Fig. 4.
Schematic illustration of cGAMP delivery using liposomes. (A) The structure of liposomal cGAMP. (B) Compared to free cGAMP, liposomal cGAMP improved cellular uptake by antigen-presenting cells due to the benefit of positive charge, and after cell endocytosis, liposomal cGAMP can facilitate cGAMP to release from endosomes to further bind STING located in cytosol, triggering STING signaling pathway. Adapted by permission from [32] Copyright 2017, WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.