MASSIVE CELL: Colored transmission electron micrograph of a macrophage cell, one of the largest cells in the body© MEDIMAGE/SCIENCE SOURCE
In the mid-1990s, while researching mice’s immune responses to nematode worms, immunoparasitologist Judi Allen of the University of Manchester spotted macrophages accumulating at the site of a multicellular parasite infection.1 This was unexpected, she told The Scientist; at the time, the immune cells were only known for their antimicrobial activity—a different type of immune response from that known to fight large parasitic worms. The mystery continued, as RNA sequencing revealed that the immune cells’ gene expression differed greatly from that of macrophages activated by a microbial infection.2 “It was so shockingly different that we were thrown,” says Allen. “It didn’t tell us at all what these macrophages were doing, because the list of genes that they were [expressing] were completely unknown.”
Only years later, when ...
