Proteins from coronaviruses (SARS-CoV-2 and less dangerous species – OC43 and HKU1), to which T cells cross-react
Kundu and. al. / Nature Communications, 2022
People who have encountered representatives of the coronavirus family before meeting SARS-CoV-2 are less likely to become infected through home contact with patients with covid, the study says. published In the magazine Nature Communications… Such people develop cross-immunity – memory T cells, which are able to respond to protein motifs in SARS-CoV-2, similar to those of less dangerous coronaviruses.
Biologists knew regarding the existence of coronaviruses (viruses with an envelope similar to the corona) long before the COVID-19 pandemic – this family described In the magazine Nature back in 1968. The viruses isolated then caused only the symptoms of a common cold. Research showthat memory T cells, specific for infection with such human coronaviruses, are able to exhibit an immune cross-reaction – to bind particles of the deadly SARS-CoV-2. However, until now it was not known exactly how the presence of such T cells affects the likelihood of infection with covid.
Researchers from Imperial College London, led by Rhia Kundu, analyzed the process of infection with covid during home contact with patients and its relationship with the presence of memory T cells to other coronaviruses. The study involved 52 people living with patients recently diagnosed with covid. After several days of contact with covid patients, blood samples were collected from the participants to determine the number of cross-reactive T cells. To do this, biologists identified similar regions of the proteins of SARS-CoV-2 and other coronaviruses – they turned out to be regions of adhesion proteins (it is it that is used for the production of many vaccines), nucleocapsid, membrane, envelope and ORF1 protein. Participants were also given PCR tests to track their contamination.
It turned out that in those 26 people who managed not to get sick following contact with patients, the level of memory T-cells was significantly higher than in those infected (p = 0.0139). Interestingly, these cells were targeted to recognize the internal proteins of the virus, but did not recognize adhesion proteins. Thus, the study not only showed that immunity to the common cold due to the harmless coronavirus can protect once morest SARS-CoV-2 infection, but also opens up a new way to produce effective vaccines – using the internal proteins of the virus instead of spike proteins.
T cell activation vaccine protests Emergex company in Switzerland. Its developers believe that their vaccination in the form of a patch with microneedles can create a more durable and resistant to mutations immunity. Read regarding how new mutations and variants of SARS-CoV-2 appear in the material “The heirs and troublemakers”.
Anna Muravyova