Neopterin: a Mediator of the Cellular Immune System

Abstract

Abstract In this review, we will summarize our investigations on the potential biochemical, physiological, and pathophysiological effects of neopterin in the course of infection and inflammation. In a number of in v/'iro-studies wc could show that the pteridine compound neopterin manifested distinct biochemical properties via interfering with cellular redox mechanisms. Among the observed actions of neopterin are the stimulation of inducible nitric oxide synthase gene expression and nitric oxide release, the activation of the transcription factor nuclear factor-κΒ, the induction of apoptotic ccll death, the inhibition of erythropoietin synthesis and release, and the stimulation of tumor necrosis factor-α generation in different cell culture as well as organic models. By these means, neopterin may represent a part of the host-defence reactions. In addition, an excessive or continous release of neopterin due to a chronically activated cellular immune system may contribute to the deleterious events commonly observed in progressive infectious or inflammatory diseases. Our data are supported by the findings of a strong correlation between raised levels of neopterin and the severity and the outcome of these disorders.