In vitro sensitization of human T lymphocytes to hapten (TNP)-conjugated and non-treated autologous cells is restricted by self-HLA-D.

By co-culturing human T lymphocytes with TNP-treated autologous B lymphocytes and macrophages for 10 days in vitro, sensitization to TNP-treated autologous cells could be detected in a proliferative assay. By restimulation with different types of allogeneic cells and with cells from donors compatible or incompatible for the HLA-ABC or -D determinants, results were obtained suggesting that the TNP-specific response was restricted by the HLA-D but not the -ABC antigens of the autologous priming cells. Furthermore, our experiments demonstrate that T lymphocytes can also be primed against non-treated autologous cells in vitro and suggest that the HLA-D determinants may be involved also in this auto-sensitization.