Endogenous Retroviruses: What risks do they pose in xenotransplant

Endogenous retroviruses are diverse in nature and found in genomes of ; vertebrates examined to date. There is also a spectrum of retrovirus-Iil transposable genetic elements that have been found in plants, fungi, and prokaryotes, which use reverse transcription as a replicative strategy. The presen of these retroviruses in various animal tissues can potentially leads to the spread animal-derived endogenous retroviruses during xenotransplantation. Althouj these retroviruses are generally inactive and non-effective in their hosts, the behavior in an immunocompromised xenograft recipient cannot be predicts There are reports that various non-human primate and pig endogenous retrovirusi can infect and replicate in various human cell lines. There is also concern ovpossible activation of latent viruses, including retroviruses, from xenograft tissue This paper discusses the possible dangers of endogenous viruses to human vi xenotransplantation.