Carbon dioxide shapes parasite-host interactions in a human-infective nematode
Year: 2024
Type: article
Abstract: Skin-penetrating nematodes infect nearly one billion people worldwide. The developmentally arrested infective larvae (iL3s) seek out hosts, invade hosts via skin penetration, and resume development inside the host in a process called activation. Activated infective larvae (iL3as) traverse the host body, ending up as parasitic adults in the small intestine. Skin-penetrating nematodes respond to many chemosensory cues, but how chemosensation contributes to host seeking, intra-host development, and intra-host navigation – three crucial steps of the parasite-host interaction – remains poorly understood. Here, we investigate the role of carbon dioxide (CO 2 ) in promoting parasite-host interactions in the human-infective threadworm Strongyloides stercoralis . We show that S. stercoralis exhibits life-stage-specific preferences for CO 2 : iL3s are repelled, non-infective larvae and adults are neutral, and iL3as are attracted. CO 2 repulsion in iL3s may prime them for host seeking by stimulating dispersal from host feces, while CO 2 attraction in iL3as may direct worms toward high-CO 2 areas of the body such as the lungs and intestine. We also identify sensory neurons that detect CO 2 ; these neurons are depolarized by CO 2 in iL3s and iL3as. In addition, we demonstrate that the receptor guanylate cyclase Ss -GCY-9 is expressed specifically in CO 2 -sensing neurons and is required for CO 2 -evoked behavior . Ss -GCY-9 also promotes activation, indicating that a single receptor can mediate both behavioral and physiological responses to CO 2 . Our results illuminate chemosensory mechanisms that shape the interaction between parasitic nematodes and their human hosts and may aid in the design of novel anthelmintics that target the CO 2 -sensing pathway.
Source: Current Biology
Institution: University of California, Los Angeles
Language: English
Subfield: Parasitology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $7,030
Funders: University of Pennsylvania, Andy Hill CARE Fund, Universität Wien, National Institutes of Health, University of California, Los Angeles, National Institute on Deafness and Other Communication Disorders, National Institute of General Medical Sciences, National Institute of Allergy and Infectious Diseases
OpenAlex ID: W4405763998