Fig. 4: SCP-Nano reveals protein expression from LNP-delivered mRNA and LNP off-targeting.
From: Nanocarrier imaging at single-cell resolution across entire mouse bodies with deep learning
a. Whole body projection view of mRNA and EGFP protein expression 72 h after intramuscular injection of 0.0005 mg kg−1 EGFP mRNA-LNPs. b–d, Detailed views of the spleen (b), liver (c) and heart (d). e, Quantitative evaluation of the SCP-Nano segmentation model (fine-tuned on EGFP data) for detecting protein expression (FN, false negatives; FP, false positives; TP, true positives, compared to manual annotation). f. Body-wide distribution of SARS-CoV-2 spike S1 protein derived from LNP-delivered mRNA administered intramuscularly at 72 h after injection (f). Spike proteins were detected in the heart (f′). g, Confocal images of heart tissue sections stained for endothelial cells in capillaries using podocalyxin antibody (red), arteries using αSMA antibody (green) and spike S1 protein using a spike nanobody (yellow). h, PCA of mass-spectrometry-based proteomics data of different groups: spike LNP, EGFP LNP, no-cargo LNP and PBS. i, Top-level pathways in Reactome database differentially expressed between the two control groups (no-cargo LNP/PBS) and the combined spike LNP and EGFP LNP groups (n = 9, mean ± s.d.; one-way ANOVA). j,k, Same analysis for proteins upregulated in no-cargo LNP in comparison to the PBS (j) and in the spike mRNA in comparison to no-cargo LNP (k) (n = 9, mean ± s.d.; one-way ANOVA). l, Analysis of vascular health using typical protein markers (Supplementary Table 3) for the three different groups. NS P > 0.05, **P < 0.01 (n = 9; one-way ANOVA). i.m., intramuscular; PC, principal component; NS, not significant.
