Kinetics of cytokine production in alloreactive human T cells. Cytokine production within donor CD4⁺CD14^– and CD4^–CD14^– cells are shown at various intervals following stimulation with pooled allogeneic PBMCs. The frequencies of T cells producing intracellular TNFα, IFNγ, and IL-2 were assessed by CFC. In each graph, frequencies of cells responding to stimulation with allogeneic pooled PBMC (•) and autologous PBMCs that were either irradiated (▾) or not irradiated (▵) are shown. Medians and standard deviations shown were derived from 6 experiments performed using unique donors and the same allogeneic PBMC pool.