Draining lymph node cells of contact-sensitized mice induce suppression of contact sensitivity

The application of hapten to the skin of mice can induce contact sensitivity (CS). It has also been well established that draining lymph node (DLN) cells can induce CS to the hapten used for skin painting when injected into naive mice. This is true for DLN cells recovered about 24 h after skin painting with hapten. It is unclear, however, whether DLN cells recovered shortly after hapten application have the same ability. By using an adoptive transfer assay system, we examined the ability of DLN cells recovered from mice at various times after skin painting with hapten to induce CS. DLN cells harvested 18-24 h after the application of fluorescein isothiocyanate (FITC) or 2,4-dinitrofluorobenzene (DNFB) induced strong CS when injected into naive mice. DLN cells harvested 3-6 h after the application of FITC or DNFB induced either only weak or no CS but induced suppression of the subsequent immunization to the two haptens. The suppression was hapten-specific, MHC restricted, and associated with the appearance of splenic suppressor T lymphocytes. Analyses with antibodies and ultraviolet (UV) B radiation demonstrated that suppression-inducing cells in DLNs were Ia+, Thy-1(-), and functionally UV-sensitive. These data suggest that epicutaneous sensitization with hapten first induces immunologically specific suppressor activity in the draining lymph nodes, whereas immunogenic activity becomes predominant later.