The porcine virome and xenotransplantation

Abstract

The composition of the porcine virome includes viruses that infect pig cells, ancient virus-derived elements including endogenous retroviruses inserted in the pig chromosomes, and bacteriophages that infect a broad array of bacteria that inhabit pigs. Viruses infecting pigs, among them viruses also infecting human cells, as well as porcine endogenous retroviruses (PERVs) are of importance when evaluating the virus safety of xenotransplantation. Bacteriophages associated with bacteria mainly in the gut are not relevant in this context. Xenotransplantation using pig cells, tissues or organs is under development in order to alleviate the shortage of human transplants. Here for the first time published data describing the viromes in different pigs and their relevance for the virus safety of xenotransplantation is analysed. In conclusion, the analysis of the porcine virome has resulted in numerous new viruses being described, although their impact on xenotransplantation is unclear. Most importantly, viruses with known or suspected zoonotic potential were often not detected by next generation sequencing, but were revealed by more sensitive methods.

Possible risks posed by single‐stranded DNA viruses of pigs associated with xenotransplantation

“…A real concern in xenotransplanation is the presence of asymptomatic viral swine infections, which are not part of routine pig veterinary screening. Viruses of pigs which are of potential risk in xenotransplantation have been widely researched and reviewed . Some of these viruses cause overt infections, others such as porcine lymphotropic herpesvirus 1 (PLHV‐1), PLHV‐2, and PLHV‐3 may cause latent infections thereby complicating any screening processes.…”

“…However, pigs are known to be a reservoir of viruses that are pathogenic to humans such as Japanese encephalitis virus, Nipah virus, swine influenza A virus, Menangle virus, and Hepatitis E virus . In addition to these viruses, porcine cytomegalovirus and vesicular stomatitis virus are also known to have zoonotic potential …”

Xenotransplantation literature update, November/December 2017

“…However, we must first know what they can potentially carry to develop detection and eradication strategies. Thus, the need to study wild or farm‐raised animals exposed to the environment …”

“…Recent studies using next‐generation sequencing techniques have attempted to characterize the virus populations or “virome” in either healthy pigs or pigs with noticeable infections. Denner reviewed a number of studies and made some interesting conclusions . First off, the porcine virome is composed of hundreds of viruses spanning the taxonomic spectrum.…”

“…Denner reviewed a number of studies and made some interesting conclusions . First off, the porcine virome is composed of hundreds of viruses spanning the taxonomic spectrum. Pigs carry many new viruses from families known to cause human diseases such as Adenoviridae (adenovirus) and Picornaviridae (poliovirus).…”