Characterization of T-cell responses against viral and tumor antigens in VSV-treated C1498.GFP tumor bearing mice. Analysis for VSV (A-C) and GFP tumor antigen (D-F) T cells by pentamer assay, IFN-γ intracellular staining, and ELISPOT IFN-γ assay. C57BL/6 mice were given C1498.GFP IV and, on day 10, received 1 dose 108 TCID50 VSV-mIFNβ-NIS IV, with or without anti-PD-L1 Ab on days 13 and 16. Mice were harvested 7 days post-VSV and splenocytes were used in assays to evaluate the presence of virus or tumor-reactive T cells. Splenocytes were stimulated with VSV NP 52 peptide or EGFP118-126 peptides to detect for VSV or GFP-reactive T cells. (A,D) Pentamer assay, (B,E) IFN-γ intracellular staining, and (C,F) ELISPOT IFN-γ assay. Mean ± SEM (n = 3 mice per group). *P ≤ .05. The unpaired Student t test was used. GP, GFP specific peptide (EGFP118–126).
