Figure 5

Hyperexpanded CD4⁺ and CD8⁺ T cells produce IFN-γ in response to tumor stimulation. CD62L^low TDLN cells were culture activated with anti-CD3 and IL-2 plus IL-7 for 23 days then were restimulated with anti-CD3 every 7 days. T cells were removed from culture on day 8, on day 36 for CD8⁺ cultures, or day 43 for CD4⁺ cultures. T cells were incubated without additional stimulus to determine spontaneous production of IFN-γ or with single cell digest of MCA205 or MCA207 tumors or with immobilized anti-CD3 mAb and Brefeldin A was added at 5 hrs and cells were harvested after 14 hrs. Intracellular IFN-γ was determined by FACS and the percentage of T cells is indicated.