Professor De’Broski Herbert | Scratching the Surface: The Role of Itch-Sensing Neurons in Fighting Parasitic Worms

However, the researchers discovered that these neurons do much more than just cause discomfort – they actually initiate our immune system’s ability to fight off parasitic worms. When these neurons are activated, they send signals to specific types of immune cells in the skin known as myeloid antigen-presenting cells – or ‘APCs’. These APCs then ramp up the production of inflammatory molecules, called cytokines, which attract other immune cells to the site of the infection and remodel the skin barrier, creating a strong defensive shield against invading parasites.

One of the fascinating aspects of this research is how the neurons manage a selective impact on the immune system. The team found that these itch-sensing neurons could suppress a key cytokine called IL-33, which acted as a molecular ‘toggle switch’ to turn on pro-inflammatory Type-17 responses.  

This work shows that myeloid-derived IL-33 is essential for shifting the body’s response from one of calm maintenance to an active defense mode. This shift is particularly important in preventing parasitic worms from successfully invading the skin and spreading throughout the body.

To put this in perspective, the study compared the human parasite Schistosoma mansoni with an avian parasite known as Trichobilharzia szidati, which causes “swimmer’s itch” in people. Unlike Schistosoma mansoni, which has evolved to sneak past the body’s defenses by suppressing the itch response, Trichobilharzia szidati, which is a zoonotic infection, prompts a strong itch reaction, preventing the parasitic worm from establishing an infection.

Professor Herbert’s study is a perfect example of how the body’s different systems – such as the nervous and immune systems – work together in ways we are only beginning to understand. It also highlights the incredible potential of using our natural sensory responses, such as itch, to develop new strategies for preventing and treating infections.