In 2005, the New Oxford American Dictionary named “podcast” its word of the year. At the time a podcast was something many had heard of but not that many actually tuned in to. My how times have changed. Now there are some two million podcasts to chose from, at least according to the New York Times, and who am I to question them.
Yesterday, in the same New York Times, TV writer Margaret Lyons, wrote about how the pandemic helped turn her from TV to podcasts: “Much in the way I grew to prefer an old-fashioned phone call to a video chat, podcasts, not television, became my go-to medium in quarantine. With their shorter lead times and intimate production values, they felt more immediate and more relevant than ever before.”
I mention this because an old colleague of ours at CIRM, Neil Littman, has just launched his own podcast and the first guest on it was Jonathan Thomas, Chair of the CIRM Board. Their conversation ranged from CIRM’s past to the future of the regenerative field as a whole, with a few interesting diversions along the way. It’s fun listening. And as Margaret Lyons said it might be more immediate and more relevant than ever before.
Elena Flowers, PhD, RN, an associate professor of physiological nursing at the University of California, San Francisco (UCSF) is joining the Board of the California Institute for Regenerative Medicine (CIRM), the state’s Stem Cell Agency.
Dr. Flowers was appointed to the Board by State Controller Betty T. Yee who said: “Ms. Flowers’ experience and express commitment to equitable health outcomes for California’s diverse communities will bring a valued perspective to the work ahead.”
Dr. Flowers is a member of the UCSF Institute for Human Genetics and the International Society of Nurses in Genetics. As a researcher her work focuses on genomics involving precision medicine and risk factors for cardiovascular health and type 2 diabetes. She is also a teacher and has lectured internationally on issues such as topics from racial disparities in Type 2 Diabetes to the implications of genomic technologies for the nursing workforce.
CIRM Board Chair, Jonathan Thomas, PhD, JD, welcomed the appointment: “Dr. Flowers brings a wealth of experience and expertise to our Board and, as a nurse, she will bring a different perspective to the work we do and help us in trying to better address the needs of underserved communities.”
“I am honored to have the opportunity to serve the citizens of California in this capacity,” says Dr. Flowers. “CIRM has ambitious goals, seeking to improve upon common limitations of public research agencies by its commitment to delivering meaningful findings and ultimately treatments for patients as rapidly as possible. I’m particularly committed to improving inclusion and access to these treatments across the entire diverse California population.”
Dr. Flowers got her undergraduate degree at UC Davis and then served as a research assistant at Zuckerberg San Francisco General Hospital. She then went on to get her MS and Doctor of Philosophy degrees at the UCSF School of Nursing.
In her spare time she has no spare time because she is the mother of two young daughters.
All this month we are using our blog and social media to highlight a new chapter in CIRM’s life, thanks to the voters approving Proposition 14. We are looking back at what we have done since we were created in 2004, and also looking forward to the future.Today we take a look at our Review team.
Many people who have to drive every day don’t really think about what’s going on under the hood of their car. As long as the engine works and gets them from A to B, they’re happy. I think the same is true about CIRM’s Review team. Many people don’t really think about all the moving parts that go into reviewing a promising new stem cell therapy.
But that’s a shame, because they are really missing out on watching a truly impressive engine at work.
Just consider the simple fact that since CIRM started about 4,000 companies, groups and individuals have applied to us for funding. Just take a moment to consider that number. Four thousand. Then consider that at no time have there been more than 5 people working in the review team. That’s right. Just 5 people. And more recently there have been substantially fewer. That’s a lot of projects and not a lot of people to review them. So how do they do it? Easy. They’re brilliant.
First, as applications come in they are scrutinized to make sure they meet specific eligibility requirements; do they involve stem cells, is the application complete, is it the right stage of research, is the budget they are proposing appropriate for the work they want to do etc. If they pass that initial appraisal, they then move on to the second round, the Grants Working Group or GWG.
The GWG consists of independent scientific experts from all over the US, all over the world in fact. However, none are from California because we want to ensure there are no possible conflicts of interest. When I say experts, I do mean experts. These are among the top in their field and are highly sought after to do reviews with the National Institutes of Health etc.
Mark Noble, PhD, the Director of the Stem Cell and Regenerative Medicine Institute at the University of Rochester, is a long-time member of the GWG. He says it’s a unique group of people:
“It’s a wonderful scientific education because you come to these meetings and someone is putting in a grant on diabetes and someone’s putting in a grant on repairing the damage to the heart or spinal cord injury or they have a device that will allow you to transplant cells better and there are people in the room that are able to talk knowledgeably about each of these areas and understand how this plays into medicine and how it might work in terms of actual financial development and how it might work in the corporate sphere and how it fits in to unmet medical needs . I don’t know of any comparable review panels like this that have such a broad remit and bring together such a breadth of expertise which means that every review panel you come to you are getting a scientific education on all these different areas, which is great.”
The GWG reviews the projects for scientific merit: does the proposal seem plausible, does the team proposing it have the experience and expertise to do the work etc. The reviewers put in a lot of work ahead of time, not just reviewing the application, but looking at previous studies to see if the new application has evidence to support what this team hope to do, to compare it to other efforts in the same field. There are disagreements, but also a huge amount of respect for each other.
Once the GWG makes its recommendations on which projects to fund and which ones not to, the applications move to the CIRM Board, which has the final say on all funding decisions. The Board is given detailed summaries of each project, along with the recommendations of the GWG and our own CIRM Review team. But the Board is not told the identity of any of the applicants, those are kept secret to avoid even the appearance of any conflict of interest.
The Board is not required to follow the recommendations of the GWG, though they usually do. But the Board is also able to fund projects that the GWG didn’t place in the top tier of applications. They have done this on several occasions, often when the application targeted a disease or disorder that wasn’t currently part of the agency’s portfolio.
So that’s how Review works. The team, led by Dr. Gil Sambrano, does extraordinary work with little fanfare or fuss. But without them CIRM would be a far less effective agency.
The passage of Proposition 14 means we now have a chance to resume full funding of research, which means our Review team is going to be busier than ever. They have already started making changes to the application requirements. To help let researchers know what those changes are we are holding a Zoom webinar tomorrow, Thursday, at noon PST. If you would like to watch you can find it on our YouTube channel. And if you have questions you would like to ask send them to firstname.lastname@example.org
All this month we are using our blog and social media to highlight a new chapter in CIRM’s life, thanks to the voters approving Proposition 14. We are looking back at what we have done since we were created in 2004, and also looking forward to the future.We kick off this event with a letter from our the Chair of our Board, Jonathan Thomas.
When voters approved Proposition 14 last November, they gave the Stem Cell Agency a new lease on life and a chance to finish the work we began with the approval of Proposition 71 in 2004. It’s a great honor and privilege. It’s also a great responsibility. But I think looking back at what we have achieved over the last 16 years shows we are well positioned to seize the moment and take CIRM and regenerative medicine to the next level and beyond.
When we started, we were told that if we managed to get one project into a clinical trial by the time our money ran out we would have done a good job. As of this moment we have 68 clinical trials that we have funded plus another 31 projects in clinical trials where we helped fund crucial early stage research. That inexorable march to therapies and cures will resume when we take up our first round of Clinical applications under Prop 14 in March.
But while clinical stage projects are the end game, where we see if therapies really work and are safe in people, there’s so much more that we have achieved since we were created. We have invested $900 million in basic research, creating a pipeline of the most promising stem cell research programs, as well as investing heavily on so-called “translational” projects, which move projects from basic science to where they’re ready to apply to the Food and Drug Administration (FDA) to begin clinical trials.
We have funded more than 1,000 projects, with each one giving us valuable information to help advance the science. Our funding has helped attract some of the best stem cell scientists in the world to California and, because we only fund research in California, it has persuaded many companies to either move here or open offices here to be eligible for our support. We have helped create the Alpha Stem Cell Clinics, a network of leading medical centers around the state that have the experience and expertise to deliver stem cell therapies to patients. All of those have made California a global center in the field.
That result is producing big benefits for the state. An independent Economic Impact Analysis reported that by the end of 2018 we had already helped generate an extra $10.7 billion in new sales revenue and taxes for California, hundreds of millions more in federal taxes and created more than 56,000 new jobs.
Used our support for stem cell research to leverage an additional $12 billion in private funding for the field.
Enrolled more than 2700 patients in CIRM funded clinical trials
In many ways our work is just beginning. We have laid the groundwork, helped enable an extraordinary community of researchers and dramatically accelerated the field. Now we want to get those therapies (and many more) over the finish line and get them approved by the FDA so they can become available to many more people around the state, the country and the world.
We also know that we have to make these therapies available to all people, regardless of their background and ability to pay. We have to ensure that underserved communities, who were often left out of research in the past, are an integral part of this work and are included in every aspect of that research, particularly clinical trials. That’s why we now require anyone applying to us for funding to commit to engaging with underserved communities and to have a written plan to show how they are going to do that.
Over the coming month, you will hear more about some of the remarkable things we have managed to achieve so far and get a better sense of what we hope to do in the future. We know there will be challenges ahead and that not everything we do or support will work. But we also know that with the team we have built at CIRM, the brilliant research community in California and the passion and drive of the patient advocate community we will live up to the responsibility the people of California placed in us when they approved Proposition 14.
Funding models are rarely talked about in excited tones. It’s normally relegated to the dry tomes of academia. But in CIRM’s case, the funding model we have created is not just fundamental to our success in advancing regenerative medicine in California, it’s also proving to be a model that many other agencies are looking at to see if they can replicate it.
A recent article in the journal Cell & Gene Therapy Insights looks at what the CIRM model does and how it has achieved something rather extraordinary.
Full disclosure. I might be a tad biased here as the article was written by my boss, Dr. Maria Millan, and two of my colleagues, Dr. Sohel Talib and Dr. Shyam Patel.
I won’t go into huge detail here (you can get that by reading the article itself) But the article “highlights 3 elements of CIRM’s funding model that have enabled California academic researchers and companies to de-risk development of novel regenerative medicine therapies and attract biopharma industry support.”
Those three elements are:
1. Ensuring that funding mechanisms bridge the entire translational “Valley of Death”
2. Constantly optimizing funding models to meet the needs of a rapidly evolving industry
3. Championing the portfolio and proactively engaging potential industry partners
As an example of the first, they point to our Disease Team awards. These were four-year investments that gave researchers with promising projects the time, support and funds they needed to not only develop a therapy, but also move it out of academia into a company and into patients. Many of these projects had struggled to get outside investment until CIRM stepped forward. One example they offer is this one.
“CIRM Disease Team award funding also enabled Dr. Irving Weissman and the Stanford University team to discover, develop and obtain first-in-human clinical data for the innovative anti-CD47 antibody immunotherapy approach to cancer. The spin-out, Forty Seven, Inc., then leveraged CIRM funding as well as venture and public market financing to progress clinical development of the lead candidate until its acquisition by Gilead Sciences in April 2020 for $4.9B.”
But as the field evolved it became clear CIRM’s funding model had to evolve too, to better meet the needs of a rapidly advancing industry. So, in 2015 we changed the way we worked. For example, with clinical trial stage projects we reduced the average time from application to funding from 22 months to 120 days. In addition to that applications for new clinical stage projects were able to be submitted year-round instead of only once or twice a year as in the past.
We also created hard and fast milestones for all programs to reach. If they met their milestone funding continued. If they didn’t, funding stopped. And we required clinical trial stage projects, and those for earlier stage for-profit companies, to put up money of their own. We wanted to ensure they had “skin in the game” and were as committed to the success of their project as we were.
Finally, to champion the portfolio we created our Industry Alliance Program. It’s a kind of dating program for the researchers CIRM funds and companies looking to invest in promising projects. Industry partners get a chance to look at our portfolio and pick out projects they think are interesting. We then make the introductions and see if we can make a match.
And we have.
“To date, the IAP has also formally enrolled 8 partners with demonstrated commitment to cell and gene therapy development. The enrolled IAP partners represent companies both small and large, multi-national venture firms and innovative accelerators.
Over the past 18 months, the IAP program has enabled over 50 one-on-one partnership interactions across CIRM’s portfolio from discovery stage pluripotent stem cell therapies to clinical stage engineered HSC therapies.”
As the field continues to mature there are new problems emerging, such as the need to create greater manufacturing capacity to meet the growth in demand for high quality stem cell products. CIRM, like all other agencies, will also have to evolve and adapt to these new demands. But we feel with the model we have created, and the flexibility we have to pivot when needed, we are perfectly situated to do just that.
It’s been a long time coming. Eighteen months to be precise. Which is a peculiarly long time for an Annual Report. The world is certainly a very different place today than when we started, and yet our core mission hasn’t changed at all, except to spring into action to make our own contribution to fighting the coronavirus.
This latest CIRM Annual Reportcovers 2019 through June 30, 2020. Why? Well, as you probably know we are running out of money and could be funding our last new awards by the end of this year. So, we wanted to produce as complete a picture of our achievements as we could – keeping in mind that we might not be around to produce a report next year.
It’s a pretty jam-packed report. It covers everything from the 14 new clinical trials we have funded this year, including three specifically focused on COVID-19. It looks at the extraordinary researchers that we fund and the progress they have made, and the billions of additional dollars our funding has helped leverage for California. But at the heart of it, and at the heart of everything we do, are the patients. They’re the reason we are here. They are the reason we do what we do.
There are stories of people like Byron Jenkins who almost died from multiple myeloma but is now back leading a full, active life with his family thanks to a CIRM-funded therapy with Poseida. There is Jordan Janz, a young man who once depended on taking 56 pills a day to keep his rare disease, cystinosis, under control but is now hoping a stem cell therapy developed by Dr. Stephanie Cherqui and her team at UC San Diego will make that something of the past.
These individuals are remarkable on so many levels, not the least because they were willing to be among the first people ever to try these therapies. They are pioneers in every sense of the word.
There is a lot of information in the report, charting the work we have done over the last 18 months. But it’s also a celebration of everyone who made it possible, and our way of saying thank you to the people of California who gave us this incredible honor and opportunity to do this work.
We have a new member on the CIRM Board – Dr. Allison Brashear is the Dean of the UC Davis School of Medicine, overseeing one of the nation’s top research, academic and medical training institutions.
Dr. Brashear is an internationally known researcher in movement disorders and an expert in ATP1A3-related diseases, a spectrum of rare neurologic disorders.
Before joining UC Davis, Dr. Brashear was professor and chair of the Department of Neurology for 14 years at Wake Forest School of Medicine.
She serves on the American Board of Psychiatry and Neurology, and has served on the boards of the American Neurological Association and the American Academy of Neurology, where she was instrumental in crafting a leadership program for women, now expanded to include leadership development for minorities.
You can read more about her background in this news release. But we wanted to get a sense of what motivates and inspires Dr. Brashear. So we asked her. And she told us.
When did you get interested in science? Was this always something you knew you wanted to do?
I loved math and science in middle school and continued with science in college. I grew up hearing my parents talk about caring for patients and the impact you could have on them and their family’s lives. My father is a pulmonologist and my mother was a Ph.D. in marriage and family therapy. Together they taught me the value of patient-centered care.
My mother was a tremendous advocate for women. When I was in middle school she took my friend and I to the state legislature and we watched the ERA (Equal Rights Amendment) debates. It’s a powerful memory but not always flattering about what people thought at the time. So, from an early age I really became a strong advocate for women, to make sure women had opportunities and that we were an inclusive culture wherever I was.
As a woman going into a male dominated field, how did you manage to push past the skeptics and doubters to succeed?
Early on I recognized the need to work with senior faculty who would give me an opportunity to lead and learn. I became a chair of neurology at Wake Forest when I was 44 and was the only woman chair for 4 years. When I was appointed to the Wake Forest Baptist Medical Center Board of Directors as one of two faculty, I was the only woman. I learned early on that it was important to have sponsorship from senior leaders to succeed. I learned that, when opportunities presented themselves, to say “yes.” This is how I became the lead investigator into ATP1A3 related diseases in 1991. That project, now 11 years funded by the NIH, is one that is led by me and three other women.
It’s still not uncommon for me to walk into a room and be the only woman. And so, making sure that there is appropriate support for women leaders is really key.
Did you have mentors to help you along the way – what was their advice to you?
I prefer the term sponsorship. Mentors advise – which is important, but more important is the role of the sponsor. A sponsor goes out of their way to advance another career. This can be a public call-out, a well-placed phone call or giving a resident what ends up being a new pathway of research. I appreciate the many sponsors in my life, and that includes men and women. I aspire to be a similar sponsor. This is my way to pay it forward.
How do you sponsor others to help them overcome barriers, etc.?
I advise women to get extra leadership training, learn about money and to make sure to have a network of advocates. I also remind them to say thank you to those who pave the way.
I think it goes down to the message that you meet these key people in your life and they go the extra mile to help you and you, as a leader, need to take that opportunity and really just launch from it. Along the way I found I really wanted to bring people in and grow them and that was the best part of being chair of the department and one of the reasons I wanted to be a dean. When faculty join our health system I want to set them up to succeed. Celebrating others’ success with them is a great feeling. Fostering these successes is how we can be a catalyst to research and care innovations that improve health, which is at the heart of our work.
These are interesting times to head a major university, what advice and encouragement do you have for students just starting out who face their first year “at university” at home?
Every change brings opportunity. University at home is hard – interpersonal relationships are so important to learning and we miss that when we are on Zoom. I advise students and faculty to nurture those social connections.
When you are not working what do you do for fun?
I hang out with my husband and our two rescue dogs. We are making plans to go explore California when the COVID-19 pandemic settles down. We had our two adult children home during the shutdown, but both are back at school on the East Coast.
There are some people who, when you think of them, always bring a smile to your face. Dr. Bert Lubin was one of those people. Sadly, we lost Bert to brain cancer two days ago. But the impact he had, not just as an advocate for stem cell research but as a pioneer in sickle cell disease research and a champion for children’s health, will live on.
Bert had a number of official titles but probably the one he was most proud of was President & CEO of Children’s Hospital Oakland (now UCSF Benioff Children’s Hospital Oakland). But it wasn’t the title that he cared about, it was the opportunity it gave him to make a difference in the life of children in Oakland, to create a program to find new treatments and cures for a life-threatening disease. And he has made a difference.
As I started to write this tribute to Bert, I thought about who I should ask for a quote. And then I realized I had the perfect person. Bert himself. I was fortunate enough to interview him in December 2018, when he decided to step down after eight years on the CIRM Board. As always, he had his own positive spin on that, saying: “I don’t see myself leaving. I’m just repurposing what is my role in CIRM. I’m recycling and reinventing.”
And Bert was always full of invention.
He grew up in Bellevue, a small town outside Pittsburgh, PA. His parents ran a fruit and vegetable market there and, growing up, Bert often worked in the store. It wasn’t something he enjoyed but he said he learned some valuable lessons.
“I think what happened in my childhood is that I learned how to sell. I am a salesman. I hated working in that store, I hated it, but I liked the communication with people, they trusted me, I could sell things and they were good things. Like Christmas. I’m Jewish, we were the only Jews in that community, and at Christmas we sold Christmas trees, but the trees were sometimes crooked and they were $2.99 a tree so I convinced families that I could go to their house and set the tree so it looked straight and I helped them decorate it and they loved it.”
He said, thinking back on his life it’s almost as if there were a plan, even if he wasn’t aware of it.
“I started thinking about that more recently, I started wondering how did this even happen? I’m not a religious person but it’s almost like there’s some fate. How did I get there? It’s not that I planned it that way and it’s certainly not that my parents planned it because I was the first in my family to go to high school let alone college. My parents, when I went to medical school and then decided I wanted to spend more time in an academic direction, they were upset. They wanted me to go into practice in a community that I grew up in and be economically secure and not be on the fringe in what an academic life is like.”
And then, fate stepped in and brought him to the San Francisco Bay Area.
“What happened was, I was at the University of Pennsylvania having trained at Boston Children’s and Philadelphia Children’s, where I had started a sickle cell disease program, and was asked to look at a job in southern California to start a sickle cell program there. So, I flew to San Francisco because a lot of people I’d studied with were now working at UCSF and I thought it would be fun to see them before going down to southern California. They took me out to dinner and showed me around and I said this place is beautiful, I can play tennis out here all year round, there’s lots of music – I love jazz – and they said ‘you know Bert, have you looked at Oakland Children’s hospital? We want to start a sickle cell program center, but the patients are all in Oakland and the patient population that would be served is in Oakland. But if you came out to the Bay Area we could partner with you to start that program.
“So, when I walked in the door here (at Oakland) and said ‘I want to create this northern California sickle cell center with UC’ the staff that was here said ‘you know we’re not a research hospital, we are a community based hospital’. I said, ‘I’m not saying you shouldn’t be that but I’m trying to create an opportunity here’ and they said to me ‘as long as you don’t ask for any money you can go and do whatever you want’.
‘They recognized that I had this fire in me to really create something that was novel. And the warmth and community commitment from this place is something that attracted me and then allowed me to build on that.
“For example, when I became the director of the research program we had $500,000 in NIH grants and when I left we had $60 million. We just grew. Why did we grow? Because we cared about the faculty and the community. We had a lovely facility, which was actually the home of the Black Panther party. It was the Black Panthers who started screening for sickle cell on street corners here in Oakland, and they were the start of the national sickle cell act so there’s a history here and I like that history.
“Then I got a sense of the opportunities that stem cell therapies would have for a variety of things, certainly including sickle cell disease, and I thought if there’s a chance to be on the CIRM Board, as an advocate for that sickle cell community, I think I’d be a good spokesperson. So, I applied. I just thought this was an exciting opportunity.
“I thought it was a natural fit for me to add some value, I only want to be on something where I think I add value.”
Bert added value to everything he did. And everyone he met felt valued by him. He was a mentor to so many people, young physicians and nurses, students starting out on their careers. And he was a friend to those in need.
He was an extraordinary man and we are grateful that we were able to call him a colleague, and a friend, for as long as we did.
When Burt stepped down from Children’s his colleagues put together this video about his life and times. It seems appropriate to share it again and remind ourselves of the gift that he was to everyone fortunate enough to know him.
In late March the CIRM Board approved $5 million in emergency funding for COVID-19 research. The idea was to support great ideas from California’s researchers, some of which had already been tested for different conditions, and see if they could help in finding treatments or a vaccine for the coronavirus.
Less than a month later we were funding a clinical trial and two other projects, one that targeted a special kind of immune system cell that has the potential to fight the virus.
Researchers use stem cells to model the immune response to COVID-19
By Tiare Dunlap
Cities across the United States are opening back up, but we’re still a long way from making the COVID-19 pandemic history. To truly accomplish that, we need to have a vaccine that can stop the spread of infection.
But to develop an effective vaccine, we need to understand how the immune system responds to SARS-CoV-2, the virus that causes COVID-19.
Vaccines work by imitating infection. They expose a person’s immune system to a weakened version or component of the virus they are intended to protect against. This essentially prepares the immune system to fight the virus ahead of time, so that if a person is exposed to the real virus, their immune system can quickly recognize the enemy and fight the infection. Vaccines need to contain the right parts of the virus to provoke a strong immune response and create long-term protection.
Most of the vaccines in development for SARS CoV-2 are using part of the virus to provoke the immune system to produce proteins called antibodies that neutralize the virus. Another way a vaccine could create protection against the virus is by activating the T cells of the immune system.
T cells specifically “recognize” virus-infected cells, and these kinds of responses may be especially important for providing long-term protection against the virus. One challenge for researchers is that they have only had a few months to study how the immune system protects against SARS CoV-2, and in particular, which parts of the virus provoke the best T-cell responses.
For years, they have been perfecting an innovative technology that uses blood-forming stem cells — which can give rise to all types of blood and immune cells — to produce a rare and powerful subset of immune cells called type 1 dendritic cells. Type 1 dendritic cells play an essential role in the immune response by devouring foreign proteins, termed antigens, from virus-infected cells and then chopping them into fragments. Dendritic cells then use these protein fragments to trigger T cells to mount an immune response.
Using this technology, Crooks and Seet are working to pinpoint which specific parts of the SARS-CoV-2 virus provoke the strongest T-cell responses.
Building long-lasting immunity
“We know from a lot of research into other viral infections and also in cancer immunotherapy, that T-cell responses are really important for long-lasting immunity,” said Seet, an assistant professor of hematology-oncology at the David Geffen School of Medicine at UCLA. “And so this approach will allow us to better characterize the T-cell response to SARS-CoV-2 and focus vaccine and therapeutic development on those parts of the virus that induce strong T-cell immunity.”
Crooks’ and Seet’s project uses blood-forming stem cells taken from healthy donors and infected with a virus containing antigens from SARS-CoV-2. They then direct these stem cells to produce large numbers of type 1 dendritic cells using a new method developed by Seet and Suwen Li, a graduate student in Crooks’ lab. Both Seet and Li are graduates of the UCLA Broad Stem Cell Research Center’s training program.
“The dendritic cells we are able to make using this process are really good at chopping up viral antigens and eliciting strong immune responses from T cells,” said Crooks, a professor of pathology and laboratory medicine and of pediatrics at the medical school and co-director of the UCLA Broad Stem Cell Research Center.
When type 1 dendritic cells chop up viral antigens into fragments, they present these fragments on their cell surfaces to T cells. Our bodies produce millions and millions of T cells each day, each with its own unique antigen receptor, however only a few will have a receptor capable of recognizing a specific antigen from a virus.
When a T cell with the right receptor recognizes a viral antigen on a dendritic cell as foreign and dangerous, it sets off a chain of events that activates multiple parts of the immune system to attack cells infected with the virus. This includes clonal expansion, the process by which each responding T cell produces a large number of identical cells, called clones, which are all capable of recognizing the antigen.
“Most of those T cells will go off and fight the infection by killing cells infected with the virus,” said Seet, who, like Crooks, is also a member of the UCLA Jonsson Comprehensive Cancer Center. “However, a small subset of those cells become memory T cells — long-lived T cells that remain in the body for years and protect from future infection by rapidly generating a robust T-cell response if the virus returns. It’s immune memory.”
Producing extremely rare immune cells
This process has historically been particularly challenging to model in the lab, because type 1 dendritic cells are extremely rare — they make up less than 0.1% of cells found in the blood. Now, with this new stem cell technology, Crooks and Seet can produce large numbers of these dendritic cells from blood stem cells donated by healthy people, introduce them to parts of the virus, then see how T cells taken from the blood can respond in the lab. This process can be repeated over and over using cells taken from a wide range of healthy people.
“The benefit is we can do this very quickly without the need for an actual vaccine trial, so we can very rapidly figure out in the lab which parts of the virus induce the best T-cell responses across many individuals,” Seet said.
The resulting data could be used to inform the development of new vaccines for COVID-19 that improve T-cell responses. And the data about which viral antigens are most important to the T cells could also be used to monitor the effectiveness of existing vaccine candidates, and an individual’s immune status to the virus.
“There are dozens of vaccine candidates in development right now, with three or four of them already in clinical trials,” Seet said. “We all hope one or more will be effective at producing immediate and long-lasting immunity. But as there is so much we don’t know about this new virus, we’re still going to need to really dig in to understand how our immune systems can best protect us from infection.”
Supporting basic research into our body’s own processes that can inform new strategies to fight disease is central to the mission of the Broad Stem Cell Research Center.
“When we started developing this project some years ago, we had no idea it would be so useful for studying a viral infection, any viral infection,” Crooks said. “And it was only because we already had these tools in place that we could spring into action so fast.”