Exploiting stem cell receptors for parasite control

Subsequent in vitro culturing using chicken serum supplemented with 50% RPMI (CS50) allowed for the culturing of F. hepatica where RNA interference against peptide GPCRs occurred. Silencing three neuropeptide Y G-Protein Coupled Receptors (NPY GPCRs) (F<i>hPep 17, FhPep 24 and FhPep 25</i>) resulted in reduced growth phenotypes with knockdown being confirmed in subsequent RT-qPCR analysis. A further three non-NPY GPCRs (<i>FhPep 1, FhPep 11 and FhPep 21</i>) were also silenced and caused reduced growth phenotypes.

The reduced growth GPCR phenotypes inspired a return to investigating neuropeptides with updated methodologies which also caused reduced growth phenotypes, strengthening the link between peptidergic signalling and growth and development of <i>F. hepatica</i> and further highlighting the neuropeptidergic system as potential drug targets. Computational modelling predicted 3D structures of both GPCRs and neuropeptides in F. hepatica.

Putative molecular interactions were identified between the terminal GRXR(Y/F) of fluke neuropeptide and fluke GPCRs, the first time this has been modelled in <i>F. hepatica</i>, inspiring future work in understanding molecular interactions and deorphanisation of GPCRs which will fuel drug discovery in <i>F. hepatica</i>. Overall, this project succeeded in better understanding how fluke peptidergic signalling affects growth and development within F. hepatica and lays the foundation for further drug discovery within the peptidergic signalling system of <i>F. hepatica</i>.