In vitro sensitization of human lymphocytes against allogeneic cells by antigen-fed macrophages

Primary in vitro sensitization of human lymphocytes against allogeneic tumor cells was induced by antigen-fed macrophages. Spleen or peripheral blood macrophages were fed with cell-free extracts of allogeneic tumor cells. Autologous lymphocytes that were sensitized by the macrophage culture for five days manifested cytotoxic activity against the corresponding target cells.