At Mississippi State University’s College of Veterinary Medicine, research goes far beyond what happens in the clinic. In laboratories across campus, faculty tackle some of the most complex questions in medicine, questions that impact both animals and people. One of those researchers is Dr. Barbara Kaplan, professor of immunotoxicology, whose work focuses on how drugs and chemicals affect the immune system.
Kaplan joined Mississippi State in 2013 and teaches undergraduate, graduate, and veterinary students, while also leading a robust research program. Her field, immunotoxicology, studies how substances interact with the immune system, a system that protects the body from disease but can also malfunction.
“The immune system is really about balance,” Kaplan said. “You want it to respond when you need it and stand down when you don’t. If it becomes overactive, you might see allergies or autoimmune disease. If it becomes too weak, then infections, or even cancer, become a concern.”
Beginning as an undergraduate majoring in environmental toxicology with a chemistry emphasis, Kaplan has invested more than 25 years studying the immune system. During graduate school, she became increasingly interested in what happens after chemicals enter the body—not just where they go in the environment, but how they affect health at the cellular level.
That curiosity eventually led her to veterinary medicine. In fact, one of her earliest exposures to veterinary science came while she was a graduate student.
“I actually had to take veterinary physiology because I didn’t have a background in it,” she said. “I sat in with vet students, which was tough, but it completely changed the way I understood the body and how it responds to drugs.”
One of Kaplan’s most recent research projects involves understanding how compounds found in cannabis impact immune function in dogs. Working alongside collaborators, including Dr. John Thomason in internal medicine and Dr. Michael Jaffe in surgery, Kaplan and her team published new findings about how two specific compounds, THC and CBD, influence immune cells.
Kaplan explained that the dogs are not given cannabis; instead, tests are run on blood samples.
“We don’t dose animals,” she said. “We work with donated blood samples taken during routine care, isolate immune cells in the lab, and expose them to specific compounds in a controlled environment.”
Through this method, Kaplan discovered that both THC, the main chemical component of marijuana, and CBD, a nonintoxicating cannabinoid found in cannabis and hemp, can suppress immune function. Immune suppression can be beneficial in instances where overactive immune systems damage the bodies they’re meant to protect.
“In dogs with immune-mediated disease, lowering immune activity can be helpful. That's why we would use drugs like steroids,” Kaplan explained. “What we are trying to find out is whether these cannabis compounds could eventually be used safely alongside, or in place of, traditional drugs with fewer side effects.”
Steroids, while effective, can cause complications, such as excessive thirst and urination. Kaplan’s research suggests that combining very small doses of steroids with certain cannabis compounds may achieve immune suppression while minimizing side effects. All of Kaplan’s research has been conducted at the cellular level. Studies in live animals have not yet been conducted, and Kaplan is careful to stress that much more research is needed.
Beyond her lab work, Kaplan also directs one of the college's most impactful programs: the Veterinary Medicine Research Scholars program. Now in its 25th year, the program allows rising second-year veterinary students to spend 12 weeks immersed in research.
Students work on projects in areas including infectious disease, veterinary pharmacology, epidemiology, toxicology, aquaculture, antimicrobial resistance and more.
“The goal is to teach students how science actually works,” Kaplan said. “They learn how to write hypotheses, run experiments, analyze data and communicate results. It’s not about memorizing facts; it’s about learning how to find the answers.”
Kaplan says she is passionate about mentoring students and introducing them to research, even if they do not plan on research careers.
“Research teaches critical thinking,” she said. “Whether you go into practice, industry or academia, those skills will serve you for life.”
In her view, pursuing research doesn’t require a lifelong commitment, just curiosity and initiative.
“Start wherever you are. Find someone doing work that interests you and jump in,” Kaplan said. “It doesn’t have to be your forever path. Just get involved and learn.”
