FIG. 3.

Increased IFN-γ production is an intrinsic property of aged CD8 T cells. CD8 and CD11c cells were purified from individual lung cell suspensions using magnetic beads. CD8 and CD11c cells were pooled by age group (n = 8). Purified CD11c cells were infected with M. tuberculosis (Mtb) (MOI of 1) and cultured with purified CD8 T cells for 48 h. (A) CD8 T cells from young and old mice were cultured with CD11c cells from the same age group. (B) CD8 T cells from young and old mice were cultured separately with M. tuberculosis-infected CD11c cells from both young and old mice. IFN-γ in culture supernatants was quantified by ELISA. Data are represented as pg/ml of IFN-γ and are representative of data from two individual experiments. nd, not detected.