Figure 2.

Encapsulated antigen is crucial to induce antigen-specific CD8⁺ T cell memory. C57BL/6 female mice were immunized subcutaneously at the base of the neck with formulations consisting of 1.75 mg soluble Ova with 5 mg of 20:80 CPTEG:CPH polyanhydride nanoparticles encapsulating 250 μg Ova with (NP x2) and without a boost (NP x1) (n=16); 2 mg soluble Ova with 5 mg of blank 20:80 CPTEG:CPH polyanhydride nanoparticles (Blank NP x2) (n=8); or PBS control (n=16). Mice that received a booster (NP x2) were given the same formulations at half the original dose subcutaneously at the base of the neck 28 days after the primary immunization. Mice were challenged subcutaneously in the flank with E.G7 Ova-expressing tumor cells 42 days after the primary or boost immunization, respectively. (A) Tumor volume of individual mice was tracked. (B) Survival was evaluated 31 days post-challenge. Statistical significance was determined using a Log rank (Mantel-Cox) test with a Bonferroni correction for multiple (6) comparisons. Significance from naïve control group is indicated in the treatment group legend as *p ≤ 0.0083. Median survival of each group is also reported parenthetically. (C) Diagram of vaccination schedule. 1 ° = primary vaccination, 2 ° = primary vaccination, following which all mice received an injection of E.G7 tumor cells as described in Materials and Methods.