Author: mantulin

3 Questions: Lindsay Case on how cells get organized and sense the world

Case’s new lab investigates why cancer arises when disruptions in cellular organization change how cells sense mechanical forces.

Saima Sidik | Department of Biology
February 2, 2021

Assistant professor of biology Lindsay Case wants to understand the protein complexes called focal adhesions that let cells move and sense the world around them. She also aims to determine how cancer arises when focal adhesions malfunction. During her postdoc work at the University of Texas Southwestern Medical Center, she discovered that some of the proteins in focal adhesions work together because of phase separation — a clumping behavior that researchers are just beginning to understand. She sat down to discuss what her work means for cancer research, and her future plans for her new lab in the Department of Biology.

Q: What is phase separation, and how does it affect the way cells function?

A: I always compare phase separation to the separation of oil and vinegar. Something similar can happen with almost any kind of molecule, including proteins. When the interactions between proteins are stronger than their interactions with their surroundings, they can segregate into something called a liquid phase, similar to oil droplets floating in vinegar.

Phase separation matters because organization is a major challenge for our cells, which contain tons of different types of molecules. Sometimes cells organize these molecules using membranes, which is like using fences to keep them in place. But many subcellular structures aren’t surrounded by membranes, and how these compartments keep their components together has been a big mystery since scientists first observed them under microscopes in the 1800s. It’s really only in the last 10 years that people have realized that phase separation is part of the answer.

When cells lose the ability to stay organized, it can have devastating consequences. Changes in how proteins phase separate might underlie serious diseases, like Alzheimer’s and ALS [amyotrophic lateral sclerosis]. I’m really interested in how phase separation organizes protein complexes called focal adhesions, which link cells to their external environment. One function of focal adhesion is to let cells sense mechanical forces from the outside world, and when cells lose this ability it can contribute to cancer progression.

Q: How did phase separation initially pique your interest, and how has your research career prepared you for the work you’ll do at MIT?

A: During my PhD, I was studying how molecules within focal adhesions are organized. I saw a talk by Michael Rosen from the University of Texas Southwestern Medical Center, who would later become my postdoc advisor. Phase separation of proteins was a new idea at the time, but Mike thought it was a powerful force underlying protein organization that we needed to understand more thoroughly. I was intrigued because, at the time, I was unsure what drove focal adhesions to assemble on the plasma membrane, and I wondered if that arrangement might be due to phase separation.

I ended up joining Mike’s lab for my postdoc so that I could apply his ideas about phase separation to my interest in cell signaling and focal adhesions. As a result, I ended up working in a field as it was being born. The first year of my postdoc there were only a few papers investigating phase separation in cellular organization, and now there are over 1,000. Seeing this rapid progress firsthand has been exciting. One of the highlights of my postdoc was showing that phase separation can actually affect the functions of signaling proteins organized on membranes, and I think this discovery went a long way towards showing that phase separation isn’t just a thing that cells can do — it’s something they need to do to survive.

MIT will be an awesome place to continue studying how phase separation lets cells sense the world around them. It’s one of the institutes where the idea of phase separation in biology took off, and the MIT scientists who work on phase separation come from so many different research backgrounds. Understanding phase separation is going to require an interdisciplinary approach, which MIT values. Plus, the students are amazing!

Q: What makes your approach to studying cancer unique?

A: A lot of cancer researchers focus on large-scale or small-scale aspects of these diseases. They either look at how cancer cells behave as a whole, or study the behavior of just one protein. But there’s a level in between where I want to focus my work. I can figure out how large, multi-protein complexes like focal adhesions — some of which form because of phase separation — affect disease progression. During my postdoc, I developed a way to recreate simplified focal adhesions outside of cells. I want to use this system to learn more about how phase separation lets these complexes sense mechanical forces, and how this changes in cancer cells.

Some of the proteins found in focal adhesions are tethered to the plasma membrane, and not many people have studied how protein phase separation changes when you throw a membrane into the mix. I’m excited to keep building up my simplified focal adhesion system in my new lab, and eventually recreate the rest of the complex.

As my lab becomes more established, I’d also like to study how phase separation affects interactions between different protein complexes and signaling pathways. Phase separation is such a rapidly evolving field that it’s hard to know where my research will lead, but that’s part of the fun — not knowing where my work will take me.

Our gut-brain connection

“Organs-on-a-chip” system sheds light on how bacteria in the human digestive tract may influence neurological diseases.

Anne Trafton | MIT News Office
January 29, 2021

In many ways, our brain and our digestive tract are deeply connected. Feeling nervous may lead to physical pain in the stomach, while hunger signals from the gut make us feel irritable. Recent studies have even suggested that the bacteria living in our gut can influence some neurological diseases.

Modeling these complex interactions in animals such as mice is difficult to do, because their physiology is very different from humans’. To help researchers better understa nd the gut-brain axis, MIT researchers have developed an “organs-on-a-chip” system that replicates interactions between the brain, liver, and colon.

Using that system, the researchers were able to model the influence that microbes living in the gut have on both healthy brain tissue and tissue samples derived from patients with Parkinson’s disease. They found that short-chain fatty acids, which are produced by microbes in the gut and are transported to the brain, can have very different effects on healthy and diseased brain cells.

“While short-chain fatty acids are largely beneficial to human health, we observed that under certain conditions they can further exacerbate certain brain pathologies, such as protein misfolding and neuronal death, related to Parkinson’s disease,” says Martin Trapecar, an MIT postdoc and the lead author of the study.

Linda Griffith, the School of Engineering Professor of Teaching Innovation and a professor of biological engineering and mechanical engineering, and Rudolf Jaenisch, an MIT professor of biology and a member of MIT’s Whitehead Institute for Medical Research, are the senior authors of the paper, which appears today in Science Advances.

The gut-brain connection

For several years, Griffith’s lab has been developing microphysiological systems — small devices that can be used to grow engineered tissue models of different organs, connected by microfluidic channels. In some cases, these models can offer more accurate information on human disease than animal models can, Griffith says.

In a paper published last year, Griffith and Trapecar used a microphysiological system to model interactions between the liver and the colon. In that study, they found that short-chain fatty acids (SCFAs), molecules produced by microbes in the gut, can worsen autoimmune inflammation associated with ulcerative colitis under certain conditions. SCFAs, which include butyrate, propionate, and acetate, can also have beneficial effects on tissues, including increased immune tolerance, and they account for about 10 percent of the energy that we get from food.

In the new study, the MIT team decided to add the brain and circulating immune cells to their multiorgan system. The brain has many interactions with the digestive tract, which can occur via the enteric nervous system or through the circulation of immune cells, nutrients, and hormones between organs.

Several years ago, Sarkis Mazmanian, a professor of microbiology at Caltech, discovered a connection between SCFAs and Parkinson’s disease in mice. He showed that SCFAs, which are produced by bacteria as they consume undigested fiber in the gut, sped up the progression of the disease, while mice raised in a germ-free environment were slower to develop the disease.

Griffith and Trapecar decided to further explore Mazmanian’s findings, using their microphysiological model. To do that, they teamed up with Jaenisch’s lab at the Whitehead Institute. Jaenisch had previously developed a way to transform fibroblast cells from Parkinson’s patients into pluripotent stem cells, which can then be induced to differentiate into different types of brain cells — neurons, astrocytes, and microglia.

More than 80 percent of Parkinson’s cases cannot be linked to a specific gene mutation, but the rest do have a genetic cause. The cells that the MIT researchers used for their Parkinson’s model carry a mutation that causes accumulation of a protein called alpha synuclein, which damages neurons and causes inflammation in brain cells. Jaenisch’s lab has also generated brain cells that have this mutation corrected but are otherwise genetically identical and from the same patient as the diseased cells.

Griffith and Trapecar first studied these two sets of brain cells in microphysiological systems that were not connected to any other tissues, and found that the Parkinson’s cells showed more inflammation than the healthy, corrected cells. The Parkinson’s cells also had impairments in their ability to metabolize lipids and cholesterol.

Opposite effects

The researchers then connected the brain cells to tissue models of the colon and liver, using channels that allow immune cells and nutrients, including SCFAs, to flow between them. They found that for healthy brain cells, being exposed to SCFAs is beneficial, and helps them to mature. However, when brain cells derived from Parkinson’s patients were exposed to SCFAs, the beneficial effects disappeared. Instead, the cells experienced higher levels of protein misfolding and cell death.

These effects were seen even when immune cells were removed from the system, leading the researchers to hypothesize that the effects are mediated by changes to lipid metabolism.

“It seems that short-chain fatty acids can be linked to neurodegenerative diseases by affecting lipid metabolism rather than directly affecting a certain immune cell population,” Trapecar says. “Now the goal for us is to try to understand this.”

The researchers also plan to model other types of neurological diseases that may be influenced by the gut microbiome. The findings offer support for the idea that human tissue models could yield information that animal models cannot, Griffith says. She is now working on a new version of the model that will include micro blood vessels connecting different tissue types, allowing researchers to study how blood flow between tissues influences them.

“We should be really pushing development of these, because it is important to start bringing more human features into our models,” Griffith says. “We have been able to start getting insights into the human condition that are hard to get from mice.”

The research was funded by DARPA, the National Institutes of Health, the National Institute of Biomedical Imaging and Bioengineering, the National Institute of Environmental Health Sciences, the Koch Institute Support (core) Grant from the National Cancer Institute, and the Army Research Office Institute for Collaborative Biotechnologies.

Department of Biology receives funds to support summer students

Generous gift from Michael Gould and Sara Moss provides endowed support for MIT’s Summer Research Program in Biology.

Department of Biology
January 27, 2021

Last month, the Department of Biology received a generous gift from Michael Gould and Sara Moss to support students participating in MIT’s Summer Research Program in Biology (MSRP-Bio). Gould is a philanthropist and the retired chair and CEO of Bloomingdales, and Moss is the vice chair of Estée Lauder Companies. Their gift will supplement the existing Bernard S. and Sophie G. Gould Fund, which the couple initiated in 2015 to honor Gould’s parents. Together, these donations will enable many undergraduate students from outside MIT who are interested in a career in life science to participate in MSRP-Bio each summer. To honor the Gould family’s generosity, MSRP-Bio will be renamed the Bernard S. and Sophie G. Gould MIT Summer Research Program in Biology, or BSG-MSRP-Bio.

“We are deeply grateful to Mike and Sara for their commitment to and support for our community,” says department head and Praecis Professor Alan Grossman. “Their willingness to enable opportunities for students will allow many talented individuals to benefit from research experiences here at MIT, and foster the next generation of scientists.”

“Mike Gould and Sara Moss are amazing people,” says Mandana Sassanfar, the Department of Biology’s director of outreach. “They’ve made a generous gift that has enabled MRSP-Bio to give many deserving undergraduates a life-changing summer research experience.”

MSRP-Bio is a 10-week summer program offered to non-MIT undergraduates, which provides access to cutting-edge facilities and supervised research in a fast-paced environment. The program encourages students from groups that are historically underrepresented in science, first-generation college students, students from economically disadvantaged backgrounds, and students with disabilities to attend graduate school and pursue careers in basic research.

Every year, roughly 20 participants are placed in laboratories affiliated with the Department of Biology. In total, nearly 400 students have participated in MSRP-Bio since its establishment in 2003. Nearly 300 have already gone to PhD or MD/PhD programs, and of these, 63 have enrolled at MIT for graduate school and 45 have joined the Department of Biology specifically.

Gould and Moss were inspired to create a fund supporting MSRP-Bio because both of Gould’s parents were MIT alumni devoted to mentorship. Bernard “Bernie” Gould ’32 was a beloved biochemistry professor in the Department of Biology and counseled many biology and pre-med students for 50 years. His wife, Sophia Gould CMP ’48, earned a master’s degree in public health at a time when there were few female graduate students at the Institute, and shared this passion for training students.

“I’ve been inspired by my father, who was a first-generation American, cared enormously about his students, and nurtured their intellectual curiosity and drive,” Michael Gould says. “MSRP-Bio does the same by giving each student the opportunity of a lifetime. My dream is for every department at MIT to create a similar program. It would enrich the Institute immeasurably.”

“This gift will have a tremendous impact on the MSRP-Bio program in the biology department, and comes at a crucial time as issues surrounding diversity, equity, and inclusion remain key priorities for the School of Science and Institute,” says Nergis Mavalvala, dean of MIT’s School of Science.

Since its inauguration in 2015, the Bernard S. and Sophie G. Gould Fund has offered scholarships to 30 MSRP-Bio students — six each year. Every summer, Gould and Moss travel to campus to get to know the current Gould fellows. The duo has been continually impressed by the caliber of students, and decided to provide more support to fund additional fellows and ensure the program’s longevity.

“Mike and Sara have a sustained interest in the well-being and success of the Gould fellows, and take pride in these students’ accomplishments,” Sassanfar says. “The Gould Fellowship stands out because of the open relationship between the Mike and Sara and the fellows, which forges meaningful connections that will last for many years.”

Participating in MSRP-Bio was a “life-changing” experience, says former Gould Fellow Meucci Ilunga. “I genuinely mean that — I can only imagine how different my life would be if I had not had that opportunity.”

Former Gould Fellow Asmita Panthi adds that MSRP-Bio showed her what she was capable of accomplishing, and gave her the confidence to apply to graduate school. “I’m so thankful for this impactful fellowship, which gives students like me — who come from small undergraduate institutions or humble backgrounds — the chance to participate in a rigorous research program.”

Four MIT scientists honored with 2021 National Academy of Sciences awards

Pablo Jarillo-Herrero, Aviv Regev, Susan Solomon, and Feng Zhang are the recipients of distinguished awards for major contributions to science.

Laura Carter | School of Science
January 25, 2021

Four MIT scientists are among the 20 recipients of the 2021 Academy Honors for major contributions to science, the National Academy of Sciences (NAS) announced at its annual meeting. The individuals are recognized for their “extraordinary scientific achievements in a wide range of fields spanning the physical, biological, social, and medical sciences.”

The awards recognize: Pablo Jarillo-Herrero, for contributions to the fields of nanoscience and nanotechnology through his discovery of correlated insulator behavior and unconventional superconductivity in magic-angle graphene superlattices; Aviv Regev, for using interdisciplinary information or techniques to solve a contemporary challenge; Susan Solomon, for contributions to understanding and communicating the causes of ozone depletion and climate change; and Feng Zhang, for pioneering achievements developing CRISPR tools with the potential to diagnose and treat disease.

Pablo Jarillo-Herrero: Award for Scientific Discovery

Pablo Jarillo-Herrero, a Cecil and Ida Green Professor of Physics, is the recipient of the NAS Award for Scientific Discovery for his pioneering developments in nanoscience and nanotechnology, which is presented to scientists in the fields of astronomy, materials science, or physics. His findings expand nanoscience by demonstrating for the first time that orientation can be used to dramatically control nanomaterial properties and to design new nanomaterials. This work lays the groundwork for developing a whole new family of 2D materials and has had a transformative impact on the field and on condensed-matter physics.

The biannual award recognizes “an accomplishment or discovery in basic research, achieved within the previous five years, that is expected to have a significant impact on one or more of the following fields: astronomy, biochemistry, biophysics, chemistry, materials science, or physics.”

In 2018, his research group discovered that by rotating two layers of graphene relative to each other by a magic angle, the bilayer material can be turned from a metal into an electrical insulator or even a superconductor. This discovery has fostered new theoretical and experimental research, inspiring the interest of technologists in nanoelectronics. The result is a new field in condensed-matter physics that has the potential to result in materials that conduct electricity without resistance at room temperature.

Aviv Regev: James Prize in Science and Technology Integration

Aviv Regev, who is a professor of biology, a core member of the Broad Institute of Harvard and MIT, a member of the Koch Institute, and a Howard Hughes Medical Institute investigator has been selected for the inaugural James Prize in Science and Technology Integration, along with Harvard Medical School Professor Allon Kelin, for “their concurrent development of now widely adopted massively parallel single-cell genomics to interrogate the gene expression profiles that define, at the level of individual cells, the distinct cell types in metazoan tissues, their developmental trajectories, and disease states, which integrated tools from molecular biology, engineering, statistics, and computer science.”

The prize recognizes individuals “who are able to adopt or adapt information or techniques from outside their fields” to “solve a major contemporary challenge not addressable from a single disciplinary perspective.”

Regev is credited with forging new ways to unite the disciplines of biology, computational science, and engineering as a pioneer in the field of single-cell biology, including developing some of its core experimental and analysis tools, and their application to discover cell types, states, programs, environmental responses, development, tissue locations, and regulatory circuits, and deploying these to assemble cellular atlases of the human body that illuminate mechanisms of disease with remarkable fidelity.

Susan Solomon: Award for Chemistry in Service to Society

Susan Solomon, the Lee and Geraldine Martin Professor of Environmental Studies in the Department of Earth, Atmospheric and Planetary Sciences who holds a secondary appointment in the Department of Chemistry, is the recipient of the Award for Chemistry in Service to Society for “influential and incisive application of atmospheric chemistry to understand our most critical environmental issues — ozone layer depletion and climate change — and for her effective communication of environmental science to leaders to facilitate policy changes.”

The award is given biannually for “contributions to chemistry, either in fundamental science or its application, that clearly satisfy a societal need.”

Solomon is globally recognized as a leader in atmospheric science, notably for her insights in explaining the cause of the Antarctic ozone “hole.” She and her colleagues have made important contributions to understanding chemistry-climate coupling, including pioneering research on the irreversibility of global warming linked to anthropogenic carbon dioxide emissions, and on the influence of the ozone hole on the climate of the southern hemisphere.

Her work has had an enormous effect on policy and society, including the transition away from ozone-depleting substances and to environmentally benign chemicals. The work set the stage for the Paris Agreement on climate, and she continues to educate policymakers, the public, and the next generation of scientists.

Feng Zhang: Richard Lounsbery Award

Feng Zhang, who is the James and Patricia Poitras Professor of Neuroscience at MIT, an investigator at the McGovern Institute for Brain Research and the Howard Hughes Medical Institute, a professor of brain and cognitive sciences and biological engineering at MIT, and a core member of the Broad Institute of MIT and Harvard, is the recipient of the Richard Lounsbery Award for pioneering CRISPR-mediated genome editing.

The award recognizes “extraordinary scientific achievement in biology and medicine” as well as stimulating research and encouraging reciprocal scientific exchanges between the United States and France.

Zhang continues to lead the field through the discovery of novel CRISPR systems and their development as molecular tools with the potential to diagnose and treat disease, such as disorders affecting the nervous system. His contributions in genome engineering, as well as his earlier work developing optogenetics, are enabling a deeper understanding of behavioral neural circuits and advances in gene therapy for treating disease.

In addition, Zhang has championed the open sharing of the technologies he has developed through extensive resource sharing. The tools from his lab are being used by thousands of scientists around the world to accelerate research in nearly every field of the life sciences. Even as biomedical researchers around the world adopt Zhang’s discoveries and his tools enter the clinic to treat genetic diseases, he continues to innovate and develop new technologies to advance science.

The National Academy of Sciences is a private, nonprofit society of distinguished scholars, established in 1863 by the U.S. Congress. The NAS is charged with providing independent, objective advice to the nation on matters related to science and technology as well as encouraging education and research, recognize outstanding contributions to knowledge, and increasing public understanding in matters of science, engineering, and medicine. Winners received their awards, which include a monetary prize, during a virtual ceremony at the 158th NAS Annual Meeting.

This story is a modified compilation from several National Academy of Sciences press releases.

Understanding antibodies to avoid pandemics

Structural biologist Pamela Björkman shared insights into pandemic viruses as part of the Department of Biology’s IAP seminar series.

Saima Sidik | Department of Biology
January 19, 2021

Last month, the world welcomed the rollout of vaccines that may finally curb the Covid-19 pandemic. Pamela Björkman, the David Baltimore Professor of Biology and Bioengineering at Caltech, wants to understand how antibodies like the ones elicited by these vaccines target the SARS-CoV-2 virus that causes Covid-19. She hopes this understanding will guide treatment strategies and help design vaccines against future pandemics. She shared her lab’s work during the MIT Department of Biology’s Independent Activities Period (IAP) seminar series, Immunity from Principles to Practice, on Jan. 12.

“Pamela is an amazing scientist, a strong advocate for women in science, and has a stellar history of studying the structural biology of virus-antibody interactions,” says Whitehead Institute for Biomedical Research Member Pulin Li, the Eugene Bell Career Development Professor of Tissue Engineering and one of the organizers of this year’s lecture series.

Immunology research often progresses from the lab bench to the clinic quickly, as was the case with Covid-19 vaccines, says Latham Family Career Development Professor of Biology and Whitehead Institute Member Sebastian Lourido, who organized the lecture series with Li. He and Li chose to focus this year’s seminar series on immunity because this field highlights the tie between basic molecular biology, which is a cornerstone of the Department of Biology, and practical applications.

“Pamela’s work is an excellent example of how fundamental discoveries can be intimately tied to real-world applications,” Lourido says.

Björkman’s lab has a long history of studying antibodies, which are protective proteins that the body generates in response to invading pathogens. Björkman focuses on neutralizing antibodies, which bind and jam up the molecular machines that let viruses reproduce in human cells. Last fall, the U.S. Food and Drug Administration (FDA) authorized a combination of two neutralizing antibodies, produced by the pharmaceutical company Regeneron, for emergency use in people with mild to moderate Covid-19. This remains one of the few treatments available for the disease.

Together with Michel Nussenzweig’s lab at The Rockefeller University, Börkman’s lab identified four categories of neutralizing antibodies that prevent a protein that decorates SARS-CoV-2’s surface, called the spike protein, from binding to a human protein called ACE2. Spike acts like the virus’s key, with ACE2 being the lock it has to open to enter human cells. Some of the antibodies that Björkman’s lab characterized bind to the tip of spike so that it can’t fit into ACE2, like sticking a wad of chewing gum on top of the virus’s key. Others block spike proteins from interacting with ACE2 by preventing them from altering their orientations. Understanding the variety of ways that neutralizing antibodies work will let scientists figure out how to combine them into maximally effective treatments.

Björkman isn’t satisfied with just designing treatments for this pandemic, however. “Coronavirus experts say this is going to keep happening,” she says. “We need to be prepared next time.”

To this end, Björkman’s lab has put pieces of spike-like proteins from multiple animal coronaviruses onto nanoparticles and injected them into mice. This made the mice generate antibodies against a mix of pathogens that are poised to jump into humans, suggesting that scientists could use this approach to create vaccines before pandemics occur. Importantly, the nanoparticles still work after they’re freeze-dried, meaning that companies could stockpile them, and that they could be shipped at room temperature.

Björkman’s talk was the second in the Immunity from Principles to Practice series, which was kicked off by Gabriel Victora from The Rockefeller University. Victora discussed how antibodies are produced in structures called germinal centers that are found in lymph nodes and the spleen.

Next in the series is Chris Garcia from Stanford University, who will speak on Jan. 19 about his lab’s work on engineering immune signaling molecules to maximize their potential to elicit therapeutic responses. To round out the series, Yasmine Belkaid from the National Institute of Allergy and Infectious Disease will speak on Jan. 26 about interactions between the gut microbiome and the pathogens we ingest. These talks complement a number of career development seminars that were organized by graduate students Fiona Aguilar, Alex Chan, Chris Giuliano, Alice Herneisen, Jimmy Ly, and Aditya Nair.

Biden taps Eric Lander and Maria Zuber for senior science posts

Lander to take a leave of absence to assume Cabinet-level post; Zuber to co-chair presidential advisory council.

Steve Bradt | MIT News Office
January 19, 2021

President-elect Joseph Biden has selected two MIT faculty leaders — Broad Institute Director Eric Lander and Vice President for Research Maria Zuber — for top science and technology posts in his administration.

Lander has been named Presidential Science Advisor, a position he will assume soon after Biden’s inauguration on Jan. 20. He has also been nominated as director of the Office of Science and Technology Policy (OSTP), a position that requires Senate confirmation.

Biden intends to elevate the Presidential Science Advisor, for the first time in history, to be a member of his Cabinet.

Zuber has been named co-chair of the President’s Council of Advisors on Science and Technology (PCAST), along with Caltech chemical engineer Frances Arnold, a 2018 winner of the Nobel Prize in chemistry. Zuber and Arnold will be the first women ever to co-chair PCAST.

Lander, Zuber, Arnold, and other appointees will join Biden in Wilmington, Delaware, on Saturday afternoon, where the president-elect will introduce his team of top advisors on science and technology, domains he has declared as crucial to America’s future. Biden has charged this team with recommending strategies and actions to ensure that the nation maximizes the benefits of science and technology for America’s welfare in the 21st century, including addressing health needs, climate change, national security, and economic prosperity.

“From Covid-19 to climate change, cybersecurity to U.S. competitiveness in innovation, the nation faces urgent challenges whose solutions depend on a broad and deep understanding of the frontiers of science and technology. In that context, it is enormously meaningful that science is being raised to a Cabinet-level position for the first time,” MIT President L. Rafael Reif says. “With his piercing intelligence and remarkable record as scientific pioneer, Eric Lander is a superb choice for this new role. And given her leadership of immensely complex NASA missions and her deep engagement with the leading edge of dozens of scientific domains as MIT’s vice president for research, it is difficult to imagine someone more qualified to co-chair PCAST than Maria Zuber. This is a banner day for science, and for the nation.”

Lander will take a leave of absence from MIT, where he is a professor of biology, and the Broad Institute, which he has led since its 2004 founding. The Broad Institute announced today that Todd Golub, currently its chief scientific officer as well as a faculty member at Harvard Medical School and an investigator at the Dana-Farber Cancer Institute, will succeed Lander as director.

Zuber, the E.A. Griswold Professor of Geophysics in MIT’s Department of Earth, Atmospheric, and Planetary Sciences, will continue to serve as the Institute’s vice president for research, a position she has held since 2013.

Separately, Biden announced earlier this week that he will nominate Gary Gensler, professor of the practice of global economics and management at the MIT Sloan School of Management, as chair of the Securities and Exchange Commission.

Eric Lander

Eric S. Lander, 63, has served since 2004 as founding director of the Broad Institute of MIT and Harvard. A geneticist, molecular biologist, and mathematician, he was one of the principal leaders of the international Human Genome Project from 1990 to 2003, and is committed to attracting, teaching, and mentoring a new generation of scientists to fulfill the promise of genomic insights to benefit human health.

From 2009 to 2017, Lander informed federal policy on science and technology as co-chair of PCAST throughout the two terms of President Barack Obama.

“Our country once again stands at a consequential moment with respect to science and technology, and how we respond to the challenges and opportunities ahead will shape our future for the rest of this century,” Lander says. “President-elect Biden understands the central role of science and technology, and I am deeply honored to have been asked to serve.”

Trained as a mathematician, Lander earned a BA in mathematics from Princeton University in 1978. As a Rhodes Scholar from 1978 to 1981, he attended Oxford University, where he earned his doctorate in mathematics. Lander served on the Harvard Business School faculty from 1981 to 1990, teaching courses on managerial economics, decision analysis, and bargaining.

In 1983, his younger brother, Arthur, a developmental neurobiologist, suggested that, with his interest in coding theory, Lander might be interested in how biological systems, including the brain, encode and process information. Lander began to audit courses at Harvard and to moonlight in laboratories around Harvard and MIT, learning about molecular biology and genetics.

In 1986, he was appointed a Whitehead Fellow of the Whitehead Institute for Biomedical Research, where he started his own laboratory. In 1990, Lander was appointed as a tenured professor in MIT’s Department of Biology and as a member of the Whitehead Institute.

Lander’s honors and awards include the MacArthur Fellowship, the Breakthrough Prize in Life Sciences, the Albany Prize in Medicine and Biological Research, the Gairdner Foundation International Award of Canada, and MIT’s Killian Faculty Achievement Award. He was elected as a member of the U.S. National Academy of Sciences in 1997 and of the U.S. Institute of Medicine in 1999.

Maria Zuber

The daughter of a Pennsylvania state trooper and the granddaughter of coal miners, Maria T. Zuber, 62, has been a member of the MIT faculty since 1995 and MIT’s vice president for research since 2013. She has served since 2012 on the 24-member National Science Board (NSB), the governing body of the National Science Foundation, serving as NSB chair from 2016 to 2019.

Zuber’s own research bridges planetary geophysics and the technology of space-based laser and radio systems. She was the first woman to lead a NASA spacecraft mission, serving as principal investigator of the space agency’s Gravity Recovery and Interior Laboratory (GRAIL) mission, an effort launched in 2008 to map the moon’s gravitational field to answer fundamental questions about the moon’s evolution and internal composition. In all, Zuber has held leadership roles associated with scientific experiments or instrumentation on nine NASA missions since 1990.

As MIT’s vice president for research, Zuber is responsible for research administration and policy. She oversees more than a dozen interdisciplinary research centers, including the David H. Koch Institute for Integrative Cancer Research, the Plasma Science and Fusion Center, the Research Laboratory of Electronics, the Institute for Soldier Nanotechnologies, the MIT Energy Initiative (MITEI), and the Haystack Observatory. She is also responsible for MIT’s research integrity and compliance, and plays a central role in research relationships with the federal government.

“Many of the most pressing challenges facing the nation and the world will require breakthroughs in science and technology,” Zuber says. “An essential element of any solution must be rebuilding trust in science, and I’m thrilled to have the opportunity to work with President-elect Biden and his team to drive positive change.”

Zuber holds a BA in astronomy and geology from the University of Pennsylvania, awarded in 1980, and an ScM and PhD in geophysics from Brown University, awarded in 1983 and 1986, respectively. She has received awards and honors including MIT’s Killian Faculty Achievement Award; the American Geophysical Union’s Harry H. Hess Medal; and numerous NASA awards, including the Distinguished Public Service Medal and the Outstanding Public Leadership Medal. She was elected as a member of the National Academy of Sciences in 2004.

Todd Golub

Todd Golub, 57, will become the next director of the Broad Institute. He joined Dana-Farber and Harvard Medical School in 1997, and is currently a professor of pediatrics at Harvard Medical School and the Charles A. Dana Investigator in Human Cancer Genetics at Dana-Farber.

Golub served as a leader of the Whitehead Institute/MIT Center for Genome Research, the precursor to the Broad Institute. He has also been an investigator with the Howard Hughes Medical Institute, and has served as chair of numerous scientific advisory boards, including at St. Jude Children’s Research Hospital and the National Cancer Institute’s Board of Scientific Advisors.

Golub is also an entrepreneur, having co-founded several biotechnology companies to develop diagnostic and therapeutic products. He has created and applied genomic tools to understand the basis of disease, and to develop new approaches to drug discovery. He has made fundamental discoveries in the molecular basis of human cancer, and has helped develop new approaches to precision medicine.

“Broad is in a stronger scientific and cultural position today than at any point in our 16-year history,” Golub says. “Moreover, the pandemic has pushed us to think differently about nearly every aspect of how we collaborate and deliver on our scientific mission. We are well-positioned to work with the larger scientific community to confront some of the most urgent challenges in biomedicine: from developing novel diagnostics and therapeutics for infectious diseases and cancer, to understanding the genetic basis of cardiovascular disease and mental illness. I am honored to serve as director of this remarkable institution.”

Members of the Broad Institute’s Board of Directors thanked Lander for his lengthy service and expressed optimism in Golub’s ability to build upon that foundation.

“Todd’s deep knowledge of the Broad Institute community, its science, and its mission to propel the understanding and treatment of disease make him the perfect choice for the Institute’s next director,” says Louis Gerstner, Jr., chair of the Broad Institute Board of Directors. “Todd is well-positioned to lead the Institute and our key scientific collaborations forward, and the board is highly confident he will continue the Broad’s culture of innovation, collegiality, and constant renewal.”

Broad board member Shirley Tilghman, professor of molecular biology and public policy and president emerita of Princeton University, adds: “In its 16 years, the Broad has become one of the most unique institutions in the biomedical ecosystem. Under Eric’s and Todd’s leadership, it has developed powerful new methods and made many contributions to genomic medicine that will benefit human health.”

Why cancer cells waste so much energy

MIT study sheds light on the longstanding question of why cancer cells get their energy from fermentation.

Anne Trafton | MIT News Office
January 19, 2021

In the 1920s, German chemist Otto Warburg discovered that cancer cells don’t metabolize sugar the same way that healthy cells usually do. Since then, scientists have tried to figure out why cancer cells use this alternative pathway, which is much less efficient.

MIT biologists have now found a possible answer to this longstanding question. In a study appearing in Molecular Cell, they showed that this metabolic pathway, known as fermentation, helps cells to regenerate large quantities of a molecule called NAD+, which they need to synthesize DNA and other important molecules. Their findings also account for why other types of rapidly proliferating cells, such as immune cells, switch over to fermentation.

“This has really been a hundred-year-old paradox that many people have tried to explain in different ways,” says Matthew Vander Heiden, an associate professor of biology at MIT and associate director of MIT’s Koch Institute for Integrative Cancer Research. “What we found is that under certain circumstances, cells need to do more of these electron transfer reactions, which require NAD+, in order to make molecules such as DNA.”

Vander Heiden is the senior author of the new study, and the lead authors are former MIT graduate student and postdoc Alba Luengo PhD ’18 and graduate student Zhaoqi Li.

Inefficient metabolism

Fermentation is one way that cells can convert the energy found in sugar to ATP, a chemical that cells use to store energy for all of their needs. However, mammalian cells usually break down sugar using a process called aerobic respiration, which yields much more ATP. Cells typically switch over to fermentation only when they don’t have enough oxygen available to perform aerobic respiration.

Since Warburg’s discovery, scientists have put forth many theories for why cancer cells switch to the inefficient fermentation pathway. Warburg originally proposed that cancer cells’ mitochondria, where aerobic respiration occurs, might be damaged, but this turned out not to be the case. Other explanations have focused on the possible benefits of producing ATP in a different way, but none of these theories have gained widespread support.

In this study, the MIT team decided to try to come up with a solution by asking what would happen if they suppressed cancer cells’ ability to perform fermentation. To do that, they treated the cells with a drug that forces them to divert a molecule called pyruvate from the fermentation pathway into the aerobic respiration pathway.

They saw, as others have previously shown, that blocking fermentation slows down cancer cells’ growth. Then, they tried to figure out how to restore the cells’ ability to proliferate, while still blocking fermentation. One approach they tried was to stimulate the cells to produce NAD+, a molecule that helps cells to dispose of the extra electrons that are stripped out when cells make molecules such as DNA and proteins.

When the researchers treated the cells with a drug that stimulates NAD+ production, they found that the cells started rapidly proliferating again, even though they still couldn’t perform fermentation. This led the researchers to theorize that when cells are growing rapidly, they need NAD+ more than they need ATP. During aerobic respiration, cells produce a great deal of ATP and some NAD+. If cells accumulate more ATP than they can use, respiration slows and production of NAD+ also slows.

“We hypothesized that when you make both NAD+ and ATP together, if you can’t get rid of ATP, it’s going to back up the whole system such that you also cannot make NAD+,” Li says.

Therefore, switching to a less efficient method of producing ATP, which allows the cells to generate more NAD+, actually helps them to grow faster. “If you step back and look at the pathways, what you realize is that fermentation allows you to generate NAD+ in an uncoupled way,” Luengo says.

Solving the paradox

The researchers tested this idea in other types of rapidly proliferating cells, including immune cells, and found that blocking fermentation but allowing alternative methods of NAD+ production enabled cells to continue rapidly dividing. They also observed the same phenomenon in nonmammalian cells such as yeast, which perform a different type of fermentation that produces ethanol.

“Not all proliferating cells have to do this,” Vander Heiden says. “It’s really only cells that are growing very fast. If cells are growing so fast that their demand to make stuff outstrips how much ATP they’re burning, that’s when they flip over into this type of metabolism. So, it solves, in my mind, many of the paradoxes that have existed.”

The findings suggest that drugs that force cancer cells to switch back to aerobic respiration instead of fermentation could offer a possible way to treat tumors. Drugs that inhibit NAD+ production could also have a beneficial effect, the researchers say.

The research was funded by the Ludwig Center for Molecular Oncology, the National Science Foundation, the National Institutes of Health, the Howard Hughes Medical Institute, the Medical Research Council, NHS Blood and Transplant, the Novo Nordisk Foundation, the Knut and Alice Wallenberg Foundation, Stand Up 2 Cancer, the Lustgarten Foundation, and the MIT Center for Precision Cancer Medicine.

Neuroscientists identify brain circuit that encodes timing of events

Findings suggest this hippocampal circuit helps us to maintain our timeline of memories.

Anne Trafton | MIT News Office
January 12, 2021

When we experience a new event, our brain records a memory of not only what happened, but also the context, including the time and location of the event. A new study from MIT neuroscientists sheds light on how the timing of a memory is encoded in the hippocampus, and suggests that time and space are encoded separately.

In a study of mice, the researchers identified a hippocampal circuit that the animals used to store information about the timing of when they should turn left or right in a maze. When this circuit was blocked, the mice were unable to remember which way they were supposed to turn next. However, disrupting the circuit did not appear to impair their memory of where they were in space.

The findings add to a growing body of evidence suggesting that when we form new memories, different populations of neurons in the brain encode time and place information, the researchers say.

“There is an emerging view that ‘place cells’ and ‘time cells’ organize memories by mapping information onto the hippocampus. This spatial and temporal context serves as a scaffold that allows us to build our own personal timeline of memories,” says Chris MacDonald, a research scientist at MIT’s Picower Institute for Learning and Memory and the lead author of the study.

Susumu Tonegawa, the Picower Professor of Biology and Neuroscience at the RIKEN-MIT Laboratory of Neural Circuit Genetics at the Picower Institute, is the senior author of the study, which appears this week in the Proceedings of the National Academy of Sciences.

Time and place

About 50 years ago, neuroscientists discovered that the brain’s hippocampus contains neurons that encode memories of specific locations. These cells, known as place cells, store information that becomes part of the context of a particular memory.

The other critical piece of context for any given memory is the timing. In 2011, MacDonald and the late Howard Eichenbaum, a professor of psychological and brain sciences at Boston University, discovered cells that keep track of time, in a part of the hippocampus called CA1.

In that study, MacDonald, who was then a postdoc at Boston University, found that these cells showed specific timing-related firing patterns when mice were trained to associate two stimuli — an object and an odor — that were presented with a 10-second delay between them. When the delay was extended to 20 seconds, the cells reorganized their firing patterns to last 20 seconds instead of 10.

“It’s almost like they’re forming a new representation of a temporal context, much like a spatial context,” MacDonald says. “The emerging view seems to be that both place and time cells organize memory by mapping experience to a representation of context that is defined by time and space.”

In the new study, the researchers wanted to investigate which other parts of the brain might be feeding CA1 timing information. Some previous studies had suggested that a nearby part of the hippocampus called CA2 might be involved in keeping track of time. CA2 is a very small region of the hippocampus that has not been extensively studied, but it has been shown to have strong connections to CA1.

To study the links between CA2 and CA1, the researchers used an engineered mouse model in which they could use light to control the activity of neurons in the CA2 region. They trained the mice to run a figure-eight maze in which they would earn a reward if they alternated turning left and right each time they ran the maze. Between each trial, they ran on a treadmill for 10 seconds, and during this time, they had to remember which direction they had turned on the previous trial, so they could do the opposite on the upcoming trial.

When the researchers turned off CA2 activity while the mice were on the treadmill, they found that the mice performed very poorly at the task, suggesting that they could no longer remember which direction they had turned in the previous trial.

“When the animals are performing normally, there is a sequence of cells in CA1 that ticks off during this temporal coding phase,” MacDonald says. “When you inhibit the CA2, what you see is the temporal coding in CA1 becomes less precise and more smeared out in time. It becomes destabilized, and that seems to correlate with them also performing poorly on that task.”

Memory circuits

When the researchers used light to inhibit CA2 neurons while the mice were running the maze, they found little effect on the CA1 “place cells” that allow the mice to remember where they are. The findings suggest that spatial and timing information are encoded preferentially by different parts of the hippocampus, MacDonald says.

“One thing that’s exciting about this work is this idea that spatial and temporal information can operate in parallel and might merge or separate at different points in the circuit, depending on what you need to accomplish from a memory standpoint,” he says.

MacDonald is now planning additional studies of time perception, including how we perceive time under different circumstances, and how our perception of time influences our behavior. Another question he hopes to pursue is whether the brain has different mechanisms for keeping track of events that are separated by seconds and events that are separated by much longer periods of time.

“Somehow the information that we store in memory preserves the sequential order of events across very different timescales, and I’m very interested in how it is that we’re able to do that,” he says.

The research was funded by the RIKEN Center for Brain Science, the Howard Hughes Medical Institute, and the JPB Foundation.

Turning microbiome research into a force for health

A diverse group of researchers is working to turn new discoveries about the trillions of microbes in the body into treatments for a range of diseases.

Zach Winn | MIT News Office
January 8, 2021

The microbiome comprises trillions of microorganisms living on and inside each of us. Historically, some researchers have guessed at its role in human health, but in the last decade or so genetic sequencing techniques have illuminated this galaxy of microorganisms enough to study it in detail.

As researchers unravel the complex interplay between our bodies and microbiomes, they are beginning to appreciate the full scope of the field’s potential for treating disease and promoting health.

For instance, the growing list of conditions that correspond with changes in the microbes of our gut includes type 2 diabetes, inflammatory bowel disease, Alzheimer’s disease, and a variety of cancers.

“In almost every disease context that’s been investigated, we’ve found different types of microbial communities, divergent between healthy and sick patients,” says professor of biological engineering Eric Alm. “The promise [of these findings] is that some of those differences are going to be causal, and intervening to change the microbiome is going to help treat some of these diseases.”

Alm’s lab, in conjunction with collaborators at the Broad Institute of MIT and Harvard, did some of the early work characterizing the gut microbiome and showing its relationship to human health. Since then, microbiome research has exploded, pulling in researchers from far-flung fields and setting new discoveries in motion. Startups are now working to develop microbiome-based therapies, and nonprofit organizations have also sprouted up to ensure these basic scientific advances turn into treatments that benefit the maximum number of people.

“The first chapter in this field, and our history, has been validating this modality,” says Mark Smith PhD ’14, a co-founder of OpenBiome, which processes stool donations for hospitals to conduct stool transplants for patients battling gut infection. Smith is also currently CEO of the startup Finch Therapeutics, which is developing microbiome-based treatments. “Until now, it’s been about the promise of the microbiome. Now I feel like we’ve delivered on the first promise. The next step is figuring out how big this gets.”

An interdisciplinary foundation

MIT’s prominent role in microbiome research came, in part, through its leadership in a field that may at first seem unrelated. For decades, MIT has made important contributions to microbial ecology, led by work in the Parsons Laboratory in the Department of Civil and Environmental Engineering and by scientists including Institute Professor Penny Chisholm.

Ecologists who use complex statistical techniques to study the relationships between organisms in different ecosystems are well-equipped to study the behavior of different bacterial strains in the microbiome.

Not that ecologists — or anyone else — initially had much to study involving the human microbiome, which was essentially a black box to researchers well into the 2000s. But the Human Genome Project led to faster, cheaper ways to sequence genes at scale, and a group of researchers including Alm and visiting professor Martin Polz began using those techniques to decode the genomes of environmental bacteria around 2008.

Those techniques were first pointed at the bacteria in the gut microbiome as part of the Human Microbiome Project, which began in 2007 and involved research groups from MIT and the Broad Institute.

Alm first got pulled into microbiome research by the late biological engineering professor David Schauer as part of a research project with Boston Children’s Hospital. It didn’t take much to get up to speed: Alm says the number of papers explicitly referencing the microbiome at the time could be read in an afternoon.

The collaboration, which included Ramnik Xavier, a core institute member of the Broad Institute, led to the first large-scale genome sequencing of the gut microbiome to diagnose inflammatory bowel disease. The research was funded, in part, by the Neil and Anna Rasmussen Family Foundation.

The study offered a glimpse into the microbiome’s diagnostic potential. It also underscored the need to bring together researchers from diverse fields to dig deeper.

Taking an interdisciplinary approach is important because, after next-generation sequencing techniques are applied to the microbiome, a large amount of computational biology and statistical methods are still needed to interpret the resulting data — the microbiome, after all, contains more genes than the human genome. One catalyst for early microbiome collaboration was the Microbiology Graduate PhD Program, which recruited microbiology students to MIT and introduced them to research groups across the Institute.

As microbiology collaborations increased among researchers from different department and labs, Neil Rasmussen, a longtime member of the MIT Corporation and a member of the visiting committees for a number of departments, realized there was still one more component needed to turn microbiome research into a force for human health.

“Neil had the idea to find all the clinical researchers in the [Boston] area studying diseases associated with the microbiome and pair them up with people like [biological engineers, mathematicians, and ecologists] at MIT who might not know anything about inflammatory bowel disease or microbiomes but had the expertise necessary to solve big problems in the field,” Alm says.

In 2014, that insight led the Rasmussen Foundation to support the creation of the Center for Microbiome Informatics and Therapeutics (CMIT), one of the first university-based microbiome research centers in the country.

Tami Lieberman, the Hermann L. F. von Helmholtz Career Development Professor at MIT, whose background is in ecology, says CMIT was a big reason she joined MIT’s faculty in 2018. Lieberman has developed new genomic approaches to study how bacteria mutate in healthy and sick individuals, with a particular focus on the skin microbiome.

Laura Kiessling, a chemist who has been recognized for contributions to our understanding of cell surface interactions, was also quick to joint CMIT. Kiessling, the Novartis Professor of Chemistry, has made discoveries relating to microbial mechanisms that influence immune function. Both Lieberman and Kiessling are also members of the Broad Institute.

Today, CMIT, co-directed by Alm and Xavier, facilitates collaborations between researchers and clinicians from hospitals around the country in addition to supporting research groups in the area. That work has led to hundreds of ongoing clinical trials that promise to further elucidate the microbiome’s connection to a broad range of diseases.

Fulfilling the promise of the microbiome

Researchers don’t yet know what specific strains of bacteria can improve the health of people with microbiome-associated diseases. But they do know that fecal matter transplants, which carry the full spectrum of gut bacteria from a healthy donor, can help patients suffering from certain diseases.

The nonprofit organization OpenBiome, founded by a group from MIT including Smith and Alm, launched in 2012 to help expand access to fecal matter transplants by screening donors for stool collection then processing, storing, and shipping samples to hospitals. Today OpenBiome works with more than 1,000 hospitals, and its success in the early days of the field shows that basic microbiome research, when paired with clinical trials like those happening at CMIT, can quickly lead to new treatments.

“You start with a disease, and if there’s a microbiome association, you can start a small trial to see if fecal transplants can help patients right away,” Alm explains. “If that becomes an effective treatment, while you’re rolling it out you can be doing the genomics to figure out how to make it better. So you can translate therapeutics into patients more quickly than when you’re developing small-molecule drugs.”

Another nonprofit project launched out of MIT, the Global Microbiome Conservancy, is collecting stool samples from people living nonindustrialized lifestyles around the world, whose guts have much different bacterial makeups and thus hold potential for advancing our understanding of host-microbiome interactions.

A number of private companies founded by MIT alumni are also trying to harness individual microbes to create new treatments, including, among others, Finch Therapeutics founded by Mark Smith; Concerto Biosciences, co-founded by Jared Kehe PhD ’20 and Bernardo Cervantes PhD ’20; BiomX, founded by Associate Professor Tim Lu; and Synlogic, founded by Lu and Jim Collins, the Termeer Professor of Medical Engineering and Science at MIT.

“There’s an opportunity to more precisely change a microbiome,” explains CMIT’s Lieberman. “But there’s a lot of basic science to do to figure out how to tweak the microbiome in a targeted way. Once we figure out how to do that, the therapeutic potential of the microbiome is quite limitless.”

Explained: Why RNA vaccines for Covid-19 raced to the front of the pack

Many years of research have enabled scientists to quickly synthesize RNA vaccines and deliver them inside cells.

Anne Trafton | MIT News Office
December 11, 2020

Developing and testing a new vaccine typically takes at least 12 to 18 months. However, just over 10 months after the genetic sequence of the SARS-CoV-2 virus was published, two pharmaceutical companies applied for FDA emergency use authorization of vaccines that appear to be highly effective against the virus.

Both vaccines are made from messenger RNA, the molecule that cells naturally use to carry DNA’s instructions to cells’ protein-building machinery. A vaccine based on mRNA has never been approved by the FDA before. However, many years of research have gone into RNA vaccines, which is one reason why scientists were able to start testing such vaccines against Covid-19 so quickly. Once the viral sequences were revealed in January, it took just days for pharmaceutical companies Moderna and Pfizer, along with its German partner BioNTech, to generate mRNA vaccine candidates.

“What’s particularly unique to mRNA is the ability to rapidly generate vaccines against new diseases. That I think is one of the most exciting stories behind this technology,” says Daniel Anderson, a professor of chemical engineering at MIT and a member of MIT’s Koch Institute for Integrative Cancer Research and Institute for Medical Engineering and Science.

Most traditional vaccines consist of either killed or weakened forms of a virus or bacterium. These provoke an immune response that allows the body to fight off the actual pathogen later on.

Instead of delivering a virus or a viral protein, RNA vaccines deliver genetic information that allows the body’s own cells to produce a viral protein. Synthetic mRNA that encodes a viral protein can borrow this machinery to produce many copies of the protein. These proteins stimulate the immune system to mount a response, without posing any risk of infection.

A key advantage of mRNA is that it is very easy to synthesize once researchers know the sequence of the viral protein they want to target. Most vaccines for SARS-CoV-2 provoke an immune response that targets the coronavirus spike protein, which is found on the surface of the virus and gives the virus its characteristic spiky shape. Messenger RNA vaccines encode segments of the spike protein, and those mRNA sequences are much easier to generate in the lab than the spike protein itself.

“With traditional vaccines, you have to do a lot of development. You need a big factory to make the protein, or the virus, and it takes a long time to grow them,” says Robert Langer, the David H. Koch Institute Professor at MIT, a member of the Koch Institute, and one of the founders of Moderna. “The beauty of mRNA is that you don’t need that. If you inject nanoencapsulated mRNA into a person, it goes into the cells, and then the body is your factory. The body takes care of everything else from there.”

Langer has spent decades developing novel ways to deliver medicines, including therapeutic nucleic acids such as RNA and DNA. In the 1970s, he published the first study showing that it was possible to encapsulate nucleic acids, as well as other large molecules, in tiny particles and deliver them into the body. (Work by MIT Institute Professor Phillip Sharp and others on RNA splicing, which also laid groundwork for today’s mRNA vaccines, began in the ’70s as well.)

“It was very controversial at the time,” Langer recalls. “Everybody told us it was impossible, and my first nine grants were rejected. I spent about two years working on it, and I found over 200 ways to get it to not work. But then eventually I did find a way to get it to work.”

That paper, which appeared in Nature in 1976, showed that tiny particles made of synthetic polymers could safely carry and slowly release large molecules such as proteins and nucleic acids. Later, Langer and others showed that when polyethylene glycol (PEG) was added to the surface of nanoparticles, they could last in the body for much longer, instead of being destroyed almost immediately.

In subsequent years, Langer, Anderson, and others have developed fatty molecules called lipid nanoparticles that are also very effective at delivering nucleic acids. These carriers protect RNA from being broken down in the body and help to ferry it through cell membranes. Both the Moderna and Pfizer RNA vaccines are carried by lipid nanoparticles with PEG.

“Messenger RNA is a large hydrophilic molecule. It doesn’t naturally enter cells by itself, and so these vaccines are wrapped up in nanoparticles that facilitate their delivery inside of cells. This allows the RNA to be delivered inside of cells, and then translated into proteins,” Anderson says.

In 2018, the FDA approved the first lipid nanoparticle carrier for RNA, which was developed by Alnylam Pharmaceuticals to deliver a type of RNA called siRNA. Unlike mRNA, siRNA silences its target genes, which can benefit patients by turning off mutated genes that cause disease.

One drawback to mRNA vaccines is that they can break down at high temperatures, which is why the current vaccines are stored at such cold temperatures.  Pfizer’s SARS-CoV-2 vaccine has to be stored at -70 degrees Celsius (-94 degrees Fahrenheit), and the Moderna vaccine at -20 C (-4 F). One way to make RNA vaccines more stable, Anderson points out, is to add stabilizers and remove water from the vaccine through a process called lyophilization, which has been shown to allow some mRNA vaccines to be stored in a refrigerator instead of a freezer.

The striking effectiveness of both of these Covid-19 vaccines in phase 3 clinical trials (roughly 95 percent) offers hope that not only will those vaccines help to end the current pandemic, but also that in the future, RNA vaccines may help in the fight against other diseases such as HIV and cancer, Anderson says.

“People in the field, including myself, saw a lot of promise in the technology, but you don’t really know until you get human data. So to see that level of protection, not just with the Pfizer vaccine but also with Moderna, really validates the potential of the technology — not only for Covid, but also for all these other diseases that people are working on,” he says. “I think it’s an important moment for the field.”