“This finding paves the way for using blood samples to provide a snapshot of whole-body immunity,” says the study’s co-first author Laura Vella,a physician-scientist who performed this work in the lab of senior author E. John Wherry,chair of the Department of Systems Pharmacology and Translational Therapeutics. Vella is also a pediatric infectious diseases physician at Children’s Hospital of Philadelphia.
Researchers say this work could help better define and monitor the condition of the immune system in vulnerable groups, such as infants and small children, the elderly, patients taking immune-suppression drugs, and those with autoimmune-based disorders like inflammatory bowel disease.
“It’s as if we’re trying to find the toxins draining from a single pipe into the Great Lakes—how do we find and characterize what is originating from that one spot in the water of an entire glacial lake?” Wherry says. “The cells we’re looking for in the bloodstream are 0.1 percent of all cell types circulating in the blood. But our ‘periscope’ allows us to see what that rare cell type can tell us about immune system events that have happened in a distant part of the body.”
Looking into the immune system to better fight disease
A rare, short-lived population of immune cells in the bloodstream may serve as “periscopes” to monitor immune status via lymph nodes deep inside the body, say researchers in the Perelman School of Medicine. Their findings are published this month in the Journal of Clinical Investigation.