Immunosuppressive effects of E-series prostaglandins have been demonstrated in many in vitro assays of immune responsiveness as well as in autoimmune diseases. To explore the mechanisms underlying prostaglandin E1 (PGE1)-associated immunosuppression in autoimmunity, we treated SJL mice immunized to produce immune-mediated interstitial nephritis with PGE1, PGF2 alpha, or vehicle alone. Mice receiving PGE1 treatment do not develop interstitial nephritis, nor do they display delayed-type hypersensitivity (DTH) to the immunizing renal tubular antigen preparation. The observed immunosuppression is critically dependent on PGE1 administration during the period of effector T cell induction. We therefore investigated the effect of PGE1 on the in vitro induction of DTH effector T cells reactive to renal tubular antigens (SRTA). PGE1 inhibits effector T cell induction in a dose-dependent, reversible manner, but has no inhibitory effect on fully differentiated DTH effector cells or SRTA-reactive cell lines. The PGE1 effect is indirect and mediated via nonspecific suppressor lymphokines. This suppression can be overcome by recombinant interleukin 1 (IL-1), which suggests a mechanism related to either diminished IL-1 secretion or target cell sensitivity to IL-1.


C J Kelly, R B Zurier, K A Krakauer, N Blanchard, E G Neilson


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