CD8 T cells and NK cells mediate the antitumor effect of FL plus Ag plus ISS.
(A) Experimental design. Groups of 8 mice were immunized with PBS alone or with FL followed by a SC injection of ISS mixed with OVA. Cohorts of mice were injected with either anti-CD4 antibody 6 days prior to immunization or with anti-CD4, anti-CD8, or anti-NK cell antibody 1 day after immunization. Mice were then challenged 1 week following immunization with 1 × 104 melanoma tumor cells. (B) Kaplan-Meier graphs showing the tumor-free survival of mice inoculated as described in panel A. Statistically significant differences in tumor-free survival were found between nondepleted mice versus CD8-depleted mice (P < .001) and between nondepleted versus NK cell-depleted mice (P = .003). ● indicates FL-ISS-OVA; ⋄, FL-ISS-OVA (CD4 depletion day +10); ▴, FL-ISS-OVA (CD4 depletion day −6); ○, FL-ISS-OVA (NK depletion); ▪, FL-ISS-OVA (CD8 depletion); ■, OVA alone.
