How Bacteria Store Information to Kill Viruses (But Not Themselves)

by Luis Melecio-Zambrano

A group of bacteriophages, viruses that infect bacteria, imaged using transmission electron microscopy. New research sheds light on how bacteria fight off these invaders without triggering an autoimmune response. (Image: ZEISS Microscopy, CC BY-NC-ND 2.0)

During the last few years, CRISPR has grabbed headlines for helping treat patients with conditions as varied as blindness and sickle cell disease. However, long before humans co-opted CRISPR to fight genetic disorders, bacteria were using CRISPR as an immune system to fight off viruses.

In bacteria, CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) works by stealing small pieces of DNA from infecting viruses and storing those chunks in the genes of the bacteria. These chunks of DNA, called spacers, are then copied to form little tags, which attach to proteins that float around until they find a matching piece of DNA. When they find a match, they recognize it as a virus and cut it up.

Now, a paper published in Current Biology by researchers from the University of Pennsylvania Department of Physics and Astronomy shows that the risk of autoimmunity plays a key role in shaping how CRISPR stores viral information, guiding how many spacers bacteria keep in their genes, and how long those spacers are.

Ideally, spacers should only match DNA belonging to the virus, but there is a small statistical chance that the spacer matches another chunk of DNA in the bacteria itself. That could spell death from an autoimmune response.

“The adaptive immune system in vertebrates can produce autoimmune disorders. They’re very serious and dangerous, but people hadn’t really considered that carefully for bacteria,” says Vijay Balasubramanian, principal investigator for the paper and the Cathy and Marc Lasry Professor of Physics in the School of Arts & Sciences.

Balancing this risk can put the bacteria in something of an evolutionary bind. Having more spacers means they can store more information and fend off more types of viruses, but it also increases the likelihood that one of the spacers might match the DNA in the bacteria and trigger an autoimmune response.

Read the full story in Penn Today.

Vijay Balasubramanian is the Cathy and Marc Lasry Professor of Physics at the Department of Physics and Astronomy of the University of Pennsylvania, a visiting professor at Vrije Universiteit Brussel, and a member of the Penn Bioengineering Graduate Group.

FDA Approves Penn Pioneered CAR T Cell Therapy for Third Indication

The U.S. Food and Drug Administration has expanded its approval for Kymriah, a personalized cellular therapy developed at the Abramson Cancer Center, this time for the treatment of adults with relapsed/refractory follicular lymphoma who have received at least two lines of systemic therapy. “Patients with follicular lymphoma who relapse or don’t respond to treatment have a poor prognosis and may face a series of treatment options without a meaningful, lasting response,” said Stephen J. Schuster, the Robert and Margarita Louis-Dreyfus Professor in Chronic Lymphocytic Leukemia and Lymphoma in the Division of Hematology Oncology. It’s the third FDA approval for the “living drug,” which was the first of its kind to be approved, in 2017, and remains the only CAR T cell therapy approved for both adult and pediatric patients.

“In just over a decade, we have moved from treating the very first patients with CAR T cell therapy and seeing them live healthy lives beyond cancer to having three FDA-approved uses of these living drugs which have helped thousands of patients across the globe,” said Carl June, MD, the Richard W. Vague Professor in Immunotherapy in the department of Pathology and Laboratory Medicine in Penn’s Perelman School of Medicine and director of the Center for Cellular Immunotherapies in the Abramson Cancer Center and director of the Parker Institute for Cancer Immunotherapy at Penn. “Today’s news is new fuel for our work to define the future of cell therapy and set new standards in harnessing the immune system to treat cancer.”

Research from June, a member of the Penn Bioengineering Graduate Group, led to the initial FDA approval for the CAR T therapy (sold by Novartis as Kymriah) for treating acute lymphoblastic leukemia (ALL), one of the most common childhood cancers.

Read the full announcement in Penn Medicine News.

Center for Engineering Mechanobiology 2.0: Developing ‘Mechanointelligence’

by Evan Lerner

The dynamics governing mechanointelligence vary greatly along time- and length-scales, so detailed models of individual cells and their components are necessary to connect the effects of their physical environments to the downstream effects those forces have on biological processes.

The National Science Foundation’s Science and Technology Center (STC) program is its flagship funding mechanism for organizing interdisciplinary research on cutting-edge topics. Penn’s Center for Engineering MechanoBiology (CEMB) is one of the 18 active STCs, bringing together dozens of researchers from Penn Engineering and the Perelman School of Medicine, as well as others spread across campus and at partner institutions around the world.

With its NSF funding now renewed for another five years, the Center is entering into a new phase of its mission, centered on the nascent concept of “mechanointelligence.”

Mechanobiology is the study of the physical forces that govern the behavior of cells and their communication with their neighbors. Mechanointelligence adds another layer of complexity, attempting to understand the forces that allow cells to sense, remember and adapt to their environments.

Ultimately, harnessing these forces would allow researchers to help multicellular organisms — plants, animals and humans — better adapt to their environments as well.

“Mechanointelligence is a key element of a cell’s ability to survive and reproduce,” says CEMB Director and Eduardo D. Glandt President’s Distinguished Professor Vivek Shenoy. “Just like with complex organisms, a cell’s ‘fitness’ depends on its environment, and adapting means rewiring how its genes are expressed.”

Read the full story in Penn Engineering Today.

Vivek Shenoy is Eduardo D. Glandt President’s Distinguished Professor in Materials Science and Engineering, Bioengineering and Mechanical Engineering and Applied Mechanics.

César de la Fuente Receives 2022 RSEQ Young Investigator Award

César de la Fuente, PhD

César de la Fuente, Presidential Assistant Professor in Psychiatry, Bioengineering, Microbiology, and in Chemical and Biomolecular Engineering has been honored with a 2022 Young Investigator Award by the Royal Spanish Society of Chemistry (RSEQ) for his pioneering research efforts to combine the power of machines and biology to help prevent, detect, and treat infectious diseases.

Read the RSEQ’s announcement here.

This story originally appeared in Penn Medicine News’s Awards & Accolades post for April 2022.

 

2022 Graduate Research Fellowships for Bioengineering Students

Congratulations to the two Bioengineering students to receive 2022 National Science Foundation Graduate Research Fellowship Program (NSF GRFP) fellowships. The prestigious NSF GRFP program recognizes and supports outstanding graduate students in NSF-supported fields. The eighteen Penn 2022 honorees were selected from a highly-competitive pool of over 12,000 applications nationwide. Further information about the program can be found on the NSF website.

 Gianna Therese Busch, PhD student, Bioengineering
Gianna is a member of the systems biology lab of Arjun Raj, Professor in Bioengineering and Genetics. Her research focuses on single-cell differences in cancer metabolism and drug resistance.

 

 

 

Shawn Kang, BSE/MSE, Bioengineering (’22)
Shawn conducted research in the BIOLines Lab of Dan Huh, Associate Professor in Bioengineering, where he worked to develop more physiologically relevant models of human health and disease by combining organs-on-a-chip and organoid technology.

 

 

 

The following Bioengineering students also received Honorable Mentions:
Michael Steven DiStefano, PhD student
Rohan Dipak Patel, PhD student
Abraham Joseph Waldman, PhD student

Read the full list of NSF GRFP Honorees on the Grad Center at Penn website.

Penn Engineers Develop a New Method that Could Enable a Patient’s Own Antibodies to Eliminate Their Tumors

Tsourkas
Andrew Tsourkas, Ph.D.

One of the reasons that cancer is notoriously difficult to treat is that it can look very different for each patient. As a result, most targeted therapies only work for a fraction of cancer patients. In many cases, patients will have tumors with no known markers that can be targeted, creating an incredible challenge in identifying effective treatments. A new study seeks to address this problem with the development of a simple methodology to help differentiate tumors from healthy, normal tissues.

This new study, published in Science Advances, was led by Andrew Tsourkas, Professor in Bioengineering and Co-Director of the Center for Targeted Therapeutics and Translational Nanomedicine (CT3N), who had what he describes as a “crazy idea” to use a patient’s antibodies to find and treat their own tumors, taking advantage of the immune system’s innate ability to identify tumors as foreign. This study, spearheaded by Burcin Altun, a former postdoctoral researcher in Tsourkas’s lab, and continued and completed by Fabiana Zappala, a former graduate student in Penn Bioengineering, details their new method for site-specifically labeling “off-the-shelf” and native serum autoantibodies with T cell–redirecting domains.

Researchers have known for some time that cancer patients will generate an antibody response to their own tumors. These anti-tumor antibodies are quite sophisticated in their ability to specifically identify cancer cells; however, they are not sufficiently potent to confer a therapeutic effect. In this study, Tsourkas’s team converted these antibodies into bispecific antibodies, thereby increasing their potency. T cell-redirecting bispecific antibodies are a new form of targeted therapeutic that forms a bridge between tumor cells and T cells which have been found to be as much as a thousand-times more potent than antibodies alone. By combining the specificity of a patient’s own antibodies with the potency of bispecific antibodies, researchers can effectively create a truly personalized therapeutic that is effective against tumors.

In order to test out this new targeted therapeutic approach, the Tsourkas lab had to develop an entirely new technology, allowing them to precisely label antibodies with T cell targeting domains, creating a highly homogeneous product.  Previously it has not been possible to convert native antibodies into bispecific antibodies, but Tsourkas’s Targeted Imaging Therapeutics and Nanomedicine or TITAN lab specializes in the creation of novel targeted imaging and therapeutic agents for detection and treatment of various diseases. “Much is yet to be done before this could be considered a practical clinical approach,” says Tsourkas. “But I hope at the very least this works stimulates new ideas in the way we think about personalized medicine.”

In their next phase, Tsourkas’s team will be working to separate anti-tumor antibodies from other antibodies found in patients’ serum (which could potentially redirect the bispecific antibodies to other locations in the body), as well as examining possible adverse reactions or unintended effects and immunogenicity caused by the treatment. However, this study is just the beginning of a promising new targeted therapeutic approach to cancer treatment.

This work was supported by Emerson Collective and the National Institutes of Health, National Cancer Institute (R01 CA241661).

Moving Away From ‘Average,’ Toward the Individual

by Michele W. Berger

In a course from Annenberg’s David Lydon-Staley, seven graduate students conducted single-participant experiments. This approach, what’s known as an “n of 1,” may better capture the nuances of a diverse population than randomized control trials can.

David Lydon-Staley is an assistant professor of communication and principal investigator of the Addiction, Health, & Adolescence Lab in the Annenberg School for Communication.

To prep for an upcoming course he was teaching, Penn researcher David Lydon-Staley decided to conduct an experiment: Might melatonin gummies—supplements touted to improve sleep—help him, as an individual, fall asleep faster?

For two weeks, he took two gummies on intervention nights and none on control nights. The point, however, wasn’t really to find out whether the gummies worked for him (which they didn’t), but rather to see how an experiment with a single participant played out, what’s known as an “n of 1.”

Randomized control experiments typically include hundreds or thousands of participants. Their aim is to show, on average, how the intervention being studied affects people in the treatment group. But often “there’s a failure to include women and members of minoritized racial and ethnic groups in those clinical trials,” says Lydon-Staley, an assistant professor in the Annenberg School for Communication. “The single-case approach says, instead of randomizing a lot of people, we’re going to take one person at a time and measure them intensively.”

In Lydon-Staley’s spring semester class, Diversity and the End of Average, seven graduate students conducted their own n-of-1 experiments—on themselves—testing whether dynamic stretching might improve basketball performance or whether yoga might decrease stress. One wanted to understand the effect of journaling on emotional clarity. They also learned about representation in science, plus which analytical approaches might best capture the nuance of a diverse population and individuals with many intersecting identities.

“It’s not just an ‘n of 1’ trying to do what the big studies are doing. It’s a different perspective,” says Lydon-Staley. “Though it’s just one person, you’re getting a much more thorough characterization of how they’re changing from moment to moment.”

Read the full story in Penn Today.

David Lydon-Staley is an Assistant Professor of communication and principal investigator of the Addiction, Health, & Adolescence Lab in the Annenberg School for Communication at the University of Pennsylvania. Lydon-Staley is a former postdoctoral research in the Complex Systems Lab of Dani S. Bassett, J. Peter Skirkanich Professor in Bioengineering and in Electrical and Systems Engineering.

Exploring the History of CAR-T Cell Therapy

Carl June, MD

A new feature in Chemistry World explores the history of CAR (chimeric antigen receptor)-T cell therapy, a revolutionary type of therapeutic treatment for certain types of cancer. One of the pioneers of CAR-T cell therapy is Carl June, Richard W. Vague Professor in Immunotherapy in the Perelman School of Medicine and member of the Penn Bioengineering Graduate Group. His groundbreaking research opened the door for FDA approval of the CAR T therapy called Kymriah, which treats acute lymphoblastic leukemia (ALL), one of the most common childhood cancers.

Read “A decade of CAR-T cell therapy” in Chemistry World.

Vijay Balasubramanian Discusses Theoretical Physics in Quanta Magazine

Cathy and Marc Lasry Professor Vijay Balasubramanian at Penn’s BioPond.

In an interview with Quanta Magazine, Vijay Balasubramanian discusses his work as a theoretical physicist, noting his study of the foundations of physics and the fundamentals of space and time. He speaks of the importance of interdisciplinary study and about how literature and the humanities can contextualize scientific exploration in the study of physics, computer science, and neuroscience.

Balasubramanian is Cathy and Marc Lasry Professor in the Department of Physics and Astronomy in the Penn School of Arts and Sciences and a member of the Penn Bioengineering Graduate Group.

Read “Pondering the Bits That Build Space-Time and Brains” in Quanta Magazine.

Bioengineering Graduate Jason Andrechak Wins Graduate Leadership Award

Jason Andrechak

Congratulations to recent Penn Bioengineering graduate Jason Andrechak on winning a Graduate Leadership Awards for 2022. Each year a select number of students across the university are recognized for their service and lasting contributions to graduate student life at Penn. Andrechak, one of only ten recipients in 2022, won a Dr. Andy Binns Award for Outstanding Service to Graduate and Professional Student Life. This award is presented to “graduate or professional students, upon their graduation from Penn, who have significantly impacted graduate and professional student life through service involvement in student life initiatives or organizations.” Andrechak won this award for his “service and leadership in advocating for equity and accessibility during the transition to virtual operations and following a period of leadership transition within the Graduate and Professional Student Assembly (GAPSA). ”

Andrechak completed his Ph.D. in Bioengineering in 2022, where he studied macrophage immunotherapy in solid tumors in the lab of Dennis E. Discher, Robert D. Bent Professor in Chemical and Biomolecular Engineering, Bioengineering, and Mechanical Engineering and Applied Mechanics. He was named a National Science Foundation Graduate Research Fellow in 2018. He has actively led the Graduate Association of Bioengineers (GABE) as Community Service & Outreach chair from 2017-2019 and as co-President from 2019-2022. He also served as the Director of Equity & Access for the Graduate & Professional Student Assembly (GAPSA) from 2020-2021, in addition to several other service and advisory roles at the department, school, and university levels.

Learn more about the Penn Graduate Leadership Awards and read the full list of recipients on the Grad Center at Penn website.