Fig. 6.

CD4⁺ tumor-infiltrating T cells produce TGF-β and IL-10. Mice were injected with TC-1 tumors on day 0, followed by 0.1 LD₅₀ of either Lm-E7 or Lm-LLO-E7 on days 7 and 14 or left unvaccinated. Splenocytes and tumor cells were incubated with or without anti-CD3/APC stimulation for 3 days, and supernatants were collected and analyzed. a TGF-β was detected using a highly sensitive MLEC assay that detects all three forms of TGF-β. Supernatants were added to mink lung epithelial cells (MLEC) expressing PAI-1 with firefly luciferase. TGF-β activates PAI-1, and the amount of TGF-β present is quantitated by the amount of luciferase activity. b IL-10 was detected using the commercially available ELISA kit from Pharmingen (San Diego, CA, USA) according to protocols provided by the manufacturer. Adapted with permission of the authors S.F. Hussain and Y. Paterson (2004) J Immunother 27:339--346