Ability to stimulate allogeneic T-cell proliferation increased in spleen cells from mice treated with either rGM-CSF or rGM-CSF/rIL-4.
Spleen cells from control and cytokine-treated C57BL/6 mice were enriched for DCs by depleting B cells and T cells with antibody and complement. DC-enriched populations were added directly to microwells containing 1 × 105 allogeneic T cells (A) or were cultured for 36 hours in vitro with rGM-CSF and rIL-4 (20 ng/mL each) before testing in the MLR assay (B). DCs from GM mice stimulated greater T-cell proliferation, and this capacity increased with in vitro culture. In contrast, DCs from GM/IL-4 mice demonstrated control levels of allostimulatory activity when directly added to the MLR assay but dramatically higher activity after in vitro culture. Data are the mean ± SE of triplicate cultures and are representative of 5 separate experiments. *P ≤ .05 compared with control. †P ≤ .05 compared with GM.
