Dr. Lindsay Cowell
Dr. Lindsay Cowell is one of an emerging new breed of scientists working in physical or computational sciences and answering biological questions. The question she is determined to answer is how do the two main parts of the body’s immune system communicate with each other in order to ward off harmful biological invaders. Armed with such understanding, scientists will be better able to produce vaccines against a range of threatening agents.
When a virus, bacteria, or parasite enters the body, the immune system detects this “antigen” and sets up a line of defense. Two parts of the immune system, the innate system and the adaptive system, spring into action. Generally, the innate system reacts first, usually on the order of minutes or hours. The system kicks into action when it recognizes the specific molecular code carried by a biological invader, and it then triggers a cascade of effects that slow or stop the agent’s reproduction. The innate immune system has no immunologic memory, meaning that on subsequent exposures to the same pathogen, the response is no more effective than it was the first time.
But all is not lost: as part of its standard operating procedure, the innate system also triggers the adaptive immune system into responding. The adaptive system marshals the forces of specific cells, including T cells (produced in the thymus gland) and B cells (produced in bone marrow). Working together, these cells are able to recognize the molecular codes of a wide diversity of biological invaders and take action to disable them from causing harm. After contraction of an immune response, specific B and T lymphocytes remain in the body so that on subsequent exposure to the same pathogen, the response is much more rapid and vigorous.
While B cells and T cells are developing, they build a wide range of different protein molecules into their plasma membrane, using a process called V(D)J recombination. These molecules, which stick out from the cells’ surfaces, are known as antigen receptors and are capable of binding to single specific antigens.
By developing the computer software and the algorithms, Dr. Cowell, an assistant professor of biostatistics and bioinformatics and immunology at Duke University and a co-director of the Duke University Laboratory of Computational Immunology, has modeled the molecular codes directing V(D)J recombination and developed new statistical approaches to understanding how the cells create the diversity of protein arrangements for the antigen receptors by rearranging the codes.
Dr. Cowell, who received a Burroughs Wellcome Fund Career Award at the Scientific Interfaces in 2002, has taken a circuitous route to her current interest in the immune system. As she recalls, she always loved mathematics, but her early academic choices took her in other directions.
During high school, she worked as a volunteer at a preschool for severely handicapped children, and this experience led her to the University of North Carolina-Chapel Hill as a major in early childhood education. But by the time she graduated, she already was feeling pulled elsewhere. “I loved the kids, but the system was frustrating,” she said. “I also felt like I wasn’t making any long-term difference. I began to feel like I couldn’t do this for the rest of my life. I had to find something else.” As an undergraduate, Dr. Cowell had worked as a teacher’s aide in a school for emotionally and behaviorally disturbed children—and trained her dogs as a hobby.
Working with her dogs got Dr. Cowell interested in how dogs could be taught to be companions to individuals with mobility and hearing impairments. “It was a way to stay involved with the special needs community and transition out of teaching,” she said. “It was something that would have a huge positive influence on the quality of life for people, something I didn’t feel like I was doing as a teacher.” She spent two summer internships at Canine Companions for Independence in Santa Rosa, California, before deciding to go back to graduate school to study zoology. Her goal was to gain practical knowledge to help in breeding service dogs.
Enrolling at North Carolina State University (NCSU), Dr. Cowell had to prepare herself for her new major by taking basic science courses. One of these courses was a population biology course. She loved it. “The course got me back in touch with math and specifically mathematical biology,” she said. She received her Ph.D. in biomathematics from NCSU’s Department of Statistics.
While at NCSU, Dr. Cowell was introduced to immunology—the study of the immune system—and the subject proved to be the icing on the cake. “After trying out all these different careers, I finally found something that I knew could keep me interested for a lifetime and where I knew I could make a difference in the world,” she said. “As convoluted as my path may seem, each experience put me in the place I needed to be in order to discover the next thing.”
By Russ Campbell, communications officer at the Burroughs Wellcome Fund.