Lymphocyte transformation in contact sensitivity.

Leucocyte suspensions containing 97–100 per cent lymphocytes were prepared from the peripheral blood of unsensitized guinea-pigs as well as animals previously sensitized with 1-chloro-2,4-dinitrobenzene. The lymphocytes were dinitrophenylated and cultured for 5 days . Transformed cells (8–22 per cent) and an increased (100–1000 fold) uptake of tritiated thymidine were observed only in cultures of lymphocytes from sensitized animals. Smaller numbers of transformed cells (1–2 per cent) were found in only a few cultures of sensitive lymphocytes incubated with either dinitrophenylated autologous erythrocytes or serum proteins. These results strongly suggest that transformation may specifically follow the conjugation of DNFB with live lymphocytes from sensitized donors.