Epstein-Barr virus-activating principle in human semen.

During the screening of natural and physiological products for their Epstein-Barr virus (EBV)-activating potency, we found that a considerable number of human semen specimens obtained from infertility clinics (30 cases) possess a marked capacity to induce EBV early antigen (EA) in non-producer Raji cell system when assayed in combination with n-butyrate. The EBV EA-inducing activity of the semen samples was comparable to that of the most efficient EBV EA inducers, the plant diterpene esters such as 12-O-tetradecanoylphorbol-13-acetate (TPA). Since many, if not all, of such active agents show overlapping with the tumor promoters in their biological reactions, these findings may provide a new insight for assessing the role of semen in the etiology of certain types of human genital malignancies.