Isolation of Salivary Epithelial Cells from Human Salivary Glands for In Vitro Growth as Salispheres or Monolayers

The salivary glands are a site of significant interest for researchers interested in multiple aspects of human disease. One goal of researchers is to restore function of glands damaged by radiation therapies or due to pathologies associated with Sjögren's syndrome. A second goal of researchers is to define the mechanisms by which viruses replicate within glandular tissue where they can then gain access to salivary fluids important for horizontal transmission. These goals highlight the need for a robust and accessible in vitro salivary gland model that can be utilized by researchers interested in the above mentioned as well as related research areas. Here we discuss a simple protocol to isolate epithelial cells from human salivary glands and propagate them in vitro. Our protocol can be further optimized to meet the needs of individual studies. Briefly, salivary tissue is mechanically and enzymatically separated to isolate single cells or small clusters of cells. Selection for epithelial cells occurs by plating onto a basement membrane matrix in the presence of media optimized to promote epithelial cell growth. These resulting cultures can be maintained as three-dimensional clusters, termed "salispheres", or grown as a monolayer on treated plastic tissue culture dishes. This protocol results in the outgrowth of a heterogenous population of mainly epithelial cells that can be propagated for 5-8 passages (15-20 population doublings) before undergoing cellular senescence.