Scientists have used a technique to control the expression of genes transplanted into salivary glands, according to an article in the Jan. 22 advance online edition of Gene Therapy.
This breakthrough can open the way for development of new therapies for treating a variety of oral conditions.
Scientists at the National Institute of Dental and Craniofacial Research used a system in which a chemical switch, which can be activated by the application of the immunosuppressant drug rapamycin, controlled the expression of genes transplanted into salivary glands.
The technique overcomes a common problem in gene transplantation in which the transplanted genes either turn off prematurely or overproduce the replacement protein they were designed to deliver.
Using the rapamycin switch technique in the salivary glands is a promising technique because of the glands’ unique ability to secrete proteins both into the mouth through the saliva and into the bloodstream. Scientists confirmed that they could control this two-way process in animal studies, varying the method of secretion from the salivary glands by changing the signal for the protein.
"What’s fascinating is, in theory, one could use gene therapy in the salivary glands to treat either oral or systemic conditions or single-gene disorders, such as diabetes and growth hormone deficiency," said senior author Dr. Bruce Baum.
Uses for the salivary gene transplant mechanism could include therapies for fungal and bacterial infections or treatment for oral ulcers resulting from chemotherapy. Both conditions could benefit from the highly localized concentrations of medication facilitated by gene transplantation.
"The large advantage of gene therapy is that only one gene delivery, instead of multiple protein injections, is needed, making it less expensive and easier to tolerate for patients," said lead author Dr. Jianghua Wang.
