Considering endogenous retroviruses present in mammalian species in environmental risk assessment

COGEM had a literature study carried out to gain more insight in the possible environmental risk associated with the presence of so-called ‘endogenous retroviruses’ (ERVs) in the DNA of humane and animal cells in biomedical research. ERVs are DNA sequences which during evolution have ended up in the DNA of animals and humans. The resulting report, written by Perseus BV, offers an overview of the current scientific knowledge on ERV’s and provides information on how ERV’s can be activated, which protein products are formed in this process and which environmental risks are associated.

In the report, following conclusions are made:

• Endogenous retroviruses (ERVs) are omnipresent in the animal kingdom and are therefore likely present in all sources of material (e.g., tissues, primary and established cell lines);
• Whether incomplete or intact, ERVs contained within an organism are unlikely to cause harm to the host and environment by themselves;
• Through manipulations (e.g., culturing, xenotransplantation) ERV sequences may become activated which could ultimately result in the production of infectious virus-like particles and replication-competent viruses, though the potential environmental impact remains unclear;
• A thorough risk assessment (provided in this report) can aid in assigning the appropriate pathogenicity group to the ERV(s) and its originating source material.

 Three annexes provide an overview of cell lines and tissues of which are known to contain ERVs (Annex I), of viruses other than retroviruses which can activate ERVs upon infection (Annex II) and of available data on chemical and physical induction of ERVs  in cells (Annex III).