Related Experiment Video
Updated: Jun 14, 2026
09:29
Early Viral Entry Assays for the Identification and Evaluation of Antiviral Compounds
Published on: October 29, 2015
Endogenous retroviruses as potential hazards for vaccines
1Laboratory of Signal Transduction, Department of Cell Biology, Institute for Virus Research, Kyoto University, 53 Shogoin-Kawaracho, Sakyo-ku, Kyoto 606-8507, Japan. takavet@gmail.com
Summary
Endogenous retroviruses (ERVs) can cause disease, and some may contaminate animal vaccines. This review examines feline ERVs, like RD-114 virus, and the risks they pose through vaccination.
Area of Science:
- Virology
- Immunology
- Veterinary Medicine
Background:
- Retroviruses are classified as exogenous or endogenous based on transmission.
- While endogenous retroviruses (ERVs) are typically non-pathogenic, some can induce disease.
- A novel gammaretrovirus, xenotropic murine leukemia virus-related virus (XMRV), has been identified in human patients.
Purpose of the Study:
- To review endogenous retroviruses (ERVs) in cats.
- To assess the potential risks of ERV infection through animal vaccination.
- To discuss the biological characteristics of the feline ERV, RD-114 virus, and its potential contamination of companion animal vaccines.
Main Methods:
- Review of existing literature on endogenous retroviruses (ERVs) in cats.
- Analysis of potential risks associated with xenospecies ERV transmission via vaccines.
- Examination of the biological properties of RD-114 virus.
- Overview of methods for detecting infectious RD-114 virus.
Main Results:
- Xenotropic murine leukemia virus (X-MLV) related virus (XMRV) may originate from rodent ERVs.
- Live attenuated animal vaccines produced in animal cell lines may carry infectious ERVs.
- The risks of xenospecies ERV infection through vaccination have been largely overlooked.
- RD-114 virus is a feline ERV that could potentially contaminate vaccines.
Conclusions:
- Endogenous retroviruses (ERVs) pose potential risks, particularly through vaccination.
- RD-114 virus, a feline ERV, is a concern for vaccine safety in companion animals.
- Further research and detection methods are needed to mitigate ERV risks in veterinary vaccines.
Related Concept Videos
02:33Retroviruses
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
01:51Mechanisms of Retrovirus-induced Cancers
Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...
01:51Mechanisms of Retrovirus-induced Cancers
Retroviruses are RNA viruses that have been shown to cause cancers in diverse species, including chickens, mice, cats, and monkeys. The RNA genomes of these viruses are first reverse-transcribed into single and then double-stranded DNA (dsDNA) copies. This dsDNA called proviral DNA then integrates into the host genome. Subsequently, the host cell transcribes the proviral DNA in concert with the chromosomal DNA. This leads to the production of viral RNA and proteins that assemble at the host...
01:10Retrovirus Life Cycles
Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the retrovirus to...
01:19Inhibitors of Virion Maturation and Assembly
As part of their replication cycle, certain viruses synthesize long precursor proteins called polyproteins within infected host cells. In human immunodeficiency virus (HIV), two major polyproteins are produced: Gag and Gag-Pol. The Gag polyprotein supplies the structural components of the virus, while Gag-Pol includes essential viral enzymes such as reverse transcriptase, integrase, and protease. After synthesis, these polyproteins move to the host cell membrane, where they assemble into an...
01:26Size and Structure of Viral Genomes
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...