Endogenous Retroviruses in Xenografts

Abstract

To the Editor: Pressed by the increasing shortage of human organs, we are rapidly moving toward the use of xenografts from pigs or nonhuman primates. We must ask whether endogenous animal retroviruses pose any public health risk when transplanted into a human host. Endogenous porcine retroviruses are not believed to undergo acute transformation; however, the expression of retroviruses has been associated with the development of leukemia and lymphoma in pigs1. Little is known about their structure, their similarities to other retroviruses, or the mechanism of their association with malignant diseases. Since these viral genomes are coded in the genomic . . .