Context
Disulfide bonds in protein antigens must be cleaved during processing for presentation by MHC class II molecules, but until recently, it has been unclear how this happens. Most class II antigen processing occurs in endosomes at mildly acidic pH, conditions not suitable for disulfide bond reduction. However, recent studies have ascribed thiol reductase enzyme activity at endosomal pH to a gamma-interferon-induced, MHC class II-associated human protein, now renamed GILT (Gamma-interferon Inducible Lysosomal Thiol reductase), which shares homology with thioredoxin and uses a similar catalytic mechanism. This study set out to clone murine GILT and to examine its role in antigen processing using a knockout approach.