Figure 1.

Immunological features of LNPs.

The cationic/ionizable lipid component of the LNP can trigger highly inflammatory responses through the activation of different innate immune sensing pathways. The resulting inflammatory milieu can support local and systemic side effects and help develop adaptive immune responses. The adaptive immune responses are dependent on the innate inflammatory environment induced by the cationic/ionizable lipids. The generated adaptive immune responses will protect from subsequent infections and might contribute to the development of side effects, as detailed in Figure 2. The PEG component of the LNP can support the development of complement activation-related pseudoallergy.