Similarities between SARS-CoV-2 and human retroelements explored

A latest examine posted to the Analysis Sq.* pre-print server, and at the moment into consideration at BMC Genomic Knowledge, investigated the similarities between extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and human retroelements (RE).

Study: SARS-CoV-2 and human retroelements: a case for molecular mimicry? Image Credit: ThSucho/Shutterstock
Examine: SARS-CoV-2 and human retroelements: a case for molecular mimicry? Picture Credit score: ThSucho/Shutterstock

Varied research relating to the viral traits and symptom manifestations of SARS-CoV-2 have been carried out up to now and plenty of extra are ongoing. A number of experiences have famous that autoimmunity and RE deregulation play an instrumental position in figuring out the end result of coronavirus illness 2019 (COVID-19) instances.   

In regards to the examine

The current examine assessed the connection of human RE to coronaviruses (CoV) based mostly on the transcriptome, genome, peptide array, and epitope-related information of RE and contaminated CoV.

Genomic sequences from SARS-CoV-1, SARS-CoV-2, Center East respiratory syndrome CoV (MERS-CoV), human pathogenic CoVs, and bat CoVs have been collected and aligned. A comparability of those sequences was carried out on a genomic scale.

Knowledge associated to SARS-CoV-2 epitope-specific antibody with respect to immunoglobulin G (IgG) ranges in sufferers who have been severely and mildly affected by SARS-CoV-2 an infection have been collected. Furthermore, information on SARS-CoV-2 ribonucleic acid (RNA)-dependent RNA polymerase (RdRp), helicase, 2′-O-ribose methyltransferase, and SARS-CoV-2-spike protein was additionally obtained. Additionally, whole RNA sequencing information was acquired from SARS-CoV-2-infected macrophages.


The examine outcomes confirmed that CoV genomes had a number of sequences an identical to human RE with many of those sequences being epitopes shared by RE and SARS-CoV-2. Antibodies associated to a few of these shared epitopes corresponded to COVID-19 severity. Moreover, the examine discovered that RE was extensively expressed in wholesome controls whereas important deregulation was noticed in COVID-19 sufferers and human cells contaminated with SARS-CoV-2.

Sequence id was shaped by sequence alignment of the RE and CoV genomes. This sequence id was fabricated from 12 to 35 base pairs (bp) of each human RE sequences and numerous CoV genomes researched on this examine. Particularly, the next variety of sequences an identical to RE have been present in CoV in sequences having 12 or extra, 15 or extra, and 18 or extra bp.

Downstream evaluation of 18 bp sequences confirmed that human CoV HKU1 (HCoV-HKU1) had the best variety of RE-identical sequences, adopted by HCoV-NL63 and SARS-CoV-2. The inclusion of single nucleotide polymorphisms confirmed that SARS-CoV-2 aligned to as much as 35 bp in RE sequences. Total, a majority of brief RE-identical sequences have been present in CoV genomes together with SARS-CoV-2.

Within the comparability of the coding areas of the SARS-CoV-2 genomes with RE-identical sequences having 18 bp, a complete of 70 sequences with an identical amino acids (aa) in RE and CoV have been discovered. The investigation of peptide arrays confirmed an overlap of SARS-CoV-2 epitopes to human LINE1 proteins from RdRp, 2′-Oribose methyltransferase, and helicase. This overlap was present in epitopes having greater than two-fold elevation in antibody ranges in extreme COVID-19 instances. Antibodies concentrating on SARS-CoV-2 RdRp polymerase epitope have been 39-fold greater in extreme COVID-19 instances as in comparison with gentle instances. Altogether, some peptide sequences shared by RE and SARS-CoV-2 genomes have epitopes comparable to COVID-19 severity.

Evaluation of RE of COVID-19 affected person information associated to bronchoalveolar lavage fluid (BALF), and lung epithelial cells and macrophages contaminated with SARS-CoV-2 explored the presence of RE expression and its alterations submit COVID-19 an infection. Extremely important and efficient deregulation of human RE was noticed in all check samples. An upregulation by 2035 RE and downregulation by 3144 RE was discovered within the comparability of BALF of COVID-19 sufferers and wholesome controls whereas probably the most deregulated RE was LINE1.

In epithelial lung cells contaminated with SARS-CoV-2, 34 RE have been discovered to be upregulated and 29 RE have been downregulated. For human macrophages contaminated with COVID-19, 8 and 24 RE have been up- and downregulated, respectively. Each of those had LINE1 as probably the most de-regulated RE. 


The examine findings confirmed that CoV genomes, together with that of SARS-CoV-2, have a number of sequences an identical to human RE. Moreover, these an identical sequences are a part of SARS-CoV-2 epitopes associated to illness severity in COVID-19.

Total, the examine findings indicated that human RE focused by autoantibodies might play a component in illnesses brought on by CoV, like COVID-19.

*Necessary discover

Analysis Sq. publishes preliminary scientific experiences that aren’t peer-reviewed and, subsequently, shouldn’t be considered conclusive, information medical observe/health-related habits, or handled as established data.

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