CEA-specific proliferation of human lymphocytes measured by uptake of [3H]-thymidine. T-bodies (labeled T-body in the figure) were produced by infection of 106 PBLs with 107 TU/ml of a virus comprising a VSV envelope and a lentiviral genome containing the CEA-CD28-CD3zeta-GFP cassette. T-bodies (■) responded to irradiated CEA+ SW 403 stimulator cells but the CEA- COLO 320 control cells () did not. PBLs transduced with a GFP cassette alone did not respond. All cells proliferated vigorously in response to anti-CD3/CD28 (□) and no CEA-CD28- CD3ζ-GFP T-bodies responded to medium alone.