Fig. 6
Adoptively transferred tumor-Ag-specific CD8+ T cells underwent T-cell exhaustion in tumor microenvironment. a Cell numbers of adoptively transferred HBc93–100-specific TCR tg CD8+ T cells in the tumors, spleens and livers of HCC-bearing mice at day 11 post adoptive transfer. b H&E staining and immunohistochemical staining of liver/tumor sections from (a) showed the tissue distribution of adoptively transferred tumor Ag-specific CD8+ T cells (CD45.1+; brown signals) and expression of PD-1, PD-L1 and PD-L2 in TME. T: tumor region, L: adjacent liver tissue, S: stroma; Expression of PD-1, LAG-3, and TIGIT on c in vitro pre-activated HBc93–100-specific CD8+ T cells at day 3 post activation by ant-CD3/anti-CD28 beads and on d intra-tumoral adoptively transferred tumor Ag-specific CD45.1+ CD8+ T cells, endogenous CD45.1− CD8+ T cells, splenic adoptively transferred tumor Ag-specific CD45.1+ CD8+ T cells, and splenic endogenous CD45.1− CD8+ T cells from the mice in (a). In vivo bioluminescence of HCC-bearing mice e receiving 2 × 105 activated HBc93–100-specific CD8+ T cells or no adoptive transfer (n = 5 per group) or f receiving 3 × 105 activated HBc93–100-specific CD8+ T cells together with anti-PD-1 blocking Ab or isotype control Ab (n = 8–9 per group). Arrows indicated the time points of Ab administration. ns, not significant; *P < 0.05, **P < 0.01 and ***P < 0.001 (unpaired Student’s t-test)