyo, specializes in medical biochemistry. His research centers on developing new genetic manipulation technologies and understanding complex brain development processes using innovative gene editing techniques. Leading competitive grant-funded projects, he focuses on optimizing GMP-compliant viral vector production systems and advancing genetic recombination technologies. With numerous publications, Tsunekawa aims to advance gene therapy and enhance the understanding of neurological disorders and brain evolution.UTokyo PEOPLE
Dr. TSUNEKAWA Yuji
About Professor Emeritus Tomoji Kawai from The Institute of Scientific and Industrial Research, Osaka University
Professor Tomoji Kawai is a leading expert in nanoscience and nanotechnology. He earned his Ph.D. in Physical Chemistry from the University of Tokyo in 1974 and has been a Professor at the Institute of Scientific and Industrial Research, Osaka University since 1992. He directs the Nanoscience and Nanotechnology Center, focusing on DNA nanotechnology and bio-electronic devices. Professor Kawai's contributions have been recognized with awards such as the Ichimura Prize of Science in 1994 and the Divisional Award of the Chemical Society of Japan in 2000.UOsaka PEOPLE
Dr. KAWAI Tomoji
About Professor Yoshinobu Baba from the Institute of Nano-Life-Systems Institutes of Innovation for Future Society, Nagoya University
Yoshinobu Baba is a prominent researcher in nanobiotechnology and bioengineering, currently the Director General, Institute for Quantum Life Science, National Institutes for Quantum Science and Technology (QST) and a Professor at Nagoya University's Institutes of Innovation for Future Society. He earned his Ph.D. in Chemistry from Kyushu University in 1986 and has held various academic roles. His research focuses on advanced nanobiodevices and biosensors, merging nanotechnology with medical and analytical sciences. Baba has authored nearly 1000 publications, including research papers, reviews, and books, and holds over 100 patents. Baba's achievements include prestigious honors such as The CSJ (Chemical Society of Japan) Award and the Medal with Purple Ribbon.UNagoya PEOPLE
Dr. BABA Yoshinobu
About Professor Takashi Okada from the Institute of Medical Science, The University of Tokyo
Takashi Okada is a distinguished Professor at the Institute of Medical Science, University of Tokyo, where he leads the Division of Molecular and Medical Genetics within the Center for Gene and Cell Therapy. His research primarily revolves around advancing virus-based vectors for gene and cell therapies. Prof. Okada's expertise spans gene therapy, virus vectors, and the application of multipotent mesenchymal stromal cells in treating neuromuscular diseases and cancer. His innovative work aims to develop novel therapeutic approaches that integrate cutting-edge biomedical technologies with clinical applications, contributing significantly to the field of molecular medicine.UTokyo PEOPLE
Dr. OKADA Takashi
About The Institute of Medical Science, The University of Tokyo
The Institute of Medical Science, The University of Tokyo (IMSUT), established in 1892 as the Institute of Infectious Diseases and renamed IMSUT in 1967, is a leading research institution with a rich history spanning over 127 years. It focuses on exploring biological phenomena and disease principles to develop innovative strategies for disease prevention and treatment. IMSUT fosters a collaborative, interdisciplinary research environment and is known for its work in genomic medicine, regenerative medicine, and advanced medical approaches like gene therapy and AI in healthcare. It operates core research departments and numerous specialized centers, including the Human Genome Center and the Advanced Clinical Research Center, and is recognized as Japan’s only International Joint Usage/Research Center in life sciences.About Nagoya University, Japan
Nagoya University, established in 1939 as the last Imperial University, is a prestigious national research university located in Nagoya, Japan. Renowned for its contributions to physics and chemistry, it has produced seven Nobel Prize winners and is known for pioneering research in fields such as the Sakata model and the Blue LED. As a Designated National University, it emphasizes a collaborative research environment and operates several key institutes, including the Institute of Transformative Bio-Molecules and the Institute for Space-Earth Environmental Research. The university supports a diverse international community and offers various global exchange programsMedia contact
Affiliation: Project Coordination Office, The Institute of Medical Science, The University of Tokyohttps://www.ims.u-tokyo.ac.jp