Scientific discovery scratching beneath the surface of itchiness

Study sheds light on how a parasitic worm can sneak into the human body by evading itch.

Schistosoma mansoni evades this very defense mechanism, bypassing itch response entirely.

Researchers used light to genetically activate neurons on ear skin prior to infection, administering chloroquine and genetically reducing population of MrgprA3 neurons in mice.

Researchers found that MrgprA3 neurons were involved in blocking parasites entering the body.

They also found that the neurons were functionally linked to the macrophage response because without them the worm infection wasn't blocked at all.

The team also found the neuropeptide CGRP plays a key role in neuron-immune cell communication.

When they examined macrophages, they discovered that IL-33 was not just being reduced but was acting within the cell nucleus.

MrgprA3 neurons drive cutaneous immunity against helminths through selective control of myeloid -derived IL-33 .

The research was supported by the National Institutes of Health (grants T32 AI007532-24 , R01 AI164715-01, P30-AR069589 , and contract HHSN272201700014I ).