Lentivirus Vector Can Be Readministered to Nasal Epithelia without Blocking Immune Responses

Abstract

For many envisioned applications of lentivirus vectors as tools in respiratory biology and therapeutic gene delivery, the efficiency of gene transfer must be improved. We previously demonstrated stable, persistent (>11 months) in vivo expression following a single application of a feline immunodeficiency virus (FIV)-based lentivirus vector (GP64-FIV) to murine nasal epithelia. Here we investigate the efficacy of repeated administration of lentivirus vectors to the airways. Using quantitative bioluminescent imaging, we found that consecutive daily dosing achieved a linear increase in gene expression and greatly increased the number of epithelial cells targeted. Surprisingly, reporter gene expression also increased additively following each of seven doses of FIV delivered over consecutive weeks (1 dose/week), without the development of systemic or local neutralizing antibodies. This approach enhanced expression of both reporter and therapeutic transgenes. Transduction efficiency achieved following a single dose of FIV expressing mouse erythropoietin was insufficient to increase hematocrit, whereas seven consecutive daily doses significantly increased hematocrit. These unexpected results contrast strikingly with findings reported for adenovirus vectors. Prolonged gene expression has been observed in vivo following a single dose of virus vector; however, depending on the application, repeated administration of vector may be necessary to achieve stable, therapeutic gene expression.

Synchrotron phase-contrast X-ray imaging reveals fluid dosing dynamics for gene transfer into mouse airways

“…AdV, FIV, etc). 14,20 Finally, the lower levels of gene expression we observe on the nasal septum compared to the lateral ciliated regions are consistent with the differences in fluid retention in these two regions. The ability to observe where the dose is retained, or the tissue-type targeted, 21 should be useful in the testing of pharmaceuticals, infectious agents, allergens and other gene vectors in these different epithelial tissues.…”

“…This method now enables the rational design of more effective delivery procedures in the airway gene transfer protocols used in normal and CF mouse models. 1,2,14,15 It should also permit improvements in reliability and repeatability to boost outcome effectiveness, reduce outcome variability, and decrease the volumes of costly gene vectors needed in mouse model studies.…”

Assessment of F/HN-Pseudotyped Lentivirus as a Clinically Relevant Vector for Lung Gene Therapy

“…We and others have previously shown that repeated administration of lentiviral vectors to the mouse nasal epithelium is feasible (10,11). To move our translational research a step closer to clinical relevance we now assessed repeat administration of the vector in the lung.…”

“…Several groups have attempted to further improve lentiviral vector uptake into airway epithelium by changing the viral envelope proteins. Glycoproteins from Ebola or Marburg virus that naturally transfect airway epithelial cells by the apical membrane showed early promise (8), but have more recently been superseded by viral vectors pseudotyped with the influenza M2 envelope glycoprotein (9), baculovirus protein GP64 (10), or the SeV-derived F and HN envelope proteins (11,12).…”

CFTR Gene Transfer and Tracking the CFTR Protein in the Airway Epithelium

“…The strategy of ''pseudotyping'' or substitution of the lentivirus envelope with the envelope protein of another virus, such as Ebola virus (Kobinger et al, 2003), baculovirus (Sinn et al, 2008) or Sendai virus (Mitomo et al, 2010) have demonstrated increase in gene transfer efficiency to the airway epithelium. Before the application of lentiviral vectors for pulmonary gene transfer, preclinical studies in large animal models will need to be carried out to carefully assess their efficacy and safety.…”