Need for cell-to-cell contact for suppressor activity of anergic T cells.
Cell-to-cell contact was found to be necessary for suppresor activity of anergic T cells. Transwell experiments were done in 24-well plates. Anergic alloantigen-specific 106 T cells (ATs) or anergic peptide (tyrosinase)–specific 105 T cells (ATs) were stimulated with (105 or 104) mature DCs (loaded with the specific antigen). Additionally, 106 allogeneic activated control (CTs) or 105 peptide-specific control T cells (CTs) were either added directly to the cultures of anergic T cells (ATs) or placed in transwell chambers (0.4 μm) (Millicell) (Millipore) in the same well with (105 or 104) mature DCs (primed with the specific antigen). After 3 days of culture, activated T cells (105 per well) were transferred to 96-well plates in triplicate. Proliferation was measured after an additional 16-hour pulse with 3H-Tdr by means of a liquid scintillation counter. Similar results were obtained in 5 independent experiments.
