Figure 3

Combination of RNA immunotherapy with radiation represents an effective treatment strategy for low immunogenic and radioresistant LLC tumor. (A) C57BL/6 mice (n = 5 per group) were vaccinated 2 times (1 vaccination/week) either with EGFR mRNA vaccine (32 μg) or with buffer. 7 days after completed vaccination splenocytes from vaccinated mice were analyzed for IFN-γ secretion in response to EGFR- or Control-peptide library using an ELISpot assay. ** - p = 0.0036 (B) C57BL/6 mice (n = 10 per group) were challenged subcutaneously on the right limb with 5 × 10⁵ 3LL-GFP cells. 18 days after tumor challenge mice were treated either with local radiation (36 Gy total, divided into 3 equal fractions on 3 consecutive days) or with radioimmunotherapy as indicated (with first vaccination given 6 h before second radiation). Vaccination therapy without radiation started on day 14 post tumor challenge. Untreated mice served as a control. Tumor growth was monitored by measuring the tumor size in 3 dimensions using calipers. (C) Median survival time of mice analyzed in Figure 3B.