Functional analysis of CC and VC TILs
To investigate whether the expanded TILs are responsive to extracellular
restimulation, VC and CC TILs are
restimulated overnight by T cell activator. Upregulation of CD107a, a
marker of degranulation indicating T cell cytotoxic activity, can be
observed on a portion of VC and CC TILs (Figure 7A). We further analyzed
the cytokine production of TILs in response to stimulation of HeLa
cells, a cervical cancer cell line, and found that both CC and VC TILs
produced high levels of IFN-γ and TNF-α, and that VC TILs tended to
release more of these two cytokines (Figure 7B and C). Finally, the
cytotoxicity potential of TILs was examined by HeLa cell lysis in a
co-culture system. VC TILs tended to show higher killing of HeLa cells
compared to CC TILs, suggesting the stronger tumor killing potential of
VC TILs (Figure 7D).