The induction of splenic suppressor T cells through an immune-privileged site requires an intact sympathetic nervous system

Abstract

Antigen injection into the eye's anterior chamber (AC) induces the antigen-specific suppression of delayed-type hypersensitivity (DTH) that is mediated by NKT cells and splenic CD8+ suppressor T cells. Because the AC, uveal tissues, the thymus and spleen required to induce anterior chamber-associated immune deviation (ACAID) have dense sympathetic innervations, we examined the effects of chemical sympathectomy of mice by 6-hydroxydopamine (6-OHDA) on the induction of the suppression of contact sensitivity to trinitrophenol (TNP) induced by the injection of TNP-bovine serum albumin (BSA) into the anterior chamber. DTH measured as contact sensitivity to picrylchloride was not induced in mice that received 6-OHDA before immunization with TNP-BSA. Although spleen cells from 6-OHDA-treated TNP-BSA-immunized mice produced IFN-gamma when stimulated by TNP-BSA, the number of DTH-initiating hepatic NKT cells was reduced markedly in 6-OHDA-treated mice. Chemically denervated mice did not produce splenic suppressor T cells or thymic NKT cells that activate splenic suppressor T cells. We suggest that an intact sympathetic nervous system (SNS) is required to maintain cellular immunoregulation.