The development of an organoid model of human salivary glands

Abstract: At present it is not possible to fully investigate the development of a number of salivary gland disorders such as tumour development, Sjogren’s syndrome, viral-associated infections or radiation-induced damage which can lead to salivary gland damage, reduced salivary flow, xerostomia and a worst case scenario of severe, debilitating mucositis with potentially life-threatening systemic infections. The aim of this project was to establish in vitro models of human salivary glands to investigate the onset and pathogenesis of disease and to further understand the development of salivary glands for regenerative studies. Organoids were developed from biopsies of normal human salivary gland tissue. The cells were isolated and cultured in matrigel with the addition of Wnt and R-spondin1 to the culture medium. Cultures were either submerged in medium (non-ALI) or grown at an Air Liquid Interface (ALI). Salivary gland cells, from single suspensions, were able to proliferate and differentiate to form small salivary gland associated structures, resembling mini-glands, following a 14-day culture period and these were initially visualised by haematoxylin and eosin staining. RT-PCR, immunohistochemistry and immunofluorescence were used to determine the differential expression of cell type-specific markers. The organoids showed many characteristics of salivary gland tissue based on their histology and expression of specific cell markers. Our current data indicates that we are able to culture human salivary gland organoids and that they will provide a useful tool to study infectious disease and the initiation and development of salivary gland diseases. This study was supported by the Ministry of Education, Malaysia.