Skip to main content
. 2018 Nov 22;10(12):464. doi: 10.3390/cancers10120464

Figure 6.

Figure 6

ISG15 activates CD8+ T cells via NK cell activation. (A) Immunolocalization of CD8+ T cells in tumor nodules isolated from C57BL/6 immune-competent mice injected with ID8 or IG10 cancer cells showed a significant increase in intraepithelial CD8+ T cells in tumors developed from mice injected with ID8 or IG10 transfected with ISG15 compared to those with the mock construct. (B) Immunostaining result showed a positive correlation between ISG15 expression in ovarian cancer cells and CD335 (NKp46) positive NK cell densities in ovarian tumor tissues (Bar = 50 μm). For the experiments performed to determine whether ISG15 could activate NK cells, experimental results showed that recombinant ISG15 significantly increased (C) NK cell proliferation, (D) IL-2 and (E) IFN-γ production in a dosage response manner. (F) To determine whether ISG15 treated NK cells could activate CD8+ T cells, conditioned media collected from NK cells treated with ISG15 were used to culture CD8+ T cells. CD8+ T cells treated with conditioned media from ISG15 treated NK cells showed a significant increase in cell number in a dosage response manner when compared to CD8+ T cells treated with conditioned media from NK cells treated with the control PBS.