Preferential induction of antigen-specific contrasuppressor T lymphocytes by trinitrophenyl (TNP)-substituted Langerhans cells.

We have tested the ability of trinitrophenyl (TNP)-labelled antigen-presenting cells (Langerhans cells (LC) and peritoneal macrophages (M phi)) administered intravenously to induce cells that mediate and regulate contact sensitivity. TNP-M phi fail to induce contrasuppressor cells (Tcs) but activate efferent T suppressor (Ts) cells. However, the activity of immune cells can be recovered after removal of Ly 2 Ts cells. In sharp contrast, TNP-substituted purified LC produced a significant contact sensitivity reaction, which is roughly equivalent to that achieved by skin sensitization with picryl chloride. Immune cells from these animals were relatively resistant to suppression by antigen-specific Ts cells, and we have found that their resistance is due to the presence of Ly 1, Vicia villosa lectin adherent, I-J+ cells. The Tcs cell induced by TNP-LC is indistinguishable by surface markers and function from Tcs cell found in mice injected with antigen-antibody complexes. Both these Tcs cells are capable of protecting immune cells from the effects of suppression by antigen-specific Ts cells if added in the proper sequence. Although they have identical surface phenotypes, it is not known at present whether or not Tcs cells induced by two different antigen presentations are identical. The possible reasons why LC are such potent inducers of contrasuppression are discussed.