Analysis of CD66a and CD117 Expression Pattern in Salivary Gland Epithelial Cells

Objectives: Stem cell therapy could provide a way to regenerate damaged salivary glands. Although salivary gland stem cells are known to reside in the ductal part of the epithelium, including the intercalated duct, lack of suitable markers has hampered isolating them. Here we report that major epithelial cell types of the mouse submandibular gland (SMG) differentially express the cell surface molecules CD117 and CD66a and are distinguishable by their combinations.

Methods:

SMGs were dissected from adult female mice, and the single cell suspensions were prepared by enzymatic digestion. Frozen sections and single cell preparations of the glands were subjected to immunofluorescence staining for CD66a, CD117, the epithelial marker E-cadherin, the acinar marker AQP5, the ductal marker CLDN4, and the basal and myoepithelial marker CK5. Specimens were observed with Zeiss LSM700. All animal experiments were approved by the Animal Care and Use Committee of Osaka Dental University.

Results:

CD66a and CD117 were expressed mainly and differentially in the SMG epithelium. CD66a staining was intense in the acini and intercalated duct and weak in the striated and excretory ducts. CD117 was undetectable in the acini but was expressed in the intercalated duct cells and a subset of striated excretory duct cells. The basal and myoepitherial cells were negative for these molecules. These observations were supported by single cell preparation analysis.

Conclusion:

The present study demonstrate that SMG epithelial cells are classified into 5 types by combinations of CD66a and CD117. Our preliminary experiments indeed show that these 5 cell types are separable by FACS, allowing us to clarify their molecular signature and stem cell activity. This study was supported by grants from the BioLegend/Tomy and JSPS.

: the CD117negCD66ahi acinar cells, the CD117posCD66ahi intercalated duct cells, the CD117posCD66alo and CD117negCD66alo striated and excretory duct cells, and the CD117negCD66aneg basal and myoepithelial cells.