The GOR gene product cannot cross-react with hepatitis C virus in humans

Abstract

SUMMARY GOR (GOR47–1) is an epitope thought to be a host-derived antigen cross-reactive with hepatitis C virus (HCV) since it was isolated from a cDNA library of host animals reactive with sera of HCV-positive patients. An enzyme immunosorbent assay (ELISA) using this epitope as antigen is of sufficient sensitivity and specificity for screening patients with HCV. However, the relationship between GOR47–1 epitope and autoimmune phenomena associated with HCV infection or autoimmune hepatitis is controversial. Here we isolated the human GOR gene and found that the GOR47–1 epitope was not translated in humans due to a single base replacement from chimpanzee. Furthermore, we found some patients who had antibodies against another epitope, which is translated (GOR1–125) in humans, although there was no correlation between the existence of anti-GOR47–1 or anti-GOR1–125 Ab and autoimmune phenomena. Serum IgG levels did not influence the titres of these antibodies. Taken together with the results of several other studies, our finding that the GOR47–1 epitope cannot be translated into a protein suggests that there is little relationship between autoimmunity and the GOR gene product in human beings. We also discuss here the possible mechanism of cross-reactivity between HCV and the GOR gene product.