Influence of route on the induction and persistence of delayed type hypersensitivity to alloantigens.

Abstract

The influence of the route on the induction and persistence of delayed type hypersensitivity (DTH) reaction to alloantigens by epidermal cells (EC) and spleen cells (SC) was investigated. Subcutaneous (sc) or intraperitoneal (ip) administration of EC and SC induced DTH reactions but the DTH reaction by the ip route was weaker than that obtained by the sc route. Time course experiments have shown that DTH reactions induced by EC lasted at least 30 days, whereas DTH induced by ip injection of SC fell to an undiscernible level by day 14. DTH induced by sc injection of SC was significant at day 14, but became undiscernible by day 30. Intravenous (iv) injection of both EC and SC induced hyporesponsiveness after subsequent sensitization with allogeneic cells. Experiments using congenic strains of mice, EC treated with anti-Ia antiserum and complement, and grafted skin revealed that H-2, non-H-2, or Ia disparities were sufficient to induce DTH. Epidermal LC played an important role in DTH induction. Taken together, these results indicate the importance of LC in DTH induction and suggest the differing contributions of antigen presenting cells in the skin and other tissues in both induction and persistence of allo-DTH reaction.