Advances in Gene Therapy, Novel Nanopore Technology, Concussion Science

Advances in Gene Therapy, Nanopore Technology, Concussion Science

This week In The News, we’re putting the spotlight on best practices for delivering adeno-associated virus gene therapy to children and new preclinical evidence for a gene therapy approach for an ultra-rare disease. Scientists develop a novel nanopore platform for more precise and comprehensive long-read sequencing, gain insights about facemasks in American football, and identify a marrow preconditioning strategy that could lead to improved bone marrow transplantation.

CIGT Symposium Spotlights AAV Gene Therapy Breakthroughs and Possibilities

CHOP’s Clinical In Vivo Gene Therapy Educational Symposium held Friday, Sept. 20, brought together scientists and clinicians from across medical specialties to highlight evidence-based research and offer best practices for delivering adeno-associated virus (AAV) gene therapy to children.

In vivo gene therapy involves directly infusing a new, corrected gene into a child’s body, to stop disease or make it less severe. Led by experts with extensive experience in gene therapy clinical trials, the Clinical In Vivo Gene Therapy (CIGT) group at CHOP seeks to make transformative discoveries and offer breakthrough therapies for patients with genetic disorders.

“There is nothing better than gene therapy when it works. The challenge is trying to make sure it works for everybody,” said Benjamin J. Samelson-Jones, MD, PhD, a pediatric hematologist at CHOP who played a key role in advancing one of the first in vivo gene therapies to treat hemophilia B.

At the symposium, CHOP experts offered fundamental knowledge about scientific foundations and approaches, AAV commercial products, potential AAV toxicities, and in vivo gene therapy in practice. Speakers highlighted CHOP’s research contributions to major AAV gene therapy breakthroughs, including, among others:

• The development of voretigene neparvovec-rzyl (LUXTURNA®, Spark Therapeutics) the groundbreaking therapy approved for inherited retinal blindness.
• The development of fidanacogene elaparvovec (Beqvez®, Pfizer) for the treatment of adults with hemophilia B. 
• The success of the first clinical trial using CRISPR/Cas9 gene editing to treat blindness in children.
• The approval of SRP-9001 (Elevidys®, Sarepta), for which CHOP served as a clinical trial site, to treat Duchenne muscular dystrophy.

“Today, it was very rewarding for me to see the whole path — starting from the level of understanding AAV, all the way through to implementation,” said CIGT Director Lindsey George, MD. “It’s been a lot of fun for us along the way, and it’s been great to be able to share our knowledge with you.”

CHOP Researchers Share First Evidence of Gene Therapy to Treat MSD

Results from preclinical testing conducted at CHOP of an experimental gene therapy provide a path for translation into clinical trials for multiple sulfatase deficiency (MSD), a multisystemic disorder with no currently approved treatment. The findings were published in Molecular Therapy.

“This is a really important first step in the design and provides proof of concept that an ex vivo gene therapy could help patients with MSD,” said senior study author Rebecca Ahrens-Nicklas, MD, PhD, an attending physician with the Metabolic Disease Program and the Division of Human Genetics at CHOP. 

Over time, researchers have identified MSD-associated biomarkers that have the potential for targeted gene therapy. One approach is to transduce a patient's bone marrow cells with a lentiviral vector to introduce a working copy of the MSD-causing gene. The corrected cells are then administered back to the patient via stem cell transplant, an approach that has proven successful in related disorders.

Researchers worked with a preclinical model of MSD and patient-derived stem cells and found that in patient-derived stem cells, the vector improved protein expression, sulfatase activities, and glycosaminoglycan accumulation, which is important for key cell functions.

In the preclinical model, the gene therapy approach rescued biochemical deficits including sulfatase activity and glycosaminoglycan accumulation that can lead to improper cell function, in MSD-affected organs post-symptom onset. The model also demonstrated improved neuroinflammation and neurocognitive function.

Learn more in this CHOP news release.

Novel Nanopore Platform Offers More Efficient and Precise Molecule Detection

Researchers at CHOP and the University of Pennsylvania created a novel platform called GURU that advances nanopore technology and enables more precise and comprehensive long-read sequencing.Nanopore sequencing analyzes biological molecules such as DNA by measuring ion current changes as they pass through an infinitesimal opening, or nanopore, in a membrane.

Dimitri S. Monos, PhD, Director of the Immunogenetics Laboratory at CHOP, and collaborator Marija Drndic, PhD, the Fay R. and Eugene L. Langberg Professor of Physics at Penn, led a team to develop the GURU platform, which allows researchers to modulate and slow the passage of molecules through a dual-layer sequencing membrane.

This first-of-its-kind guiding and reusable system for studying molecules improves upon current nanopore systems, especially for applications like human leukocytic antigen (HLA) genes that require long DNA reads, according to Dr. Monos, who is also the Evelyn Willing Bromley Endowed Chair in Clinical Laboratories and Pathology at the Penn Perelman School of Medicine.

Their findings were published in Nature Nanotechnology. Read more in Penn Today.

New Findings Identify Facemask as Main Source of High-severity Impacts in Professional American Football

CHOP researchers presented findings that nearly one-third of concussions in American football are the result of impacts to the facemask, the design of which has remained mostly the same for a decade.

“These findings suggest that facemask redesign should be the focus of future innovation that can continue to improve the safety of football players at all skill levels,” said first study author Kristy Arbogast, PhD, scientific director of the Center for Injury Research and Prevention and Co-Director of Minds Matter Concussion Program at CHOP.

The study followed 98 players in the National Football League who were equipped with instrumented mouthpieces during the 2019-2022 seasons to measure the kinematics of head acceleration events (HAEs). Researchers recorded 5,104 HAEs during the prescribed study period, evaluating the sample of HAEs in the 90th percentile of severity for head acceleration response metric (HARM), peak angular acceleration (PAA), and peak linear acceleration (PLA). Impacts to the facemask represent nearly 60% of the sample. This is of particular importance for linemen, who experienced the highest rate of facemask impacts at 66%, regardless of whether the metric is HARM or PAA.

The study authors suggest that future work in this area focus on interventions to reduce the frequency and magnitude of these impacts, including improvement in facemask design, changes to player techniques, and rules that mitigate facemask contact. They presented their work at the 2024 International Research Council on the Biomechanics of Injury Conference in Stockholm.

Learn more in the CHOP news release.

Study Shows Chemokine Receptor Synergy Promotes Bone Marrow Homing

Researchers in the Comprehensive Bone Marrow Failure Center at CHOP gained insights into the cross-talk between hematopoietic stem and progenitor cells (HSPCs) and bone marrow cells that are critical for homing and sustained engraftment after transplantation. Their findings will inform novel translational conditioning strategies to improve HSPC transplantation.

Therapy outcomes after hematopoietic stem cell transplantation for non-malignant disorders continue to be limited by toxicity from conditioning and failure of donor cells to engraft in the patient's bone marrow. Likewise, the modification of patient stem cells for emerging gene therapies results in inadvertent losses during manipulation and subsequent reinfusion.

A comprehensive understanding of the mechanisms by which stem cells are attracted and retained in the bone marrow is critical to overcome this bottleneck and maximize treatment success for hematologic and bone marrow failure disorders, in particular.

First study author Stephanie Hurwitz, PhD, now a faculty member at Indiana University, and senior author Peter Kurre, MD, Director of the Comprehensive Bone Marrow Failure Center, and colleagues demonstrated for the first time that C-C motif chemokine receptor 2 (CCR2) ligands cooperate with C-X-C chemokine receptor 4 (CXCR4) to boost HSPCs homing to bone marrow. Mechanistically, they discovered a novel reciprocal signaling cascade, whereby donor HSPC-derived, nanoscale extracellular vesicles induce up-regulation of the CCR2 ligands that synergize with CXCL12-CXCR4 in bone marrow endothelial cells to promote homing.

The scientists worked with nonirradiated murine models to show that marrow preconditioning with HSPC extracellular vesicles ligands improves homing and early graft occupancy after transplantation. Replication of these results using recombinant CCR2 suggest translational value in a clinical scenario.

Science Advances published the study results.

ICYMI

Catch up on our headlines from our Sept. 13 In The News:

• Psychological Risk Factors May Affect Health-related Quality of Life Post Concussion
• CHOP Cardiology Specialists Advocate for Energy Drink Regulation in the US
• CHOP Contributes to First-of-its-Kind AIRFoundry for RNA Research
• AML Inflammatory Memory in Hematopoietic Stem and Progenitor Cells

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