The annual prize for the most outstanding PhD thesis in Infectious Diseases has been awarded to Mabel Tettey in the School of Biological Sciences. Image Ker Prize winner Dr Mabel Tettey Mabel carried out her PhD with Prof Keith Matthews, and was supported by the Darwin Trust. Her thesis studied the role of released peptidases in the transmission biology of African trypanosomes.The judges – Elly Gaunt, Roslin Institute, and Katie Atkins, Usher Institute – were most impressed with her outstanding intellectual contributions to excellent scientific research, attested by development of collaborations with other labs across the UK.As part of her prize Mabel will present her work at the Annual Edinburgh Infectious Diseases symposium on Thursday 23 June. About MabelMabel obtained her undergraduate studies in Biological Sciences at the Kwame Nkrumah University of Science and Technology in Ghana, before joining the Matthews’ lab in 2017.She is currently a postdoctoral research associate at Brown University where she is investigating the cytoskeletal changes that occur during trypanosome differentiation from one developmental form to the other.About her workTrypanosoma brucei is a unicellular protozoan parasite that causes sleeping sickness in humans and ‘nagana’ (from the Zulu ‘unakane’, or ‘low spirits’) in animals in sub-Sahara Africa. They are transmitted through the bites of an infected tsetse fly.Two developmental forms of the parasite exist in the bloodstream of the mammalian host: the proliferative slender and the cell-cycle arrested stumpy forms. At peak parasitaemia, accumulated oligopeptides generated through the activities of peptidases released by the parasites stimulate the dividing slender forms to differentiate into non-dividing stumpy forms in a form of quorum sensing. This mechanism controls the increasing parasitaemia to keep the host alive and also prepares the parasites for survival and development in the tsetse fly.Mabel's work sought to identify the peptidases released by the parasites by mass spectrometry and to explore their contribution to stumpy formation. Out of the twelve peptidases identified to be released, two were found to significantly contribute to the generation of the trypanosome’s quorum-sensing signal: oligopeptidase B and metallocarboxypeptidase 1.This work further strengthens our model of Trypanosoma differentiation through peptidase-mediated oligopeptide signal generation and identifies the key molecules driving inter-parasite communication.Highly commendedThe prize judges also wanted to note the extremely high standard of nominations for this year's prize, and in particular highlighted for commendation Dr Tessa Nash for her work with Prof Lonneke Vervelde (Roslin Institute) on chicken enteroids.All the nominees are listed below - many congratulations to all.NomineeSupervisorAffiliationThesis titleDanladi AmaduChristine CampbellUsher InstituteCervical Cancer Control in Gombe State, Nigeria: Preparing for the FutureJordan MitchellDanielle Gunn-MooreRoyal (Dick) School of Veterinary StudiesDevelopment of multi-parametric tests for the diagnosis of feline tuberculosisTessa NashLonneke VerveldeRoslin InstituteApical-out chicken enteroids with leukocyte component as a model to study host-pathogen interactions. **Judges commendation**Mabel TetteyKeith MatthewsSchool of Biological SciencesAnalysis of released peptidases and their role in the transmission biology of African trypanosomes **Prize winner**Zhishuo WangSteven SpoelSchool of Biological SciencesFunctional analysis of proteasome- associated ubiquitin ligases in plantFeifei ZhangMark WoolhouseUsher InstituteThe epidemiology of emerging human-infective RNA viruses: discovery, geographical extent, and disappearanceAbout the Ker Memorial PrizeThe Ker Prizes are very generously supported by Miss Aileen Ker, in memory of two outstanding Edinburgh physicians, her grandfather Dr. Claude Buchanan Ker, and his son (her father), Dr. Frank Leighton Ker.The Ker family also support the presentation of the Ker Memorial Lecture, given by an eminent invited scientist in Infectious Diseases.Dr. Claude Buchanan Ker (1867-1925) spent his professional medical career in Edinburgh, working ceaselessly to improving the treatment of infectious diseases. He is best remembered for his tireless efforts to build the City Fever Hospital which opened in Colinton in 1903, and of which he was medical superintendent for 21 years.Dr. Frank Leighton Ker (1907-1966), began his medical career in Edinburgh and went on to carry out his main work at the East Birmingham Hospital, where he became medical superintendent in 1950.The glowing and heartfelt obituaries written for both these men, show the enormous regard and affection in which they were held, and to which the Ker Memorial Prize and Lecture now provide fitting testimony.Related linksRegister for the Edinburgh Infectious Diseases Annual Symposium School of Biological SciencesMatthews labVervelde lab Publication date 30 May, 2022
