He Beat Lymphoma at 31, While Pioneering Breakthroughs in Cancer Research
Taylor Schreiber, now 39, runs an immunotherapy company testing drugs that may be less toxic alternative to chemotherapy.
It looked like only good things were ahead of Taylor Schreiber in 2010.
Schreiber had just finished his PhD in cancer biology and was preparing to return to medical school to complete his degree. He also had been married a year, and, like any young newlyweds up for adventure, he and his wife Nicki decided to go backpacking in the Costa Rican rainforest.
He was 31, and it was April Fool's Day—but no joke.
During the trip, he experienced a series of night sweats and didn't think too much about it. Schreiber hadn't been feeling right for a few weeks and assumed he had a respiratory infection. Besides, they were sleeping outdoors in a hot, tropical jungle.
But the night sweats continued even after he got home, leaving his mattress so soaked in the morning it was if a bucket of water had been dumped on him overnight. On instinct, he called one of his thesis advisors at the Sylvester Comprehensive Cancer Center in Florida and described his symptoms.
Dr. Joseph Rosenblatt didn't hesitate. "It sounds like Hodgkins. Come see me tomorrow," he said.
The next day, Schreiber was diagnosed with Stage 3b Hodgkin Lymphoma, which meant the disease was advanced. He was 31, and it was April Fool's Day—but no joke.
"I was scared to death," he recalls. "[Thank] goodness it's one of those cancers that is highly treatable. But being 31 years old and all of a sudden being told that you have a 30 percent of mortality within the next two years wasn't anything that I was relieved about."
For Schreiber, the diagnosis was a personal and professional game-changer. He couldn't work in the hospital as a medical student while undergoing chemotherapy, so he wound up remaining in his post-doctorate lab for another two years. The experience also solidified his decision to apply his scientific and medical knowledge to drug development.
Today, now 39, Schreiber is co-founder, director and chief scientific officer of Shattuck Labs, an immuno-oncology startup, and the developer of several important research breakthroughs in the field of immunotherapy.
After his diagnosis, he continued working full-time as a postdoc, while undergoing an aggressive chemotherapy regimen.
"These days, I look back on [my cancer] and think it was one of the luckiest things that ever happened to me," he says. "In medical school, you learn what it is to treat people and learn about the disease. But there is nothing like being a patient to teach you another side of medicine."
Medicine first called to Schreiber when his maternal grandfather was dying from lung cancer complications. Schreiber's uncle, a radiologist at the medical center where his grandfather was being treated, took him on a tour of his department and showed him images of the insides of his body on an ultrasound machine.
Schreiber was mesmerized. His mother was a teacher and his dad sold windows, so medicine was not something to which he had been routinely exposed.
"This weird device was like looking through jelly, and I thought that was the coolest thing ever," he says.
The experience led him to his first real job at the Catholic Medical Center in Manchester, NH, then to a semester-long internship program during his senior year in high school in Concord Hospital's radiology department.
"This was a great experience, but it also made clear that there was not any meaningful way to learn or contribute to medicine before you obtained a medical degree," says Schreiber, who enrolled in Bucknell College to study biology.
Bench science appealed to him, and he volunteered in Dr. Jing Zhou's nephrology department lab at the Harvard Institutes of Medicine. Under the mentorship of one of her post-docs, Lei Guo, he learned a range of critical techniques in molecular biology, leading to their discovery of a new gene related to human polycystic kidney disease and his first published paper.
Before his cancer diagnosis, Schreiber also volunteered in the lab of Dr. Robert "Doc" Sackstein, a world-renowned bone marrow transplant physician and biomedical researcher, and his interests began to shift towards immunology.
"He was just one of those dynamic people who has a real knack for teaching, first of all, and for inspiring people to want to learn more and ask hard questions and understand experimental medicine," Schreiber says.
It was there that he learned the scientific method and the importance of incorporating the right controls in experiments—a simple idea, but difficult to perform well. He also made what Sackstein calls "a startling discovery" about chemokines, which are signaling proteins that can activate an immune response.
As immune cells travel around our bodies looking for potential sources of infection or disease, they latch onto blood vessel walls and "sniff around" for specific chemical cues that indicate a source of infection. Schreiber and his colleagues designed a system that mimics the blood vessel wall, allowing them to define which chemical cues efficiently drive immune cell migration from the blood into tissues.
Schreiber received the best overall research award in 2008 from the National Student Research Foundation. But even as Schreiber's expertise about immunology grew, his own immune system was about to fight its hardest battle.
After his diagnosis, he continued working full-time as a postdoc in the lab of Eckhard Podack, then chair of the microbiology and immunology department at the University of Miami's Leonard M. Miller School of Medicine.
At the same time, Schreiber began an aggressive intravenous chemotherapy regimen of adriamycin, bleomycin, vincristine and dacarbazine, every two weeks, for 6 months. His wife Nicki, an obgyn, transferred her residency from Emory University in Atlanta to Miami so they could be together.
"It was a weird period. I mean, it made me feel good to keep doing things and not just lay idle," he said. "But by the second cycle of chemo, I was immunosuppressed and losing my hair and wore a face mask walking around the lab, which I was certainly self-conscious. But everyone around me didn't make me feel like an alien so I just went about my business."
The experience reinforced his desire to stay in immunology, especially after having taken the most toxic chemotherapies.
He stayed home the day after chemo when he felt his worst, then rested his body and timed exercise to give the drugs the best shot of targeting sick cells (a strategy, he says, that "could have been voodoo"). He also drank "an incredible" amount of fluids to help flush the toxins out of his system.
Side effects of the chemo, besides hair loss, included intense nausea, diarrhea, a loss of appetite, some severe lung toxicities that eventually resolved, and incredible fatigue.
"I've always been a runner, and I would even try to run while I was doing chemo," he said. "After I finished treatment, I would go literally 150 yards and just have to stop, and it took a lot of effort to work through it."
The experience reinforced his desire to stay in immunology, especially after having taken the most toxic chemotherapies.
"They worked, and I could tolerate them because I was young, but people who are older can't," Schreiber said. "The whole field of immunotherapy has really demonstrated that there are effective therapies out there that don't come with all of the same toxicities as the original chemo, so it was galvanizing to imagine contributing to finding some of those."
Schreiber went on to complete his MD and PhD degrees from the Sheila and David Fuente Program in Cancer Biology at the Miller School of Medicine and was nominated in 2011 as a Future Leader in Cancer Research by the American Association for Cancer Research. He also has numerous publications in the fields of tumor immunology and immunotherapy.
Sackstein, who was struck by Schreiber's enthusiasm and "boundless energy," predicts he will be a "major player in the world of therapeutics."
"The future for Taylor is amazing because he has the capacity to synthesize current knowledge and understand the gaps and then ask the right questions to establish new paradigms," said Sackstein, currently dean of the Herbert Wertheim College of Medicine at Florida International University. "It's a very unusual talent."
Since then, he has devoted his career to developing innovative techniques aimed at unleashing the immune system to attack cancer with less toxicity than chemotherapy and better clinical results—first, at a company called Heat Biologics and then at Pelican Therapeutics.
His primary work at Austin, Texas-based Shattuck is aimed at combining two functions in a single therapy for cancer and inflammatory diseases, blocking molecules that put a brake on the immune system (checkpoint inhibitors) while also stimulating the immune system's cancer-killing T cells.
The company has one drug in clinical testing as part of its Agonist Redirected Checkpoint (ARC) platform, which represents a new class of biological medicine. Two others are expected within the next year, with a pipeline of more than 250 drug candidates spanning cancer, inflammatory, and metabolic diseases.
Nine years after his own cancer diagnosis, Schreiber says it remains a huge part of his life, though his chances of a cancer recurrence today are about the same as his chances of getting newly diagnosed with any other cancer.
"I feel blessed to be in a position to help cancer patients live longer and could not imagine a more fulfilling way to spend my life," he says.
Catching colds may help protect kids from Covid
A new study shows that the immune system's response to colds can help prepare it to defend against COVID-19 - but only in the very young.
A common cold virus causes the immune system to produce T cells that also provide protection against SARS-CoV-2, according to new research. The study, published last month in PNAS, shows that this effect is most pronounced in young children. The finding may help explain why most young people who have been exposed to the cold-causing coronavirus have not developed serious cases of COVID-19.
One curiosity stood out in the early days of the COVID-19 pandemic – why were so few kids getting sick. Generally young children and the elderly are the most vulnerable to disease outbreaks, particularly viral infections, either because their immune systems are not fully developed or they are starting to fail.
But solid information on the new infection was so scarce that many public health officials acted on the precautionary principle, assumed a worst-case scenario, and applied the broadest, most restrictive policies to all people to try to contain the coronavirus SARS-CoV-2.
One early thought was that lockdowns worked and kids (ages 6 months to 17 years) simply were not being exposed to the virus. So it was a shock when data started to come in showing that well over half of them carried antibodies to the virus, indicating exposure without getting sick. That trend grew over time and the latest tracking data from the CDC shows that 96.3 percent of kids in the U.S. now carry those antibodies.
Antibodies are relatively quick and easy to measure, but some scientists are exploring whether the reactions of T cells could serve as a more useful measure of immune protection.
But that couldn't be the whole story because antibody protection fades, sometimes as early as a month after exposure and usually within a year. Additionally, SARS-CoV-2 has been spewing out waves of different variants that were more resistant to antibodies generated by their predecessors. The resistance was so significant that over time the FDA withdrew its emergency use authorization for a handful of monoclonal antibodies with earlier approval to treat the infection because they no longer worked.
Antibodies got most of the attention early on because they are part of the first line response of the immune system. Antibodies can bind to viruses and neutralize them, preventing infection. They are relatively quick and easy to measure and even manufacture, but as SARS-CoV-2 showed us, often viruses can quickly evolve to become more resistant to them. Some scientists are exploring whether the reactions of T cells could serve as a more useful measure of immune protection.
Kids, colds and T cells
T cells are part of the immune system that deals with cells once they have become infected. But working with T cells is much more difficult, takes longer, and is more expensive than working with antibodies. So studies often lags behind on this part of the immune system.
A group of researchers led by Annika Karlsson at the Karolinska Institute in Sweden focuses on T cells targeting virus-infected cells and, unsurprisingly, saw that they can play a role in SARS-CoV-2 infection. Other labs have shown that vaccination and natural exposure to the virus generates different patterns of T cell responses.
The Swedes also looked at another member of the coronavirus family, OC43, which circulates widely and is one of several causes of the common cold. The molecular structure of OC43 is similar to its more deadly cousin SARS-CoV-2. Sometimes a T cell response to one virus can produce a cross-reactive response to a similar protein structure in another virus, meaning that T cells will identify and respond to the two viruses in much the same way. Karlsson looked to see if T cells for OC43 from a wide age range of patients were cross-reactive to SARS-CoV-2.
And that is what they found, as reported in the PNAS study last month; there was cross-reactive activity, but it depended on a person’s age. A subset of a certain type of T cells, called mCD4+,, that recognized various protein parts of the cold-causing virus, OC43, expressed on the surface of an infected cell – also recognized those same protein parts from SARS-CoV-2. The T cell response was lower than that generated by natural exposure to SARS-CoV-2, but it was functional and thus could help limit the severity of COVID-19.
“One of the most politicized aspects of our pandemic response was not accepting that children are so much less at risk for severe disease with COVID-19,” because usually young children are among the most vulnerable to pathogens, says Monica Gandhi, professor of medicine at the University of California San Francisco.
“The cross-reactivity peaked at age six when more than half the people tested have a cross-reactive immune response,” says Karlsson, though their sample is too small to say if this finding applies more broadly across the population. The vast majority of children as young as two years had OC43-specific mCD4+ T cell responses. In adulthood, the functionality of both the OC43-specific and the cross-reactive T cells wane significantly, especially with advanced age.
“Considering that the mortality rate in children is the lowest from ages five to nine, and higher in younger children, our results imply that cross-reactive mCD4+ T cells may have a role in the control of SARS-CoV-2 infection in children,” the authors wrote in their paper.
“One of the most politicized aspects of our pandemic response was not accepting that children are so much less at risk for severe disease with COVID-19,” because usually young children are among the most vulnerable to pathogens, says Monica Gandhi, professor of medicine at the University of California San Francisco and author of the book, Endemic: A Post-Pandemic Playbook, to be released by the Mayo Clinic Press this summer. The immune response of kids to SARS-CoV-2 stood our expectations on their head. “We just haven't seen this before, so knowing the mechanism of protection is really important.”
Why the T cell immune response can fade with age is largely unknown. With some viruses such as measles, a single vaccination or infection generates life-long protection. But respiratory tract infections, like SARS-CoV-2, cause a localized infection - specific to certain organs - and that response tends to be shorter lived than systemic infections that affect the entire body. Karlsson suspects the elderly might be exposed to these localized types of viruses less often. Also, frequent continued exposure to a virus that results in reactivation of the memory T cell pool might eventually result in “a kind of immunosenescence or immune exhaustion that is associated with aging,” Karlsson says. https://leaps.org/scientists-just-started-testing-a-new-class-of-drugs-to-slow-and-even-reverse-aging/particle-3 This fading protection is why older people need to be repeatedly vaccinated against SARS-CoV-2.
Policy implications
Following the numbers on COVID-19 infections and severity over the last three years have shown us that healthy young people without risk factors are not likely to develop serious disease. This latest study points to a mechanism that helps explain why. But the inertia of existing policies remains. How should we adjust policy recommendations based on what we know today?
The World Health Organization (WHO) updated their COVID-19 vaccination guidance on March 28. It calls for a focus on vaccinating and boosting those at risk for developing serious disease. The guidance basically shrugged its shoulders when it came to healthy children and young adults receiving vaccinations and boosters against COVID-19. It said the priority should be to administer the “traditional essential vaccines for children,” such as those that protect against measles, rubella, and mumps.
“As an immunologist and a mother, I think that catching a cold or two when you are a kid and otherwise healthy is not that bad for you. Children have a much lower risk of becoming severely ill with SARS-CoV-2,” says Karlsson. She has followed public health guidance in Sweden, which means that her young children have not been vaccinated, but being older, she has received the vaccine and boosters. Gandhi and her children have been vaccinated, but they do not plan on additional boosters.
The WHO got it right in “concentrating on what matters,” which is getting traditional childhood immunizations back on track after their dramatic decline over the last three years, says Gandhi. Nor is there a need for masking in schools, according to a study from the Catalonia region of Spain. It found “no difference in masking and spread in schools,” particularly since tracking data indicate that nearly all young people have been exposed to SARS-CoV-2.
Both researchers lament that public discussion has overemphasized the quickly fading antibody part of the immune response to SARS-CoV-2 compared with the more durable T cell component. They say developing an efficient measure of T cell response for doctors to use in the clinic would help to monitor immunity in people at risk for severe cases of COVID-19 compared with the current method of toting up potential risk factors.
In this week's Friday Five: The eyes are the windows to the soul - and biological aging?
Plus, what bean genes mean for health and the planet, a breathing practice that could lower levels of tau proteins in the brain, AI beats humans at assessing heart health, and the benefits of "nature prescriptions"
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on new scientific theories and progress to give you a therapeutic dose of inspiration headed into the weekend.
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Here are the stories covered this week:
- The eyes are the windows to the soul - and biological aging?
- What bean genes mean for health and the planet
- This breathing practice could lower levels of tau proteins
- AI beats humans at assessing heart health
- Should you get a nature prescription?