Lung-targeting lentiviral vector for passive immunisation against influenza

Abstract

When recombinant simian immunodeficiency virus (SIV) is pseudotyped with the F and HN glycoproteins from murine respiratory Sendai virus (rSIV.F/HN), it provides efficient lung cell targeting and lifelong transgene expression in the murine airways. We have shown that a single dose of rSIV.F/HN can direct stable expression of neutralising antibody against influenza in the murine airways and systemic circulation, and protects mice against two different influenza strains in lethal challenge experiments. These data suggest that rSIV.F/HN could be used as a vector for passive immunisation against influenza and other respiratory pathogens.

Keywords: infection control; respiratory infection; viral infection.

Figure 1

Intranasal delivery of rSIV.F/HN vector can lead to robust antibody expression in the murine lung lumen and serum. Mice (BALB/c, n=6–8 per group) were dosed with rSIV.F/HN.hCEF.T13B (6e5, 6e6 or 5e7 TU/mouse) via nasal instillation or remained naive. Serum was collected at the indicated time points and mice culled at day 28 postdelivery to collect lavage fluid for T1-3B quantification using ELISA. (A) Serum levels of T1-3B presented as group mean and SEM. (B) Levels of T1-3B in the ELF with each data point representing an individual animal and horizontal bars representing group means. The dotted line represents the lowest detection limit of the ELISA. Values plotted as 0.002 µg/mL in B indicates no detectable T1-3B. ELF, epithelial lining fluid; SIV, simian immunodeficiency virus; SEM, SE of the mean; TU, transducing units.

Figure 2

Supralethal influenza challenge in mice expressing T13B antibody via the rSIV.F/HN vector. Mice (n=5–6 per group) were dosed intranasally with rSIV.F/HN.hCEF.T13B at a dose of 1E7 TU (blue), 1e8 TU (red), 2.7e8 TU (magenta) or with 1e8 TU (black) of rSIV.F/HN.hCEF.GLux (Gaussia Luciferase) as mock control. (A–D) BALB/c mice were challenged with 10 or 100 median lethal dose (LD₅₀) of H1N1 A/PR/8/1934 (Cambridge). (E, F) DBA/2 mice were challenged with 10 LD₅₀ of reassortant pandemic H1N1 A/CA/7/2009-X179A. Body weight was measured daily for 14 days and mice were euthanised if weight loss declined ≥20% as depicted in the Kaplan-Meier survival curve (right column). SIV, simian immunodeficiency virus; TU, transducing units.

Figure 3

Protection of mice against influenza challenge mediated by rSIV.F/HN is comparable to protection offered by rAAV8 or rAAV9. Mice (BALB/c, n=5–6 per group) were dosed with rSIV.F/HN.hCEF.T13B (2.7e8 TU, magenta), rSIV.F/HN.hCEF.GLux (1e8 TU black) or rAAV2/9.hCEFI.T13B (1e11 GCs, green) via intranasal instillation, or with rAAV2/8.CASI.T13B (1e11 GC, purple) delivered via intramuscular injection. After 1 month, mice were challenged with 10 LD₅₀ of H1N1 A/PR/8/1934 (Cambridge). Body weight (A) was measured daily for 14 days and mice were euthanised if weight loss declined ≥20% as depicted in the Kaplan-Meier survival curve (B). GCs, genome copies; rAAV, recombinant adeno-associated virus; SIV, simian immunodeficiency virus; TU, transducing units.