Listen to this article
We’ve said it before and we’ll say it again: these are unprecedented times. Never before has the medical community delved deep into an infection with such urgency as they are now with covid-19.
As more and more research on SARS-CoV-2—the virus responsible for covid-19—surfaces, the more alarmed we seem to be. After all, science has proven how this virus not only attacks the respiratory system, but also the brain and nervous system.
But a recent revelation by the scientific community on our body’s ability to fight off SARS-CoV-2 has come as a ray of sunshine in the grey and cloudy word of covid-19 news. Turns out, some patients suffering from severe respiratory symptoms due to the novel coronavirus infection can rapidly generate an immune response in the form of virus-attacking T cells.
These are the findings of a study, published in the journal Science Immunology, in which the researchers assessed T cells from 10 covid-19 patients under intensive care treatment.
According to the researchers, including those from the University of California in the US, two out of 10 healthy individuals without prior exposure to the virus also harboured SARS-CoV-2-reactive T cells.
Based on this observation, they said these T cells may be cross-reacting to SARS-CoV-2, due to past infection with related coronaviruses that cause common cold symptoms.
What are T cells?
T cells or T lymphocytes are an integral part of the immune system as they are responsible for attacking and killing pathogen-carrying host cells in the body. They also activate the body’s immune response by urging other immune cells to jump into the action.
Needless to say that T-cells are terribly important when it comes to fighting off infections, and even more so in the context of covid-19.
Why is this research so important?
For one, it helps the medical community understand whether SARS-CoV-2-specific T cell responses vary in patients over time depending on disease severity.
They researchers also say that the study may help understand whether patients with more severe symptoms can generate protective virus-specific T cells at all, and offer clues regarding the cells responsible for excessive immune responses which has led to the deaths of many covid-19 patients.
The researchers found that SARS-CoV-2-specific CD4 helper T cells were active in all 10 patients, and CD8 “killer” T cells were present in 8 out of 10 patients.
They also characterised the cells’ production of specific inflammation-triggering cell-cell signalling molecules called cytokines.
According to the scientists, the strongest responses were directed to the virus’ spike (S) surface protein, supporting prior work that has pointed to this protein as a promising target to induce virus-specific T cells.
On screening all patients at 0, 7, and 14 days after inclusion in the study, it was revealed that SARS-CoV-2-specific T cells were present relatively early during the course of infection, and increased in these patients over time.
The researchers believe a future study of how pre-existing SARS-CoV-2-specific T cells in healthy controls correlate to protection against covid-19 can help shed more light on the disease and “and also inform vaccine design and evaluation.