Figure 1.

Activation of immune cells and recruitment of innate immune response to site of administration in rodents

(A) ISH staining of EGFP mRNA (brown) was detected in mouse and rat muscle 24 h post-mRNA-LNP administration using RNAScope assay. IHC staining of muscle with anti-EGFP antibody (brown) showed positive expression in tissue resident and infiltrating immune cells. No protein expression or mRNA observed in the muscle fiber. (B) EGFP positive mRNA and protein in mouse and rat dLN post-i.m. injection. Majority of mRNA signal is cleared from the LN and residual mRNA signal is localized to B cell follicles and interfollicular regions by 24 h EGFP expression was primarily in macrophages located within the subcapsular and medullary sinus of the draining LNs. Scale bar, 100 μm.