Allopeptides were immunogenic.
(A) Irradiated autologous PBLs were pulsed with allopeptides and cocultured with nonirradiated autologous PBLs. After 4 days,3H-thymidine uptake was measured. P10 and P12 induced significant cell proliferation (P > .0001). Cells incubated with allogeneic stimulator cells (MLC) but no peptides showed, as expected, the highest proliferation. (B) To test whether APCs were required for peptide presentation, PBLs, purified T cells, APCs, and a mixture of reconstituted APCs and T cells were incubated with P10, and 3H-thymidine uptake was measured. Proliferation was only measured in cells containing APCs, suggesting the requirement of indirect presentation through the APCs. (C) Allopeptides augment allostimulation. Responder PBLs were stimulated in a 4-day mixed-day culture with irradiated allogeneic REH stimulator cells. Cell cultures were supplemented with various peptides, and [3H-thymidine uptake was measured. P10 and P12 induced elevated T-cell proliferation over the control cultures (Med) containing no peptides.
