“Switchable” Bispecific Antibodies Pave Way for Safer Cancer Treatment

by Nathi Magubane

Bispecific T cell engagers are emerging as a powerful class of immunotherapy to treat cancer but are sometimes hindered by unwanted outcomes, such as on-target, off-tumor toxicity; cytokine release syndrome; and neurotoxicity. Now, researchers Penn researchers have developed a novel “switchable” bispecific T cell engager that mitigates these negative effects by co-opting a drug already approved by the FDA. (Image: iStock / CIPhotos)

In the ever-evolving battle against cancer, immunotherapy presents a turning point. It began with harnessing the body’s immune system to fight cancer, a concept rooted more than a century ago but only gaining significant momentum in recent years. Pioneering this shift were therapies like CAR T cell therapy, which reprograms a patient’s T cells to attack cancer cells. Within this domain, bispecific T cell engagers, or bispecific antibodies, have emerged as effective treatments for many blood-borne cancers in the clinic and are being evaluated for solid tumor therapy.

These antibodies simultaneously latch onto both a cancer cell and a T cell, effectively bridging the gap between the two. This proximity triggers the T cells to unleash their lethal arsenal, thereby killing the cancer cells. However, bispecific T cell engagers, like many cancer therapies, face hurdles such as cell-specific targeting limitations, known as on-target off-tumor toxicity, which means the tumor is correctly targeted but so are other healthy cells in the body, leading to healthy tissue damage. Moreover, bispecific antibodies may also lead to immune system overactivation, a precursor for cytokine release syndrome (CRS), and neurotoxicity.

Now, researchers led by Michael Mitchell of the University of Pennsylvania have found a way to circumvent many of these deleterious effects by developing a bispecific T cell nanoengager that is equipped with an “off switch.” Their findings are published in Nature Biomedical Engineering.

“We’re excited to show that bispecific antibodies can be tweaked in a way that allows us to tap into their powerful cancer-killing potential without inducing toxicity to healthy tissues,” says Mitchell, associate professor of bioengineering at Penn’s School of Engineering and Applied Science. “This new controllable drug-delivery mechanism, which we call switchable bispecific T cell nanoengagers, or SiTEs, adds this switchable component to the antibody via administering an FDA-approved small-molecule drug, amantadine.”

Read the full story in Penn Today.

What Makes a Breakthrough? “Eight Steps Back” Before Making it to the Finish Lit

by Meagan Raeke

(From left to right) Breakthrough Prize recipients Drew Weissman, Virginia M-Y Lee, Katalin Karikó, and Carl June at a reception on Feb. 13. (Image: Courtesy of Penn Medicine News)

In popular culture, scientific discovery is often portrayed in “Eureka!” moments of sudden realization: a lightbulb moment, coming sometimes by accident. But in real life—and in Penn Medicine’s rich history as a scientific innovator for more than 250 years—scientific breakthroughs can never truly be distilled down to a single, “ah-ha” moment. They’re the result of years of hard work, perseverance, and determination to keep going, despite repeated, often discouraging, barriers and setbacks. 

“Research is [like taking], four, or six, or eight steps back, and then a little stumble forward,” said Drew Weissman, MD, PhD, the Roberts Family Professor of Vaccine Research. “You keep doing that over and over and somehow, rarely, you can get to the top of the step.” 

For Weissman and his research partner, Katalin Karikó, PhD, an adjunct professor of Neurosurgery, that persistence—documented in thousands of news stories across the globe—led to the mRNA technology that enabled two lifesaving COVID-19 vaccines, earning the duo numerous accolades, including the highest scientific honor, the 2023 Nobel Prize in Medicine

Weissman and Karikó were also the 2022 recipients of the Breakthrough Prize in Life Sciences, the world’s largest science awards, popularly known as the “Oscars of Science.” Founded in 2012 by a group of web and tech luminaries including Google co-founder Sergey Brin and Meta CEO Mark Zuckerberg, the Breakthrough Prizes recognize “the world’s top scientists working in the fundamental sciences—the disciplines that ask the biggest questions and find the deepest explanations.” With six total winners, including four from the Perelman School of Medicine (PSOM), Penn stands alongside Harvard and MIT as the institutions whose researchers have been honored with the most Breakthrough Prizes. 

Virginia M.Y. Lee, PhD, the John H. Ware 3rd Professor in Alzheimer’s Research, was awarded the Prize in 2020 for discovering how different forms of misfolded proteins can move from cell to cell and lead to neurodegenerative disease progression. Carl June, MD, the Richard W. Vague Professor in Immunotherapy, is the most recent recipient and will be recognized at a star-studded red-carpet event in April for pioneering the development of CAR T cell therapy, which programs patients’ own immune cells to fight their cancer.

The four PSOM Breakthrough Prize recipients were honored on Tuesday, Feb. 13, 2024, when a new large-scale installation was unveiled in the lobby of the Biomedical Research Building to celebrate each laurate and their life-changing discoveries. During a light-hearted panel discussion, the honorees shared how a clear purpose, dogged determination, and a good sense of humor enabled their momentum forward. 

Read the full story in Penn Medicine News.

Carl June and Jon Epstein are members of the Penn Bioengineering Graduate Group. Read more stories featuring them in the BE Blog here and here, respectively.

Weissman presented the Department of Bioengineering’s 2022 Herman P. Schwan Distinguished Lecture: “Nucleoside-modified mRNA-LNP therapeutics.” Read more stories featuring Weissman in the BE Blog here.

Researchers Breathe New Life into Lung Repair

by Nathi Magubane

Image: iStock/Mohammed Haneefa Nizamudeen

In the human body, the lungs and their vasculature can be likened to a building with an intricate plumbing system. The lungs’ blood vessels are the pipes essential for transporting blood and nutrients for oxygen delivery and carbon dioxide removal. Much like how pipes can get rusty or clogged, disrupting normal water flow, damage from respiratory viruses, like SARS-CoV-2 or influenza, can interfere with this “plumbing system.”

In a recent study, researchers looked at the critical role of vascular endothelial cells in lung repair. Their work, published in Science Translational Medicine, was led by Andrew Vaughan of the University of Pennsylvania’s School of Veterinary Medicine and shows that, by using techniques that deliver vascular endothelial growth factor alpha (VEGFA) via lipid nanoparticles (LNPs), that they were able to greatly enhance modes of repair for these damaged blood vessels, much like how plumbers patch sections of broken pipes and add new ones.

“While our lab and others have previously shown that endothelial cells are among the unsung heroes in repairing the lungs after viral infections like the flu, this tells us more about the story and sheds light on the molecular mechanisms at play,” says Vaughan, assistant professor of biomedical sciences at Penn Vet. “Here we’ve identified and isolated pathways involved in repairing this tissue, delivered mRNA to endothelial cells, and consequently observed enhanced recovery of the damaged tissue. These findings hint at a more efficient way to promote lung recovery after diseases like COVID-19.”

They found VEGFA’s involvement in this recovery, while building on work in which they used single cell RNA sequencing to identify transforming growth factor beta receptor 2 (TGFBR2) as a major signaling pathway. The researchers saw that when TGFBR2 was missing it stopped the activation of VEGFA. This lack of signal made the blood vessel cells less able to multiply and renew themselves, which is vital for the exchange of oxygen and carbon dioxide in the tiny air sacs of the lungs.

“We’d known there was a link between these two pathways, but this motivated us to see if delivering VEGFA mRNA into endothelial cells could improve lung recovery after disease-related injury,” says first author Gan Zhao, a postdoctoral researcher in the Vaughan Lab.

The Vaughan Lab then reached out to Michael Mitchell of the School of Engineering and Applied Science, whose lab specializes in LNPs, to see if delivery of this mRNA cargo would be feasible.

“LNPs have been great for vaccine delivery and have proven incredibly effective delivery vehicles for genetic information. But the challenge here was to get the LNPs into the bloodstream without them heading to the liver, which is where they tend to congregate as its porous structure lends favor to substances passing from the blood into hepatic cells for filtration,” says Mitchell, an associate professor of bioengineering at Penn Engineering and a coauthor of the paper. “So, we had to devise a way to specifically target the endothelial cells in the lungs.”

Lulu Xue, a postdoctoral researcher in the Mitchell Lab and a co-first author of the paper, explains that they engineered the LNP to have an affinity for lung endothelial cells, this is known as extra hepatic delivery, going beyond the liver.

Read the full story in Penn Today.

Secondary Cancers Following CAR T Cell Therapy Are Rare, Penn Medicine Analysis Shows

by Meagan Raeke

3d illustration of a damaged and disintegrating cancer cell. (Image: iStock/vitanovski)

The development of any type of second cancer following CAR T cell therapy is a rare occurrence, as found in an analysis of more than 400 patients treated at Penn Medicine, researchers from the Perelman School of Medicine at the University of Pennsylvania reported today in Nature Medicine. The team also described a single case of an incidental T cell lymphoma that did not express the CAR gene and was found in the lymph node of a patient who developed a secondary lung tumor following CAR T cell therapy.

CAR T cell therapy, a personalized form of immunotherapy in which each patient’s T cells are modified to target and kill their cancer cells, was pioneered at Penn. More than 30,000 patients with blood cancers in the United States—many of whom had few, if any, remaining treatment options available—have been treated with CAR T cell therapy since the first such therapy was approved in 2017. Some of the earliest patients treated in clinical trials have gone on to experience long-lasting remissions of a decade or more.

Secondary cancers, including T cell lymphomas, are a known, rare risk of several types of cancer treatment, including chemotherapy, radiation, and stem cell transplant. CAR T cell therapy is currently only approved to treat blood cancers that have relapsed or stopped responding to treatment, so patients who receive CAR T cell therapies have already received multiple other types of treatment and are facing dire prognoses.

In November 2023, the FDA announced an investigation into several reported cases of secondary T cell malignancies, including CAR-positive lymphoma, in patients who previously received CAR T cell therapy products. In January 2024, the FDA began requiring drugmakers to add a safety label warning to CAR T cell products. While the FDA review is still ongoing, it remains unclear whether the secondary T cell malignancies were caused by CAR T cell therapy.

As a leader in CAR T cell therapy, Penn has longstanding, clearly established protocols to monitor each patient both during and after treatment – including follow-up for 15 years after infusion – and participates in national reporting requirements and databases that track outcomes data from all cell therapy and bone marrow transplants.

Marco Ruella, M.D.

“When this case was identified, we did a detailed analysis and concluded the T cell lymphoma was not related to the CAR T cell therapy. As the news of other cases came to light, we knew we should go deeper, to comb through our own data to better understand and help define the risk of any type of secondary cancer in patients who have received CAR T cell products,” said senior author Marco Ruella, MD, an assistant professor of Hematology-Oncology and Scientific Director of the Lymphoma Program. “What we found was very encouraging and reinforces the overall safety profile for this type of personalized cell therapy.”

Read the full story in Penn Medicine News.

Marco Ruella is Assistant Professor of Medicine in the Perelman School of Medicine. He is a member of the Penn Bioengineering Graduate Group.

Building Tiny Organs

by David Levin

Dan Huh, Ph.D. (Photo credit: Leslie Barbaro)

More than 34 million Americans suffer from pulmonary diseases like asthma, emphysema and chronic bronchitis. While medical treatments can keep these ailments in check, there are currently no cures. Part of the reason, notes Dan Huh, is that it’s incredibly hard to study how these diseases actually work. While researchers can grow cells taken from human lungs in a dish, they cannot expect them to act like they would in the body. In order to mimic the real deal, it’s necessary to recreate the complex, 3D environment of the lung — right down to its tiny air sacs and blood vessels — and to gently stretch and release the tissue to simulate breathing.

Huh, Associate Professor in Bioengineering, is the cofounder of Vivodyne, a Penn Engineering biotech spinoff that is creating tissues like these in the lab. Vivodyne uses a bioengineering technology that Huh has been developing for more than a decade. While a postdoctoral fellow at Harvard’s Wyss Institute, he played a central role in creating a novel device called an “organ on a chip,” which, as the name implies, assembles multiple cell types on a tiny piece of engineered plastic to create an approximation of an organ.

“While those chips represented a major innovation,” says Huh, “they still weren’t truly lifelike. They lacked many of the essential features of their counterparts in the human body, such as the network of blood vessels running between different kinds of tissue, which are essential for transporting oxygen, nutrients, waste products and various biochemical signals.”

Read the full article in the Fall 2023 issue of the Penn Engineering Magazine.

Penn Scientists Reflect on One Year of ChatGPT

by Erica Moser

René Vidal, at the podium, introduces the event “ChatGPT turns one: How is generative AI reshaping science?” Bhuvnesh Jain, left at the table, moderated the discussion with Sudeep Bhatia, Konrad Kording, Andrew Zahrt, and Nick Pangakis.

As a neuroscientist surveying the landscape of generative AI—artificial intelligence capable of generating text, images, or other media—Konrad Kording cites two potential directions forward: One is the “weird future” of political use and manipulation, and the other is the “power tool direction,” where people use ChatGPT to get information as they would use a drill to build furniture.

“I’m not sure which of those two directions we’re going but I think a lot of the AI people are working to move us into the power tool direction,” says Kording, a Penn Integrates Knowledge (PIK) University professor with appointments in the Perelman School of Medicine and School of Engineering and Applied Science. Reflecting on how generative AI is shifting the paradigm of science as a discipline, Kording said he thinks “it will push science as a whole into a much more collaborative direction,” though he has concerns about ChatGPT’s blind spots.

Kording joined three University of Pennsylvania researchers from the chemistry, political science, and psychology departments sharing their perspectives in the recent panel “ChatGPT turns one: How is generative AI reshaping science?” PIK Professor René Vidal opened the event, which was hosted by the School of Arts & Sciences’ Data Driven Discovery Initiative (DDDI), and Bhuvnesh Jain, physics and astronomy professor and co-faculty director of DDDI, moderated the discussion.

“Generative AI is moving so rapidly that even if it’s a snapshot, it will be very interesting for all of us to get that snapshot from these wonderful experts,” Jain said. OpenAI launched ChatGPT, a large language model (LLM)-based chatbot, on Nov. 30, 2022, and it rapidly ascended to ubiquity in news reports, faculty discussions, and research papers. Colin Twomey, interim executive director of DDDI, told Penn Today that it’s an open question as to how it will change the landscape of scientific research, and the` idea of the event was to solicit colleagues’ opinions on interesting directions in their fields.

Read the full story in Penn Today.

Konrad Paul Kording is Nathan Francis Mossell University Professor in Bioengineering and Computer and Information Science in Penn Engineering and in Neuroscience in the Perelman School of Medicine.

Combined Treatment Takes a Bite Out of Tooth Decay

by Nathi Magubane

Michel Koo of the School of Dental Medicine and David Cormode of the Perelman School of Medicine and the School of Engineering and Applied Science led a team of researchers that uncovered a way to combine two FDA-approved treatments to treat tooth decay that taps into the blend’s bacteria-killing capabilities without disrupting the mouth’s microbiome. (Image: iStock / Alex Sholom)

The sting of a toothache or the discovery of a cavity is a universal dread. Dental caries, more commonly known as tooth decay, is an insidious adversary, taking a toll on millions of mouths worldwide. Caries can lead to pain, tooth loss, infection, and, in severe cases, even death.

While fluoride-based treatments have long been the gold standard in dentistry, this singular approach is now dated and has limited effect. Current treatments do not sufficiently control biofilm—the main culprit behind dental caries—and prevent enamel demineralization at the same time. This dual dilemma becomes particularly pronounced in high-risk populations where the onset of the disease can be both rapid and severe.

Now, a study from a team of researchers led by Hyun (Michel) Koo of the University of Pennsylvania’s School of Dental Medicine in collaboration with David Cormode of Penn’s Perelman School of Medicine and School of Engineering and Applied Science has unveiled an unexpected synergy in the battle against dental caries. Their research revealed that the combination of ferumoxytol (Fer) and stannous fluoride (SnF2) could point at a potent solution against dental caries. Their findings were published in Nature Communications.

“Traditional treatments often come short in managing the complex biofilm environment in the mouth,” Koo, senior co-author on the study, says. “Our combined treatment not only amplifies the effectiveness of each agent but does so with a lower dosage, hinting at a potentially revolutionary method for caries prevention in high-risk individuals.”

Read the full story in Penn Today.

Hyun (Michel) Koo is a professor in the Department of Orthodontics and in the divisions of Pediatric Dentistry and Community Oral Health and the co-founder of the Center for Innovation & Precision Dentistry in the School of Dental Medicine at the University of Pennsylvania. He is a member of the Penn Bioengineering Graduate Group.

David Cormode is an associate professor of radiology and bioengineering with appointments in Penn’s Perelman School of Medicine and School of Engineering and Applied Science.

Other authors are Yue Huang, Nil Kanatha Pandey, Shrey Shah, and Jessica C. Hsu of Penn’s Perelman School of Medicine; Yuan Liu, Aurea Simon-Soro, Zhi Ren, Zhenting Xiaang, Dongyeop Kim, Tatsuro Ito, Min Jun Oh, and Yong Li of Penn’s School of Dental Medicine; Paul. J Smeets, Sarah Boyer, Xingchen Zhao, and Derk Joester of Northwestern University; and Domenick T. Zero of Indiana University.

The work was supported by the National Institute of Health (grants R01-DE025848 and TL1TR001423 and awards S10OD026871 and R90DE031532) and the National Science Foundation (awards ECCS-2025633 and DMR-1720139).

Leveraging the Body’s Postal System to Understand and Treat Disease

by Nathi Magubane

Microwell device with a solution in the reservoir (Image: Courtesy of David E. Reynolds)

Akin to the packages sent from one person to another via an elaborate postal system, cells send tiny parcels that bear contents and packaging material that serve key purposes: To protect the contents from the outside world and to make sure it gets to the right place via a label with an address. 

These packages are known as extracellular vesicles (EVs)—lipid-bound molecules that serve a variety of regulatory and maintenance functions throughout the body. They assist in the removal of unwanted materials within the cell, and they transport proteins, aid in DNA and RNA transfer, and promote tumorigeneses in cancerous cells. 

Given their myriad roles, EVs have taken center stage for many researchers in the biomedical space as they have the potential to improve current methods of disease detection and treatment. The main challenge, however, is accurately identifying the molecular contents of EVs while also characterizing the EVs, which, unlike other cellular components that are more homogenous, have more heterogeneity.

Now, a team of researchers at the University of Pennsylvania has developed a novel platform, droplet-free double digital assay, for not only profiling individual EVs but also accurately discerning their molecular contents. The researchers took the digital assay, which quantifies the contents of a molecule via binary metric—a 1 corresponds to the presence of a molecule and a zero to the lack thereof—and applies it to the EV. The work is published in Advanced Science.

The team was led by Jina Ko, an assistant professor with appointments in the School of Engineering and Applied Science and Perelman School of Medicine. “Our method allows for highly accurate quantification of the individual molecules inside an EV,” Ko says . “This opens up many doors in the realm of early disease detection and treatment.”

The researchers first compartmentalized individual EVs utilizing a microwell approach to isolate the EVs. Next, they captured individual molecules within the EVs and amplified the signal for clarity. The team then was able to determine the expression levels of pivotal EV biomarkers with remarkable precision via fluorescence.

Read the full story in Penn Today.

Jina Ko is an assistant professor in the Department of Pathology and Laboratory Medicine in the Perelman School of Medicine and an assistant professor in the Department of Bioengineering in the School of Engineering and Applied Science at the University of Pennsylvania.

David Reynolds is a Ph.D. candidate in the Department of Bioengineering in Penn Engineering.

Other authors include, Menghan Pan, George Galanis, Yoon Ho Roh, Renee-Tyler T. Morales, Shailesh Senthil Kumar, and Su-Jin Heo of the Department of Bioengineering at Penn Engineering; Jingbo Yang and Xiaowei Xu of the Department of Pathology and Laboratory Medicine at Penn Medicine; and Wei Guo of the Department of Biology in the School of Arts & Sciences at Penn.

The research was supported by the National Institutes of Health: grants R00CA256353, R35 GM141832, and CA174523 (SPORE).

Innovation and Impact: “RNA: Past, Present and Future”

by Melissa Pappas

(Left to right): Mike Mitchell, Noor Momin, and David Meaney recording the Innovation & Impact podcast.

In the most recent episode of the Penn Engineering podcast Innovation & Impact, titled “RNA: Past, Present and Future,” David F. Meaney, Senior Associate Dean of Penn Engineering and Solomon R. Pollack Professor in Bioengineering, is joined by Mike Mitchell, Associate Professor in Bioengineering, and Noor Momin, who will be joining Penn Engineering as an Assistant Professor in Bioengineering early next year, to discuss the impact that RNA has had on health care and biomedical engineering technologies.

Mitchell outlines his lab’s research that spans drug delivery, new technology in protecting RNA and its applications in treating cancer. Momin details her research, which is focused on optimizing the immune system to protect against illnesses such as cardiovascular diseases and cancer. With Meaney driving the discussion around larger questions, including the possibility of a cancer vaccine, the three discuss what they are excited about now and where the field is going in the future with these emerging, targeted treatments.

Read the full story in Penn Engineering Today.

Subscribe to the Innovation & Impact podcast on Apple Music, Spotify or your favorite listening platforms or find all the episodes on the Penn Engineering YouTube channel.

How the Hippocampus Distinguishes True and False Memories

by Erica Moser

Image: iStock/metamorworks

Let’s say you typically eat eggs for breakfast but were running late and ate cereal. As you crunched on a spoonful of Raisin Bran, other contextual similarities remained: You ate at the same table, at the same time, preparing to go to the same job. When someone asks later what you had for breakfast, you incorrectly remember eating eggs.

This would be a real-world example of a false memory. But what happens in your brain before recalling eggs, compared to what would happen if you correctly recalled cereal?

In a paper published in Proceedings of the National Academy of Sciences, University of Pennsylvania neuroscientists show for the first time that electrical signals in the human hippocampus differ immediately before recollection of true and false memories. They also found that low-frequency activity in the hippocampus decreases as a function of contextual similarity between a falsely recalled word and the target word.

“Whereas prior studies established the role of the hippocampus in event memory, we did not know that electrical signals generated in this region would distinguish the imminent recall of true from false memories,” says psychology professor Michael Jacob Kahana, director of the Computational Memory Lab and the study’s senior author. He says this shows that the hippocampus stores information about an item with the context in which it was presented.

Researchers also found that, relative to correct recalls, the brain exhibited lower theta and high-frequency oscillations and higher alpha/beta oscillations ahead of false memories. The findings came from recording neural activity in epilepsy patients who were already undergoing invasive monitoring to pinpoint the source of their seizures.

Noa Herz, lead author and a postdoctoral fellow in Kahana’s lab at the time of the research, explains that the monitoring was done through intracranial electrodes, the methodology researchers wanted to use for this study. She says that, compared to scalp electrodes, this method “allowed us to more precisely, and directly, measure the neural signals that were generated in deep brain structures, so the activity we are getting is much more localized.”

Read the full story in Penn Today.

Michael Kahana is the Edmund J. and Louise W. Kahn Term Professor of Psychology in the School of Arts & Sciences and director of the Computational Memory Lab at the University of Pennsylvania. He is a member of the Penn Bioengineering Graduate Group.