Liisa Selin, MD, PhD, and Anna Gil, PhD, will seek insights into links between myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and viral infections, now including COVID-19, with a five-year, $2.5 million grant from the National Institute of Allergy and Infectious Diseases. The research may have implications for those who experience long-term post-viral illness from COVID-19, commonly known as long COVID.
Dr. Selin, professor of pathology and principal investigator for the grant, and Dr. Gil, instructor in pathology, are examining the role of malfunctioning T cells in the development of ME/CFS. Not yet well understood, it is a complex disease with a constellation of disabling symptoms including exhaustion and cognitive dysfunction that affects up to 2.5 million Americans.
In four of five patients, a viral or bacterial infection preceded its onset. New research anticipates 10 to 50 percent of COVID-19 patients will experience long COVID symptoms, many similar to those of ME/CFS, after their initial infection has cleared.
“We are finding that an aberrant response to an immunological trigger, like an infection, results in a dysregulated immune system that is partially immunosuppressed due to exhaustion of the CD8 T cells, which fight infection,” said Selin. “A comprehensive understanding of the mechanisms associated with the generation and modulation of immunological T cell memory will lead to a better understanding of how the immune system not only controls viral infections but can also cause immune-mediated pathology.”
In preliminary studies, Selin and Gil found that certain CD8 T cells were altered in patients with chronic ME/CFS as compared to those who do not have ME/CFS. This suggests that an aberrant response to an immunological trigger, like infection, results in a permanently dysregulated immune system, as a result of CD8 T cell exhaustion, a phenomenon they previously discovered in patients who developed ME/CFS following an infection with the Epstein-Barr virus.
With ongoing studies, they hope to identify biomarkers and mechanisms driving the immunopathogenesis of ME/CFS, with a goal of identifying targets for therapies. Their new study will further examine whether the unique subset of T cells is increased in all ME/CFS patients, or only occurs in a subgroup.
“Millions in the United States already have ME/CFS. Millions more will soon be presenting with long COVID,” said Selin. “We hope our research translates into concrete help for patients.”
