Figure 4
TIL responses to viral peptides recognized by TIB-IgG. The top five viral peptides that induced the most robust IgG responses (stongest signal intensity) on the peptide microarrays were selected for determining whether they also contained T-cell epitopes. Selected peptides were chemically synthesized and co-cultured with the corresponding TIL from four patients with cancer (BRT8, BRT9, PanTT32 and PanTT24) over a 3-day period. The anti-human CD3 monoclonal antibody OKT3 was used a positive control for T-cell receptor (TCR) stimulation, thus as an indicator of T-cell functionality. Supernatants were then harvested for measuring IFN-γ production by ELISA, the concentration values of which are expressed as pg/10e5 T cells. TIL from patient PanTT32 showed a robust responses to two CMV pp65 peptides and three EBV EBNA-3a peptides, while TIL from BRT9 exhibited the weakest immune reactivity to any of the viral peptides tested, probably due to reduced overall functionality – marked by poor stimulation by OKT3. PanTT24 TIL displayed strong anti-EBV responses, while TIL from patient BRT8 elicited measurable responses to a single CMV pp65 peptide. Note that other immune readouts, i.e. production of different cytokines, other than IFN-γ or T-cell proliferation have not been captured in the current assay readout.
