Identification of Novel Porcine Endogenous Betaretrovirus Sequences in Miniature Swine

Abstract

PCR amplification of genomic DNA from miniature swine peripheral blood lymphocytes, using primers corresponding to highly conserved regions of the polymerase (pol) gene, allowed the identification of two novel porcine endogenous retrovirus (PERV) sequences, PMSN-1 and PMSN-4. Phylogenetic analyses of the nucleotide sequences of PMSN-1 and PMSN-4 revealed them to be most closely related to betaretroviruses. The identification of PERVs belonging to the Betaretrovirus genus shows that endogenous retroviruses of this family are more broadly represented in mammalian species than previously appreciated. Both sequences contained inactivating mutations, implying that these particular loci are defective. However, Southern blot analysis showed additional copies of closely related proviruses in the miniature swine genome. Analyses of fetal and adult miniature swine tissues revealed a broad mRNA expression pattern of both PMSN-1 and PMSN-4. The most abundant expression was detected in whole bone marrow c-kitprogenitor bone marrow cells, fetal liver, salivary gland, and thymus. It appears unlikely that functional loci encoding these novel PERV sequences exist, but this remains to be established. The betaretrovirus sequences described in this report will allow such investigations to be actively pursued.

Microchimerism and transmission of porcine endogenous retrovirus from a pig cell line or specific pathogen-free pig islets to mouse tissues and human cells during xenografts in nude mice

“…The risk of conventional zoonosis led us to isolate islets from specific pathogen-free (SPF) pigs [1,2,3,4,5,6,7,8]. However, there is also a risk of transmitting porcine endogenous retroviruses (PERV) [9,10,11,12]. The ability of PERV [10] produced by pig cells to infect human cells in vitro has been documented [8,9,13,14,15,16,17].…”

Methods and Tools for Detection and Evaluation of the Risks of Porcine Endogenous Retrovirus in Porcine to Human Xenotransplantation

“…In addition to the known gammaretroviral form of PERV, studies have also identified endogenous sequences in the pig genome representative of the betaretroviral genus (Ericsson, Oldmixon et al 2001) (Patience, Switzer et al 2001). Analysis of existing members of the subfamily Suidae and related families suggested that the gammaretroviral sequences representing PERV entered into the subfamily Suidae approximately 3.5 million years ago (Patience, Switzer et al 2001) (Niebert and Tonjes 2003).…”

Detection of PERV by polymerase chain reaction and its safety in bioartificial liver support system

“…Cells were removed from supernate by centrifugation at 200×g for 10 min, thereafter cell debris was removed by centrifugation at 3 500×g for 10 min and an additional centrifugation step at 10 000×g for 30 min. Viral RNA was extracted using the RNA isolation kits (Qiagen) [15][16][17][18] . RNA was reverse transcribed using a one-step RT-PCR kit (promega) with no-RT PCR controlled.…”