"Memory when suffering from a common cold" may be effective for new coronavirus infection
There is a possibility that the immune system of a person who has a “cold coronavirus'' that causes a common cold can recognize a new coronavirus (SARS-CoV-2) that causes a new coronavirus infection (COVID-19) But it turned out by a new experiment. It is hoped that this discovery will help understand why some people may suffer from COVID-19 with mild illness, or may end up asymptomatic without losing their physical condition.
Selective and cross-reactive SARS-CoV-2 T cell epitopes in unexposed humans | Science
Exposure to common cold coronaviruses can teach the immune system to recognize SARS-CoV-2: Researchers caution: It is too soon to say whether pre-existing immune cell memory affects COVID-19 clinical outcomes –ScienceDaily
COVID-19 is an infectious disease that causes death when it becomes severe, but there are many COVID-19 infected people who remain mild and who do not feel ill at all. Previous studies have shown that older people and people with chronic illness are more likely to become severe, but it is difficult to explain why such inter-individual symptoms differ so much. ..
Therefore, the research team of Alessandro Sette, an immunologist at the La Jolla Immunology Institute in California, is a type of immune cellT cellsI paid attention to. There are multiple types of T cells, one of which is the "memory T cell" that survives in the body for a long time and retains the memory of the pathogen, and quickly responds to the same infectious disease next time. To do. This mechanism is called immune memory.
According to Sette et al., an experiment in which T cells of a patient recovered from COVID-19 are exposed to a fragment of SARS-CoV-2, "the T cells of a person with COVID-19 can respond to SARS-CoV-2". I confirmed. From this, it was found that people with COVID-19 are more likely to acquire immunity to SARS-CoV-2.
In the above experiment, "T cells of humans recovered from COVID-19" were used, but in a new study published this time, "SVs before the discovery of COVID-19 3 Human T cells collected from March to March 2018" cause SARS-CoV-2 and common coldHuman coronavirusExposed to a fragment of (cold coronavirus).
As a result, it was found that even those who have never had COVID-19 produce memory T cells that show equivalent responses to SARS-CoV-2 and four cold coronaviruses.
“I knew that the immune system could respond to SARS-CoV-2, but this experiment shows that memory T cells capture similar features between cold coronavirus and SARS-CoV-2,'' said Sette. I got very strong and direct evidence that I can do that."
“Our study found that T-cell memory for the common cold coronavirus captured the precise molecular structure of the virus, SARS-CoV-2. It has been shown to be able to cause a cross-reactivity to, which explains why some people with COVID-19 become more severe while others have milder symptoms. May be useful."
In addition, this study, which exposed T cells to fragments of SARS-CoV-2, revealed that T cells can recognize the various types of proteins that SARS-CoV-2 possesses. Many COVID-19 vaccines currently under development possess SARS-CoV-2Spike proteinHowever, since it was shown that the protein of SARS-CoV-2 that human T cells can recognize is not limited to spike protein, we will approach SARS-CoV-2 by a wider method in the future. It is expected that a vaccine that will