Lab studies of genetically engineered human cells suggest the RNA (blue) of SARS-CoV-2 could convert to DNA in infected people and slip into their chromosomes.
Credit: CLAUS LUNAU/SCIENCE SOURCE
In an open access paper published in PNAS today, a group of scientists have repeated their claim that the SARS-CoV-2 virus can act like a retrovirus and hide inside our genome even after we've recovered from an infection. If this is true, people could remain potentially infectious for months or years without realising it, although the team say this is unlikely.
Basically, RNA retroviruses perform this neat little trick by reversing the transcription process which normally converts lengths of DNA to RNA in preparation for making the protein for which it is the template. To do this they use an enzyme known as reverse transcriptase. The resulting length of the DNA template for the viral RNA is then inserted into the normal DNA of an infected cell and replicates with it as the cell replicates normally. The resulting daughter cells then all carry the DNA for making new viral RNA and our immune system has no way of recognising it as foreign. To all intents and purposes, it becomes part of our genome.
This claim is treated with some scepticism by virologists, but the team, led by Stem cell biologist Rudolf Jaenisch and gene regulation specialist Richard Young, of the Massachusetts Institute of Technology, produce what they say is "unambiguous evidence that coronavirus sequences can integrate into the genome".
Although the coronaviruses don't code for reverse transcriptase themselves, they can use our DNA which contains multiple copies of the templates for it in LINE-1 elements, the remnants of ancient retroviruses that account for about 17% of our genome. The team showed that when human cell cultures infected with SARS-CoV-2 are supplied with additional copies of LINE-1 elements, they are found to contain DNA versions of the viral RNA, embedded in their genome.
If it were even remotely possible that Creationist claims that all life-forms are the work of a magical intelligent [sic] designer, and if this research translates to what happens in vivo, this designer can only have the most malevolent of reasons for being this sneaky and going to such lengths to kill as many people as possible with this creation, even using the remnants of earlier attempts to make our remote ancestors sick with retroviruses.
The team's paper in PNAS can be read here:
Regardless of whether this controversial paper is subsequently accepted as reflecting the real capabilities of the SARS-CoV-2 virus in vivo, here is a challenge to Creationists, if any have had the courage to read this far. Which of you is going to:Significance
An unresolved issue of SARS-CoV-2 disease is that patients often remain positive for viral RNA as detected by PCR many weeks after the initial infection in the absence of evidence for viral replication. We show here that SARS-CoV-2 RNA can be reverse-transcribed and integrated into the genome of the infected cell and be expressed as chimeric transcripts fusing viral with cellular sequences. Importantly, such chimeric transcripts are detected in patient-derived tissues. Our data suggest that, in some patient tissues, the majority of all viral transcripts are derived from integrated sequences. Our data provide an insight into the consequence of SARS-CoV-2 infections that may help to explain why patients can continue to produce viral RNA after recovery.
Abstract
Prolonged detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA and recurrence of PCR-positive tests have been widely reported in patients after recovery from COVID-19, but some of these patients do not appear to shed infectious virus. We investigated the possibility that SARS-CoV-2 RNAs can be reverse-transcribed and integrated into the DNA of human cells in culture and that transcription of the integrated sequences might account for some of the positive PCR tests seen in patients. In support of this hypothesis, we found that DNA copies of SARS-CoV-2 sequences can be integrated into the genome of infected human cells. We found target site duplications flanking the viral sequences and consensus LINE1 endonuclease recognition sequences at the integration sites, consistent with a LINE1 retrotransposon-mediated, target-primed reverse transcription and retroposition mechanism. We also found, in some patient-derived tissues, evidence suggesting that a large fraction of the viral sequences is transcribed from integrated DNA copies of viral sequences, generating viral–host chimeric transcripts. The integration and transcription of viral sequences may thus contribute to the detection of viral RNA by PCR in patients after infection and clinical recovery. Because we have detected only subgenomic sequences derived mainly from the 3′ end of the viral genome integrated into the DNA of the host cell, infectious virus cannot be produced from the integrated subgenomic SARS-CoV-2 sequences.
Zhang, Liguo; Richards, Alexsia; Barrasa, M. Inmaculada; Hughes, Stephen H.; Young, Richard A.; Jaenisch, Rudolf Reverse-transcribed SARS-CoV-2 RNA can integrate into the genome of cultured human cells and can be expressed in patient-derived tissues
Proceedings of the National Academy of Sciences May 2021, 118 (21) e2105968118; DOI: 10.1073/pnas.2105968118
Copyright: © 2021 The authors. Published by the National Academy of Sciences of the United States of America
Open access Reprinted under a Creative Commons Attribution 4.0 International License (CC BY 4.0)
- Stick your head above the parapet and risk the ire of your cult and declare that the SARS-CoV-2 could not the creation of your magic creator, but the result of a natural, undirected, amoral process?
- Explain why an entity capable of creating this virus should be regarded as an all-loving god, worthy of love and worship, and who should be turned to for moral guidance and help in adversity?
No comments:
Post a Comment
Obscene, threatening or obnoxious messages, preaching, abuse and spam will be removed, as will anything by known Internet trolls and stalkers, by known sock-puppet accounts and anything not connected with the post,
A claim made without evidence can be dismissed without evidence. Remember: your opinion is not an established fact unless corroborated.