REVIEW Gene expression changes in mammalian hosts during schistosomiasis: a review [version 1; peer review: awaiting peer review] Joyce Namulondo 1 , Julius Mulindwa 2 , Oscar A. Nyangiri 1 , Moses Egesa 3,4 , Harry Noyes 5 , Enock Matovu 1 , TrypanoGEN+ research group of the H3Africa consortium 1 School of Bio-security, Biotechnical and Laboratory Sciences, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda 2 School of Biosciences, College of Natural Sciences, Makerere University, Kampala, Uganda 3 Immunomodulation and Vaccines Programme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe, Uganda 4 Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK 5 Centre for Genomic Research, University of Liverpool, Liverpool, L69 7ZB, UK First published: 23 Nov 2021, 4:54 https://doi.org/10.12688/aasopenres.13312.1 Latest published: 23 Nov 2021, 4:54 https://doi.org/10.12688/aasopenres.13312.1 v1 Abstract Schistosomiasis affects over 250 million people worldwide with an estimated mortality of more than 200,000 deaths per year in sub- Saharan Africa. Efforts to control schistosomiasis in the affected areas have mainly relied on mass administration of praziquantel, which kills adult but not immature worms of all Schistosoma species. Mammalian hosts respond differently to Schistosoma infection with some being more susceptible than others, which is associated with risk factors such as sociodemographic, epidemiological, immunological and/or genetic. Host genetic factors play a major role in influencing molecular processes in response to schistosomiasis as shown in gene expression studies. These studies highlight gene profiles expressed at different time points of infection using model animals. Immune function related genes; cytokines (Th1 and Th17) are upregulated earlier in infection and Th2 upregulated later indicating a mixed Th1/Th2 response. However, Th1 response has been shown to be sustained in S. japonicum infection. Immune mediators such as matrix metalloproteinases (Mmps) and tissue inhibitors of matrix metalloproteinases (Timps) are expressed later in the infection and these are linked to wound healing and fibrosis. Downregulation of metabolic associated genes is recorded in later stages of infection. Most mammalian host gene expression studies have been done using rodent models, with fewer in larger hosts such as bovines and Open Peer Review Approval Status AWAITING PEER REVIEW Any reports and responses or comments on the article can be found at the end of the article. AAS Open Research Page 1 of 9 AAS Open Research 2021, 4:54 Last updated: 16 MAY 2022