A team of researchers affiliated with a group of institutions in the United Kingdom and Brazil has partly solved the mystery of why some people are naturally less resistant to Covid-19 than others.
A new study shows that small differences in an individual’s genetic makeup may help explain why some people build a strong natural defense against Covid infection, while others become severely ill.
Researchers at the University of Glasgow’s Center for Virus Research have identified a specific protein called OAS1, which is believed to play a key role in shaping the early stages of an individual’s response to Sars-CoV-2.
When a human cell is infected, the OAS1 protein interacts with interferon signaling by calling for an immune response when the SARS-CoV-2 virus is detected, allowing the cell to begin attacking the virus’s genetic material.
Previous studies have also shown that these signals can prevent the replication of the SARS-CoV-2 virus.
The study, published in the journal Science, suggests that some people express a more protective version of OAS1 that binds to membranes using a prenyl group as part of the signaling process, which is the addition of a single fat molecule to the protein encoded by the OAS1 gene.
Because coronaviruses hide inside cells and replicate their genomes inside vesicles made of lipids, pre-OAS1 is better suited to seek out Sars-CoV-2 and direct cellular weapons to attack it.
The researchers looked at the transcriptomes of 500 Covid-19 patients who experienced a wide range of symptoms, and found that those who had not been exposed to prior OAS1 experienced more severe symptoms. Why some people are born without this enzyme is still a mystery, but the team’s work could help lead to new types of vaccines against Covid-19 and other types of infections.
Based on their findings, the researchers turned their attention to another mammal, the horseshoe bat, one of the presumed sources of SARS-CoV-2, and found that it did not possess the OAS1 preform that protects humans from the virus. This discovery could help explain why bats are such prolific hosts for a variety of viruses.
This means that the virus never needed to adapt to evade this line of defense, but if the SARS-CoV-2 virus mutates and gains the ability to circumvent the defenses generated by OAS1 protein promerization, the virus could potentially become more virulent or transmissible.