Figure 7.

T-cell costimulation enhances VSV-cDNA therapy of i.c. tumors. (a) C57BL/6 mice bearing 5d established intra-cranial B16-ova tumors were treated intravenously with PBS+PBS, or with a total of 5 × 10⁶ pfu of (VSV-HIF2α+VSV-SOX-10+VSV-C-MYC+VSV-TYRP-1)+PBS; or with 5 × 10⁶ pfu (VSV-HIF2α+VSV-SOX-10+VSV-C-MYC+VSV-TYRP-1)+IL-2Cx; or with 5 × 10⁶ pfu of VSV-GFP + IL-2Cx, with virus on days 6, 8, 10, 13, 15, 17 and IL-2Cx on days 13, 15, 17. Survival with time is shown. (b–d) Pooled LN/splenocytes (10⁶/well) from mice bearing i.c. B16-ova tumors treated with VSV-GFP+IL-2Cx (A1-A4); (VSV-HIF2α+VSV-SOX-10+VSV-C-MYC+VSV-TYRP-1)+PBS (VSV-cDNA+PBS, B1-B3); (VSV-HIF2α+VSV-SOX-10+VSV-CMYC+VSV-TYRP-1)+IL-2Cx (VSV-cDNA+IL-2Cx, C1-C5); or PBS+PBS (D1-D3) were re-stimulated in vitro with (b) freeze/thaw lysates of TC2 cells (white bars), or TC2 cells preinfected for 24 hours with VSV-GFP (MOI 0.1) (black bars); (c) freeze/thaw lysates of B16-ova cells freshly resected from s.c. (white bars) or i.c. (black bars) tumors; or (d) with freeze/thaw lysates of GL261 cells freshly resected from i.c. tumors (black bars) or cultured long-term in vitro (white bars). 24 hours later, the cultures were replenished with an additional 10⁶ LN/splenocytes with a further round of re-stimulation 24 after that. 48 hours following the final re-stimulation, supernatants were assayed for IFN-γ by ELISA. (e,f) The same supernatants from b–d were also assayed for IL-17 secretion following re-stimulation as shown.