Induction of contact sensitivity. Selective induction of delayed hypersensitivity by the injection of cells from draining lymph nodes into the footpads of normal recipients.

Cells taken from the draining lymph nodes of mice 1 day after painting with picryl chloride can induce contact hypersensitivity when injected into the footpads of normal recipients. Previous studies have presented evidence to show that this is an immunizing process rather than a transfer of sensitized cells. This study shows that footpad injection of 5 times 10(6) 1-day draining lymph node cells induces a similar degree of hypersensitivity to the original skin painting with picryl chloride but no antibody, as judged by anti-TNP splenic PFC and serum antibody, in contrast to the moderate antibody response found after skin painting. The apparent inability to induce a response did, however, correlate with the finding that the draining lymph nodes of mice painted with picryl chloride had few PFC. Some effect of the cells on antibody was noted in that after mice were challenged on the ear to produce contact sensitivity reactions they produced an antibody response larger than that of mice not injected with cells. This was not a large phenomenon but was unusual because 2-5 times 10(6) cells was more effective than either 10(6) or 5 times 10(6) cells, even though 5 times 10(6) cells produced the largest contact sensitivity reactions. The augmentation was antigen specific and the same dose-response effect could be obtained with irradiated cells (2000 rad). It is suggested that the ability of these cells to induce large contact sensitivity reactions without antibody indicates that they may have an important role in the immunogenicity of contact sensitizing agents, which can induce large delayed-type hypersensitivity reactions accompanied only by moderate antibody responses.