Fig. 5.

IL-2/anti-CD40 Ab restores tumor-induced macrophage dysfunction leading to elderly T cell production of IFN-γ. Peritoneal macrophages from young C57BL/6J mice were cultured overnight with AE17 tumor cell-conditioned media (AE17 sup) or LL tumor cell-conditioned media (LL sup), stimulated overnight with IL-2/anti-CD40 Ab then co-cultured with CFSE-labelled young or elderly Balb/c splenic lymphocytes and proliferating CFSE⁺CD4⁺ T cells (a) and CFSE⁺CD8⁺ T cells calculated (b); note only macrophage: T cell ratio of 1:2 shown. Controls included no stimuli, AE17 sup only, LL sup only and M1 stimuli only. MLR supernatants were assayed for T cell-derived IFN-γ by CBA, as described above (c). The data from two to four experiments is shown at the macrophage: T cell ratio of 1:2 as mean ± SEM. *p < 0.05