Periodic Reporting for period 2 - RNACOM (RNA functions in parasite-host communication in the gut)
Reporting period: 2022-08-01 to 2024-01-31
RNACOM examines how parasitic worms use small ribonucleic acids (sRNAs) to directly manipulate gene expression in mammalian (host) cells and investigates ways to block or disrupt RNA transmission as a pathogen control strategy. Parasitic worms infect more than a quarter of the human population and are highly prevalent in livestock, ranking first in terms of the global health burden of the neglected tropical diseases and causing substantial economic burdens in Europe. RNACOM builds on our recent discovery of a specific Argonaute protein that gastrointestinal nematodes use to shuttle their RNAs to host cells to change the gut environment and enable parasite survival. The first objective is to capture this protein with antibodies and identify the host genes that are targeted by parasite RNA-induced silencing complexes (RISCs) during chronic infection. We will then determine the specific cells the parasites RISCs enter and examine how they change the host epithelium to allow parasite survival. Finally we use synthetic and recombinant strategies to learn exactly how parasite RISCs cause gene silencing and build on this knowledge to develop new strategies to block RNA transmission by the parasite to treat or control infections.
RNACOM will bring key quantitative and molecular understanding to the processes by which RNA from one species can influence another. The knowledge gained in the gastrointestinal models could illuminate mechanisms used by other pathogens infecting animals and plants that impact health and agriculture. Studying how parasites can effectively deliver their RNAs to mammalian cells could also illuminate new strategies for RNA drug delivery relevant to a range of human diseases.
RNACOM will bring key quantitative and molecular understanding to the processes by which RNA from one species can influence another. The knowledge gained in the gastrointestinal models could illuminate mechanisms used by other pathogens infecting animals and plants that impact health and agriculture. Studying how parasites can effectively deliver their RNAs to mammalian cells could also illuminate new strategies for RNA drug delivery relevant to a range of human diseases.
The work performed to date has identified the host cell populations targeted by the parasite extracellular vesicles (EVs) and Argonaute protein. Strikingly we find different cell populations targeted at the different stages of infection and our results suggest there is high specificity in terms of where the EVs and Argonaute protein traffic naturally in vivo. Our ongoing work has been focused on refining the methods to capture and analyze the parasite RNA-induced silencing complexes (RISCs) in these specific cell populations. We have also invested in studying which form of the Argonaute protein (vesicular or non-vesicular) gets internalized by host cells and have been awarded a Proof of Concept Grant to study the properties of the non-vesicular Argonaute in terms of uptake by mammalian cells and scope for using this natural product as an RNA delivery vehicle. Lastly we have identified and are testing one candidate protein that may be required for parasite Argonaute entry/function in host cells. We are testing the importance of this host factor in parasite survival, in parallel with testing efficacy of different vaccine designs directed against the parasite Argonaute protein.
RNACOM has pushed new technologies and collaborations to robustly bring quantitative and molecular understanding to the mechanisms by which RNA from one species can influence another. RNACOM has gone beyond understanding extracellular vesicles and RNA transmission mechanisms to discover novel interactions and cell types associated with infection and inflammation in the gut. In parallel RNACOM develops a unique platform for identifying gene networks that underpin intestinal cell functions and gut health that is relevant to other human disease.