New coronavirus mutations affect spike proteins that invade human cells

Egon Ozar, an infectious disease specialist at the Northwestern University of Fineburg School of Medicine, I recently told the Washington Post I noticed a mutation in a sample of coronavirus that I studied in Chicago. Initially, they were genetically identical to those from China to the United States, but by May, 95% of the genomes he had sequenced were “614 D” (rather than “G” (abbreviation for glycine). Abbreviation for aspartic acid), one of those amino acids, number 614.

Mutations are important because the changes occurred in the part of the genome responsible for the “spike proteins” that give the coronavirus a crown-like appearance. In fact, spike proteins are responsible for the virus’ ability to enter human cells. “The surge is part of the business, as far as viral entry is concerned,” says David Veesler, Assistant Professor of Biochemistry at the UW School of Medicine. Before See previous studies on coronavirus spike proteins.

As the post said, “Of the approximately 50,000 new viral genomes uploaded to shared databases by researchers around the world, approximately 70% carry mutations, officially designated D614G, , Better known to scientists as “G”. “

It was not only Ozen who observed this. Ah Investigation The same observations were made earlier this month by Scripps Research, which said virologist Dr. Hyeryun Choe was “a virus with this mutation was far more infectious than a virus without mutations in the cell culture system we used.” I wrote. The authors emphasized that the conclusions should be considered preliminary, as the study is still undergoing peer review. However, the effects of the mutations on the viral spike “can allow the newly created viral particles to travel from the producer cell to the target cell in a completely intact manner and are less likely to fall prematurely,” he said. did.

The salon contacted an expert for their thoughts on what the mutation meant.

“Of course this is a normal process as the virus evolves,” Dr. George Benjamin, director of the American Public Health Association, told Salon by email. “It can affect the infectivity of an organism. It’s not much evidence that it’s still affecting severity. It might increase its ability to enter your cells. Theoretically We know that people will get more illness, and if the people at risk are more severe, the illness becomes more severe.”

“There is no evidence to date that it affects the ability of spike proteins to generate an immune response. However, only time will be known.”

Benjamin observed that there was no evidence that mutations would affect efforts to develop vaccines, but said, “Because we always have to pay attention to large genetic changes, new or more effective vaccines. This may be necessary this year because of the relatively small changes in the influenza virus. Sufficient changes in the SARS-2 virus mean that you need to get a new shot every year. I assume there is a safe and effective vaccine.”

Another expert reiterated Benjamin’s view of the potential effects of mutations.

“What we know today is that a strain of the SARS-CoV2 virus containing the D614G mutation occurs frequently in patients with COVID-19.” Chairman of Global Health Innovation and Center for Global Health Crisis Coordination, Dr. Russell Medford Center, told Salon by email. “We also demonstrate that the D614G mutation confers functional properties to the important viral protein S, stabilizes the protein, and infects human cells under highly controlled conditions in the laboratory using innocuous artificial viruses. We also found that higher infectivity might contribute to the increased frequency of D614G SARS-CoV2 found in COVID-19 patients. But most importantly, this mutation increases the severity of symptoms or mortality in infected individuals.

“But and most importantly, we don’t know if this mutation affects the severity of symptoms in infected people or increases mortality, so more research is needed.”

last month, Investigation Scientists at the Los Alamos National Laboratory have warned that mutated coronavirus strains can be contagiously transmitted and exacerbate an ongoing pandemic.

“The mutation spike D614G is an urgent concern. It began to spread in Europe in early February and rapidly becomes dominant when introduced in new regions. Also, a pair between locally circulating strains showing multiple strain infections. Providing replacement evidence: “A researcher at Los Alamos wrote.” These findings [sic] It has important implications for SARS-CoV-2 infection, etiology and immune intervention. “

“The D614G’s frequency is increasing at an alarming rate, demonstrating a fitness advantage that allows for more rapid spread compared to the original Wuhan strain,” he added.