Using the nose as a factory to secrete proteins into the lungs or circulation

Targeting of the nasal epithelium for sustained therapeutic protein secretion represents a potential non-invasive lentiviral vector application strategy. Using reporter imaging, molecular, and radiopharmaceutical tracing methods in mice, we have developed an intranasal (nose-only) dosing strategy with a Sendai virus envelope glycoprotein pseudotyped lentiviral vector (rSIV.F/HN). Using multiple (up to 10) small-volume (5 μL) intranasal bolus applications, a technetium radiotracer showed >90% liquid retention in the murine head and <1% in the lung. Following vector administration, transgene expression was dose-related in the nose, with minimal lung expression. No acute nasal toxicity was associated with nose-only delivery. Next, we compared levels of a secreted protein, Gaussia luciferase (Gluc), in the airways and serum after nose-only and intravenous administration of rSIV.F/HN-Gluc (2e8 TU/mouse). Gluc expression in the nose and lungs was higher following nose-only versus intravenous administration. Serum levels were similar after either route of administration. Finally, nose-only delivery of rSIV.F/HN encoding granulocyte-macrophage colony-stimulating factor (GM-CSF) led to sufficient lung levels of this therapeutic protein to correct disease biomarkers in a mouse model of pulmonary alveolar proteinosis. We conclude that non-invasive administration of a lentiviral vector to the nasal epithelium provides a safe and convenient route for secreted protein production and is readily translatable into humans.