Figure 3.

Intranasal LNP delivery induces robust lung inflammation

(A) LNP injection leads to fast and homogeneous dispersion in the lung. Animals were inoculated with PBS or 10 μg of DiI-labeled LNP. Six hours later the lungs were harvested, prepared for histology, stained with DAPI, and imaged using a confocal microscope. One representative image is shown.

(B) Lungs harvested at the indicated time points from PBS, and the 10 μg LNP group were harvested and photographed.

(C) Animals inoculated with 10 μg of LNP were sacrificed 9 h post inoculation and their lungs' leukocytic composition determined by flow cytometry following a published gating strategy (Yu et al., 2016). Neut. = neutrophils, Eosi. = eosinophils, DC = dendritic cells, NK = natural killer, aMac. = alveolar macrophages, iMac. = interstitial macrophages, iMon. = inflammatory monocytes, rMon. = resident monocytes.

(D–F) Animals were inoculated with the indicated doses of LNP and the survival rate (D), weight (E), and clinical scores (F) recorded daily for up to 8 days. Data were pooled from two independent experiments. N = 9 for each group except PBS/naive where n = 5. For all the charts the data were pooled from at least two separate experiments and displayed as percent ±SD. Each dot represents a separate animal. Student's two-tailed t test was used to determine the significance between naive and the experimental samples. ∗∗∗p < 0.0005, ∗∗p < 0.005, ∗p < 0.05, ns = not significant.

See also Figure S3.