A Conversation with Adam Williamson

The assistant professor of biology talks about phagocytes, mentoring, and the beauties of rural Pennsylvania.

Assistant Professor of Biology Adam Williamson studies immune cells called phagocytes. Most of the research in his Park Science lab is led by undergraduates, up to six at a time, and Williamson sees his mentorship of these young scientists as an exciting and integral part of his job. Williamson, who joined the campus in 2019, also appreciates the small class sizes and cross-disciplinary collaborations possible at a place like Bryn Mawr.

What made you want to run a research lab here?
really goes back to when I was an undergraduate student at Carleton College in Minnesota. I was incredibly lucky to have the opportunity to conduct plant biology research fairly early in my undergraduate training with a professor named Susan Singer, who remains a really important mentor to me. In Susan I had a mentor who really believed in having undergraduate students take ownership of the projects in her lab the way we do it at Bryn Mawr. This experience opened up to me the reality that science is all about finding the edge of what we think we know and then pushing those boundaries further and trying to describe new knowledge as best we can.

How did your interest in cell biology and immunology began?
went to graduate school in biochemistry at UC Berkeley and looked at how cells degrade their proteins and progress through the cell cycle and divide in ways that are relevant to human cancers. While I was doing that work, I became really interested in this idea that cells and organisms are regulating all of these processes in space and time. That led me to pursue fellowship training at University of California San Francisco in cell biology and immunology, using microscopes to look at immune cells performing functions to really understand how cells control these important protective behaviors and trying to watch those processes in action.

And your current research?
e study immune cells called phagocytes. These are specialized cells that recognize potentially dangerous things and eat them to protect the organism. It’s probably one of the most ancient modes of immunity. The process involves a cell recognizing a relatively large piece of debris, like a dead cell or a bacterium, and using receptors on its cell surface as molecular hands to latch on to that target and then literally eat it. One of the things that’s remarkable to me is how fast the process itself is. Once a phagocyte decides to eat a target—it could be almost as big as the cell itself—within seconds it delineates whether the target is something it should eat or not, and then often within minutes it fully ingests its meal.

There are three general areas of inquiry that we’re working on right now. One project is focused on programming phagocytes to eat neurotoxic debris in the brain to potentially alleviate some of the symptoms associated with devastating neurodegenerative diseases. A second area of inquiry is the collaborative work with May Cheng [see below). And another group of students is working on the basic behaviors that phagocytes have retained across about a billion years of evolution. What makes a cell good phagocyte? What cues do phagocytes use to decide what to eat?

We’re really lucky that Bryn Mawr just invested in a new microscope that allows us to take live cell imaging videos of these cells in action to support our work and other ongoing work on campus. For example, there’s a student in the microscope room in Park Science right now who’s watching living phagocytes recognize and ingest a model for neurotoxic debris in the brain that’s linked to a neurodegenerative frontotemporal disorder.

What drew you to a smaller liberal arts college rather than a large research institution?
I love to teach, and I love the small class sizes. I really appreciate how engaged the students are. I absolutely love having the privilege to combine research and teaching in a meaningful way and to have students be the heart and soul of my research program. In biology, since we don’t have a graduate program nearly all the research in the department is led by undergraduate students. I have six undergraduate students in my lab right now ranging from first years to seniors. I think it’s super cool that a student relatively new to biology can come into the laboratory in the morning and use microscopes to look at things that no one’s ever really seen before. Working with these students in my lab is such a key part of this job and such an exciting part of the work we’re doing.

When I interviewed here, I had the opportunity to go out with students for lunch in the dining hall. That’s really what solidified my decision. Right after the interview was done, I remember calling my wife Ellen and being so excited about the interactions with students and the prospect of coming here. I really like the intellectual freedom that an institution like this can afford. I feel like we have some flexibility to think about how we might productively and creatively contribute to this field.

The people I have had the opportunity to interact with here on a daily basis, both faculty and students and staff across different departments, represent a much broader slice of different disciplines than I was able to interact with even at Berkeley. For its size, the amount of disciplinary space Bryn Mawr covers is breathtaking. I’ve been so fortunate to interact with both newer and more senior faculty from across various disciplines, and I really find those interactions enjoyable.

How do you balance mentoring your students with moving the research forward?
don’t think my solution is necessarily perfect yet. As a mentor I’m still very much a work in progress and I’m still learning how to best support each student that comes through the lab. I think that’s an important part of my job.

For the work that we do, it’s important to me that the specialized techniques that students learn in the lab don’t leave the lab when they graduate. So, we’ll have one to three seniors and then one or two students from other class years ranging from first year students all the way through seniors.

As a mentor, I spend a lot of time training students in new lab techniques. It’s important to me that they be able to do these things with accuracy, precision, and safety. The type of microscopy and biochemistry research work that we do in my lab involves techniques that are broadly applicable to many problems in biology other than phagocytosis. So, the students are potentially trained to go out and ask other questions in other fields, equipped with some idea of what modern methods look like.

I also try to be intentional about setting up cross class year networks. The underclass students are hopefully getting some vision of what the senior thesis looks like at Bryn Mawr, and the more senior students are getting some informal mentoring experience working with students newer in their journeys in biology. In terms of running the lab, this has the practical advantage that multiple students at a time are trained in these specialized techniques that we use.

At the end of the day, the mission of the lab is to train undergraduate research scientists to be independent, to ask questions rigorously, to use methods that work, and to identify new unanswered questions. Like all of my colleagues I’m fully invested in doing this work with our students. Some aspects of this would be more efficient if I disappeared into my lab and did it by myself, but that’s not really the mission of the lab, and that’s not really why I’m here.

Tell me about your collaboration with Professor Xuemei May Cheng.
ust months after I moved to Bryn Mawr—my lab wasn’t even renovated yet—I was sitting in my office reading papers and writing our first grant proposals and thinking about what we were going to work on, and May reached out to me.

She’s been such an amazing mentor in various capacities throughout my time here. So supportive and a champion of science at the institution more generally. She’s a specialist in nanomaterials so her lab is really good at fabricating advanced materials with defined physical properties.

One of the big problems in the field of immunology right now is that biological systems are characterized generally as being very squishy and dynamic. Our tissues are pretty soft, right? Our cells are navigating environments whose properties are changing all the time, but unfortunately, nearly all the microscopy information that we have about how immune cells work is collected on glass slides. We’re essentially studying phagocytes sitting on surfaces that are way stiffer than they normally would ever see and, even worse, eating model targets that are incredibly hard—closer to pebbles than the squishy dead cells and debris they target when they actually do their job inside the organism. So the way we study phagocytes outside of the organism often does not recapitulate what they actually see in vivo in the living organism. This is a huge problem.

So, when May introduced herself and we started talking about our varied interests, we became really excited about the possibility of using her expertise in fabricating nanomaterials of defined properties with our ability in my lab to build cell models for phagocytosis.

Now we’re in a three-way collaboration with Elise Corbin in the bioengineering department at the University of Delaware where we’re growing phagocytes in these physiologically squishy environments, and we’re seeing some interesting behaviors that are different than what phagocytes do in the environments under which they’ve historically been studied.

What have you enjoyed about moving to Pennsylvania?
’ve enjoyed opportunities to ride my bike around the area. The Schuylkill River Trail is a huge highlight. Being able to get on my bike from the lab and be at Penn or in Center City within an hour, I feel lucky to have that opportunity. I love to fish and hike and camp and I find central PA just absolutely beautiful. I love that part of the country—the rolling hills and the farm country, and the fishing is great.

What might readers be surprised to learn about you?
first time in Pennsylvania was when I hiked the Appalachian Trail from Georgia to Maine when I was 18. To see the Smokies and the south and experience various parts of the rural U.S. on foot was very eye-opening at that age. I was really struck by the beauty of Pennsylvania at that time too. The sweep of those mountains through the center of the state as you’re working your way up the Appalachians, it’s a really gorgeous part of the world. I feel lucky to have landed here.