Figure 5. Selective delivery of cGAMP to PV FR-β+ TAMs in Myc-CaP tumors reverses the effect of ADT on the activation status of CD8+T cells in Myc-CaP tumors. (A) Representative fluorescence image showing CD8+T cells in a vascularized area of a tumor treated with ADT plus FR-β antibody-coated LNPs containing active cGAMP (“LNPs(E)”). (B) ADT increased the PV accumulation of CD8+T cells (a change that was unaffected by coadministration with FR-β antibody-coated LNPs containing either inactive cGAMP (“LNPs(C)”) or LNPs(E)). (C) Representative fluorescence image showing colocalization of PD-1 and CD8 in a vascularized area of a tumor treated with ADT plus LNPs(E). (D, E) ADT administered with LNPs(E) reversed the PV accumulation of inactive (PD-1-) CD8+T cells induced by ADT alone, and led to an increase in both the PV density (D) and proportion (E) of CD8+T cells expressing PD-1. (F) The majority of PD-1+CD8+ T cells did not express the exhaustion marker, LAG3 following treatment with ADT plus LNPs(E). (NPV=non-PV). Data are presented as means±SEMs. *p<0.05, **p<0.01, ***p<0.001. Magnification bars=50 µm. ADT, androgen deprivation therapy; LNP, lipid nanoparticle.