SPECIFICITY OF ANTIBODIES DIRECTED AGAINST ENV PROTEIN OF HUMAN ENDOGENOUS RETROVIRUSES IN PATIENTS WITH GERM-CELL TUMORS

We report here that 85% of the patients with germ cell tumors (GCTs) p roduce antibodies directed against Env protein of human endogenous ret roviruses. Individuals that received antitumor treatment showed a decr ease with time in their antibody titers. Importantly, of the rare case s of non-GCT individuals with Env-antibodies (n = 15, 0.8%), none prod uced antibodies directed against the transmembrane domain (TM), wherea s all tested Env-positive GCT patients (n = 49) generated such antibod ies at high titers. TM is required for Env to be expressed at the cell surface. Thus, anti-TM antibodies constitute highly specific markers for GCT and may hint at a function of Env during tumorigenesis.