Interaction between contact sensitizing agents and sensitized lymph node cells in mice.

Using a local passive transfer system in mice it has been possible to detect interaction between sensitized lymph node cells and antigen inducing contact sensitivity. Cells were injected into the ears of mice intracutaneously and antigen applied to the skin. A late inflammatory response at the site was detected by measuring the 24-hour uptake of 51Cr-labelled indicator `inflammatory cells' (peritoneal exudate or oxazolone-sensitized lymph node cells). Three days after local transfer the uptake in ears receiving sensitized cells and challenged with antigen was three- to ten-fold greater than in the ears of animals receiving cells or antigen alone. This phenomenon was dependent upon challenge with the appropriate antigen. Interaction was also detected when cells were transferred into one ear and antigen applied to the other. Experiments to explain this effect showed that transferred cells disappeared rapidly from the site of transfer. Antigen applied elsewhere enhanced their mobility and increased their arrival at the antigen site.