Leading expert on role of immune cells in atherosclerosis featured at Heart Institute scientific colloquium

A leading expert on the role of monocytes and macrophages (types of immune cells) in atherosclerosis and other chronic inflammatory conditions delivered the keynote address Nov. 7 at the USF Health Heart Institute’s 2nd Annual Scientific Colloquium.

Gwendalyn Randolph, PhD, an immunologist by training, began her career by studying how innate immune cells travel around the body and along the way began discovering connections between cardiovascular disease, lipid metabolism and the gut.

USF Health Heart Institute Director Samuel Wickline, MD, with speakers at the Institute’s 2nd Annual Scientific Symposium. From left: David Lominadze, PhD, USF Health professor of surgery; Gwendalyn Randolph, PhD, Unanue Distinguished Professor of Pathology and Immunology at Washington University School of Medicine in St. Louis; Dr. Wickline; and Travis Jackson, PhD, USF Health associate professor of molecular pharmacology and physiology.

For the Heart Institute talk, Dr. Randolph, the Emil R. Unanue Distinguished Professor of Pathology and Immunology at Washington University School of Medicine in St. Louis, focused on research investigating what drives inflammation in atherosclerosis – the most common cause of heart attacks.  She shared her work on the trafficking of immune cells and the lipoproteins that carry cholesterol through the bloodstream to deposit inside the artery walls.

“Dr. Randolph’s work in the field of atherosclerosis has produced novel and important insights into the critical cell types that are responsible for forming atherosclerotic plaques in patients with heart disease,” said Samuel Wickline, MD, professor of cardiology and director of the USF Health Heart Institute. “She also has elucidated the molecular factors that attract these cells to plaques and cause them to grow and become unstable, which leads the plaques to break down and clot. This process can ultimately result in blockage of vessels that supply blood to the heart and brain, causing heart attacks and strokes.”

Research by Dr. Randolph, this year’s keynote speaker at the colloquium, has yielded new insights into how immune cells drive inflammation contributing to atherosclerotic plaques in heart disease.

Mouse model studies by Dr. Randolph and others have shown white blood cells, known as monocytes, contribute to the initial build-up of atherosclerotic plaques.

The cascade of events leading to atherosclerosis can take decades.  Initial damage to the inner wall (endothelium) of arteries under the influence of high cholesterol levels triggers a molecular signal that attracts monocytes to travel from the bloodstream into developing plaques. These recruited monocytes are converted into macrophages that take up (eat) the cholesterol trapped in blood vessels and eventually die off. But before that happens, they stay busy secreting molecules that drive plaque inflammation  and weaken the vessel wall, leading to plaque rupture, clotting, and coronary artery obstruction.

In terms of developing new therapies to halt or reverse atherosclerosis, Dr. Randolph said, her research suggests that upstream targeting of recruited monocytes — either before or just after these immune cells arrive in plaques — may be more beneficial than targeting the fat-laden macrophages known as foam cells. Experiments with fluorescent tracers indicate that monitoring endothelial cells lining the arterial wall may be a way to track monocyte migration, she added.

Thomas McDonald, MD, a professor in the USF Health Morsani College of Medicine’s Department of  Molecular Pharmacology and Physiology and member of the Heart Institute, listens to Dr. Randolph’s talk.

In addition to Dr. Randolph, two new faculty members recruited this summer to the USF Health Heart Institute – Travis Jackson, PhD, and David Lominadze, PhD — provided overviews of their National Institutes of Health-funded research.

Dr. Jackson, an associate professor in the Department of Molecular Pharmacology and Physiology, discussed his translational work in therapeutic hypothermia — investigating ways to optimize cold-shock proteins and cold-stress hormones to increase the benefits of cerebroprotective cooling for traumatic brain injury. Dr. Lominadze, a professor in the Department of Surgery, presented research looking into the interactions of blood cells and the endothelium, with the aim of better understanding the microcirculatory disorders associated with cardiovascular and cerebrovascular diseases.

.

The USF Health Heart Institute is scheduled to move to the new USF Health Morsani College of Medicine building in Water Street Tampa in late February 2020.  Its annual scientific colloquium will be held in the new home next year, and continue to evolve with the growth of the Institute, Dr. Wickline said.

“We will expand the program to cover other topics of interest to the cardiovascular community such as genetic heart diseases, heart failure, peripheral vascular disease, and gene therapy.”

-Photos by Allison Long, USF Health Communications and Marketing