Fig. 1: The hMet + S45Y ß-Catenin sleeping beauty transposon system induces liver tumors which are infiltrated by PD-1+ CD8 T cells.
From: Expression of tumor antigens within an oncolytic virus enhances the anti-tumor T cell response
Following hydrodynamic injection of hMet + S45Y ß-Catenin plasmids, animals were euthanized at 4 and 7 weeks for pathologic studies. A Livers (animals A1 and A4) demonstrated appreciable neoplasia with a well-differentiated morphology and minimal immune infiltration by week 4. This progressed by week 7 (animals C1 and C4) with neoplastic cells overtaking the majority of the tumor, with large pseudo-cysts, fat deposits, and signs of extramedullary hematopoiesis (more prominent in C4). B Livers from a control mouse and from a mouse 7 weeks after hMet + S45Y ß-Catenin hydrodynamic tail-vein injection. C, D Following hydrodynamic injection of hMet + S45Y ß-Catenin, animals were euthanized at day 22 and day 29 and analyzed for CD8+ (p = 0.0162) (C) and CD4+ (p > 0.1) (D) T cells by flow cytometry. D Similar to (C), tumor-infiltrating CD4 T cells were evaluated. E, F Proportions of CD8+ (Tim3- PD1- Naïve vs. Day 22 and 29, p < 0.0001; Tim3 + PD1+ Naïve vs. Day 22 and 29, p < 0.0001) (E) and CD4+ (p > 0.1 except for Tim3- PD1- Naïve vs. Day 22, p = 0.0260) (F) T cells expressing Tim3 and/or PD1+ in livers of tumor bearing or tumor naïve mice at days 22 and day 29. G Proportions of PD-L1+ CD86+ dendritic cells (DCs) in mice 22 and 29 days after hMet + S45Y ß-Catenin injection compared to tumor naïve mice. (PD-L1 + CD86+ Naïve vs. Day 22, p = 0.0054; PD-L1 + CD86- Naïve vs. Day 29, p = 0.0028; PD-L1 + CD86- Day 22 vs. Day 29, p = 0.0002). H Hematoxylin and eosin staining combined with PD-L1 immunohistochemistry of the livers of FVB mice at weeks 4, 5, 6, and 7 after hMet + S45Y ß-Catenin hydrodynamic tail-vein injection. 10x magnification. Significance for (C, D) determined by ordinary one-way ANOVA, data are presented as mean values +/− SEM. Significance for (E–G) was determined by 2-way ANOVA with multiple comparisons using Tukey’s multiple comparisons test, data are presented as mean values +/− SEM.
