Development of a human cell-based model for otitis media

Project details:
Otitis media (OM) is the leading cause of paediatric surgery and the most frequent reason for the prescribing of antibiotics. Over 80% of children develop at least one incident of OM by the age of three and global estimates suggest over 100 million people have mild hearing loss due OM. Remodelling of the middle ear epithelium is key to the pathophysiology of OM but the mechanism underpinning this remodelling remains unclear. A true understanding of the pathogenesis of disease requires the development of a tractable model system. The aim of this project is to establish a novel in vitro model of human, primary middle ear epithelial cells (MEECs) for the study of OM and middle ear infection. Previously we have established MEEC cultures from mice that spontaneously develop chronic middle ear inflammation, differentiated the cells in vitro and infected with nontypeable Haemophilus influenzae (NTHi). Cells collected from middle ear lining (usually scraped off and discarded) of patients suffering the consequences of OM will be used to pure populations of MEECs, which will then be cultured to establish appropriate conditions that support growth and differentiation at an air-liquid interface. A key outcome of the study will be detailed characterisation of the cellular phenotype of the MEEC cultures. Having established this model we will use it to study aspects of both infectious (using NTHi, specifically NTHi (357-SR GFP)) and non-infectious OM. One of the main characteristics of OM is the differentiation of MEECs into goblet cells in the middle ear epithelium leading to the formation of a mucin rich effusion (glue) that is not cleared from the ear. Our model will be used to elucidate the pathogenesis of this process by modulating the phenotype of the cells through induction of goblet cell metaplasia. The role of excessive mucin secretion can then be compared with “normal” cellular morphology. Gene-editing techniques will determine the role of specific genes in the pathogenesis of OM.
Expected outcome. This PhD project will establish and validate a 3D model of human middle ear epithelium and use this to investigate cellular differentiation and the development of OM. We will determine whether mesenchymal signals and pharmacological mediators can be used to modulate epithelial phenotype and lead to the development of epithelial cultures representative of OM. The model will aprovide a valuable tool for testing novel compounds that may alter cellular phenotypes and modify aspects of OM and we believe that it will be of significant value to the wider OM community.