[Measurement of ADF/thioredoxin in human serum and its clinical significance].

The adult T cell leukemia (ATL)-derived factor (ADF) was first described as an interleukin 2 receptor alpha chain (IL-2R alpha) inducing factor which is produced by an HTLV-I infected cell line. Subsequent purification and gene cloning proved that it is a human homologue of a bacterial reducing coenzyme, thioredoxin (TRX). ADF/human TRX (hTRX) has multiple functions both in the extracellular and intracellular compartments, such as cytokine activity, dithiol-reducing activity and radical scavenging activity. ADF/hTRX can facilitate the interactions between the transcriptional factors and its target DNA sequences, which may result in the overexpression of IL -2R alpha in HTLV-I infected cells. Recently, we have detected the presence of ADF/hTRX in human serum (sADF) obtained from healthy volunteers using the insulin reducing assay and Western blotting analysis. Another endogenous redox regulator, glutathione (GSH) system, has long been studied for its relation to cell proliferation and activation. Our recent data showed that thiol compounds such as L-cysteine and GSH may be involved in the activation and cell cycle progression of stimulated lymphocytes. We have also found that ADF/hTRX promotes L-cysteine transport into the cells and increases intracellular GSH content, indicating the close association between ADF/hTRX and GSH systems. Redox regulation by ADF/hTRX and GSH systems seems to play an important role in regulating cell proliferation and activation. To assess the possible alteration of the sADF level in pathological conditions, such as viral infections, an ELISA system for ADF/hTRX was recently established using two different monoclonal antibodies against rADF.(ABSTRACT TRUNCATED AT 250 WORDS)