Figure 5.

CD8⁺ T cell response and tumor protection induced by coentrapped melanoma peptide-archaeosome vaccine. Mice were vaccinated (days 0 and 21) with 25 μg of peptides (coentrapped 5 μg TRP and 20 μg Gp100) or an equivalent admixed formulation of Ms-TRP and Ms-Gp100. In vitro CTL response of spleen effectors from representative mice (n = 2) was evaluated at 5 weeks (a, b) on TRP and Gp100 specific targets. Mean ± SD of triplicate cultures of effectors: targets at various ratios are indicated. At 6 weeks mice were challenged subcutaneously with B16 melanoma, and survival (n = 4/group) was evaluated based on a maximum tumor size of 300 mm² (c). Loadings were 13 μg Gp100 and 3 μg TRP/mg archaeosomes for the coentrapped vaccine used in (a, c), and 60 μg Gp100/mg lipid and 30 μg TRP/mg archaeosomes for the admixed used in (b, c). Archaeosome size ranged from 104 to 110 nm. Survival for the vaccinated groups was significantly different compared to naïve animals by log-rank test (*P < .05; **P < .01).