Ever had an itchy nose or, worse, an unreachable spot on your back that drives you mad? Now imagine an itch that refuses to go away, no matter how hard or long you scratch. That persistent itch, or pruritus, may actually be one of the skin’s first lines of defense against harmful invaders, according to neuroimmunologist Juan Inclan-Rico of the University of Pennsylvania.
“It’s inconvenient, it’s annoying, but sensations like pain and itch are crucial. They’re ever-present, especially when it comes to skin infections,” says Inclan-Rico, a postdoctoral researcher in the Herbert Lab at Penn’s School of Veterinary Medicine, who has been exploring what he calls “sensory immunity,” the idea that “if you can feel it, you can react to it.” Itch, he explains, is the body’s way of detecting threats such as skin infections before they can take hold.
But in a recent paper published in Nature Immunology, De’Broski Herbert, professor of pathobiology at Penn Vet, and his team flipped that theory on its head. They shed light on how a parasitic worm, Schistosoma mansoni, can sneak into the human body by evading this very defense mechanism, bypassing the itch response entirely. And while there are prophylactic therapeutics for those who may encounter S. mansoni, options for treating someone who has unknowingly been exposed are relatively scant, and these research findings pave the way for addressing this concern.
“These blood flukes, which are among the most prevalent parasites in humans, infecting nearly 250 million people, have seemingly evolved to block the itch, making it easier for them to enter the body undetected,” Inclan says. “So, we wanted to figure out how they do it. What are the molecular mechanisms underlying how they turn off such an essential sensory alarm? And what can this teach us about the sensory apparatus that drives us to scratch a pesky itch?”
Read more on Penn Today!