By Mary C. Farach-Carson, PhD, and Simon Young, DDS, MD, PhD
2019 Research Support Grant recipients: “Development of Surgically Implantable Minor Salivary Gland-Based Constructs for Treatment of Xerostomia”– The University of Texas Health Science Center at Houston School of Dentistry
A major focus of the work in our labs is to isolate human stem/progenitor cells from minor glands for salivary tissue engineering and cell therapy applications. Millions of patients suffer from dry mouth caused by postsurgical radiation for head and neck cancers, gland loss due to injury or disease, aging and medications.
We work to create “avatars,” tissue-engineered, cell-based replacement tissue that will restore saliva production and provide a permanent cure. Our tissue source has traditionally been the major glands, parotid primarily, from surgical patients. This project sought to determine if an equivalent and more available source could be obtained from minor salivary glands in the lips, easily extracted during common oral and maxillofacial surgical procedures.
COVID-19 halted all clinical research, including recruitment and enrollment for our IRB-approved protocols, from March 23 until May 7. We took advantage of the time to write a review article that was published in December. We were able to resume work (in shifts to reduce population density) in May 2020. Our team persevered in spite of supply chain disruptions, manufacturing inconsistencies and personnel changes by sharing and borrowing from other labs. We were able to perform proof-of-concept experiments showing that minor salivary gland cells are likely to be a great new cell source for our efforts.
In a fortuitous twist, the pandemic also provided us an opportunity to use our tissue-engineered salivary “avatars” for new studies to research how SARS-CoV-2, the virus that causes COVID-19, enters oral tissues, including salivary glands. Using salivary tissue “avatars,” we are using a SARS-CoV-2 pseudovirus with the spike protein to study infection of salivary glands that leads to presence of spreadable virus in saliva. We are preparing to seek funding to examine salivary gland infection with the new variants of SARS-CoV-2 to determine if a salivary route might explain part of the increase in infectivity that has been reported in the United Kingdom and South Africa variants.
