To effectively combat an infection, the body first has to sense it's been invaded, then the affected tissue must send out signals to marshal resources to fight the intruder. Knowing more about these early stages of pathogen recognition and response may provide scientists with crucial clues when it comes to preventing infections or treating inflammatory diseases resulting from overactive immunity. That was the intent behind a new study, led by researchers at the University of Pennsylvania School of Veterinary Medicine (Penn Vet), examining infection with the parasite Cryptosporidium (image). When the team looked for the very first "danger" signals emitted by a host infected with the parasite, they traced them not to an immune cell, as might have been expected, but to epithelial cells lining the intestines, where Cryptosporidium sets up shop during an infection. Known as enterocytes, these cells take up nutrients from the gut, and here they were shown to alert the body to danger via the molecular receptor NLRP6, which is a component of what's known as the inflammasome (https://en.wikipedia.org/wiki/Inflammasome). "You can think about the inflammasome as an alarm system in a house," says Boris Striepen, PhD, a Professor in the Department of Pathobiology at Penn Vet and senior author on the paper, which was published online on December 28, 2020 in PNAS. "It has various components--like a camera that watches the door, and sensors on the windows--and once triggered it amplifies those first signals to warn of danger and send a call for help.Login Or Register To Read Full Story