Fig. 3.
Antigen-specific IFN-γ responses and survival of patients with GBM based on univariate analysis. Diluted peripheral blood of patients with GBM was exposed to viral targets (CMV pp65 (A), EBNA-1 (B) and EBNA-3a (C)) as well as the surviving97–111 peptide (D) over a 7-day period. Supernatants were then harvested for measuring antigen-specific IFN-γ production. Kaplan-Meier survival curves show the relationship between IFN-γ concentrations and patient survival based on median concentration values for the viral targets (since the net IFN-γ was very high after medium control subtraction) or detectable and non-detectable IFN-γ levels for the survivin peptide (since the net IFN-γ production was generally low after medium control subtraction) following antigen stimulation. Blood samples from 145 patients with GBM were used in all whole blood assays, using the entire set of candidate targets, except for the testing of survivin97–111 peptide, for which blood samples from 134 patients with GBM were used. Only antigen-specific IFN-γ responses with a statistically significant positive correlation with patient survival are shown. IFN-γ production in response to other TAAs tested i.e. NY-ESO-1, survivin (combination of peptides spanning the entire surviving protein) and EGFRvIII peptide pools, respectively did not exhibit a statistically significant correlation with improved survival of patients with GBM (data not shown).