He Beat Lymphoma at 31, While Pioneering Breakthroughs in Cancer Research
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.
Two-and-a-half year-old Huckleberry, a blue merle Australian shepherd, pulls hard at her leash; her yelps can be heard by skiers and boarders high above on the chairlift that carries them over the ski patrol hut to the top of the mountain. Huckleberry is an avalanche rescue dog — or avy dog, for short. She lives and works with her owner and handler, a ski patroller at Breckenridge Ski Resort in Colorado. As she watches the trainer play a game of hide-and-seek with six-month-old Lume, a golden retriever and avy dog-in-training, Huckleberry continues to strain on her leash; she loves the game. Hide-and-seek is one of the key training methods for teaching avy dogs the rescue skills they need to find someone caught in an avalanche — skier, snowmobiler, hiker, climber.
Lume’s owner waves a T-shirt in front of the puppy. While another patroller holds him back, Lume’s owner runs away and hides. About a minute later — after a lot of barking — Lume is released and commanded to “search.” He springs free, running around the hut to find his owner who reacts with a great amount of excitement and fanfare. Lume’s scent training will continue for the rest of the ski season (Breckenridge plans operating through May or as long as weather permits) and through the off-season. “We make this game progressively harder by not allowing the dog watch the victim run away,” explains Dave Leffler, Breckenridge's ski patroller and head of the avy dog program, who has owned, trained and raised many of them. Eventually, the trainers “dig an open hole in the snow to duck out of sight and gradually turn the hole into a cave where the dog has to dig to get the victim,” explains Leffler.
By the time he is three, Lume, like Huckleberry, will be a fully trained avy pup and will join seven other avy dogs on Breckenridge ski patrol team. Some of the team members, both human and canine, are also certified to work with Colorado Rapid Avalanche Deployment, a coordinated response team that works with the Summit County Sheriff’s office for avalanche emergencies outside of the ski slopes’ boundaries.
There have been 19 avalanche deaths in the U.S. this season, according to avalanche.org, which tracks slides; eight in Colorado. During the entirety of last season there were 17. Avalanche season runs from November through June, but avalanches can occur year-round.
High tech and high stakes
Complementing avy dogs’ ability to smell people buried in a slide, avalanche detection, rescue and recovery is becoming increasingly high tech. There are transceivers, signal locators, ground scanners and drones, which are considered “games changers” by many in avalanche rescue and recovery
For a person buried in an avalanche, the chance of survival plummets after 20 minutes, so every moment counts.
A drone can provide thermal imaging of objects caught in a slide; what looks like a rock from far away might be a human with a heat signature. Transceivers, also known as beacons, send a signal from an avalanche victim to a companion. Signal locators, like RECCO reflectors which are often sewn directly into gear, can echo back a radar signal sent by a detector; most ski resorts have RECCO detector units.
Research suggests that Ground Penetrating Radar (GPR), an electromagnetic tool used by geophysicists to pull images from inside the ground, could be used to locate an avalanche victim. A new study from the Department of Energy’s Sandia National Laboratories suggests that a computer program developed to pinpoint the source of a chemical or biological terrorist attack could also be used to find someone submerged in an avalanche. The search algorithm allows for small robots (described as cockroach-sized) to “swarm” a search area. Researchers say that this distributed optimization algorithm can help find avalanche victims four times faster than current search mechanisms. For a person buried in an avalanche, the chance of survival plummets after 20 minutes, so every moment counts.
An avy dog in training is picking up scent
Sarah McLear
While rescue gear has been evolving, predicting when a slab will fall remains an emerging science — kind of where weather forecasting science was in the 1980s. Avalanche forecasting still relies on documenting avalanches by going out and looking,” says Ethan Greene, director of the Colorado Avalanche Information Center (CAIC). “So if there's a big snowstorm, and as you might remember, most avalanches happened during snowstorms, we could have 10,000 avalanches that release and we document 50,” says Greene. “Avalanche forecasting is essentially pattern recognition,” he adds--and understanding the layering structure of snow.
However, determining where the hazards lie can be tricky. While a dense layer of snow over a softer, weaker layer may be a recipe for an avalanche, there’s so much variability in snowpack that no one formula can predict the trigger. Further, observing and measuring snow at a single point may not be representative of all nearby slopes. Finally, there’s not enough historical data to help avalanche scientists create better prediction models.
That, however, may be changing.
Last year, an international group of researchers created computer simulations of snow cover using 16 years of meteorological data to forecast avalanche hazards, publishing their research in Cold Regions Science and Technology. They believe their models, which categorize different kinds of avalanches, can support forecasting and determine whether the avalanche is natural (caused by temperature changes, wind, additional snowfall) or artificial (triggered by a human or animal).
With smell receptors ranging from 800 million for an average dog, to 4 billion for scent hounds, canines remain key to finding people caught in slides.
With data from two sites in British Columbia and one in Switzerland, researchers built computer simulations of five different avalanche types. “In terms of real time avalanche forecasting, this has potential to fill in a lot of data gaps, where we don't have field observations of what the snow looks like,” says Simon Horton, a postdoctoral fellow with the Simon Fraser University Centre for Natural Hazards Research and a forecaster with Avalanche Canada, who participated in the study. While complex models that simulate snowpack layers have been around for a few decades, they weren’t easy to apply until recently. “It's been difficult to find out how to apply that to actual decision-making and improving safety,” says Horton. If you can derive avalanche problem types from simulated snowpack properties, he says, you’ll learn “a lot about how you want to manage that risk.”
The five categories include “new snow,” which is unstable and slides down the slope, “wet snow,” when rain or heat makes it liquidly, as well as “wind-drifted snow,” “persistent weak layers” and “old snow.” “That's when there's some type of deeply buried weak layer in the snow that releases without any real change in the weather,” Horton explains. “These ones tend to cause the most accidents.” One step by a person on that structurally weak layer of snow will cause a slide. Horton is hopeful that computer simulations of avalanche types can be used by scientists in different snow climates to help predict hazard levels.
Greene is doubtful. “If you have six slopes that are lined up next to each other, and you're going to try to predict which one avalanches and the exact dimensions and what time, that's going to be really hard to do. And I think it's going to be a long time before we're able to do that,” says Greene.
What both researchers do agree on, though, is that what avalanche prediction really needs is better imagery through satellite detection. “Just being able to count the number of avalanches that are out there will have a huge impact on what we do,” Greene says. “[Satellites] will change what we do, dramatically.” In a 2022 paper, scientists at the University of Aberdeen in England used satellites to study two deadly Himalayan avalanches. The imaging helped them determine that sediment from a 2016 ice avalanche plus subsequent snow avalanches contributed to the 2021 avalanche that caused a flash flood, killing over 200 people. The researchers say that understanding the avalanches characteristics through satellite imagery can inform them how one such event increases the magnitude of another in the same area.
Avy dogs trainers hide in dug-out holes in the snow, teaching the dogs to find buried victims
Sarah McLear
Lifesaving combo: human tech and Mother Nature’s gear
Even as avalanche forecasting evolves, dogs with their built-in rescue mechanisms will remain invaluable. With smell receptors ranging from 800 million for an average dog, to 4 billion for scent hounds, canines remain key to finding people caught in slides. (Humans in comparison, have a meager 12 million.) A new study published in the Journal of Neuroscience revealed that in dogs smell and vision are connected in the brain, which has not been found in other animals. “They can detect the smell of their owner's fingerprints on a glass slide six weeks after they touched it,” says Nicholas Dodman, professor emeritus at Cummings School of Veterinary Medicine at Tufts University. “And they can track from a boat where a box filled with meat was buried in the water, 100 feet below,” says Dodman, who is also co-founder and president of the Center for Canine Behavior Studies.
Another recent study from Queens College in Belfast, United Kingdom, further confirms that dogs can smell when humans are stressed. They can also detect the smell of a person’s breath and the smell of the skin cells of a deceased person.
The emerging avalanche-predicting human-made tech and the incredible nature-made tech of dogs’ olfactory talents is the lifesaving “equipment” that Leffler believes in. Even when human-made technology develops further, it will be most efficient when used together with the millions of dogs’ smell receptors, Leffler believes. “It is a combination of technology and the avalanche dog that will always be effective in finding an avalanche victim.”
Living with someone changes your microbiome, new research shows
Some roommate frustration can be expected, whether it’s a sink piled high with crusty dishes or crumbs where a clean tabletop should be. Now, research suggests a less familiar issue: person-to-person transmission of shared bacterial strains in our gut and oral microbiomes. For the first time, the lab of Nicola Segata, a professor of genetics and computational biology at the University of Trento, located in Italy, has shown that bacteria of the microbiome are transmitted between many individuals, not just infants and their mothers, in ways that can’t be explained by their shared diet or geography.
It’s a finding with wide-ranging implications, yet frustratingly few predictable outcomes. Our microbiomes are an ever-growing and changing collection of helpful and harmful bacteria that we begin to accumulate the moment we’re born, but experts are still struggling to unravel why and how bacteria from one person’s gut or mouth become established in another person’s microbiome, as opposed to simply passing through.
“If we are looking at the overall species composition of the microbiome, then there is an effect of age of course, and many other factors,” Segata says. “But if we are looking at where our strains are coming from, 99 percent of them are only present in other people’s guts. They need to come from other guts.”
If we could better understand this process, we might be able to control and use it; perhaps hospital patients could avoid infections from other patients when their microbiome is depleted by antibiotics and their immune system is weakened, for example. But scientists are just beginning to link human microbiomes with various ailments. Growing evidence shows that our microbiomes steer our long-term health, impacting conditions like obesity, irritable bowel syndrome, type 2 diabetes, and cancer.
Previous work from Segata’s lab and others illuminated the ways bacteria are passed from mothers to infants during the first few months of life during vaginal birth, breastfeeding and other close contact. And scientists have long known that people in close proximity tend to share bacteria. But the factors related to that overlap, such as genetics and diet, were unclear, especially outside the mother-baby dyad.
“If we look at strain sharing between a mother and an infant at five years of age, for example, we cannot really tell which was due to transmission at birth and which is due to continued transmission because of contact,” Segata says. Experts hypothesized that they could be caused by bacterial similarities in the environment itself, genetics, or bacteria from shared foods that colonized the guts of people in close contact.
Strain sharing was highest in mother-child pairs, with 96 percent of them sharing strains, and only slightly lower in members of shared households, at 95 percent.
In Italy, researchers led by Mireia Valles-Colomer, including Segata, hoped to unravel this mystery. They compared data from 9,715 stool and saliva samples in 31 genomic datasets with existing metadata. Scientists zoomed in on variations in each bacterial strain down to the individual level. They examined not only mother-child pairs, but people living in the same household, adult twins, and people living in the same village in a level of detail that wasn’t possible before, due to its high cost and difficulties in retrieving data about interactions between individuals, Segata explained.
“This paper is, with high granularity, quantifying the percent sharing that you expect between different types of social interactions, controlling for things like genetics and diet,” Gibbons says. Strain sharing was highest in mother-child pairs, with 96 percent of them sharing strains, and only slightly lower in members of shared households, at 95 percent. And at least half of the mother-infant pairs shared 30 percent of their strains; the median was 12 percent among people in shared households. Yet, there was no sharing among eight percent of adult twins who lived separately, and 16 percent of people within villages who resided in different households. The results were published in Nature.
It’s not a regional phenomenon. Although the types of bacterial strains varied depending on whether people lived in western and eastern nations — datasets were drawn from 20 countries on five continents — the patterns of sharing were much the same. To establish these links, scientists focused on individual variations in shared bacterial strains, differences that create unique bacterial “fingerprints” in each person, while controlling for variables like diet, demonstrating that the bacteria had been transmitted between people and were not the result of environmental similarities.
The impact of this bacterial sharing isn’t clear, but shouldn’t be viewed with trepidation, according to Sean Gibbons, a microbiome scientist at the nonprofit Institute for Systems Biology.
“The vast majority of these bugs are actually either benign or beneficial to our health, and the fact that we're swapping and sharing them and that we can take someone else's strain and supplement or better diversify our own little garden is not necessarily a bad thing,” he says.
"There are hundreds of billions of dollars of investment capital moving into these microbiome therapeutic companies; bugs as drugs, so to speak,” says Sean Gibbons, a microbiome scientist at the Institute for Systems Biology.
Everyday habits like exercising and eating vegetables promote a healthy, balanced gut microbiome, which is linked to better metabolic and immune function, and fewer illnesses. While many people’s microbiomes contain bacteria like C. diff or E. coli, these bacteria don’t cause diseases in most cases because they’re present in low levels. But a microbiome that’s been wiped out by, say, antibiotics, may no longer keep these bacteria in check, allowing them to proliferate and make us sick.
“A big challenge in the microbiome field is being able to rationally predict whether, if you're exposed to a particular bug, it will stick in the context of your specific microbiome,” Gibbons says.
Gibbons predicts that explorations of microbe-based therapeutics will be “exploding” in the coming decades. “There are hundreds of billions of dollars of investment capital moving into these microbiome therapeutic companies; bugs as drugs, so to speak,” he says. Rather than taking a mass-marketed probiotic, a precise understanding of an individual’s microbiome could help target the introduction of just the right bacteria at just the right time to prevent or treat a particular illness.
Because the current study did not differentiate between different types of contact or relationships among household members sharing bacterial strains or determine the direction of transmission, Segata says his current project is examining children in daycare settings and tracking their microbiomes over time to understand the role genetics and everyday interactions play in the level of transmission that occurs.
This relatively newfound ability to trace bacterial variants to minute levels has unlocked the chance for scientists to untangle when and how bacteria leap from one microbiome to another. As researchers come to better understand the factors that permit a strain to establish itself within a microbiome, they could uncover new strategies to control these microbes, harnessing the makeup of each microbiome to help people to resist life-altering medical conditions.