COVID-19, Retroelements, and Aging

The review presents an analysis of the scientific data on the characteristics of COVID-19 from the perspective of potential interactions between the virus and the host genome retroelements. According to global statistical data, severe COVID-19 with immune-system hyperactivity is observed mainly in elderly people. At the same time, aging is characterized by a decrease in immune responses. This paradox may be resolved by the assumption that DNA regions that can move along the genome with the "copy and paste" mechanism (retroelements) may play a role in COVID-19 development; these elements are characterized by abnormal expression patterns in aging. Their interaction with SARS-CoV-2 may occur at the level of RNA interference or RNA recombination, or the virus can use retroelement proteins to integrate into the host genome. There is supporting evidence of this interaction: data indicating the efficiency of antiretroviral drugs at the early stage of COVID-19, the isolation of SARS-CoV-2 for a long time after recovery, the persistence of coronavirus infections, and changes in the L1 retrotransposon expression patterns in the lung tissues of COVID-19 patients. In additional, retroelements affect the functioning of the immune system and affect the receptors interacting with SARS-CoV-2. Recombination with retroelements and viral insertions into host genomes have been demonstrated in the case of other infections caused by nonretroviral, RNA-containing viruses. The presumable interaction between SARS-CoV-2 and retroelements may explain the differences in the severity and lethality of COVID-19 in different countries as a result of specific insertional patterns in the genomes of individuals belonging to different human populations. The possible insertion of SARS-CoV-2 cDNA into the genome should be kept in mind in the design of anti-COVID-19 vaccines. Peptide preparations are the most promising in this regard.