Induction of delayed hypersensitivity by dinitrophenylated lymphocytes.

Erythrocytes, serum proteins and both living and killed lymphocytes from the peripheral blood of guinea-pigs were dinitrophenylated and then injected intraperitoneally into either the donor or other guinea-pigs. Animals sensitized by intradermal DNCB and unsensitized normal guinea-pigs served as positive and negative controls respectively. Eleven to 14 days after injection, the animals were tested with topically applied DNCB and the intensity of the reactions assessed by the local exudation of bovine serum albumin labelled with radio-iodine ([I]BSA.) Sensitization was achieved with dinitrophenylated living autologous lymphocytes, to a lesser degree with homologous lymphocytes, but not with erythrocytes, serum proteins or killed lymphocytes.