COVID-19 variants likely escaped the immune response
Given the thousands of different HLA molecules in the human population and the thousands of possible epithelia in any given virus, experimental evaluation of the immune response of every human HLA allele to any variant virus is not viable. However, computational methods can facilitate this work.
In the new study, the researchers identified for the first time the complete set of epitopes from an original reference strain of SARS-CoV-2 from Wuhan, China. The team discovered 1,222 epitopes of SARS-CoV-2 that are associated with major HLA subtypes, which account for about 90% of the population; At least 9 out of 10 people can initiate a T-cell response to COVID-19 based on these 1,222 epitopes.
The researchers then computationally analyzed any of the 118,000 different strains of SARS-CoV-2 from around the world, described in the Information Center dataset. National Biotechnology (NCBI), whether there are mutations in these epithelium. They showed that 47% of the epitopes were mutated in at least one existing strain.
In some cases, current isolates have mutations in multiple epitope regions, but cumulative mutations never affect more than 15% of epitopes for any given HLA allele.
When the team analyzed the susceptibility alleles and geographical origins of the respective escapist strains, the team found that they coexisted in several geographic regions — including sub-Saharan Africa and Eastern Europe. and Southeast Asia—, suggesting potential genetic pressure on responsive cytotoxic T cells in these domains.
“The accumulation of these changes in isolated species is still too low to threaten the global population,” the authors said. “Our protocol identified mutations that might be associated with specific populations and warranted further monitoring.”
However, Martín-Galiano noted that “unnoticed SARS-CoV-2 mutations” in the future could “threaten cytotoxic T-responses in human populations”.
Source: Medindia