Fig. 12
Adopted from [419]
Activation of innate and adaptive immune cells upon mRNA-LNP administration: A intramuscular injection of mRNA-LNP vaccines leads to local inflammation, recruiting neutrophils, monocytes, and dendritic cells (DCs) from the bloodstream to the site of injection through the release of chemokines and cytokines, facilitating the migration of other immune cells; B mRNA-LNPs alone, or along with antigen-presenting cells (APCs), are localized in the nearby lymph nodes; C DCs, monocytes or macrophages present antigens and initiate the activation of T cells; D Tfh cells assist B cells during germinal center (GC) reactions, alongside follicular DCs, to refine antibody affinity. In mouse models, LNP-induced IL-6 is crucial for developing T follicular helper (Tfh) and GC B cell responses, while type I IFNs are known to enhance cytotoxic T lymphocyte (CTL) reactions