Fig. 6.

The anti-proliferative effect of tumor infiltrating CD4⁺CD25^high cells. CD4⁺CD25^high cells and CD4⁺CD25⁻ cells purified from tumor tissues were mixed at a ratio of 1:1. After 6 days of culture with appropriate stimuli, the proliferation of CD4⁺CD25⁻ responder cells was measured by ³H thymidine incorporation. a Inhibition of cell proliferation induced by anti-CD3 with autologous irradiated TIL as APC. b Resistance of anti-CD3/CD28-induced proliferation to the inhibition by CD4⁺CD25^high cells. Similar results were obtained with cells from four individual patients. Results from one representative patient are shown