Retrovirus-mediated gene transfer into salivary glands in vivo

In the present report, we show prolonged expression of beta-galactosidase (beta-Gal) in the acinar cells of the submandibular and sublingual glands of rats following retrograde ductal injection of the retroviral vector BAG. To facilitate integration of viral DNA, cell division in the gland was induced by the administration of the beta-adrenergic agonist isoproterenol prior to the delivery of the vector. The frequency of cells stained for beta-Gal was higher if the virus was injected 4-20 hr after the two injections of isoproterenol given 24 hr apart than after the injection of only one dose of the drug. Without stimulation of cell division, no integration of the viral DNA was observed. Expression of the marker enzyme was observed up to 43 days, the limit of the observation period. The data indicate that salivary glands are potential targets of retrovirus-mediated gene transfer for somatic gene therapy.